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1.
Am J Mens Health ; 18(3): 15579883241255830, 2024.
Article in English | MEDLINE | ID: mdl-38819006

ABSTRACT

In this study, we formally examine the association between penis size dissatisfaction and gun ownership in America. The primary hypothesis, derived from the psychosexual theory of gun ownership, asserts that men who are more dissatisfied with the size of their penises will be more likely to personally own guns. To test this hypothesis, we used data collected from the 2023 Masculinity, Sexual Health, and Politics (MSHAP) survey, a national probability sample of 1,840 men, and regression analyses to model personal gun ownership as a function of penis size dissatisfaction, experiences with penis enlargement, social desirability, masculinity, body mass, mental health, and a range of sociodemographic characteristics. We find that men who are more dissatisfied with the size of their penises are less likely to personally own guns across outcomes, including any gun ownership, military-style rifle ownership, and total number of guns owned. The inverse association between penis size dissatisfaction and gun ownership is linear; however, the association is weakest among men ages 60 and older. With these findings in mind, we failed to observe any differences in personal gun ownership between men who have and have not attempted penis enlargement. To our knowledge, this is the first study to formally examine the association between penis size and personal gun ownership in America. Our findings fail to support the psychosexual theory of gun ownership. Alternative theories are posited for the apparent inverse association between penis size dissatisfaction and personal gun ownership, including higher levels of testosterone and constructionist explanations.


Subject(s)
Firearms , Masculinity , Ownership , Penis , Humans , Male , Middle Aged , Adult , United States , Penis/anatomy & histology , Young Adult , Surveys and Questionnaires , Body Dissatisfaction/psychology , Adolescent , Aged
2.
Toxics ; 11(2)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36851052

ABSTRACT

Bisphenol A (BPA) is one of the most widely produced chemicals in the world used in the production of epoxy resins and polycarbonate plastics. BPA is easily migrated from the outer packaging to the contents. Due to the lipophilic property, BPA is easily accumulated in organisms. Perinatal low-dose BPA exposure alters brain neural development in later generations. In this study, after BPA treatment, the spontaneous movement of zebrafish larvae from the cleavage period to the segmentation period (1-24 hpf) was significantly decreased, with speed decreasing by 18.97% and distance decreasing between 18.4 and 29.7% compared to controls. Transcriptomics analysis showed that 131 genes were significantly differentially expressed in the exposed group during the 1-24 hpf period, among which 39 genes were significantly upregulated and 92 genes were significantly downregulated. The GO enrichment analysis, gene function analysis and real-time quantitative PCR of differentially expressed genes showed that the mRNA level of guanine deaminase (cypin) decreased significantly in the 1-24 hpf period. Moreover, during the 1-24 hpf period, BPA exposure reduced guanine deaminase activity. Therefore, we confirmed that cypin is a key sensitive gene for BPA during this period. Finally, the cypin mRNA microinjection verified that the cypin level of zebrafish larvae was restored, leading to the restoration of the locomotor activity. Taken together, the current results show that the sensitive period of BPA to zebrafish embryos is from the cleavage period to the segmentation period (1-24 hpf), and cypin is a potential target for BPA-induced neurodevelopmental toxicity. This study provides a potential sensitive period and a potential target for the deep understanding of neurodevelopmental toxicity mechanisms caused by BPA.

3.
Inorg Chem ; 60(15): 11485-11495, 2021 Aug 02.
Article in English | MEDLINE | ID: mdl-34263604

ABSTRACT

A novel two-dimensional double-layer anionic uranyl-organic framework, U-TBPCA {[NH2(CH3)2][(UO2)(TBPCA)], where H3TBPCA = 4,4',4″-s-triazine-1,3,5-triyltripamino-methylene-cyclohexane-carboxylate}, with abundant active sites and stability was obtained by assembling UO2(NO3)2·6H2O and a triazine tricarboxylate linker, TBPCA3-. Due to the flexibility of the ligand and diverse coordination modes between carboxyl groups and uranyl ions, U-TBPCA exhibits an intriguing topological structure and steric configuration. This double-layer anionic uranyl-organic framework is highly porous and can be used for selective adsorption of cationic dyes. Due to the presence of high-density metal ions and basic -NH- groups, U-TBPCA acts as an effective heterogeneous catalyst for the cycloaddition reaction of carbon dioxide with epoxy compounds. Moreover, the various modes of coordination between the tricarboxylic ligand and uranyl ion were studied by density functional theory calculations, and several simplified models were established to probe the influence of hydrogen bonding between carbon dioxide and U-TBPCA on the ability of U-TBPCA to bind carbon dioxide. This work should aid in improving our understanding of the coordination behavior of uranyl ion as well as the development and utilization of new actinide materials.

4.
J Relig Health ; 60(4): 2573-2591, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33970412

ABSTRACT

In this paper, we employed data from the 2011 Miami-Dade Health Survey (n = 444) to formally test whether the association between religious struggles and psychological distress is mediated by psychosocial resources. We found that religious struggles were associated with lower levels of social support, self-esteem, the sense of control, and self-control. We also observed that religious struggles were associated with higher levels of non-specific emotional distress, depression, and anxiety, but not somatization. Our mediation analyses revealed significant indirect effects of religious struggles on emotional distress (not somatization) through social support, self-esteem, and the sense of control, but not self-control.


Subject(s)
Psychological Distress , Anxiety , Anxiety Disorders , Depression , Humans , Self Concept , Social Support , Stress, Psychological
5.
Chemistry ; 27(34): 8730-8736, 2021 Jun 16.
Article in English | MEDLINE | ID: mdl-33872429

ABSTRACT

We present here the synthesis of a novel fluorescent actinide polyrotaxane compound URCP1 through the utilization of an end-cutting pseudorotaxane precursor with only the cucurbit[6]uril (CB[6]) macrocyclic components acting as linking struts. The non-coordinating guest motif in the obtained polyrotaxane, with increased freedom and structural flexibility, can display intriguing temperature-triggered conformational variations inside the cavity of CB[6], which was clearly evidenced by crystallographic snapshots at different temperatures. Notably, this observation of temperature-triggered structural dynamics in URCP1 represents the first report of actinide polyrotaxane with such feature in solid-state. Moreover, URCP1 has a high photoluminescence quantum yield (PLQY) of 49.8 %, comparable to other luminescent uranyl compounds, and can work as a fluorescent probe to selectively detect Fe3+ over other eight competing cations in aqueous solution, with the limit of detection being as low as 4.4×10-3  ppm.

6.
Dalton Trans ; 50(13): 4499-4503, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33877170

ABSTRACT

Herein, we report a new uranyl-organic polyhedron U4L4 (L = BTPCA) assembled from uranyl and a semirigid tritopic ligand. By adjusting the carbon chain length of organic templates, two complexes can be obtained based on the diverse secondary assembly of U4L4 cages. The mechanism of different arrangements of U4L4 cages induced by organic templates was explored in detail.

7.
J Hypertens ; 39(2): 310-317, 2021 02 01.
Article in English | MEDLINE | ID: mdl-32868641

ABSTRACT

BACKGROUND: The role of adrenal venous sampling (AVS) has been challenged by some recent evidence. This study aimed to compare the role of AVS and computed tomography (CT) in the management of primary aldosteronism. METHODS: Patients who underwent unilateral adrenalectomy for primary aldosteronism at a single center between January 2015 and December 2018 were included, and postoperative outcomes of the patients who underwent surgery based on CT (n = 195) or AVS (n = 40) were compared. The data of all the patients who underwent AVS successfully (n = 75) during this period were also collected and analyzed. RESULTS: There were no significant differences between the CT-guided and AVS-guided adrenalectomies in most of the postoperative outcomes, and the proportion of patients achieving cure of hypokalemia (CT vs. AVS, 98.3 vs. 96.4%) and alleviation of hypertension (89.2 vs. 92.9%) were similar between the two groups. However, since the baseline characteristics of the two groups were not identical, the AVS-guided group showed greater improvement in postoperative hypokalemia and greater reduction in the number of antihypertensive medications than the CT-guided group. In addition, for the 75 patients who underwent AVS successfully, the concordance rate between CT abnormalities and AVS lateralization was 60.0% in total, and 22.7% patients changed treatment plans according to the AVS results. CONCLUSION: Although the clinical outcomes were not significantly different between the CT-guided and AVS-guided group, the AVS-guided group seemed to benefit more from the surgery, and a considerable number of patients with primary aldosteronism would have received inappropriate treatment if they did not undergo AVS.


Subject(s)
Adrenal Glands , Hyperaldosteronism , Adrenal Glands/diagnostic imaging , Adrenal Glands/surgery , Adrenalectomy , Aldosterone , Humans , Hyperaldosteronism/diagnostic imaging , Hyperaldosteronism/surgery , Retrospective Studies , Tomography, X-Ray Computed
8.
Angew Chem Int Ed Engl ; 59(46): 20666-20671, 2020 Nov 09.
Article in English | MEDLINE | ID: mdl-32790246

ABSTRACT

Herein we present a new viologen-based radical-containing metal-organic framework (RMOF) Gd-IHEP-7, which upon heating in air undergoes a single-crystal-to-single-crystal transformation to generate Gd-IHEP-8. Both RMOFs exhibit excellent air and water stability as a result of favorable radical-radical interactions, and their long-lifetime radicals result in wide spectral absorption in the range 200-2500 nm. Gd-IHEP-7 and Gd-IHEP-8 show excellent activity toward solar-driven nitrogen fixation, with ammonia production rates of 128 and 220 µmol h-1 g-1 , respectively. Experiments and theoretical calculations indicate that both RMOFs have similar nitrogen fixation pathways. The enhanced catalytic efficiency of Gd-IHEP-8 versus Gd-IHEP-7 is attributed to intermediates stabilized by enhanced hydrogen bonding.

9.
Dalton Trans ; 49(4): 983-987, 2020 Jan 28.
Article in English | MEDLINE | ID: mdl-31904068

ABSTRACT

Two novel thorium-based organic frameworks (Th-IHEP-5 and Th-IHEP-6) were assembled from a hexanuclear thorium cluster, porphyrin derivative ligand and linear carboxylic acid ligands via a mixed-ligand strategy. As a stable heterogeneous catalyst, Th-IHEP-5 exhibited high photocatalytic activity for the oxidation of 2-chloroethyl ethyl sulfide (CEES) and the fixation of CO2. The good catalytic effect is attributed to the large conjugated system of porphyrin and the photosensitizer enhancing effects of bipyridine.

10.
Inorg Chem ; 58(20): 14075-14084, 2019 Oct 21.
Article in English | MEDLINE | ID: mdl-31573800

ABSTRACT

As well-known functional groups with excellent electro/photochromic and ion-exchange properties, bipyridinium motifs have been used in functionalized metal-organic coordination polymers, but they are still rarely applied to construct actinide coordination polymers. In this work, we utilized a bipyridinium-based carboxylic acid, 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridinium bis(chloride) ([H2bcbp]Cl2), as the organic ligand to assemble with uranyl cations. By the introduction of different kinds of auxiliary ligands and adjustment of the pH, five novel uranyl coordination compounds, 1-5, have been synthesized through hydrothermal reactions. Starting from uranyl ions and terephthalic acid (H2TP) and H2bcbp ligands, [(UO2)2(bcbp)(TP)2]·3H2O (1) has a wave-shaped two-dimensional (2D) structure consisting of dinuclear units connected by terephthalate linkers and further supported by the longer H2bcbp ligands. [(UO2)2(bcbp)(PA)2]·4H2O (2) has a zigzag chain of dimeric uranium units, and [(UO2)2(bcbp)(bpdc)2]·5H2O (3) forms a one-dimensional ribbonlike structure. The 2D structures of [(UO2)(bcbp)(OH)(H2O)]·Cl (4) and [(UO2)(bcbp)Cl]·Cl (5) are similar, both of which are constructed from dinuclear uranyl units and bcbp2- ligands. Furthermore, the performance for perrhenate removal of compound 4 with a cationic framework is assessed, and we found that compound 4 can efficiently remove ReO4- from an aqueous solution in a wide range of pH values. This work extends the library of viologen derivative-based uranyl coordination polymers, provides to some extent broader insights into actinide coordination chemistry of functionalized ligands, and may facilitate the ion-exchange applications of related coordination polymers.

11.
Biochem Biophys Res Commun ; 513(3): 560-566, 2019 06 04.
Article in English | MEDLINE | ID: mdl-30981507

ABSTRACT

Both type 1 and type 2 diabetes are associated with loss of functional beta cell mass, and strategies to restore beta cells are urgently needed. We reported previously that overexpression of the nuclear receptor TLX induces beta cell proliferation, but the underlying molecular mechanism has not been defined. Here, we identified direct targets of TLX in beta cells at the genome-wide level by ChIP-Seq. These targets include a cadre of regulators that are known to be critical for proliferation. Among these ChIP targets, E2F6 was tightly associated with the cell cycle modules, and thus, we further analyzed E2F6 expression and function in beta cells. We showed that E2F6 is strongly downregulated by TLX, and its expression inhibits beta cell proliferation. Moreover, coexpression of E2F6 with TLX partially abrogated the proliferative effects of TLX. These results strongly suggest that TLX acts through E2F6 to regulate beta cell proliferation. Together, the results of this study reveal a direct interaction between TLX and E2F6 and suggest new targets for the expansion of functional beta cell mass.


Subject(s)
E2F6 Transcription Factor/metabolism , Insulin-Secreting Cells/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Cell Line , Cell Proliferation , E2F6 Transcription Factor/genetics , E2F6 Transcription Factor/physiology , Gene Expression Regulation , Genome , Insulin-Secreting Cells/cytology , Mice , Promoter Regions, Genetic
12.
Mitochondrial DNA B Resour ; 4(1): 21-22, 2019.
Article in English | MEDLINE | ID: mdl-33365403

ABSTRACT

We describe the complete mitochondrial genome of the Endangered fish Anabarilius liui yalongensis. It is a circular molecule of 16,608 bp in size, and all genes show the typical gene arrangement conforming to the vertebrate consensus. The cytochrome c oxidase subunit I (COI) sequence of A. liui yalongensis and other 21 species from 14 genera were used for phylogenetic analysis by Bayesian inference and maximum likelihood methods. The topology demonstrated that the A. liui yalongensis clustered with A. grahami are closely to Hemiculter branch within the subfamily Cultrinae.

13.
Popul Res Policy Rev ; 37(2): 181-204, 2018 Apr.
Article in English | MEDLINE | ID: mdl-30270953

ABSTRACT

Despite acquiring lower levels of attainment and earnings, Mexican immigrants exhibit favorable health outcomes relative to their native-born counterparts. And while scholars attempt to reconcile this so-called paradoxical relationship with a variety of theoretical and empirical approaches, patterns of selective migration continue to receive considerable attention. The present study contributes to the literature on health selection by extending the healthy migrant hypothesis in a number of ways. First, we rely on a unique combination of data sets to assess whether the healthy are disproportionately more likely to migrate. We use the latest wave of the Mexican Family Life Survey and the 2013 Migrante Study, a survey that is representative of Mexican-born persons who are actively migrating through Tijuana. Pooling these data also allow us to differentiate between internal and US-bound migrants to shed light on their respective health profiles. Results provide modest support for the healthy migrant hypothesis. Although those who report better overall health are more likely to migrate, we find that the presence of certain chronic conditions increases migration risk. Our findings also suggest that internal migrants are healthier than those traveling to the US, though this is largely because those moving within Mexico reflect a younger and more educated population. This study takes an important step in uncovering variation across migrant flows and highlights the importance of the timing at which health is measured in the migration process.

14.
Med Sci Monit ; 23: 4021-4027, 2017 Aug 19.
Article in English | MEDLINE | ID: mdl-28822231

ABSTRACT

BACKGROUND This study investigated the outcomes of preoperative HGT as an adjunct treatment for severe thoracic kyphoscoliosis, its role in radiographic correction, and pulmonary function improvement, together with nursing strategy and incidence of complications. MATERIAL AND METHODS Eleven patients with a mean age of 18.8 years were retrospectively reviewed. Inclusion criteria were: patients with severe kyphoscoliosis (coronal Cobb angle and kyphosis angle ≥80°); duration of HGT ≥8 weeks; patients undergoing HGT for at least 12 h per day; traction weight no less than 40% of body weight; and patients not receiving physical therapies. All patients underwent respiratory training. RESULTS The major coronal curve scoliosis averaged 114.00±24.43° and was reduced to 80.55±17.98° after HGT. The major kyphosis was 103.91±18.95° and was reduced to 80.55±17.98°. Significantly improved percent-predicted values for FVC was found after HGT (p=0.014), and significantly increased forced expiratory volume in 1 s (FEV1%) was also observed (p<0.001), with significantly improved percent-predicted values for PEF (p=0.003) after HGT. CONCLUSIONS Our data reveal that preoperative HGT can be performed safely, and can help achieve excellent curve correction in both the coronal and sagittal planes, together with improved respiratory function and no severe complications in patients with severe thoracic kyphoscoliosis.


Subject(s)
Kyphosis/therapy , Scoliosis/therapy , Traction/methods , Adolescent , Child , Female , Forced Expiratory Volume , Humans , Kyphosis/diagnostic imaging , Kyphosis/physiopathology , Lung/physiopathology , Male , Preoperative Care/methods , Respiratory Function Tests , Retrospective Studies , Scoliosis/diagnostic imaging , Scoliosis/physiopathology , Spinal Fusion/methods , Tibet , Young Adult
15.
Clin Rehabil ; 26(6): 483-92, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21975470

ABSTRACT

OBJECTIVE: To analyze the clinical significance of postoperative back muscle exercises after percutaneous vertebroplasty for spinal osteoporotic compression fracture patients. DESIGN: Clinical randomized controlled trials of parallel group nonpharmacologic study. SETTING: Patients practised back muscle exercises in the spinal surgery department, rehabilitation department and at their residences. SUBJECTS: Osteoporotic compression fracture patients who had undergone percutaneous vertebroplasty and processed sufficient muscle strength to participate in the training were studied. INTERVENTIONS: Patients were randomized into two groups, which were titled A and B. General postoperation therapy, including antiosteoporotic medications and education, was offered to all patients. Group B patients received additional systematic back muscle exercise. MAIN MEASURES: Both Oswestry Disability Index (ODI) and visual analogue scale (VAS) were recorded preoperatively and postoperatively at three-day, one-month, six-month, one-year and two-year follow-up. RESULTS: From January 2006 to January 2009, a total of 82 patients were assessed for eligibility, 60 patients were enrolled and randomized into two groups. Forty-two (70%) patients (20 of 30 in Group A and 22 of 30 in Group B) were successfully followed-up for two years. Systematic back muscle exercises resulted in a significant advantage in both measurements. The ODI of Group B was significantly better than Group A at the six-month, one-year and two-year follow-ups (P < 0.05). The pain level of Group B was significantly lower than in Group A at the one- and two-year follow-ups (P < 0.05). At the end of our study, the mean (SD) of the ODI in Groups A and B were 39.1 (9.14) and 23.4 (5.62); the mean (SD) of the VAS in Groups A and B were 3.4 (1.15) and 2.1 (0.84), respectively. CONCLUSIONS: Our findings suggest that the benefit of the exercises required at least six months to be observed; however, the favourable effects could last for two years. Therefore, systematic back muscle exercise should be recommended as one of the treatment guidelines for postpercutaneous vertebroplasty patients.


Subject(s)
Exercise Therapy , Fractures, Compression/therapy , Low Back Pain/therapy , Osteoporotic Fractures/therapy , Spinal Fractures/therapy , Vertebroplasty , Aged , Female , Humans , Low Back Pain/etiology , Male , Muscle, Skeletal/physiology , Pain Measurement
16.
Clin Rheumatol ; 30(12): 1583-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21968692

ABSTRACT

Interleukin-33 (IL-33) is implicated in rheumatoid arthritis with effects of promoting tumor necrosis factor-alpha (TNF-α) and interleukin-17 (IL-17) productions, which have been demonstrated to play a pivotal role in ankylosing spondylitis (AS). However, changes of IL-33 levels and its effects in AS have not been investigated. Eighty-nine and 178 healthy controls were included in the current study. Erythrocyte sedimentation rate, serum levels of C-reactive protein, IL-17, and IL-33 were determined. Effects of IL-33 on TNF-α and IL-6 productions were investigated. Effects of IL-33 on neutrophil migration were also evaluated. Serum levels of IL-33 were elevated in AS patients. Moreover, IL-33 was significantly higher in active AS patients according to Bath Ankylosing Spondylitis Disease Activity Index. IL-33 concentrations in serum were positively correlated with TNF-α and IL-17 levels (IL-33 and TNF-α, r = 0.54, P < 0.01; IL-33 and IL-17, r = 0.47, P < 0.01). IL-33 dose-dependently enhanced TNF-α and IL-6 productions by peripheral blood mononuclear cells (PBMCs) responding to lipopolysaccharide. IL-33 induced neutrophil migration only in higher doses (≥10 ng/ml). Serum levels of IL-33 were elevated in AS patients. IL-33 may play a role in AS development via enhancing TNF-α production by PBMCs and inducing neutrophil migration.


Subject(s)
Interleukins/blood , Neutrophils/physiology , Spondylitis, Ankylosing/blood , Tumor Necrosis Factor-alpha/blood , Adult , Blood Sedimentation , C-Reactive Protein/metabolism , Case-Control Studies , Cell Movement , Female , Humans , Interleukin-17/blood , Interleukin-33 , Leukocytes, Mononuclear/metabolism , Male , Middle Aged
17.
J Spinal Disord Tech ; 24(6): E49-56, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21685804

ABSTRACT

STUDY DESIGN: An in vitro biomechanical cadaver study. OBJECTIVES: To evaluate the pull-out strength after 5000 cyclic loading among 4 revision techniques for the loosened iliac screw using corticocancellous bone, longer screw, traditional cement augmentation, and boring cement augmentation. SUMMARY OF BACKGROUND DATA: Iliac screw loosening is still a clinical problem for lumbo-iliac fusion. Although many revision techniques using corticocancellous bone, larger screw, and polymethylmethacrylate (PMMA) augmentation were applied in repairing pedicle screw loosening, their biomechanical effects on the loosened iliac screw remain undetermined. METHODS: Eight fresh human cadaver pelvises with the bone mineral density values ranging from 0.83 to 0.97 g/cm were adopted in this study. After testing the primary screw of 7.5 mm diameter and 70 mm length, 4 revision techniques were sequentially established and tested on the same pelvis as follows: corticocancellous bone, longer screw with 100 mm length, traditional PMMA augmentation, and boring PMMA augmentation. The difference of the boring technique from traditional PMMA augmentation is that PMMA was injected into the screw tract through 3 boring holes of outer cortical shell without removing the screw. On an MTS machine, after 5000 cyclic compressive loading of -200∼-500 N to the screw head, axial maximum pull-out strengths of the 5 screws were measured and analyzed. RESULTS: The pull-out strengths of the primary screw and 4 revised screws with corticocancellous bone, longer screw and traditional and boring PMMA augmentation were 1167 N, 361 N, 854 N, 1954 N, and 1820 N, respectively. Although longer screw method obtained significantly higher pull-out strength than corticocancellous bone (P<0.05), the revised screws using these 2 techniques exhibited notably lower pull-out strength than the primary screw and 2 PMMA-augmented screws (P<0.05). Either traditional or boring PMMA screw showed obviously higher pull-out strength than the primary screw (P<0.05); however, no significant difference of pull-out strength was detected between the 2 PMMA screws (P>0.05). CONCLUSIONS: Wadding corticocancellous bone and increasing screw length failed to provide sufficient anchoring strength for a loosened iliac screw; however, both traditional and boring PMMA-augmented techniques could effectively increase the fixation strength. On the basis of the viewpoint of minimal invasion, the boring PMMA augmentation may serve as a suitable salvage technique for iliac screw loosening.


Subject(s)
Bone Cements , Bone Screws , Ilium/surgery , Lumbar Vertebrae/surgery , Prosthesis Failure , Aged , Biomechanical Phenomena , Female , Humans , Internal Fixators , Male , Middle Aged , Reoperation
18.
Clin Biomech (Bristol, Avon) ; 26(6): 556-61, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21345556

ABSTRACT

BACKGROUND: Iliac screw loosening has been a clinical problem in the lumbo-pelvic reconstruction. Although iliac screws are commonly inserted into either upper or lower iliac column, the biomechanical effects of the two fixations and their revision techniques with bone cement remain undetermined. The purpose of this study was to compare the anchoring strengths of the upper and lower iliac screws with and without cement augmentation. METHODS: 5 pairs of formalin fixed cadaveric ilia with the bone mineral density values ranged from 0.82 to 0.97 g/cm(2) were adopted in this study. Using screws with 70-mm length and 7.5-mm diameter, 2 conventional iliac screw fixations and their revision techniques with cement augmentation were sequentially established and tested on the same ilium as follows: upper screw, upper cement screw, lower screw, and lower cement screw. Following 2000 cyclic compressive loading of -300 N to -100 N to the screw on a material testing machine, the maximum pull-out strengths were measured and analyzed. FINDINGS: The average pull-out strengths of upper, upper cement, lower, and lower cement screws were 964 N, 1462 N, 1537 N, and 1964 N, respectively. The lower screw showed significantly higher pull-out strength than the upper one (P=0.008). The cement augmentation notably increased the pull-out strengths of both upper and lower screws. The positive correlation between pull-out strength and bone mineral density value was obtained for the 4 fixations. INTERPRETATION: The lower iliac screw technique should be the preferred choice in lumbo-pelvic stabilization surgery; cement augmentation may serve as a useful salvage technique for iliac screw loosening; preoperative evaluation of bone quality is crucial for predicting fixation strength of iliac screw.


Subject(s)
Bone Cements/chemistry , Bone Screws , Aged , Biomechanical Phenomena , Bone Density , Female , Humans , Ilium/chemistry , Male , Middle Aged , Pelvic Bones/pathology , Pelvis/pathology , Stress, Mechanical
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