27 research outputs found

    The influence of over-distraction on biomechanical response of cervical spine post anterior interbody fusion: a comprehensive finite element study

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    Introduction: Anterior cervical discectomy and fusion (ACDF) has been considered as the gold standard surgical treatment for cervical degenerative pathologies. Some surgeons tend to use larger-sized interbody cages during ACDF to restore the index intervertebral disc height, hence, this study evaluated the effect of larger-sized interbody cages on the cervical spine with ACDF under both static and cyclic loading.Method: Twenty pre-operative personalized poro-hyperelastic finite element (FE) models were developed. ACDF post-operative models were then constructed and four clinical scenarios (i.e., 1) No-distraction; 2) 1 mm distraction; 3) 2 mm distraction; and 4) 3 mm distraction) were predicted for each patient. The biomechanical responses at adjacent spinal levels were studied subject to static and cyclic loading. Non-parametric Friedman statistical comparative tests were performed and the p values less than 0.05 were reflected as significant.Results: The calculated intersegmental range of motion (ROM) and intradiscal pressure (IDP) from 20 pre-operative FE models were within the overall ranges compared to the available data from literature. Under static loading, greater ROM, IDP, facet joint force (FJF) values were detected post ACDF, as compared with pre-op. Over-distraction induced significantly higher IDP and FJF in both upper and lower adjacent levels in extension. Higher annulus fibrosus stress and strain values, and increased disc height and fluid loss at the adjacent levels were observed in ACDF group which significantly increased for over-distraction groups.Discussion: it was concluded that using larger-sized interbody cages (the height of ≥2 mm of the index disc height) can result in remarkable variations in biomechanical responses of adjacent levels, which may indicate as risk factor for adjacent segment disease. The results of this comprehensive FE investigation using personalized modeling technique highlight the importance of selecting the appropriate height of interbody cage in ACDF surgery

    Hypercalciuria and febrile convulsion in children under 5 years old

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    PurposeThe association between hypercalciuria and febrile convulsion is controversial. The present study aimed to investigate the statistical association between hypercalciuria and childhood febrile convulsions.MethodsOverall, 160 children aged 6 months to 5 years, including 80 children with febrile convulsion and 80 febrile children without convulsion (comparison group), were recruited. All laboratory tests, including 24-hour urine calcium, were undertaken in an academic clinical laboratory.ResultsForty-five children of the febrile convulsion group (60%) and 30 of the comparison group (40%) had hypercalciuria. There was a significant difference between the 2 groups (P=0.02).ConclusionOur results indicated that there is a statistical association between convulsion and hypercalciuria in children. Since we found this association with a cross-sectional assessment, further studies, especially prospective and controlled designs, are needed

    Lupus and the Nervous System: A Neuroimmunoloigcal Update on Pathogenesis and Management of Systemic Lupus Erythematosus with Focus on Neuropsychiatric SLE

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    An autoimmune condition is characterized by a misdirected immunological system that interacts with host antigens. Excess activation of T- and B-lymphocytes, autoantibody generation, immune complex deposition, and multi-organ injury are found in systemic lupus erythematosus (SLE), an early autoimmune condition with a substantial hereditary element. A number of environmental factors and lifestyle changes also play a role in the development of SLE. The imbalanced immunity could take part in the dysfunction and injury of different biological organs, including the central and peripheral nervous systems. Neuropsychiatric SLE (NPSLE) can present with focal and diffuse involvements. Clinical manifestations of NPSLE vary from mild cognitive deficits to changed mental status, psychosis, and seizure disorders. Headaches, mood, and cognitive problems are the most common neuropsychiatric presentations associated with SLE. NPSLE could be found in 40% of all people who have SLE. The diagnostic inference of NPSLE can be made solely following these secondary causes have been ruled out. The present chapter provides an updated discussion of the clinical presentation, molecular processes, diagnosis, management, and therapy of SLE with emphasizing on NPSLE

    Inhibition of MicroRNA miR-222 with LNA Inhibitor Can Reduce Cell Proliferation in B Chronic Lymphoblastic Leukemia

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    MicroRNAs (miRNAs) are small regulatory molecules that negatively regulate gene expression by base-pairing with their target mRNAs. miRNAs have contribute significantly to cancer biology and recent studies have demonstrated the oncogenic or tumor-suppressing role in cancer cells. In many tumors up-regulation miRNAs has been reported especially miR-222 has been shown to be up-regulated in B chronic lymphocytic leukemia (B-CLL). In this study we assessed the effected inhibition of miR-222 in cell viability of B-CLL. We performed inhibition of mir-222 in B-CLL cell line (183-E95) using locked nucleic acid (LNA) antagomir. At different time points after LNA-anti-mir-222 transfection, miR-222 quantitation and cell viability were assessed by qRT-real time polymerase chain reaction and MTT assays. The data were analyzed by independent t test and one way ANOVA. Down-regulation of miR-222 in B-CLL cell line (183-E95) with LNA antagomir decreased cell viability in B-CLL. Cell viability gradually decreased over time as the viability of LNA-anti-mir transfected cells was <47 % of untreated cells at 72 h post-transfection. The difference in cell viability between LNA-anti-miR and control groups was statistically significant (p < 0.042). Based on our findings, the inhibition of miR-222 speculate represent a potential novel therapeutic approach for treatment of B-CLL

    Mechanical Vulnerability of L3-L4 Spinal Segment after Fusion Surgery Utilizing Dynamic Stress Analysis

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    Introduction: Pedicle screw-based spine fusion has been employed as a felicitous approach for treatment of degenerative lumbar spinal diseases.  Although the pedicle screw designs and fixation techniques have progressed, many clinical studies have reported the adjacent segment degeneration (ASD) and several other adverse effects after surgery. In the case of fixation techniques, the use of semi-rigid rods such as Polyarylether ether ketone (PEEK) rods can be an appropriate substitute for rigid fusion instrumentation. However, the biomechanical effects of using viscoelastic PEEK rods for use in clinical studies are still unclear. Materials and Methods: In this study, the effects of using two pedicle screw-based stabilization systems, i.e. viscoelastic PEEK rods and elastic Titanium rods, on the stress distribution in L3-L4 intervertebral disc and the surrounding osseous tissue were investigated. An L1-L5 lumbar region was modeled. Subsequently, a mild degenerative disc disease was simulated in the L3-L4 lumbar level. Next, an axial cyclic torque was applied to the model.Results: The results showed that, at the end of the loading cycle, the maximum von-Mises stress in the L3-L4 intervertebral disc as well as the overall value of stress in the surrounding osseous tissue were slightly greater in the viscoelastic model as compared to the elastic one. Nonetheless, the stress distribution contours and the location of maximum stress were different in the two models. Conclusion: It can be postulated that the vulnerable areas of lumbar bone are different in two models

    Anterior Chamber Contamination at the Conclusion of Phacoemulsification

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    &lt;!--[if gte mso 9]&gt;&lt;xml&gt; Normal 0 false false false MicrosoftInternetExplorer4 &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;/xml&gt;&lt;![endif]--&gt; &lt;!--[if gte mso 10]&gt; &lt;style&gt;&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Table Normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; &lt;/style&gt; &lt;![endif]--&gt; &lt;p&gt;PURPOSE: To evaluate anterior chamber aspirates at the conclusion of phacoemulsification and intraocular lens implantation (PE+IOL) for bacterial and fungal contamination. METHODS: We prospectively evaluated 80 eyes of 80 patients undergoing routine PE+IOL by performing bacterial and fungal culture on aspirates obtained from the anterior chamber at the end of the surgery. RESULTS: Anterior chamber fluid aspirates were positive for bacteria in 5 eyes (6.33%) with coagulase-negative staphylococcus being the most common organism (three eyes). No instance of positive fungus culture was observed. One of the culture-positive eyes developed postoperative uveitis which resolved during a week of treatment with topical corticosteroids and antibiotics.  None of the eyes developed endophthalmitis. CONCLUSION: In the current series, the rate of anterior chamber contamination by bacteria at the end of phacoemulsification was in the lower range reported by previous studies.  &lt;/p&gt; &lt;!--[if gte mso 9]&gt;&lt;xml&gt; Normal 0 false false false MicrosoftInternetExplorer4 &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;/xml&gt;&lt;![endif]--&gt; &lt;!--[if gte mso 10]&gt; &lt;style&gt;&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Table Normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; &lt;/style&gt; &lt;![endif]--&gt; &lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;w:WordDocument&gt; &lt;w:View&gt;Normal&lt;/w:View&gt; &lt;w:Zoom&gt;0&lt;/w:Zoom&gt; &lt;w:PunctuationKerning /&gt; &lt;w:ValidateAgainstSchemas /&gt; &lt;w:SaveIfXMLInvalid&gt;false&lt;/w:SaveIfXMLInvalid&gt; &lt;w:IgnoreMixedContent&gt;false&lt;/w:IgnoreMixedContent&gt; &lt;w:AlwaysShowPlaceholderText&gt;false&lt;/w:AlwaysShowPlaceholderText&gt; &lt;w:Compatibility&gt; &lt;w:BreakWrappedTables /&gt; &lt;w:SnapToGridInCell /&gt; &lt;w:WrapTextWithPunct /&gt; &lt;w:UseAsianBreakRules /&gt; &lt;w:DontGrowAutofit /&gt; &lt;/w:Compatibility&gt; &lt;w:BrowserLevel&gt;MicrosoftInternetExplorer4&lt;/w:BrowserLevel&gt; &lt;/w:WordDocument&gt; &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;w:LatentStyles DefLockedState="false" LatentStyleCount="156"&gt; &lt;/w:LatentStyles&gt; &lt;/xml&gt;&lt;![endif]--&gt; &lt;!-- /* Font Definitions */ @font-face {font-family:Palatino; mso-font-alt:"Book Antiqua"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:7 0 0 0 147 0;} @font-face {font-family:Nazanin; mso-font-alt:"Courier New"; mso-font-charset:178; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:24577 0 0 0 64 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; mso-bidi-font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Nazanin;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&gt; &lt;!--[if gte mso 10]&gt; &lt;style&gt;&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Table Normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; &lt;/style&gt; &lt;![endif]--&gt

    Evaluating the Expression of Oct-4, NANOG, Sox2 and Nucleostemin in Colon Cancer Cell Lines (Caco-2 and HT-29)

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    Objective: Evaluating the expression of Oct-4, NANOG, Sox2 and Nucleostemin in coloncancer cell lines (Caco-2 and HT-29).Materials and Methods: Caco-2 and HT-29 human colon cancer cell lines were culturedin Dulbecco’s modified eagles medium (DMEM) and Roswell Park Memorial Institute medium(RPMI) respectively, containing 10% fetal bovin serum (FBS) with 1% peniciline andstreptomycinen in 37°, 5% CO2 incubator. Total RNA was isolated using the ISOGENmethod. RNA integrity was checked with the use of agarose gel electrophoresis and spectrophotometry.Reverse transcriptase polymerase chain reaction (RT-PCR) was used toexamin the samples. The expression of Oct-4 and Nucleostemin at the protein level wasfurther determined using immunocytochemistry.Results: RT-PCR analysis of Caco2 and HT-29 colon cancer cell lines showed expressionof Oct-4, NANOG, Sox2 and Nucleostemin genes . Also immunocytochemical analysisconfirmed the cytoplasmic and nuclear expression of the Oct-4 protein and Nucleosteminproteins.Conclusion: Collectively, our data confirmed the expression of Oct-4, NANOG, Sox2and Nucleostemin in colon cancer cells and suggested that their expression can be usedas potential tumor markers in diagnosis and /or prognosis of colon tumors. These resultsconfirm the potential value of the cancer stem-cell theory in cancer therapy
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