The HUKM Spinal Instrumentation System for adolescent idiopathic scoliosis. A biomechanical comparison study using finite element analysis

This finite element analysis is aimed at comparing relative stiffness of three different posterior instrumentation constructs: the Hospital Universiti Kebangsaan Malaysia Spinal Instrumentation System (HUKM-SIS), the Cotrell-Dubousset Instrumentation (CDI) and Harrington Instrumentation System (HIS), used in the treatment of adolescent idiopathic scoliosis (AIS). The constructs were tested under various loads using MSC Patran 2001 r2a. Under increasing flexion loads, there was a linearly corresponding increase in deflection magnitudes for all constructs on the load-deflection curve. The CDI was the stiffest construct under axial, forward flexion and extension loads, followed by the HUKM-SIS and HIS. Under lateral bending loads, the HUKM-SIS construct was the stiffest followed by CDI and HIS. The HUKM-SIS construct was stiffer than HIS under torsional loads. We conclude that multiple pedicle screws increase the stiffness of posterior instrumentation constructs under all loads and inter-segmental spinous processes wiring increase the stiffness against lateral bending.

Effect of truncated platelet-derived growth factor-alpha receptor on apoptosis and expression of c-sis mRNA of pulmonary artery smooth muscle cells / 中华儿科杂志

<p><b>OBJECTIVE</b>Platelet-derived growth factor (PDGF) plays an important role during the pathophysiological changes in vascular remodeling. The study aimed to investigate the effect of truncated PDGF-alpha receptor on apoptosis and expression of c-sis mRNA of pulmonary artery smooth muscle cells (VSMCs).</p><p><b>METHODS</b>Tissue mass culture was done to get vascular smooth muscle cells of pulmonary artery in newborn pigs. Two methods were used to interfere VSMCs: adding adenoviral recombined body (Ad5CMV-PalphaRtr, ACP) with three different concentrations of truncated PDGF-alpha receptor into the cultures, or adding three concentrations of PDGF-BB after the treatment with mid-concentration of ACP. VSMC apoptosis, cellular cycle and expression of c-sis were observed using flow-cytometry, and the expression of c-sis mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>ACP with mid- to- high concentrations could restrain the proliferation of VSMCs apparently with the increase of G(0)/G(1) cells. The apoptotic rate presented an ascending tendency. The differences among the groups were of statistically significant. Affected by mid- concentration of ACP, PDGF-BB did not exhibit a significantly accelerating effect on the changes of cellular cycle and VSMC apoptosis. The expression of c-sis mRNA was up-regulated under the effect of ACP. Affected by mid-concentration of ACP and PDGF-BB, c-sis mRNA expressed was down-regulated.</p><p><b>CONCLUSION</b>Mid- to- high concentration of ACP is a powerful inhibitor of cellular proliferation for pulmonary artery VSMCs. It can significantly increase cells in number in G(0)/G(1) phase, apoptosis and c-sis mRNA expression.</p>

Detection of COL1A1/PDGFB fusion transcripts in dermatofibroscoma protuberans by revers transcriptase-polymerase chain reaction using paraffin-embedded tissues / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect the COL1A1/PDGFB fusion transcripts and discuss its clinicopathological significance in dermatofibroscoma protuberans.</p><p><b>METHODS</b>Formalin fixed, paraffin-embedded tumor specimens from 12 patients with DFSP were reviewed by light microscope and the expression of COL1A1/PDGFB mRNA resulting from the reciprocal translocation t(17;22) (q22;q13.1) was detected by one-step revers transcriptase-polymerase chain reaction. The following tumor specimens were included as controls: 2 fibrosarcoma, 2 malignant fibrous histocytoma, 3 leiomyosarcoma, 1 dermarofibroma and 1 nerve shealth tumor.</p><p><b>RESULTS</b>The COL1A1/PDGFB fusion transcripts were detected in 8 (67%) of 12 samples from patients with DFSP. Nucleotide sequence analysis using the PCR products confirmed that different regions of the COL1A1 gene, respectively, were fused with of PDGFB gene. No COL1A1/PDGFB fusion transcripts were detected in the control tumors.</p><p><b>CONCLUSION</b>Detection of specific COL1A1/PDGFB fusion transcripts in DFSP will help to diagnose the nature of DFSP and research the mechanism of its molecular histogenesis.</p>