In keratinocytes the human Bag-1 gene produces three different protein isoforms from a single messenger RNA, BAG-1L, BAG-1M and BAG-1S. In this study we questioned whether BAG-1L or the shorter ...isoforms would promote keratinocyte differentiation in organotypic cultures of HaCaT. HaCaT parental and vector cells showed stratification, but terminal differentiation was not complete. Cultures overexpressing BAG-1L isoform-specifically were of increased thickness, demonstrated pronounced expression of basal cytokeratin 5 and β1-integrin, suprabasal involucrin, cytokeratin 1 and plasma membrane-localised filaggrin, and a marked keratinized layer of cells at the surface. We were unable to overexpress BAG-1S and BAG-1M isoform-specifically. Overexpression of BAG-1M gave rise to organotypic cultures intermediate in differentiation to controls and those overexpressing BAG-1L. Cells overexpressing BAG-1S also exhibited elevated endogenous BAG-1. These produced slow growing cultures with high levels of basal cytokeratin 5, but little involucrin or cytokeratin 1. Suprabasal β1-integrin and Ki67 positive cells indicated defective stratification. The results suggest that BAG-1L potentiates epidermal differentiation, but disruption in the relative balance of isoforms towards overexpression of BAG-1S can lead to defective tissue patterning. Hence, a delicate balance of BAG-1 isoforms may be required to regulate normal epidermal stratification and differentiation, with important implications for aberrant differentiation in cancer.
Cell motility is important in maintaining tissue homeostasis, facilitating epithelial wound repair and in tumour formation and progression. The aim of this study was to determine whether BAG-1 ...isoforms regulate epidermal cell migration in
in vitro models of wound healing. In the human epidermal cell line HaCaT, endogenous BAG-1 is primarily nuclear and increases with confluence. Both transient and stable p36-Bag-1 overexpression resulted in increased cellular cohesion. Stable transfection of either of the three human BAG-1 isoforms p36-Bag-1 (BAG-1S), p46-Bag-1 (BAG-1M) and p50-Bag-1 (BAG-1L) inhibited growth and wound closure in serum-containing medium. However, in response to hepatocyte growth factor (HGF) in serum-free medium, BAG-1S/M reduced communal motility and colony scattering, but BAG-1L did not. In the presence of HGF, p36-Bag-1 transfectants retained proliferative response to HGF with no change in ERK1/2 activation. However, the cells retained E-cadherin localisation at cell–cell junctions and exhibited pronounced cortical actin. Point mutations in the BAG domain showed that BAG-1 inhibition of motility is independent of its function as a chaperone regulator. These findings are the first to suggest that BAG-1 plays a role in regulating cell–cell adhesion and suggest an important function in epidermal cohesion.
Objective— To evaluate the effects of diode laser surgery (LS), surgical drilling (SD), and intraarticular sodium monoiodoacetate (MIA) as methods for fusing the distal intertarsal (DIT) and ...tarsometatarsal (TMT) joints in horses.
Study Design— Experimental study.
Animals— Adult horses (15) without radiographic signs of osteoarthritis (OA) of the DIT and TMT joints.
Methods— Group 1 (n=3) had LS performed bilaterally on DIT and TMT joints; 1 horse was evaluated for 1 week and 2 horses were evaluated for 2 weeks. Group 2 (n=6) had LS on DIT and TMT joints of 1 tarsus and MIA administration into the contralateral DIT and TMT joints and were evaluated for 6 months. Group 3 (n=6) had LS performed on DIT and TMT joints of 1 tarsus and SD of the contralateral DIT and TMT joints and were evaluated for 12 months. Postoperative comfort, lameness, radiography, microradiography, and histology scores were compared using repeated measures ANOVA, and paired or 2 sample t‐tests; significance was set at P<.05.
Results— LS caused the least postoperative morbidity. In group 2, horses were less lame in 4 LS‐treated limbs and 2 MIA‐treated limbs at 6 months when compared with the contralateral limb. In group 3, horses were less lame in 5 LS‐treated limbs and 1 SD‐treated limb at 6 and 12 months compared with the contralateral limb. On microradiography, 11 MIA joints and 2 LS joints had bone bridging the joint at 6 months whereas 8 SD joints and 5 LS joints had bone bridging at 12 months. Significantly more joint space was bridged by bone in MIA‐ (51.4%) and SD (46.2%)‐treated joints compared with LS joints at 6 (30.6%) and 12 (28.5%) months, respectively (P<.05).
Clinical Relevance— SD and MIA resulted in more bone bridging of the distal 2 tarsal joints, than LS. However, LS seemingly caused less pain and discomfort to horses in the immediate postoperative period; horses were generally less lame in the LS limb. More laser energy may need to be applied to these joints to promote fusion; however, it may also have beneficial effects beyond fusion. Further research on horses with OA of the distal 2 tarsal joints is needed to determine whether LS can cause soundness without facilitating bony fusion.
BAG-1 is a multifunctional protein that interacts with a wide range of target molecules to regulate apoptosis, proliferation, transcription, metastasis and motility. Interaction with chaperone ...molecules may mediate many of the effects of BAG-1. The pathways regulated by BAG-1 play key roles in the development and progression of cancer and determining response to therapy, and there has been considerable interest in determining the clinical significance of BAG-1 expression in malignant cells. There is an emerging picture that BAG-1 expression is frequently altered in a range of human cancers relative to normal cells and a recent report suggests the exciting possibility that BAG-1 expression may have clinical utility as a prognostic marker in early breast cancer. However, other studies of BAG-1 expression in breast cancer and other cancer types have yielded differing results. It is important to view these findings in the context of current knowledge of BAG-1 expression and function. This review summarises recent progress in understanding the clinical significance of BAG-1 expression in cancer in light of our understanding of BAG-1 function.
As BCL-2 oncoprotein has been implicated as a survival factor in a number of tissues, we examined colorectal tumour specimens and cell lines for BCL-2 expression. BCL-2 protein was expressed in 19/22 ...adenocarcinomas and 12/13 adenomas. 6/9 carcinoma cell lines and 7/8 adenoma cell lines were also BCL-2 positive. BCL-2 expression was retained in metastases to the regional lymph nodes (3/3 specimens) and in the cell line SW620, derived from a lymph node metastasis. These studies suggest a role for BCL-2 in promoting cell survival of benign and malignant colorectal tumours and that BCL-2 deregulation may be a relatively early event in colorectal carcinogenesis. The retention of BCL-2 expression in the carcinomas and lymph node metastases may explain the resistance of colorectal tumours to chemotherapeutic treatment.
Magnetic Resonance Imaging (MRI) is considered the mainstay imaging investigation in patients suspected of lumbar disc herniations. Both imaging and clinical findings determine the final decision of ...surgery. The objective of this study was to assess MRI observer variation in patients with sciatica who are potential candidates for lumbar disc surgery.
Patients for this study were potential candidates (n = 395) for lumbar disc surgery who underwent MRI to assess eligibility for a randomized trial. Two neuroradiologists and one neurosurgeon independently evaluated all MRIs. A four point scale was used for both probability of disc herniation and root compression, ranging from definitely present to definitely absent. Multiple characteristics of the degenerated disc herniation were scored. For inter-agreement analysis absolute agreements and kappa coefficients were used. Kappa coefficients were categorized as poor (<0.00), slight (0.00-0.20), fair (0.21-0.40), moderate (0.41-0.60), substantial (0.61-0.80) and excellent (0.81-1.00) agreement.
Excellent agreement was found on the affected disc level (kappa range 0.81-0.86) and the nerve root that most likely caused the sciatic symptoms (kappa range 0.86-0.89). Interobserver agreement was moderate to substantial for the probability of disc herniation (kappa range 0.57-0.77) and the probability of nerve root compression (kappa range 0.42-0.69). Absolute pairwise agreement among the readers ranged from 90-94% regarding the question whether the probability of disc herniation on MRI was above or below 50%. Generally, moderate agreement was observed regarding the characteristics of the symptomatic disc level and of the herniated disc.
The observer variation of MRI interpretation in potential candidates for lumbar disc surgery is satisfactory regarding characteristics most important in decision for surgery. However, there is considerable variation between observers in specific characteristics of the symptomatic disc level and herniated disc.
The death ligand TRAIL (Apo2L) has potential for cancer therapy, since tumour cells are thought to be more sensitive than normal cells. We investigated whether sensitivity to TRAIL increases during ...the adenoma to carcinoma transition of colorectal carcinogenesis. Under the same culture conditions, we compared the extent of TRAIL-induced apoptosis in four premalignant adenoma and three carcinoma cell lines. Although TRAIL induced some apoptosis in adenoma cultures, the carcinoma cell lines were significantly more sensitive (P<0.001). This finding was recapitulated in an in vitro model of tumour progression in which conversion of the adenoma cell line AA/C1 to a tumorigenic phenotype was associated with increased TRAIL sensitivity (P<0.001). Increased TRAIL sensitivity during colorectal carcinogenesis has been previously attributed to changes in the balance between TRAIL receptors TRAIL-R1 and -R2 and "decoy" receptors TRAIL-R3 and -R4 during malignant progression. To address this, cell surface receptor expression was measured by flow cytometry. In summary, during colorectal carcinogenesis, there is a marked increase in sensitivity to TRAIL-induced apoptosis associated with progression from benign to malignant tumour that could be exploited for colon cancer therapy, but alterations in cell surface TRAIL receptor expression may not be the primary reason for this change.
Abstract Background context In the 1980s, a new implant was developed to treat patients with intermittent neurogenic claudication caused by lumbar spinal stenosis (LSS). This implant is now widely ...used. Purpose The objective of this study is to determine whether a favorable cost-effectiveness for interspinous process devices (IPDs) compared with conventional bony decompression is attained. Study design/setting Cost-utility analysis was performed alongside a double-blind randomized controlled trial. Five neurosurgical centers (including one academic and four secondary level care centers) included participants for this study. Patient sample One hundred fifty-nine patients with LSS were treated with the implantation of IPD and with bony decompression. Eighty participants received an IPD, and seventy-nine participants underwent spinal bony decompression. Outcome measures Outcome measures were quality-adjusted life-years (QALYs) and societal costs in the first year (estimated per quarter), estimated from patient-reported utilities (US and The Netherlands EuroQol 5D EQ-5D and EuroQol visual analog scale) and diaries on costs (health-care costs, patient costs, and productivity costs). Methods All analyses followed the intention-to-treat principle. Given the statistical uncertainty of differences between costs and QALYs, cost-effectiveness acceptability curves graph the probability that a strategy is cost effective, as a function of willingness to pay. Paradigm Spine funded this trial but did not have any part in data analysis or the design and preparation of this article. Results According to the EQ-5D, the valuation of quality of life after IPD and decompression was not different. Mean utilities during all four quarters were, not significantly, less favorable after IPD according to the EQ-5D with a decrease in QALYs according to the US EQ-5D of 0.024 (95% confidence interval, −0.031 to 0.079). From a health-care perspective, the costs of IPD treatment were higher (difference €3,030 per patient, 95% confidence interval, €561–€5,498). This significant difference is mainly because of additional cost of implants of €2,350 apiece. From a societal perspective, a nonsignificant difference of €2,762 (95% confidence interval, −€1,572 to €7,095) in favor of conventional bony decompression was found. Conclusions Implantation of IPD as indirect decompressing device is highly unlikely to be cost effective compared with bony decompression for patients with intermittent neurogenic claudication caused by LSS. Trial registration Dutch Trial Register Number: NTR1307.
Objective To assess whether interspinous process device implantation is more effective in the short term than conventional surgical decompression for patients with intermittent neurogenic ...claudication due to lumbar spinal stenosis. Design Randomized controlled trial. Setting Five neurosurgical centers (including one academic and four secondary level care centers) in the Netherlands. Participants 203 participants were referred to the Leiden-The Hague Spine Prognostic Study Group between October 2008 and September 2011; 159 participants with intermittent neurogenic claudication due to lumbar spinal stenosis at one or two levels with an indication for surgery were randomized. Interventions 80 participants received an interspinous process device and 79 participants underwent spinal bony decompression. Main outcome measures The primary outcome at short term (eight weeks) and long term (one year) follow-up was the Zurich Claudication Questionnaire score. Repeated measurements were made to compare outcomes over time. Results At eight weeks, the success rate according to the Zurich Claudication Questionnaire for the interspinous process device group (63%, 95% confidence interval 51% to 73%) was not superior to that for standard bony decompression (72%, 60% to 81%). No differences in disability (Zurich Claudication Questionnaire; P=0.44) or other outcomes were observed between groups during the first year. The repeat surgery rate in the interspinous implant group was substantially higher (n=21; 29%) than that in the conventional group (n=6; 8%) in the early post-surgical period (P<0.001). Conclusions This double blinded study could not confirm the hypothesized short term advantage of interspinous process device over conventional “simple” decompression and even showed a fairly high reoperation rate after interspinous process device implantation. Trial registration Dutch Trial Register NTR1307.
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