Effects of the quorum sensing related luxS gene and lsr operon on Klebsiella michiganensis resisting copper stress.

Industrial wastewater is a major environmental concern due to its high copper content, which poses significant toxicity to microbial life. Autoinducer-2 (AI-2) can participate in the inter- and intra-species communication and regulate the physiological functions of different bacterial species by producing AI-2 signal molecules. However, there are few research reports on the luxS gene and lsr operon functions for AI-2 in bacteria with a certain tolerance to copper. This study delves into the potential of quorum sensing mechanisms, particularly the AI-2 system, for enhancing microbial resistance to copper toxicity in Klebsiella michiganensis (KM). We detail the critical roles of the luxS gene in AI-2 synthesis and the lsr operon in AI-2 uptake, demonstrating their collective impact on enhancing copper resistance. Our findings show that mutations in the lsr operon, alongside the knockout of the luxS gene in KM strain (KMΔluxSΔlsr), significantly impair the strain's motility (p < 0.0001) and biofilm formation (p < 0.01), underscoring the operon's role in AI-2 transport. These genetic insights are pivotal for developing bioremediation strategies aimed at mitigating copper pollution in wastewater. By elucidating the mechanisms through which KM modulates copper resistance, this study highlights the broader ecological significance of leveraging microbial quorum sensing pathways for sustainable wastewater management.

Distribution and predictive value of initial presenting symptoms in spinal metastases from primary cancer patients.

PURPOSE: Primary cancer patients may have some symptoms and develop spinal metastases in their disease progression. This study was to report the distribution and predictive value of specific initial presenting symptoms in patients with spine metastatic disease. METHODS: The clinical information about patients with primary cancers was retrospectively collected and analyzed at their initial diagnosis from January 2008 to December 2017. The distribution and specific value of initial presenting symptoms were analyzed in predicting spinal metastases. RESULTS: A total of 14,603 cancer patients were finally included, of whom 1665 (11.4%) cases were confirmed with spinal metastases. 41.55% (6067/14,603) patients had initial presenting symptoms, while 92.19% (1535/1665) patients with spinal metastases presented at least one initial presenting symptoms. Among 6269 patients with symptoms, 1535 (24.49%) were diagnosed with spinal metastases. Factors including primary tumor type, local pain, night-aggravating pain, limb numbness, limb weakness, unstable gait, claudication, loss of sphincter control, and weight loss are associated with the distribution of spinal metastases. The pooled sensitivity, specificity, positive predictive value, and negative predictive value were 90.9% (89.4-92.2%), 64.9% (64.0-65.7%), 24.99% (23.91-26.11%), and 98.23% (97.92-98.50%), respectively. Positive likelihood ratio of "night-aggravating pain" was 33.25 (12.65-87.36) and 17.26 (12.25-24.32) in patients < 45 and 45-64 years old, respectively. CONCLUSIONS: The distribution of spinal metastases is associated with primary tumor type and initial presenting symptoms. The predictive value of initial presenting symptoms differs in age groups, but resembles in cancer types. The presence of night-aggravating pain had relative high value in predicting metastases in cancer patients under 65 years old.

Surgical treatment of upper cervical spine metastases: a retrospective study of 39 cases.

BACKGROUND: The surgical treatment of upper cervical spine metastases are controversial up to now. By summarizing and analyzing the clinical data of the upper cervical spine involved metastases treated surgically in our center, we mainly aimed to investigate the surgical decisions and outcomes so as to provide more references for the clinical treatment of this special and complex spine metastasis. METHODS: We evaluated the patients' pre- and post-operative neck pain and neurologic function with paired t test, followed by the statistics of the selection of surgical approaches, ways of reconstruction, and related complications. Moreover, the Kaplan-Meier survival analysis was adopted to analyze the patients' survival according to different growth group (rapid, moderate, and slow). RESULTS: There were 39 patients with atlantoaxial metastases in this study. The most common symptom (94.87%) was occipital-cervical pain, which relieved greatly after surgical interventions (p < 0.01). The metastases mainly resulted from lung cancer and nasopharyngeal cancer with an incidence of 38.46 and 10.26%, respectively. As to different growth group, the rapid-growth tumors accounted for 69.23% in all atlantoaxial metastases. Tumor resection and stabilization were performed mainly via the combined anterior and posterior approach (66.67%). The 1-, 2-, and 3-year overall survival rate at the last follow-up was 58.5, 40, and 28.3%, respectively, with a median survival time of 18 months. The rate of complications associated with the surgical intervention was 12.82% (5/39), which is lower than that of the previous reports and generally controllable. CONCLUSIONS: Relatively radical interventions with surgery for upper cervical spine metastases offered satisfactory outcomes with a low mortality. Together with adjuvant therapy, surgical treatment benefits patients with atlantoaxial metastases by relieving regional pain, restoring or improving the neurologic function, stabilizing the quality of life, and prolonging the survival time of such patients.

[Retracted] MicroRNA-493 inhibits the proliferation and invasion of osteosarcoma cells through directly targeting specificity protein 1.

[This retracts the article DOI: 10.3892/ol.2018.8268.].

Interdisciplinary Surgical Treatments and Long-Term Outcomes of Lumbar Spinal Tumors With Retroperitoneal Involvements: A Retrospective Case Series Study.

PURPOSE: Surgical treatments are technically challenging for lumbar spinal tumor (LST) with extensive retroperitoneal involvements. Our study aimed to report the experience and outcomes concerning interdisciplinary surgical collaborations in managing such LSTs. PATIENTS AND METHODS: Nine patients underwent interdisciplinary surgical treatments which were performed by specialists, namely, spinal, vascular, and urinary surgeries. Data on clinical characteristics were collected, and the Visual Analogue Scale (VAS) and the Japanese Orthopaedic Association Score (JOAS) were used in the evaluation before and after surgery. The postoperative complications and the long-term outcomes were reported as well. RESULTS: The interdisciplinary work included double J catheter indwelling (n = 9), nephrostomy (n = 5), replacement of the common iliac vein (n = 2), abdominal aorta repair (n = 3), and vital vessel repair (n = 8). The early-stage complications included complaints of moderate low back pain and slight implant shift (n = 1, 11.1%) and tardive ureterodialysis (n = 1, 11.1%). The 3- and 5-year disease-free survival rates were 76.2 ± 14.8 and 50.8 ± 23.0%, respectively, during the mean follow-up of 34.6 ± 17.9 months (range, 9.5-68.7). Besides this, more blood loss was associated with recurrent and metastatic tumor status (p = 0.043) and surgery time >5 h (p = 0.023). Remarkable pain relief and favorable quality of life were achieved based on the postoperative VAS (3.3 ± 0.9, p < 0.001) and JOAS (16.6 ± 0.5, p < 0.001). CONCLUSIONS: The treatments of LSTs with wide-range retroperitoneal involvements require interdisciplinary surgical collaborations to lower the risks and improve the long-term outcomes. High-quality prospective cohort studies with large samples are warranted to establish general surgical protocols in managing LSTs with extensive retroperitoneal involvements.

A Novel Technique for Total En bloc Spondylectomy of the Fifth Lumbar Tumor Through Posterior-Only Approach.

STUDY DESIGN: A retrospective study. OBJECTIVE: To describe a new surgical technique for total en bloc spondylectomy (TES) of the fifth lumbar (L5) tumor and evaluate the efficacy and safety of this new technique. SUMMARY OF BACKGROUND DATA: TES has been considered an optimal treatment for tumor, including certain spinal tumors, but it requires a combined posterior-anterior approach, which is often complicated by a long operation time, considerable blood loss and severe trauma. METHODS: Seven patients with primary or solitary metastatic tumors of L5 were treated with this new technique in our center between March 2014 and November 2017. The critical points were fabrication of the iliac graft, dissection, resection, and reconstruction. Other parameters including surgical time, blood loss, complications, pre- and postoperative neurological function, tumor control, and overall survival (OS) were presented and analyzed. RESULTS: All the included patients received one stage TES. The mean surgical time was 365.7 minutes with an average blood loss of 2514.3 mL. No serious perioperative complication was observed or reported during the mean follow-up period of 27.4 months. Wound disruption occurred in one patient and numbness of the left lower limb in another, but both recovered rapidly after appropriate management. Adventitial avulsion of the abdominal aorta occurred during dissection in one patient. Two patients died during the follow-up period due to advanced malignancy. One patient was alive but developed a newly diagnosed thoracolumbar tumor in 40 months. The other four patients recovered well without evidence of disease. All patients were able to walk independently 3 to 4 weeks after operation, with satisfied fusion of the iliac grafts in a mean period of 6.7 months after operation. No evidence of internal fixation failure occurred. CONCLUSION: This new technique offers satisfactory surgical exposure, total en bloc spondylectomy, reliable reconstruction, and good tumor control for certain L5 tumors through the posterior-only approach. LEVEL OF EVIDENCE: 4.

One-Stage Wedge Osteotomy Through Posterolateral Approach for Cervical Postlaminectomy Kyphosis with Anterior Fusion.

OBJECTIVE: Osteotomy through anterior exposure is challenging with severe complications for upper cervical kyphosis (CK), especially for cases with previous anterior fusion. A novel technique comprising 1-stage osteotomy via a posterolateral-only approach is introduced for treatment of CK secondary to C2-4 laminectomy for neurofibroma removal and subsequent anterior fusion. METHODS: A 42-year-old man presented with progressive numbness and weakness of upper and lower limbs. As an adolescent, he underwent posterior laminectomy and neurofibroma excision without effective fixation and anterior C2-4 vertebra fusion 6 years later. Sagittal computed tomography indicated that Cobb angle between C2 and C6 was 68° with complete fusion between C2 and C4 vertebral bodies. Secondary CK was diagnosed based on medical history and radiographic findings, and modified Japanese Orthopaedic Association scale score was 10. Piezosurgery was used for osteotomy by shortening the vertebral height through posterolateral approach after cervical pedicle screw placement. Occipitocervical fusion was performed with compression between C2 and C4. RESULTS: Cobb angle was adjusted to 8° postoperatively. Modified Japanese Orthopaedic Association score increased to 14 with obvious muscle strength improvement. The 6-month postoperative x-ray indicated good position of C2-4 vertebrae and occipitocervical fixation system. No neurologic complications or local recurrence was found at final follow-up at 8 months. The patient returned to work in his full capacity. CONCLUSIONS: Preliminary outcomes reveal wedge osteotomy via piezosurgery through a posterolateral-only approach is feasible and effective in revision surgery for upper CK with previous anterior fusion.

MicroRNA-493 inhibits the proliferation and invasion of osteosarcoma cells through directly targeting specificity protein 1.

Osteosarcoma (OS) is the most common type of primary bone tumor and accounts for ~60% of all malignant bone tumors in children and adolescents. A large number of studies have proposed that the dysregulated and dysfunctional microRNAs may serve important roles in the occurrence, progression and metastasis of various types of human cancer, including OS. MicroRNA-493 (miR-493) has been identified to act as a tumor suppressor in several types of human cancer. However, little is known regarding the expression pattern and clinical significance of miR-493 in OS. In the present study, reverse transcription-quantitative polymerase chain reaction analysis revealed that miR-493 was markedly downregulated in OS tissues and cell lines and a low miR-493 level were associated with distant metastasis and clinical stage. Furthermore, functional experiments demonstrated that enforced expression of miR-493 led to a significant decrease in OS cell proliferation and invasion in vitro. Furthermore, through bioinformatics analysis, specificity protein 1 (SP1) was identified as a direct target gene of miR-493 in OS. Its expression was upregulated in OS tissues and was negatively associated with miR-493 expression levels. Inhibition of SP1 expression also suppressed the proliferation and invasion of OS, exerting a similar effect to that induced by miR-493 overexpression. These results suggested that miR-493 inhibited OS cell proliferation and invasion through negative regulation of SP1. Therefore, miR-493/SP1 may represent a potential therapeutic target for the treatment of OS.

miR-215 suppresses proliferation and migration of non-small cell lung cancer cells.

The expression of microRNA-215 (miR-215) in non-small cell lung cancer (NSCLC) tissues and the effects of miR-215 on the proliferation and migration of NSCLC cells were investigated. qRT-PCR was used to detect the expression of miR-215 in NSCLC tissues and paired normal tumor-adjacent lung tissues; MTT assay, transwell assay and soft-agar assay were used in vitro to evaluate the role of miR-215 on proliferation, migration and cell clonality on NSCLC cells, after transfecting miR-215 mimics to NSCLC cell line A549 or miR-215 to H1299. miR-215 was significantly decreased in NSCLC tissues compared to the paired normal tissues; Overexpression of miR-215 in A549 cells resulted in reduction of the cell proliferation, migration and cell clonality, while downregulation of miR-215 in H1299 cells could promote cell proliferation, migration and clonality. In conclusion, miR-215 was downregulated in NSCLC tissues and may play a key role in the development of NSCLC.