RARP in high-risk prostate cancer： use of multi-parametric MRI and nerve sparing techniques

To examine the outcomes of patients with high-risk prostate cancer （PCa） treated by robot-assisted radical prostatectomy （RARP） and evaluate the value of multi-parametric magnetic resonance imaging （MRI） in estimating tumor stage, extracapsular extension, and grade, and the application of nerve sparing （NS） techniques. Patient demographics, preoperative imaging, surgical parameters, pathological features, functional and recurrence outcomes were collected retrospectively in patients with high-risk PCa who underwent RARP between December 2009 and October 2013. Pathological whole mount slides to assess NS were compared with potency, recovery of continence, and surgical margins （SM）. Forty-four cases of high-risk PCa were identified with a median followup of 24 months and positive surgical margins （PSM） rate of 14%. Continence returned in 86%, with potency rate of 58%. Of the 25 cases with a preoperative multi-parametric MRI, MRI improved clinical staging from 28% to 88%, respectively. Following risk stratification of NS by microscopic analysis of whole mount pathology, patients with Group A （bilateral NS）, Group B （unilateral NS）, Group C （partial NS）, and Group D （non-NS） had 100%, 92%, 91%, and 50% continence rates, and 100%, 80%, 45%, and 0% potency rates, respectively, with an inverse correlation to PSM. RARP in men with high-risk PCa can achieve favorable oncologic and functional outcomes. Preoperative MRI may localize high-grade tumors and improve clinical staging. Extent of NS is influenced by clinical staging and may balance potency and continence with PSMs.

Epigenetic combined with transcriptomic analysis of the m6A methylome after spared nerve injury-induced neuropathic pain in mice

Epigenetic changes in the spinal cord play a key role in the initiation and maintenance of nerve injury-induced neuro pathic pain.N6-methyladenosine(m6A)is one of the most abundant internal RNA modifications and plays an essential function in gene regulation in many diseases.However,the global m6A modification status of mRNA in the spinal cord at different stages after neuropathic pain is unknown.In this study,we established a neuropathic pain model in mice by preserving the complete sural nerve and only damaging the common peroneal nerve.High-throughput methylated RNA immunoprecipitation sequencing res ults showed that after spared nerve injury,there were 55 m6A methylated and diffe rentially expressed genes in the spinal cord.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway results showed that m6A modification triggered inflammatory responses and apoptotic processes in the early stages after spared nerve injury.Over time,the diffe rential gene function at postoperative day 7 was enriched in "positive regulation of neurogenesis" and "positive regulation of neural precursor cell prolife ration." These functions suggested that altered synaptic morphological plasticity was a turning point in neuropathic pain formation and maintenance.Results at postoperative day 14 suggested that the persistence of neuropathic pain might be from lipid metabolic processes,such as "very-low-density lipoprotein particle clearance," "negative regulation of choleste rol transport" and "membrane lipid catabolic process." We detected the expression of m6A enzymes and found elevated mRNA expression of Ythdf2 and Ythdf3 after spared nerve injury modeling.We speculate that m6A reader enzymes also have an important role in neuropathic pain.These results provide a global landscape of mRNA m6A modifications in the spinal cord in the spared nerve injury model at diffe rent stages after injury.

Nerve preserving vs standard laparoscopic sacropexy: Postoperative bowel function

To compare our developed nerve preserving technique with the non-nerve preserving one in terms of de novo bowel symptoms. METHODSPatients affected by symptomatic apical prolapse, admitted to our department and treated by nerve preserving laparoscopic sacropexy (LSP) between October, 2010 and April, 2013 (Group A or “interventional group”) were compared to those treated with the standard LSP, between September, 2007 and December, 2009 (Group B or “control group”). Functional and anatomical data were recorded prospectively at the first clinical review, at 1, 6 mo, and every postsurgical year. Questionnaires were filled in by the patients at each follow-up clinical evaluation. RESULTSForty-three women were enrolled, 25/43 were treated by our nerve preserving technique and 18/43 by the standard one. The data from the interventional group were collected at a similar follow-up (> 18 mo) as those collected for the control group. No cases of de novo bowel dysfunction were observed in group A against 4 cases in group B (P = 0.02). Obstructed defecation syndrome (ODS) was highlighted by an increase in specific questionnaires scores and documented by the anorectal manometry. There were no cases of de novo constipation in the two groups. No major intraoperative complications were reported for our technique and it took no longer than the standard procedure. Apical recurrence and late complications were comparable in the two groups. CONCLUSIONOur nerve preserving technique seems superior in terms of prevention of de novo bowel dysfunction compared to the standard one and had no major intraoperative complications.

Proteomic analysis of the dorsal spinal cord in the mouse model of spared nerve injury-induced neuropathic pain

Peripheral nerve injury often causes neuropathic pain and is associated with changes in the expression of numerous proteins in the dorsal horn of the spinal cord. To date, proteomic analysis method has been used to simultaneously analyze hundreds or thousands of proteins differentially expressed in the dorsal horn of the spinal cord in rats or dorsal root ganglion of rats with certain type of peripheral nerve injury. However, a proteomic study using a mouse model of neuropathic pain could be attempted because of abundant protein database and the availability of transgenic mice. In this study, whole proteins were extracted from the ipsilateral dorsal half of the 4th-6th lumbar spinal cord in a mouse model of spared nerve injury（SNI）-induced neuropathic pain. In-gel digests of the proteins size-separated on a polyacrylamide gel were subjected to reverse-phase liquid-chromatography coupled with electrospray ionization ion trap tandem mass spectrometry（MS/MS）. After identifying proteins, the data were analyzed with subtractive proteomics using ProtAn, an in-house analytic program. Consequently, 15 downregulated and 35 upregulated proteins were identified in SNI mice. The identified proteins may contribute to the maintenance of neuropathic pain,and may provide new or valuable information in the discovery of new therapeutic targets for neuropathic pain.

Contribution of spinal glia activation to mechanical hyperalgesia induced by spared nerve injury in rats

Objective: To investigate the role of spinal glial cells activation in neuropathic pain in a recently developed spared nerve injury (SNI) animal model by Decosterd and Woolf. Methods: A lesion was made to two of the three terminal branches of the sciatic nerve of rats (tibial and common peroneal nerves) leaving the sural nerve intact. Continuous intrathe-cal administration of propentofylline, a glial modulating agent, 1 d before and 5 d after operation, was performed to disrupt spinal cord glia function. The vehicle was intrathecally administrated as control. The paw withdrawal threshold to mechanical stimulation (paw withdrawal mechaical threshold PWMT), body mass and motor function were determined pre- and post-surgery. Results: It produced a prolonged mechanical allodynia in the medial and lateral part of the ipsilateral hind paw in SNL models. The treatment with propentofylline significantly prevented the development of mechanical allodynia located in either medial or lateral plantar surface. Rats in two groups showed normal motor function and body weight increase. Conclusion: SNI model can be applied as a useful method with little variance in searching the mechanism of neuropathic pain. These study suggest that spinal glia activation may contribute to mechanical allodynia induced by SNI.

Surgical approach affecting long-term urinary continence status after robot-assisted laparoscopic prostatectomy prospectively evaluated using self-reported functional status(Expanded Prostate Cancer Index Composite,EPIC-26)

Purpose:The aim of the study was to examine the influence of the surgical approach for robot-assisted laparoscopic prostatectomy(RALP)on long-term urinary continence status in the era of self-reported functional status measures using the Expanded Prostate Cancer Index Composite 26.Materials and methods:This is a prospective evaluation of 232 patients undergoing RALP between September,2019 and September,2020.Urinary continence status and postoperative incontinence(pad usage)were evaluated 12 months after RALP using Expanded Prostate Cancer Index Composite 26 questionnaires.Patients were categorized according to their surgical approach and outcome into the following groups:successful nerve sparing(NS),primarily without nerve sparing(prim.NNS),and no nerve sparing by secondary resection(NNS by SR).The median levels of their questionnaire outcomes were evaluated and compared using the Wilcoxon rank sum test with continuity correction.Results:Urinary continence status 12 months after RALP differed significantly between the NS and prim.NNS(p=0.0071)and the NS and NNS by SR(p=0.0076)groups.There was no significant difference between the prim.NNS and NNS by SR(p=0.53)groups.Pad usage 12 months after RALP had no significant difference with regard to SR of the neurovascular bundle(p=0.14).Conclusions:Patient-reported outcomes of long-term urinary continence status seem to show no difference in postoperative continence,regardless of whether a non-nerve-sparing result was planned or reached through SR.Instead,preservation of neurovascular bundle seems to lead to better long-term continence rates.

Upregulation of Chemokine CXCL12 in the Dorsal Root Ganglia and Spinal Cord Contributes to the Development and Maintenance of Neuropathic Pain Following Spared Nerve Injury in Rats

Emerging evidence indicates that CXCL12/ CXCR4 signaling is involved in chronic pain. However, few studies have systemically assessed its role in direct nerve injury-induced neuropathic pain and the underlying mech- anism. Here, we determined that spared nerve injury （SNI） increased the expression of CXCL12 and its cognate receptor CXCR4 in lumbar 5 dorsal root ganglia （DRG） neurons and satellite glial cells. SNI also induced long- lasting upregulation of CXCL12 and CXCR4 in the ipsi- lateral L4-5 spinal cord dorsal horn, characterized by CXCL12 expression in neurons and microglia, and CXCR4 expression in neurons and astrocytes. Moreover, SNI- induced a sustained increase in TNF-α expression in the DRG and spinal cord. Intraperitoneal injection （i.p.） of the TNF-α synthesis inhibitor thalidomide reduced the SNI-in- duced mechanical hypersensitivity and inhibited the expression of CXCL12 in the DRG and spinal cord. Intrathecal injection （i.t.） of the CXCR4 antagonist AMD3100, both 30 rain before and 7 days after SNI, reduced the behavioral signs of allodynia. Rats given an i.t. or i.p. bolus of AMD3100 on day 8 of SNI exhibited attenuated abnormal pain behaviors. The neuropathic pain established following SNI was also impaired by i.t. admin- istration of a CXCL12-neutralizing antibody. Moreover, repetitive i.t. AMD3100 administration prevented the acti- vation of ERK in the spinal cord. The mechanical hyper- sensitivity induced in nai＇ve rats by i.t. CXCL12 was alleviated by pretreatment with the MEK inhibitor PD98059. Collectively, our results revealed that TNF-α might mediate the upregulation of CXCL12 in the DRG and spinal cord following SNI, and that CXCL 12/CXCR4 sig- naling via ERK activation contributes to the development and maintenance of neuropathic pain.

Evaluation of NR2B peptide as subunit vaccines against experimental neuropathic pain

Background NR2B containing N-methyI-D-aspartate （NMDA） receptor plays an important role in the facilitation and maintenance of neuropathic pain. The discrete distribution of NR2B subunit in the central nervous system （CNS） may support reduced side effects of agents that act selectively at this site. Therefore, we investigated the hypothesis that a humoral autoimmune response targeting the NR2B subunit of NMDA receptor relieves pain like behaviours produced by peripheral injury. Methods Rats were immunized subcutaneously with NR2B-Keyhole Limpet Hemocyanin （NR2B-KLH） three times at two-week intervals. NR2B specific IgG titres in sera and cerebrospinal fluid were determined by indirect ELISA. Seven days after the third immunization, 2 of the 3 terminal branches of the sciatic nerve （tibial and common peroneal nerves） were tightly ligated. Behavioural testing was carried out on every other day after surgery, until 7 days after surgery. The lumbar spinal cord （L4-6） was removed on day 7 after ligation. The expression of NR2B protein in the lumbar spinal cord was determined using Western blotting. Results After the second vaccination, NR2B specific IgG in sera was detected to be 〉0.5 μg/ml in six of nine rats. After the third vaccination, all the immunized rats had 〉2.2 μg/ml. Titres of NR2B specific IgG in sera peaked 42 days post initial immunization and persisted for over 70 days. No NR2B specific IgG was detected in sera from PBS or KLH group. The behavioural thresholds in NR2B group were significantly higher than those in PBS and KLH groups on day 7 after ligation. NR2B specific IgG in CSF in NR2B group could not be detected on day 1 before spinal dissection; but could be detected on day 7 after surgery. The expression of NR2B protein in group NR2B was significantly lower than in PBS and KLH groups on day 7 after surgery. Conclusion The NR2B peptide could be used as a vaccine against neuropathic pain, which could be associated with reduction of NR2B protein in the lumbar spinal cord.