Robotic surgery for pelvic organ prolapse with complete bladder eversion.

Introduction: Pelvic organ prolapse with complete bladder eversion is extremely rare. Case presentation: An 82-year-old woman was diagnosed with uterine prolapse 3 years ago and underwent occasional urethral catheter placement for difficulty in micturition. She presented with vulvar bleeding and prolapsed uterus from the vagina. Pelvic examination revealed uterine prolapse and a 65 × 65-mm red mass ventrally with urinary outflow. Contrast medium leakage from the vulvar mass and guidewire observed on antegrade pyeloureterography indicated pelvic organ prolapse with complete bladder eversion. Manual reduction of the everted bladder, robotic sacrocolpopexy, and bladder neck reconstruction was performed. However, eversion recurred 10 months postoperatively. Subsequently, robotic Burch colposuspension, cystopexy to the rectus fascia, bladder neck reconstruction, colpoclesis, and cystostomy were performed. There was no recurrence postoperatively. Conclusion: Robotic Burch colposuspension, cystopexy to the rectus fascia, bladder neck reconstruction, colpoclesis, and cystostomy were performed for complete bladder eversion.

Novel Intraoperative Navigation Using Ultra-High-Resolution CT in Robot-Assisted Partial Nephrectomy.

To assess the perioperative and short-term functional outcomes of robot-assisted partial nephrectomy (RAPN) with intraoperative navigation using an ultra-high-resolution computed tomography (UHR-CT) scanner, we retrospectively analyzed 323 patients who underwent RAPN using an UHR-CT or area-detector CT (ADCT). Perioperative outcomes and the postoperative preservation ratio of estimated glomerular filtration rate (eGFR) were compared. After the propensity score matching, we evaluated 99 patients in each group. Although the median warm ischemia time (WIT) was less than 25 min in both groups, it was significantly shorter in the UHR-CT group than in the ADCT group (15 min vs. 17 min, p = 0.032). Moreover, the estimated blood loss (EBL) was significantly lower in the UHR-CT group than in the ADCT group (33 mL vs. 50 mL, p = 0.028). However, there were no significant intergroup differences in the postoperative preservation ratio of eGFR at 3 or 6 months of follow-up (ADCT 91.8% vs. UHR-CT 93.5%, p = 0.195; and ADCT 91.7% vs. UHR-CT 94.0%, p = 0.160, respectively). Although no differences in short-term renal function were observed in intraoperative navigation for RAPN in this propensity score-matched cohort, this study is the first to demonstrate that UHR-CT resulted in a shorter WIT and lower EBL than ADCT.

Perioperative and long-term functional outcomes of robot-assisted versus open partial nephrectomy: A single-center retrospective study of a Japanese cohort.

Objective: This study aimed to compare the perioperative and long-term functional outcomes between robot-assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN) in Japanese patients. Methods: We retrospectively analyzed 242 patients who underwent either RAPN or OPN between 2007 and 2017 at our hospital. Propensity score matching was carried out between the two groups at a ratio of 1:1. Perioperative outcomes and postoperative estimated glomerular filtration rates (eGFR) were compared at one and three years of follow-up. Results: After propensity score matching, we evaluated 39 patients from each group. The ischemia duration of the RAPN group was significantly shorter than that of the OPN group (18 vs. 24, p < 0.001). Moreover, the estimated blood loss (EBL) was significantly lower in the RAPN group than in the OPN group (50 vs. 174, p < 0.001). However, there were no significant differences in the postoperative eGFR between the two groups at one or three years of follow-up (OPN 54.8 vs. RAPN 61.2, p = 0.109, and OPN 54.8 vs. RAPN 55.5, p = 0.262, respectively). Conclusion: RAPN resulted in shorter ischemia durations and lower rates of EBL than did OPN; however, no differences in long-term renal function were observed between RAPN and OPN in our propensity-score matched Japanese cohort.

Risk factors for postoperative ileus after robot-assisted radical cystectomy with intracorporeal urinary diversion.

OBJECTIVES: To evaluate the risk factors for postoperative ileus in patients who underwent robot-assisted radical cystectomy with intracorporeal urinary diversion. METHODS: We retrospectively analyzed 78 patients with bladder cancer who underwent robot-assisted radical cystectomy with intracorporeal urinary diversion at Fujita Health University between 2011 and 2021. Baseline characteristics and perioperative outcomes were compared between the cohorts with and without ileus. Logistic regression analysis was used to identify the risk factors for postoperative ileus. RESULTS: Out of the 78 patients included in this study, 20 (25.6%) developed postoperative ileus. The ileus cohort was associated with a significantly lower Geriatric-8 score (P = 0.003) and a higher rate of previous abdominal/pelvic surgery (P = 0.04) compared with those of the nonileus cohort. Significantly longer intestinal tract reconstruction time, hospital stay, time to mobilization, fluid intake, solid intake, flatus, and stool were observed in the ileus cohort. According to the results of the logistic regression analysis, the Geriatric-8 sum (P = 0.009), time to mobilization (P = 0.03), and time to fluid intake (P = 0.004) were independent predictors of postoperative ileus. In the model predicting postoperative ileus, the area under the receiver operating characteristic curve was 0.716, and the cutoff value of the Geriatric-8 sum was 13. CONCLUSIONS: Early mobilization and fluid intake and low Geriatric-8 scores were significant risk factors for postoperative ileus. Preoperative Geriatric-8 evaluation is a useful tool for predicting postoperative ileus. Comprehensive enhanced recovery after surgery, including key components, may help bowel recovery and prevent subsequent ileus.

A case of direct inguinal hernia incarceration after transperitoneal robot-assisted radical prostatectomy.

In this study, we report a case of incarcerated direct inguinal hernia (DIH) after robot-assisted radical prostatectomy (RARP) in a patient with concomitant DIH. The 71-year-old man underwent RARP. Six days later, he developed a right DIH incarceration. His laparoscopy findings revealed an incarcerated intestine that was adherent to the hernia orifice. After reducing the hernia, the peritoneum was found to be defective in the right DIH orifice. The DIH was then repaired via the Lichtenstein method. The patient was discharged without complications on postoperative day 13. No recurrence was observed at 3-year follow-up. When repair and peritoneum closure for concomitant DIH are not performed in RARP, it should be kept in mind that the nonrepaired concomitant DIH orifice may develop intestinal incarceration and adhesion to the hernia orifice without the peritoneum immediately after RARP.

Predictors of Secondary Bladder Cancer in Patients with Prostate Cancer Treated with Brachytherapy: A Single-institution Study of a Japanese Cohort.

PURPOSE: The incidence of secondary bladder cancer after treatment for localized prostate cancer (PCa) remains unclear. In this study, PCa cases treated with brachytherapy (BT) were evaluated to assess the incidence of a second malignancy of bladder cancer in a Japanese cohort. MATERIALS AND METHODS: Overall, 969 patients treated with BT at our hospital between July 2006 and January 2019 were included in the study cohort. The incidence and predictors of secondary bladder cancer were also assessed. RESULTS: The incidence of secondary bladder cancer was 1.5% (n = 14). Of the seven factors (age, pretreatment PSA, Gleason score, cTNM stage, prostate volume, total activity, and combined external beam), prostate volume and total activity showed significant differences between the cohorts with and without secondary bladder cancer (P = .03 and P = .001, respectively). Upon comparison of the seven parameters for the 969 patients treated with BT, we found that only the total activity factor was affected by the incidence of secondary bladder cancer in the multivariate analysis (P = .007). CONCLUSION: The incidence of secondary bladder cancer was evaluated after BT for PCa. Total activity was associated with the incidence of secondary bladder cancer in Japanese patients who received BT.

Intra-corporeal robot-assisted versus open radical cystectomy: a propensity score-matched analysis comparing perioperative and long-term survival outcomes and recurrence patterns.

BACKGROUND: To compare perioperative and long-term oncological outcomes and recurrence patterns between robot-assisted radical cystectomy with intra-corporeal urinary diversion (iRARC) and open radical cystectomy (ORC). METHODS: We retrospectively analyzed 177 bladder cancer patients who received iRARC or ORC at Fujita Health University between 2008 and 2020. Our primary endpoint was long-term oncological outcomes. As a secondary endpoint, we examined perioperative outcomes, complications, and recurrence patterns. These outcome measures were compared between the propensity score (PS)-matched cohorts. RESULTS: PS-matched analysis resulted in 60 matched pairs from iRARC and ORC groups. The iRARC cohort was associated with significantly longer operative time (p = 0.02), lower estimated blood loss (p < 0.001), lower blood transfusion rate (p < 0.001), shorter length of hospital stay (p < 0.001), fewer overall complications (p = 0.03), and lower rate of postoperative ileus (p = 0.02). There was no statistically significant difference between iRARC and ORC in 5-year RFS (p = 0.46), CSS (p = 0.63), and OS (p = 0.71). RFS and CSS were also comparable, even in locally advanced (≥ cT3) disease. Multivariate analysis identified lymphovascular invasion as a robust predictor of RFS, CSS, and OS. The number of recurrence was similar between the groups, while extra-pelvic lymph nodes were more frequent in iRARC than that in ORC (22.7% vs. 7.7%). CONCLUSIONS: iRARC has favorable perioperative outcomes, fewer complications, and comparable long-term survival outcomes, including locally advanced (≥ cT3) disease, compared to that in ORC. Our results need to be validated in prospective randomized clinical trials.

Combined α-methylacyl-CoA racemase inhibition and docetaxel treatment reduce cell proliferation and decrease expression of heat shock protein 27 in androgen receptor-variant-7-positive prostate cancer cells.

BACKGROUND: Disease progression in castrate-resistant prostate cancer (PCa) is most commonly driven by the reactivation of androgen receptor (AR) signaling and involves AR splice variants including ARV7. MATERIALS AND METHODS: We used the ARV7-positive PCa cell line, 22Rv1, to study the relationship of the PCa marker α-methylacyl-CoA racemase (AMACR), AR, and ARV7 in PCa. RESULTS: Docetaxel addition but not AMACR inhibition decreased the proliferation of 22Rv1 cells. The combination of AMACR inhibition and docetaxel treatment resulted in a maximum reduction of cell proliferation. The Western blotting analysis revealed that both AR and ARV7 expression were significantly decreased with the use of charcoal-stripped serum following AMACR inhibition and docetaxel treatment. AMACR inhibition and docetaxel treatment in the charcoal-stripped serum condition reduced the proliferation of 22Rv1, possibly via the downregulation of the heat shock protein 27. CONCLUSION: Using cell proliferation and Western blot analysis, we demonstrated that AMACR inhibition and docetaxel treatment, under androgen deprivation conditions, significantly reduced the proliferation of ARV7 positive cancer cells and decreased the levels of AR and ARV7 expression, possibly via downregulation of heat shock protein 27.

Tryptophan 2,3-dioxygenase in tumor cells is associated with resistance to immunotherapy in renal cell carcinoma.

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme associated with immunomodulation through its regulation of the tryptophan-kynurenine (Kyn) pathway in advanced cancers, including metastatic renal cell carcinoma (mRCC). However, the failure of IDO1 inhibitors when used in combination with immune checkpoint inhibitors (ICIs), as observed in clinical trials, raises a number of questions. This study aimed to investigate the association of tryptophan 2,3-dioxygenase (TDO) and IDO1 with cancer development and resistance to immunotherapy in patients with RCC. In our analysis of RCC tissue samples, tissue Kyn levels were elevated in advanced-stage RCC and correlated well with TDO expression levels in RCC tumor cells. In patients with mRCC, TDO rather than IDO1 was expressed in RCC tumor cells, showing a strong association with Kyn expression. Furthermore, immunohistochemical staining of TDO was strongly associated with the staining intensity of forkhead box P3, as well as ICI therapy response and survival in patients with mRCC. Our study is the first to show that TDO expression in tumor tissues is associated with progression and survival, confirming its potential as a predictive biomarker of primary resistance to immunotherapy in patients with mRCC. Our findings suggest that strategies aimed at inhibiting TDO, rather than IDO1, in combination with ICI therapy may aid in the control of mRCC progression.

Two cycles of neoadjuvant chemotherapy improves survival in patients with high-risk upper tract urothelial carcinoma.

OBJECTIVES: To assess the impact of two cycles of neoadjuvant chemotherapy (NAC) in patients who underwent nephroureterectomy for high-risk cN0M0 upper tract urothelial carcinoma (UTUC), and to evaluate the efficacy of NAC in patients with localised disease (≤cT2). PATIENTS AND METHODS: We retrospectively analysed patients with high-risk cN0M0 UTUC who received NAC followed by surgery, compared with a matched cohort who underwent initial surgery at Fujita Health University during 2005-2019. Baseline and tumour characteristics, overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) were compared between the cohorts. Cox proportional hazards models were used to identify predictors of survival. RESULTS: There were 117 and 67 patients in the study group and the control group, respectively. Significantly higher pathological downstaging (pDS) and lower lymphovascular invasion (LVI) were observed in the study group than in the control group (48% vs 22%, P = 0.008 and 29% vs 46%, P = 0.045, respectively). The NAC group had significantly better 5-year OS (79% vs 53%, P = 0.003), 5-year CSS (84% vs 66%, P = 0.008), and 5-year RFS (80% vs 61%, P = 0.001) than the control group. The OS benefit of NAC was observed even in patients with localised (≤cT2) disease (P = 0.019). Patients with LVI showed significantly worse CSS both in pathologically locally advanced (≥pT3) and in localised (≤pT2) tumours (P = 0.048 and P = 0.018, respectively). Multivariate analysis identified LVI, NAC, and pDS as independent predictors of OS. Male sex and post-NAC LVI were identified as predictors of worse survival in patients who underwent NAC. CONCLUSIONS: Two cycles of NAC improved the survival of patients with high-risk UTUC, even in patients with localised disease. Although two cycles of NAC appear to be effective in cN0M0 high-risk UTUC including localised disease, additional larger sample size multicentre prospective studies comparing short-course NAC regimens followed by surgery and surgery alone are required.

Long-Term Functional and Oncologic Outcomes of Robot-Assisted Partial Nephrectomy for Cystic Renal Tumors: A Single-Center Retrospective Study.

Objectives: To evaluate the outcomes of robot-assisted partial nephrectomy (RAPN) in cystic renal tumors. Materials and Methods: We retrospectively analyzed patients who underwent RAPN for either cystic (n = 46) or solid (n = 271) renal tumors at Fujita Health University between 2010 and 2019. Cystic renal tumors were diagnosed using cross-sectional imaging. Perioperative, oncologic, and functional outcomes were assessed. Results: The median follow-up periods were 38, 41, and 37 months in the total, cystic, and solid groups, respectively. Most patient characteristics were similar among both groups, while the median age of the cystic group was significantly lower than that of the solid group (p = 0.02). Most perioperative variables and complications were comparable between the two groups. There was no significant difference between the groups in perioperative renal function. The estimated glomerular filtration rate preservation rates were 93.1% and 89.2% in the cystic and solid groups, respectively (p = 0.17). The cystic group showed a higher benign histology rate (19.6% vs 7%) and lower Fuhrman grade than the solid group (24.3% vs 15.1% in grade 1, and 73% vs 81.3% in grade 2), although there was no statistically significant difference between the two groups. In the solid group, 10 patients (3.7%) experienced recurrence, and 2 patients (0.7%) died of renal-cell carcinoma, while none of the patients with cystic tumors experienced recurrence. There was no statistically significant difference between the cystic and solid tumors with respect to 5-year recurrence-free survival (p = 0.18), cancer-specific survival (p = 0.55), and overall survival (p = 0.35). Conclusions: RAPN for cystic renal tumors appears to be safe and feasible with perioperative, long-term functional and oncologic outcomes comparable with those in solid tumors. RAPN can be a safe and effective surgical option for cystic renal tumors.

Deep learning using preoperative magnetic resonance imaging information to predict early recovery of urinary continence after robot-assisted radical prostatectomy.

OBJECTIVES: To investigate whether a deep learning model from magnetic resonance imaging information is an accurate method to predict the risk of urinary incontinence after robot-assisted radical prostatectomy. METHODS: This study included 400 patients with prostate cancer who underwent robot-assisted radical prostatectomy. Patients using 0 or 1 pad/day within 3 months after robot-assisted radical prostatectomy were categorized into the "good" group, whereas the other patients were categorized into the "bad" group. Magnetic resonance imaging DICOM data, and preoperative and intraoperative covariates were assessed. To evaluate the deep learning models from the testing dataset, their sensitivity, specificity and area under the receiver operating characteristic curve were analyzed. Gradient-weighted class activation mapping was used to visualize the regions of deep learning interest. RESULTS: The combination of deep learning and naive Bayes algorithm using axial magnetic resonance imaging in addition to clinicopathological parameters had the highest performance, with an area under the receiver operating characteristic curve of 77.5% for predicting early recovery from post-prostatectomy urinary incontinence, whereas machine learning using clinicopathological parameters only achieved low performance, with an area under the receiver operating characteristic curve of 62.2%. The gradient-weighted class activation mapping methods showed that deep learning focused on pelvic skeletal muscles in patients in the good group, and on the perirectal and hip joint regions in patients in the bad group. CONCLUSIONS: Our results suggest that deep learning using magnetic resonance imaging is useful for predicting the severity of urinary incontinence after robot-assisted radical prostatectomy. Deep learning algorithms might help in the choice of treatment strategy, especially for prostate cancer patients who wish to avoid prolonged urinary incontinence after robot-assisted radical prostatectomy.

Predictors for trifecta achievement of robot-assisted partial nephrectomy in high-complexity tumors (Preoperative Aspects and Dimensions Used for an Anatomical score ≥10).

INTRODUCTION: Robot-assisted partial nephrectomy (RAPN) is emerging as an effective treatment oncologically and functionally for clinically localized renal tumors. However, RAPN in high-complexity tumors with a Preoperative Aspects and Dimensions Used for an Anatomical score ≥10 remains challenging. In this study, the feasibility of RAPN for high-complexity tumors was assessed. METHODS: The study cohort consisted of 177 cases with clinically localized renal cell carcinoma who had undergone RAPN at our hospital from July 2010 to February 2018. They were assessed for perioperative parameters and trifecta achievement (ie, negative surgical margins, warm ischemia time <25 minutes, and no complications). RESULTS: Among the 177 cases who had undergone RAPN, 60 had high-complexity tumors, and 117 had non-high-complexity (ie, intermediate- or low-complexity) tumors. There were no significant differences in the operative and console times between the cohorts, but estimated intraoperative blood loss was much lower in the non-high-complexity group. Although the average warm ischemia time was less than 25 minutes in both groups, it was significantly shorter in the non-high-complexity group. Trifecta achievement rates significantly differed between the high- and non-high-complexity groups (68.3% vs 86.3%). Comparisons of four operative parameters (ie, BMI, tumor size, endophytic properties, and hilar tumor) using univariate analysis in the 60 high-complexity tumor cases showed that BMI and tumor size were independent factors (P = 0.05 and 0.018, respectively). In multivariate analysis, tumor size was the only factor directly associated with trifecta achievement (P = 0.029). CONCLUSION: The trifecta achievement rate was significantly lower in the high-complexity group. Only tumor size affected trifecta achievement during RAPN in cases with high-complexity tumors (Preoperative Aspects and Dimensions Used for an Anatomical score ≥10).

Clinical and oncological outcomes of robot-assisted radical prostatectomy with nerve sparing vs. non-nerve sparing for high-risk prostate cancer cases.

Robot-assisted radical prostatectomy (RARP) is one of the most widely used procedures for localized prostate cancer (PCa). In the present study, the clinical and oncological outcomes of RARP with bilateral or unilateral nerve sparing (NS) for D'Amico high-risk PCa cases were assessed. Among the 767 cases who received RARP at Fujita Health University Hospital between August 2009 and December 2016, 230 high-risk PCa cases who were observed for >6 months comprised the retrospective study cohort. Bilateral NS was performed with the bilateral neurovascular bundle in eight, unilateral in 125 and none in 97 cases. Perioperative parameters [surgery time, console time, estimated blood loss, pathological stage, positive lymph node metastases [pN (+)], and surgical margin positivity] did not exhibit significant differences between the NS and non-NS cohorts. During a median follow-up time of 25 months, the 1- and 3-year biochemical recurrence (BCR)-free survival rates in the NS/non-NS cohorts were 84.4/86.0 and 72.7/75.0%, respectively. There were no significant differences identified between the two groups at each time period. According to multivariate analysis, the resection margin was an important factor for time to BCR, regardless of the NS technique used. The numbers of pads used daily at 3 and 6 months after RARP between the NS/non-NS cohorts were 1.1/1.5 and 0.6/1.0, respectively (P=0.045 and P=0.009), suggesting that the NS technique resulted in significantly improved outcomes regarding urinary continence recovery. In selected high-risk PCa cases, the NS technique resulted in equivalent oncological outcomes and improved urinary continence compared with the non-NS RARP group.

[Robotic Surgery for Urologic Malignancy - Prostate, Kidney and Bladder].

Robotic-assisted surgery has been wide-spreading rapidly as a technique to develop laparoscopic surgery by innovative technological improvement such as high magnifided 3D-image and multi-degree freedom of forceps, leading to safety enhancement and better functional recovery. Robotic surgery in the urological field made it possible to highly fine operation in a narrow field, such as pelvic cavity or retroperitoneal space. Better outcomes were recognized especially in perioperative complications and postoperative QOL recovery than other procedures like open or laparoscopic. According to these results, radical prostatectomy, partial nephrectomy and radical cystectomy were approved for health insurance coverage in 2012, 2016 and 2018, respectively. Robotic-assistance has definitely brought a paradigm shift in urologic surgery. The application to more and more a variety of procedure and the improvement of treatment outcomes are expected in the future.

Robot-assisted partial nephrectomy: Superiority over laparoscopic partial nephrectomy.

Nephron-sparing surgery has been proven to positively impact the postoperative quality of life for the treatment of small renal tumors, possibly leading to functional improvements. Laparoscopic partial nephrectomy is still one of the most demanding procedures in urological surgery. Laparoscopic partial nephrectomy sometimes results in extended warm ischemic time and severe complications, such as open conversion, postoperative hemorrhage and urine leakage. Robot-assisted partial nephrectomy exploits the advantages offered by the da Vinci Surgical System to laparoscopic partial nephrectomy, equipped with 3-D vision and a better degree in the freedom of surgical instruments. The introduction of the da Vinci Surgical System made nephron-sparing surgery, specifically robot-assisted partial nephrectomy, safe with promising results, leading to the shortening of warm ischemic time and a reduction in perioperative complications. Even for complex and challenging tumors, robotic assistance is expected to provide the benefit of minimally-invasive surgery with safe and satisfactory renal function. Warm ischemic time is the modifiable factor during robot-assisted partial nephrectomy to affect postoperative kidney function. We analyzed the predictive factors for extended warm ischemic time from our robot-assisted partial nephrectomy series. The surface area of the tumor attached to the kidney parenchyma was shown to significantly affect the extended warm ischemic time during robot-assisted partial nephrectomy. In cases with tumor-attached surface area more than 15 cm(2) , we should consider switching robot-assisted partial nephrectomy to open partial nephrectomy under cold ischemia if it is imperative. In Japan, a nationwide prospective study has been carried out to show the superiority of robot-assisted partial nephrectomy to laparoscopic partial nephrectomy in improving warm ischemic time and complications. By facilitating robotic technology, robot-assisted partial nephrectomy will be more frequently carried out as a safe, effective and minimally-invasive nephron-sparing surgery procedure.

The Olfactory Transcriptome and Progression of Sexual Maturation in Homing Chum Salmon Oncorhynchus keta.

Reproductive homing migration of salmonids requires accurate interaction between the reception of external olfactory cues for navigation to the spawning grounds and the regulation of sexual maturation processes. This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory rosettes in homing chum salmon Oncorhynchus keta Walbaum from the coastal sea to 75 km upstream the rivers at the pre-spawning ground. The progression of sexual maturation along the brain-pituitary-gonadal axis was assessed through determination of plasma steroid levels by time-resolved fluoroimmunoassays (TR-FIA), pituitary gonadotropin subunit expression and salmon gonadotropin-releasing hormone (sgnrh) expression in the brain by quantitative real-time PCR. RNAseq revealed the expression of 75 known and 27 unknown salmonid olfactory genes of which 13 genes were differentially expressed between fish from the pre-spawning area and from the coastal area, suggesting an important role of these genes in homing. A clear progression towards final maturation was characterised by higher plasma 17α,20ß-dihydroxy-4-pregnen-3-one (DHP) levels, increased pituitary luteinizing hormone ß subunit (lhß) expression and sgnrh expression in the post brain, and lower plasma testosterone (T) and 17ß-estradiol (E2) levels. Olfactomedins and ependymin are candidates among the differentially expressed genes that may connect olfactory reception to the expression of sgnrh to regulate final maturation.

Diurnal changes in salmon GnRH secretion in the brain of masu salmon (Oncorhynchus masou).

The day-night changes of salmon GnRH (sGnRH), which is secreted from various brain regions, were analyzed in maturing and matured masu salmon (Oncorhynchus masou). In maturing males, the levels of sGnRH secreted from the olfactory bulb (OB), terminal nerve (TN), and ventral telencephalon and preoptic area (VT+POA) were all significantly higher during midnight than daytime. However, the contents of sGnRH in the pituitary gland during midnight were not higher than those during daytime. In maturing females, the levels of sGnRH secreted from the VT+POA were higher during midnight than daytime, and the contents of sGnRH in the pituitary gland were also higher during midnight. In matured fish, the levels of sGnRH secreted from the OB, TN and VT+POA during midnight were significantly higher than those during daytime. There were also no significant differences in the contents of sGnRH in the pituitary gland. These results suggest that a short photoperiod may be involved in diurnal secretion rhythms of sGnRH in various brain regions and the pituitary gland.