Urosymphyseal fistula development following treatment for radiation-induced urethral stenosis in three patients with prostate cancer

Introduction

Urosymphyseal fistula is a rare and devastating complication that develops after radiation therapy for prostate cancer and is often triggered by the treatment of radiation-induced urethral stenosis. Here, we report our experience with urosymphyseal fistulas in three patients with prostate cancer.

Case presentation

Three patients with prostate cancer developed urethral stenosis after radiotherapy. The management of urethral stenosis was suprapubic tube placement in case 1, direct vision internal urethrotomy in case 2, and excision with primary anastomosis in case 3. All patients presented with severe suprapubic or thigh pain or both. Urosymphyseal fistulas were detected on magnetic resonance imaging. Conservative treatment was unsuccessful, and all patients required debridement of the necrotic pubic symphysis and simple cystectomy. In cases 1 and 2, ileal conduit urinary diversion was performed.

Conclusion

Urologists need to be aware that urosymphyseal fistulas can occur in irradiated patients with prostate cancer, especially after urethral stenosis treatment.

The Japanese Urological Association's clinical practice guidelines for urotrauma 2023

The Japanese Urological Association's guidelines for the treatment of renal trauma were published in 2016. In conjunction with its revision, herein, we present the new guidelines for overall urotrauma. Its purpose is to provide standard diagnostic and treatment recommendations for urotrauma, including iatrogenic trauma, to preserve organ function and minimize complications and fatality. The guidelines committee comprised urologists with experience in urotrauma care, selected by the Trauma and Emergency Medicine Subcommittee of the Specialty Area Committee of the Japanese Urological Association, and specialists recommended by the Japanese Association for the Surgery of Trauma and the Japanese Society of Interventional Radiology. The guidelines committee established the domains of renal and ureteral, bladder, urethral, and genital trauma, and determined the lead person for each domain. A total of 30 clinical questions (CQs) were established for all domains; 15 for renal and ureteral trauma and five each for the other domains. An extensive literature search was conducted for studies published between January 1, 1983 and July 16, 2020, based on the preset keywords for each CQ. Since only few randomized controlled trials or meta-analyses were found on urotrauma clinical practice, conducting a systematic review and summarizing the evidence proved challenging; hence, the grade of recommendation was determined according to the 2007 "Minds Handbook for Clinical Practice Guidelines" based on a consensus reached by the guidelines committee. We hope that these guidelines will be useful for clinicians in their daily practice, especially those involved in urotrauma care.

Myofibroblast-dominant proliferation associated with severe fibrosis in bulbar urethral strictures

OBJECTIVES

Myofibroblast-dominant proliferation (relative to fibroblast proliferation) is the key process in urethral fibrosis, but its association with clinical features is not understood. We conducted a histological analysis of urethral strictures and examined the association between myofibroblast proliferation and stricture characteristics.

METHODS

Formalin-fixed, paraffin-embedded urethral sections sliced axially from 175 male patients with bulbar urethral strictures were retrospectively analyzed. All patients underwent excision and primary anastomosis between September 2008 and January 2021 by a surgeon (AH). Masson's trichrome stain was used to estimate the area of fibrosis. Corresponding unstained slides with the largest area of fibrosis were selected and double-immunostained with anti-smooth muscle actin (SMA) and anti-TE-7 mouse monoclonal antibodies for the assessment of myofibroblasts and fibroblasts, respectively. The ratio of the number of SMA-positive cells to the number of TE-7-positive cells (SMA/TE-7 ratio) was calculated.

RESULTS

The area of fibrosis in strictures due to perineal trauma (n = 85, median 108.9 mm² ) was significantly larger than that in non-traumatic strictures (n = 90, median 42.9 mm² , p < 0.0001). The area of fibrosis positively correlated with SMA expression (r = 0.35, p < 0.0001) and the SMA/TE-7 ratio (r = 0.36, p < 0.0001), but not with TE-7 expression (r = -0.01, p = 0.75). In a multivariate linear regression model, traumatic etiology (standard coefficient 0.37, t value 3.9, p < 0.0001) and increased SMA expression (standard coefficient 0.17, t value 2.1, p = 0.03) were the predictors of wide fibrosis area.

CONCLUSIONS

Myofibroblast-dominant proliferation may contribute to the pathogenesis of severe urethral fibrosis.

Transperineal bulbovesical anastomosis for extensive posterior urethral stenoses after treatment of prostatic disease

OBJECTIVES

We report our surgical experience of transperineal bulbovesical anastomosis (BVA) for extensive posterior urethral stenosis (PUS).

METHODS

Six male patients who had extensive PUS extending from the bulbomembranous urethra to the bladder neck due to prostatic disease treatment and underwent transperineal BVA between 2014 and 2020 were retrospectively reviewed. BVA was performed according to the elaborate perineal approach for pelvic fracture urethral repair with minor modifications. After confirming the absence of recurrent stenosis 6 months postoperatively, the patients were offered artificial urinary sphincter (AUS) placement for subsequent urinary incontinence (UI).

RESULTS

Median patient age was 68, and the etiology of PUS was radical prostatectomy for prostate cancer in four patients, brachytherapy for prostate cancer in one, and transurethral resection of the prostate for benign prostatic hyperplasia in one. All patients had been previously treated with multiple transurethral procedures such as urethrotomy and dilation. Median operative time and blood loss were 211 min and 154 ml, respectively. Five cases (83.3%) had no recurrent stenosis with a median follow-up of 45 months, but a single direct vision internal urethrotomy was performed in one (16.7%) due to restenosis. Four (66.7%) patients underwent AUS placement via transcorporal approach for subsequent UI, but two had it removed due to urethral erosion.

CONCLUSION

Transperineal BVA could effectively manage extensive PUS after prostatic disease treatment. Staged AUS placement could be a viable option for subsequent UI, but the risk of urethral erosion seemed high.

Efficacy of urethral reconstruction for urethral stricture associated with hypospadias surgery in adults

OBJECTIVES

We report our experience with urethral reconstruction for hypospadias surgery-related urethral stricture in terms of surgical and patient-reported outcomes.

METHODS

Twenty-nine adult males who underwent urethral reconstruction for hypospadias surgery-related urethral stricture between August 2008 and January 2022 were retrospectively reviewed. Uroflowmetry and patient-reported outcomes were evaluated at 3, 6, and 12 months, and annually thereafter. Surgical success was defined as the absence of additional procedures. Patients were asked to rate their satisfaction with urethral reconstruction as "very satisfied", "satisfied", "unsatisfied", or "very unsatisfied".

RESULTS

The median patient age at referral was 43 years. The median number of previously performed hypospadias surgeries was three, and 18 patients (62.8%) had been treated with repeated transurethral procedures. The median stricture length was 54 mm (interquartile range 36-81). Performed urethral reconstruction included staged urethroplasty in 22 (75.9%), one-stage onlay augmentation in 3 (10.2%), and perineal urethrostomy in 4 (13.8%) cases. Urethral reconstruction was successful in 26 patients (89.7%) over a median postoperative period of 31 months. Patient-reported outcomes were assessed in 25 (86.2%) patients. The mean maximum flow rate, international prostate symptom score total score, international prostate symptom score quality of life score, and EuroQol-5 dimensions index significantly improved postoperatively. Twenty-three patients (92%) were "very satisfied" or "satisfied" with the outcome of their urethral reconstruction.

CONCLUSIONS

Urethral reconstruction is a highly successful and patient-satisfying treatment for hypospadias surgery-related urethral stricture in adult patients. Perineal urethrostomy is a reasonable alternative for elderly patients and for patients with complicated hypospadias surgery-related urethral strictures.

Surgical and Patient-Reported Outcomes of Delayed Anastomotic Urethroplasty for Male Pelvic Fracture Urethral Injury at a Japanese Referral Center

We aimed to assess the surgical and patient-reported outcomes of delayed anastomotic urethroplasty (DAU) for pelvic fracture urethral injury (PFUI). We included 211 male patients who underwent DAU for PFUI. DAU success was considered when the urethral lumen was sufficiently large for the passage of a flexible cystoscope, without additional treatment required. The patients completed the lower urinary tract symptoms (LUTS)-related quality of life (QOL) questionnaire (scores: 0, not at all; 1, a little; 2, somewhat; 3, a lot), EuroQol-5 dimensions (EQ-5D), and EQ-5D visual analog scale (EQ-VAS). Postoperative overall satisfaction was evaluated using the following responses: “very satisfied,” “satisfied,” “unsatisfied,” or “very unsatisfied.” DAU was successful in 95.3% cases, with a median postoperative follow-up duration of 48 months. Multivariate logistic regression analysis revealed that “greater blood loss” was an independent predictor of failed urethroplasty. Questionnaire responses were obtained from 80.1% patients. The mean LUTS-related QOL, EQ-5D score and EQ-VAS improved significantly from 2.8, 0.63 and 54.4 at baseline to 0.9, 0.81 and 76.6 postoperatively (p < 0.0001 for all parameters). Moreover, 35.5% and 59.2% of the patients responded being “satisfied” and “very satisfied,” respectively, with their DAU outcomes. DAU not only had a high surgical success rate, but also a significant beneficial effect on both LUTS-related QOL and overall health-related QOL.

Ability of photocurable gelatin to prevent stricture recurrence after urethral dilation in rabbits

OBJECTIVES

To evaluate the ability of photocurable gelatin to prevent stricture recurrence after urethral dilation in a rabbit urethral stricture model.

METHODS

We created urethral strictures in the bulbar urethras of 10 male Japanese white rabbits using electrocoagulation. After 1 month, the rabbits were randomly divided into Group A (n = 5; urethral stricture dilation and the local application of photocurable gelatin using a ruthenium photoinitiator and irradiation with a light-emitting diode light [λ = 455 nm, 50 mW/cm2 ] for 1 min) and Group B (n = 5; dilation only). Urethral stricture status was evaluated 1-2 months later by retrograde urethrography and urethroscopy. The lumen ratio (urethral width at the stricture site to the normal urethral width on retrograde urethrography) was calculated. Urethral patency was considered to be improved when the urethral lumen could accommodate a 10-Fr urethroscope without resistance. Urethral specimens were harvested for histopathological examination.

RESULTS

The mean lumen ratio did not differ significantly between Groups A and B before dilation (25.8% vs 23.4%; P = 0.40), but differed significantly after dilation (65.5% vs 27.3%, respectively; P = 0.03). Urethral patency improved in all rabbits in Group A (100%) versus one rabbit in Group B (20%; P = 0.02). The mean circumference of the regenerated urethral epithelium at the stricture site was larger in Group A than in Group B (14 mm vs 6.6 mm; P = 0.06).

CONCLUSIONS

Photocurable gelatin can reduce urethral stricture recurrence after dilation in a rabbit model.

Role of magnetic resonance imaging in the management of male pelvic fracture urethral injury

The management of male pelvic fracture urethral injury remains a urological challenge. Pelvic fracture urethral injury can be associated with sequelae, such as urethral gap, erectile dysfunction and urinary incontinence. Delayed anastomotic urethroplasty, the gold standard treatment for urethral gaps caused by pelvic fracture urethral injuries, is technically demanding, and reconstructive urologists should preoperatively obtain as much detailed anatomical information as possible. A combination of antegrade and retrograde urethrography is the fundamental preoperative evaluation, but it cannot accurately assess the urethral gap length, the degree of lateral prostatic displacement, the anatomical relationship of the urethra with its surrounding structures (such as the rectum and dorsal venous complex) or periurethral problems (such as minor fistulae or cavitation). To make up for these limitations of urethrography, magnetic resonance imaging has emerged as a non-invasive, multiplanar and high-resolution modality for the evaluation of pelvic fracture urethral injury. Magnetic resonance imaging has excellent soft-tissue contrast, and can clearly show the urethra and periurethral tissues without the effects of radiation, thus enabling clinicians to anticipate the required ancillary techniques for delayed anastomotic urethroplasty and to predict functional outcomes, such as erectile function and urinary continence, after delayed anastomotic urethroplasty. This review discusses the role of magnetic resonance imaging in the evaluation of pelvic fracture urethral injury and its impact on patient management.

In Vitro Culture Expansion and Characterization of Buccal Mucosal Epithelial Cells for Tissue Engineering Applications in Urethral Stricture After Transportation Using a Thermoreversible Gelation Polymer

Introduction: The transportation of tissues from hospitals to clinical laboratories for cell therapy is an essential component of regenerative medicine. Previously, we used laboratory-cultured mucosal cells from buccal epithelium expanded and encapsulated using a scaffold-hybrid approach to the urethral stricture (BEES-HAUS) procedure. In this study, to improve the outcomes, we compared the thermoreversible gelation polymer (TGP) transportation procedure with conventional culture methods, and reported its advantages. Methods: Human buccal mucosal tissues in Phase I of the study were transported in Euro-Collins solution (ECS) and the cells obtained were cultured in two-dimensional (2D) Dulbecco's modified Eagle's medium (DMEM), CnT-Prime epithelial 2D differentiation medium (CnT-PR), and a three-dimensional (3D)-TGP scaffold. In Phase II, tissues were transported in a TGP cocktail and the ECS. The cells were cultured in 2D-DMEM and 3D-TGP, quantified, and characterized by immunohistochemistry. Results: The cells in 3D-TGP culture maintained epithelial morphology in a better manner compared with 2D-DMEM, in which they developed fibroblast-like morphology. The TGP-transported cells grew rapidly. Immunohistochemical analysis results for AE1/AE3, EGFR, integrin-β1, p63, and p75 were intensely positive in 3D-TGP. Conclusion: The TGP-based cocktail used in human buccal tissue transportation yielded cells with better morphology maintenance. The TGP scaffold provides an optimal in vitro environment wherein epithelial cells better maintain their native phenotype compared to those cultured through conventional methods. These results suggest using TGP for the transportation and culture of human buccal tissues for clinical applications. In addition, the use of a TGP-based cocktail for the transport of other tissues for regenerative medicine applications is worth further analysis.

Photocrosslinked gelatin hydrogel improves wound healing and skin flap survival by the sustained release of basic fibroblast growth factor

Biomaterials traditionally used for wound healing can act as a temporary barrier to halt bleeding, prevent infection, and enhance regeneration. Hydrogels are among the best candidates for wound healing owing to their moisture retention and drug-releasing properties. Photo-polymerization using visible light irradiation is a promising method for hydrogel preparation since it can easily control spatiotemporal reaction kinetics and rapidly induce a single-step reaction under mild conditions. In this study, photocrosslinked gelatin hydrogels were imparted with properties namely fast wound adherence, strong wet tissue surface adhesion, greater biocompatibility, long-term bFGF release, and importantly, ease of use through the modification and combination of natural bio-macromolecules. The production of a gelatin hydrogel made of natural gelatin (which is superior to chemically modified gelatin), crosslinked by visible light, which is more desirable than UV light irradiation, will enable its prolonged application to uneven wound surfaces. This is due to its flexible shape, along with the administration of cell growth factors, such as bFGF, for tissue regeneration. Further, the sustained release of bFGF enhances wound healing and skin flap survival. The photocrosslinking gelatin hydrogel designed in this study is a potential candidate to enhance wound healing and better skin flap survival.

Impact of urethroplasty on overactive bladder symptoms in patients with anterior urethral strictures

OBJECTIVES

To investigate the incidence of overactive bladder in men with anterior urethral stricture and to evaluate the impact of urethroplasty on its improvement.

METHODS

A total of 104 men with anterior urethral stricture who underwent urethroplasty between 2016 and 2020 completed a validated urethral stricture surgery patient-reported outcome measure comprising six lower urinary tract symptoms questions on voiding symptoms and overactive bladder symptom score before and 3, 6, and 12 months after urethroplasty. Patients with an urgency score of ≥2 for overactive bladder symptom score question 3, and a total overactive bladder symptom score of ≥3 were considered to have overactive bladder. An improvement in overactive bladder was defined as a decrease in the total overactive bladder symptom score by at least three points.

RESULTS

Thirty-nine patients (37.5%) were considered to have overactive bladder, and improvement in overactive bladder after urethroplasty was found in 30 (76.9%). Maximum flow rate on uroflowmetry, postvoid residual urine volume, lower urinary tract symptoms total score, and total overactive bladder symptom score were all significantly improved after urethroplasty (P < 0.0001 for all variables). There was a positive correlation between changes in lower urinary tract symptoms total score and total overactive bladder symptom score (Spearman's correlation 0.48, P < 0.0001). Multivariate logistic regression analysis showed that greater change in lower urinary tract symptoms score was an independent predictor of improvement in overactive bladder (odds ratio 1.30, 95% confidence interval 1.06-1.59; P = 0.002).

CONCLUSIONS

Overactive bladder is prevalent in patients with anterior urethral stricture, and can be effectively improved after urethroplasty. Improvement of voiding symptoms are key for improving overactive bladder symptoms.

Membranous urethral length on magnetic resonance imaging as a novel predictor of urinary continence after delayed anastomotic urethroplasty for pelvic fracture urethral injury

PURPOSE

We studied the impact of membranous urethral length (MUL) on magnetic resonance imaging (MRI) on post-urethroplasty continence in male patients with pelvic fracture urethral injury (PFUI).

METHODS

Of 169 male patients with PFUI who underwent delayed anastomotic urethroplasty between 2008 and 2020, 85 who underwent preoperative MRI, had no recurrent stenosis on cystoscopy, and underwent a 1-h pad test 1 year after surgery were included. MUL was defined as the distance from the distal end of the disrupted proximal urethra to the apex of the prostate, as measured using T2-weighted MRI. Urinary incontinence (UI) was defined as a 1-h pad test weight > 2.0 g.

RESULTS

None of the patients had UI before a pelvic fracture. Eighty-two patients (96.5%) had a measurable MUL, and the median length was 8.1 (interquartile range [IQR], 5.2-10.8) mm. The median weight of the 1-h pad test was 1.0 (IQR, 0.0-4.0) g, and 26 (30.6%) patients had UI. An open bladder neck (odds ratio [OR], 4.6; 95% confidence interval [CI], 1.0-22.0; p = 0.04) and a short measurable membranous urethra (for every extra mm: OR, 1.2; 95% CI, 1.0-1.3; p = 0.04) were significant UI predictors on multivariate analysis.

CONCLUSIONS

A long MUL is significantly positively associated with urinary continence in male patients with PFUI. This could be of potential value to reconstructive urologists when counseling patients regarding post-urethroplasty continence before urethroplasty.

Deep lateral transurethral incision for vesicourethral anastomotic stenosis after radical prostatectomy

OBJECTIVES

To investigate the outcomes of deep lateral incision for vesicourethral anastomotic stenosis after radical prostatectomy and its impact on postoperative urinary incontinence.

METHODS

We retrospectively investigated 43 men who underwent deep lateral incision for non-obliterated vesicourethral anastomotic stenosis after radical prostatectomy between 2011 and 2020. The bladder neck was deeply incised through its circular fibers into the surrounding perivesical fat at 3 and 9 o'clock through electrocautery incision using needle-type electrodes. Successful deep lateral incision was defined as the absence of additional treatment, including self-dilatation. The postoperative urinary incontinence status was evaluated based on the number of pads used daily.

RESULTS

Deep lateral incision was successful in 35 (81.4%) patients, with a median follow-up period of 43 months (interquartile range 15-80 months). There was no significant association of age (P = 0.66), body mass index (P = 0.49) and history of diabetes mellitus (P = 0.39), radiation therapy (P = 0.89) or previous vesicourethral anastomotic stenosis treatment (P = 0.71) with the incision outcomes; however, there were significantly more unsuccessful cases in those with preoperative urinary retention (P = 0.04) or indwelling urinary catheters for >5 days post-incision (P = 0.01). A second incision was carried out in eight patients and a third incision in two patients, resulting in 42 (97.7%) successful incisions. A total of 37 (88.1%) patients had urinary incontinence and used at least one pad daily; seven (16.7%) underwent artificial urinary sphincter implantation after the last incision.

CONCLUSIONS

Deep lateral incision is highly effective for treating vesicourethral anastomotic stenosis after radical prostatectomy. Appropriate treatment is required for urinary incontinence, which occurs frequently after incision.

Successful engraftment of epithelial cells derived from autologous rabbit buccal mucosal tissue, encapsulated in a polymer scaffold in a rabbit model of a urethral stricture, transplanted using the transurethral approach

Background

A pilot study reported an autologous buccal mucosal cell transplant in humans through the trans-urethral route using the buccal epithelium expanded and encapsulated in scaffold-hybrid approach to urethral stricture (BEES-HAUS), a minimally invasive approach to treat urethral stricture. Although successful outcomes were achieved in that study, for further validation, it is essential to prove that the transplanted buccal epithelium was engrafted over the urothelium through histological examination of the urethra, harvested post-transplant, which is infeasible in humans. Herein, we report the successful creation of an animal model of urethral stricture and the engraftment of epithelial cells derived from autologous buccal mucosal tissue, encapsulated in a thermo-reversible gelation polymer (TGP) scaffold, transplanted by trans-urethral route.

Methods

An animal model of urethral stricture was created in Japanese white male rabbits using electro-coagulation. Buccal tissue was harvested from the rabbits and subjected to enzyme digestion, followed by 5-7 days of in vitro culture in conventional two-dimensional (2D) culture and in a 3D platform of thermo-reversible gelation polymer (3D-TGP) culture. The cells harvested from the groups were mixed and encapsulated and transplanted with TGP, by transurethral catheterization. Fourteen days later, the urethra was harvested and subjected to histological examination. The buccal biopsy tissue, cells after digestion and cells post-culture were also subjected to histological examination. Urethrogram and endoscopy images were recorded at different time points.

Results

The stricture was successfully created, with the coagulated area markedly stenosed. Histological staining of the cells after in vitro processing showed that the cells grew with native epithelial and rounded cell morphology in 3D-TGP while they differentiated into fibroblast like-cells in 2D culture. Histological staining of the urethral tissue after transplantation revealed the engraftment of the transplanted buccal mucosal cells, with stratified squamous epithelium over the specialized stratified urothelium in the urethrotomy site.

Conclusion

We used histology to prove the successful engraftment of TGP-encapsulated buccal mucosal epithelial cells in an animal model of urethral injury with healing of the injured tissue. The model of urethral stricture and cell therapy, using a transurethral approach, recapitulates the previously reported BEES-HAUS approach and lays the foundation for larger multi-centric translational clinical studies.

Triangular extension of hinge flaps: A novel technique to resolve stomal stenosis and prevent restenosis in staged buccal mucosal urethroplasty

OBJECTIVES

To verify the utility of triangular extension of a hinge flap in buccal mucosal staged urethroplasty to resolve stomal stenosis after the first stage and ultimately prevent restenosis.

METHODS

A total of 23 patients (triangular extension group) were studied in 2013-2019. In the first stage, buccal mucosa was transplanted, and an extended triangle portion of the mucosa was placed beside the proximal and/or distal stoma that was created when the stricture segment of the urethra was resected. In the second stage, during tubularization of the urethral plate, an incision was made at the stoma to increase the caliber to which the triangular extension was inserted. The procedure was considered successful when a 17-Fr flexible cystoscope passed through the reconstructed urethra at 6 months after the second-stage urethroplasty and no additional surgery or bougie dilation required. The clinical course of the triangular extension group was compared with 24 patients who underwent conventional staged urethroplasty (control group).

RESULTS

In total, 20 patients from each group underwent second-stage surgery. No patients in the triangular extension group required additional revision surgery because of stomal stenosis after first-stage surgery, whereas five (20%) control patients did. Urethroplasty was successful in 19 patients (95%) in the triangular extension group and in 19 patients (95%) in the control group. Uroflowmetry after the second-stage surgery indicated that the mean maximum urinary flow rate was 21.5 and 15.8 mL/s after triangular extension and the control procedure, respectively (P = 0.027).

CONCLUSIONS

The triangular extension technique reduces the need for revision surgery and prevents postoperative restenosis.

A 3D Polymer Scaffold Platform for Enhanced in vitro Culture of Human & Rabbit Buccal Epithelial Cells for Cell Therapies

BACKGROUND

Buccal mucosal epithelial cells show promising application for various regenerative medicine approaches. In this study, we examined the feasibility of culturing rabbit and human buccal mucosal epithelial cells in a novel thermoreversible gelation polymer (TGP) scaffold, without feeder layers or other foreign proteins.

METHODS & RESULTS

The results of this 28-day in vitro culture, u sing the conventional technique (2D) and TGP (3D) showed that the epithelial cell morphology could be maintained only in the TGP group while cells in the 2D group de-differentiated to fibroblast morphology in both human and rabbit samples. CK3 expression, a marker for epithelial differentiation was higher in 3D-TGP cultured cells than 2D.

CONCLUSION

TGP based in vitro cell culture is a prospective methodology to culture buccal mucosal epithelial cells efficiently without using foreign biological components for tissue engineering applications.

Efficacy of re-do urethroplasty for post-traumatic urethral stricture: An analysis of the anatomical and functional outcomes

OBJECTIVES

To investigate the efficacy of re-do urethroplasty for post-traumatic urethral stricture in terms of anatomical and functional outcomes.

METHODS

A total of 48 patients who underwent re-do urethroplasty for post-traumatic urethral stricture due to perineal trauma (n = 21) and pelvic fracture urethral injury (n = 27) between October 2010 and March 2020 were retrospectively reviewed. Patients were followed by uroflowmetry, post-void residual volume assessment and 17-Fr flexible cystoscopy after re-do urethroplasty. Successful urethroplasty was defined as having a urethral caliber adequate for the passage of a cystoscope and requiring no additional treatments. Patients completed a validated patient-reported outcome measure for urethral stricture surgery, including overall satisfaction, and the sexual health inventory for men.

RESULTS

The type of re-do urethroplasty was anastomotic urethroplasty in 45 (94%) patients and buccal mucosa urethroplasty in three (6%) patients. Urethroplasty was successful in 47 (98%) patients (median follow up 35 months, interquartile range 21-75). The patient-reported outcome measure for urethral stricture surgery and Sexual Health Inventory for Men were assessed in 36 (75%) patients, and the mean lower urinary tract symptom-specific quality of life, EuroQol-5D and EuroQol-visual analog scale scores improved from 2.86, 0.63 and 54.17 preoperatively to 0.78 (P < 0.001), 0.86 (P < 0.001) and 76.94 (P < 0.001) postoperatively, respectively. The pre- and postoperative mean Sexual Health Inventory for Men scores (5.92 and 4.94, respectively) did not significantly differ (P = 0.318). All 36 patients were satisfied with their urethroplasty outcomes, with 20 (56%) very satisfied patients.

CONCLUSIONS

Re-do urethroplasty for post-traumatic urethral stricture shows a high success rate and beneficial effects on both anatomical and functional outcomes.

Is pre-referral management of anterior urethral strictures prior to urethroplasty appropriate?

OBJECTIVES

To evaluate whether the management of anterior urethral strictures prior to definitive urethroplasty is appropriate.

METHODS

Of a total of 419 men diagnosed with anterior urethral strictures at hospitals across Japan and thereafter referred to our institution for definitive urethroplasty between 2004 and 2019, the medical records of 371, for whom data on stricture characteristics at the initial diagnosis and pre-referral management were available, were retrospectively reviewed. A pre-referral single transurethral procedure, such as direct vision internal urethrotomy or urethral dilation, was considered appropriate only for favorable stricture, defined as a single nontraumatic untreated bulbar urethral stricture ≤2 cm in size, and repeat transurethral procedures were considered inappropriate in any circumstances. The association between the appropriateness of the pre-referral management strategy and patient and clinical characteristics was analyzed.

RESULTS

A total of 242 patients (65.2%) had a pre-referral history of at least one transurethral procedure, and performing the procedure was considered inappropriate for 221 patients (59.6%). On multivariate logistic regression analysis, location of the patient's residence far from our institution (outside of the Kanto area; odds ratio 3.35, 95% confidence interval 1.86-6.04; P < 0.0001), voiding with intermittent dilation (odds ratio 2.38, 95% confidence interval 1.38-4.12; P = 0.002), iatrogenic stricture (odds ratio 11.18, 95% confidence interval 5.30-23.61; P < 0.0001), and stricture longer than 20 mm (odds ratio 3.05, 95% confidence interval 1.47-6.38; P = 0.003) were the independent predictors of inappropriate use of transurethral procedures.

CONCLUSIONS

Transurethral procedures are often inappropriately used. There is a clear need to promote appropriate management strategies for urethral strictures among general urologists.

Acquired Cystic Disease-Associated Renal Cell Carcinoma Extending to the Renal Pelvis Mimicking Urothelial Carcinoma on Computed Tomography (CT): Two Case Reports

Case series

Patients: Male, 66-year-old • Male, 67-year-old

Final Diagnosis: Acquired cystic disease-associated renal cell carcinoma

Symptoms: Hematuria

Medication: —

Clinical Procedure: —

Specialty: Oncology • Radiology

Usefulness of a high-speed surgical air drill in pubectomy during delayed anastomotic urethroplasty for pelvic fracture urethral injury

OBJECTIVES

Pubectomy is an ancillary technique used to increase exposure of the disrupted urethra and reduce anastomotic tension, which can be difficult for inexperienced surgeons. The objective of the present study was to illustrate the use of an air drill enabling delicate and precise bone resection in pubectomy for delayed anastomotic urethroplasty for pelvic fracture urethral injury.

METHODS

Between 2009 and 2019, 88 male patients underwent delayed anastomotic urethroplasty with pubectomy for pelvic fracture urethral injury. A total of 73 procedures used a high-speed surgical air drill (HiLAN HS; Aesculap, Tuttlingen, Germany) equipped with a short-hand piece. Operative time and blood loss in the air drill patient group (group 1) were compared with that of patients who underwent pubectomy using a rongeur and/or gouge (group 2, n = 15).

RESULTS

In 65 group 1 patients, urethroplasty was carried out using the perineal approach, with partial inferior pubectomy. Eight group 1 patients, whose proximal urethral end was displaced upward superior to the upper edge of pubis, underwent urethroplasty using the perineal and abdominal approach, with a superior partial pubectomy and supracrural urethral rerouting. No difficulty was encountered using the air drill in any of the cases. There was no significant difference in median operative time between the groups (group 1 256 min vs group 2 228 min; P = 0.31). The median blood loss in group 1 was significantly lower than group 2 (149 mL vs 453 mL; P < 0.0001).

CONCLUSIONS

Surgical air drills might facilitate pubectomy in patients undergoing delayed anastomotic urethroplasty for pelvic fracture urethral injury. This tool offers the advantage of a delicate bone resection with reduced blood loss.

[A CASE OF NEO-MEATAL STENOSIS AFTER PENECTOMY FOR PENILE CANCER, REPAIRED BY BLANDY PERINEAL URETHROSTOMY]

Surgical resection is the standard treatment for the management of localized penile cancer and a neo-urethral meatus is generally created on the penile stump or perineum. Neo-urethral meatus is often stenosed and requires repeated transurethral manipulations such as dilation and urethrotomy. These procedures are generally futile and are associated with poor quality of life. Here, we report a case of penile cancer that developed a neo-meatal stenosis after total penectomy, which was subsequently salvaged by perineal urethrostomy using Blandy technique. A 72-year-old male who was diagnosed with localized penile cancer, underwent total penectomy and creation of neo-meatus on the perineum. Neo-meatus stenosis had developed in the patient and he received repeated urethral dilations without any success. Finally, when the patient was unable to void, he was referred to us for the amelioration of meatal stenosis through the placement of a suprapubic catheter. Because the condition of the residual bulbar urethra was adequate and its length was enough, we planned to create a non-transecting perineal urethrostomy by Blandy technique. An inverted U-shaped perineal incision was made, and a skin flap was created. The scarred neo-meatus and spongiofibrosis at the distal bulbar urethra were completely excised. The residual bulbar urethra was exposed, and a longitudinal ventral incision of 4 cm was made. The edge of the bare urethral mucosa and tunica albuginea of the corpus spongiosum were sutured by 4-0 PDS for hemostasis. The apex of the U-shaped skin flap was brought to the proximal margin of the urethrotomy and a tension-free anastomosis was created between the skin flap and the urethral plate. Thereafter, the skin of the perineum was sutured to the open longitudinal urethrotomy. The patient started to void on the 5^th day post-surgery. The subject could void without the help of any intervention and did not require any instrument, sixteen weeks after the surgery.

Comparing pig breeds with genetically low and high backfat thickness: differences in expression of adiponectin, its receptor, and blood metabolites

Here we characterized gene expressions in subcutaneous adipose tissue and blood metabolites of pigs with genetically low backfat (Landrace) and high backfat (Meishan). As pigs aged from 1 wk-to 3-mo old, mRNA levels of adipose-specific genes increased, although their gene expressions coding for major enzymes involved in lipid metabolism (lipoprotein lipase, fatty acid synthase, and hormone-sensitive lipase) did not differ between lean and fat pigs. Instead, there were significant effects for adiponectin and its receptor AdipoR1 mRNA levels between the two breeds of which respective expressions were lower and higher in Meishan by 3 mo of age. Contrary to changes in gene expressions, the concentrations of blood glucose, triglyceride (TG), and NEFA in both breeds decreased during growth, and 3-mo-old Meishan evidenced lower glucose with higher TG than the Landrace. The homeostasis model assessment insulin resistance (HOMA-IR) index was also calculated from the measurements of fasting glucose and insulin concentration, and Meishan showed a higher value than the Landrace. We next examined these differences in Landrace and Meishan crossbreds, which were phenotypically distinguishable by the backfat thickness as the former lean type and the latter fat type. As with the purebreds, high backfat Meishan crosses showed the characteristics of lower glucose and higher TG in circulating levels and also lower adiponectin transcripts in subcutaneous adipose tissue. Collectively, our results demonstrate that levels of adiponectin and its receptor gene expressions, blood glucose, blood lipids, and HOMA-IR in pigs vary between lean and fat. These observations strongly suggest the possibility that overall metabolic differences rather than adipocyte ability itself contribute to the fatness of genetically high backfat pigs.

Penile-preserving surgery for male distal urethral carcinoma followed by buccal mucosa urethroplasty

Introduction

We report a case of distal urethral carcinoma treated with segmental urethral excision and reconstruction by staged buccal mucosa urethroplasty.

Case presentation

A 60‐year‐old man presented with difficulty urinating and a palpable mass on the ventral side of his penis. He was diagnosed as having localized distal urethral carcinoma (cT2N0M0) and underwent penile‐preserving surgery with staged urethroplasty using buccal mucosa as substitute tissue. The pathological diagnosis was squamous cell carcinoma of the urethra (T2) with negative surgical margin. At 2 years of follow‐up, there was no recurrence or metastasis, he could void in a standing position with an acceptable urinary stream, and he found the appearance of his external genitalia acceptable.

Conclusion

In cases of distal primary urethral carcinoma, urethroplasty using buccal mucosa graft could be alternative treatment option providing a better postoperative quality of life.

Thiamine accumulation and thiamine triphosphate decline occur in parallel with ATP exhaustion during postmortem aging of pork muscles

We aimed to clarify the mechanisms affecting postmortem thiamine and its phosphoester contents in major edible pork muscles, namely the longissimus lumborum (LL) in addition to vastus intermedius (VI). Metabolomic analysis by capillary electrophoresis-time of flight mass spectrometry revealed that the level of thiamine triphosphate (ThTP), approximately 1.8-fold higher in LL than in VI muscle at 0h postmortem, declined in the first 24hrs, resulting in an undetectable level at 168h postmortem in both muscles. In contrast, the thiamine content in both muscles increased after 24h postmortem during the aging process. The thiamine accumulation and ThTP decline progressed in parallel with a drastic reduction of the ATP level. The intermuscular differences in pH at 24h and in expression of thiamine transporter and thiamine pyrophosphokinase might result in delayed thiamine generation in LL. These results suggest that postmortem ATP exhaustion forced ThTP hydrolysis and further depyrophosphorylation of thiamine diphosphate in the porcine muscles, which resulted in thiamine accumulation.

Efficacy of Mitiglinide Combined with Dapagliflozin in Streptozotocin-nicotinamide-induced Type 2 Diabetic Rats and in Zucker Fatty Rats

The efficacy of the combination of the rapid-acting insulin secretagogue mitiglinide and the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin was explored in streptozotocin-nicotinamide-induced type 2 diabetic (STZ-NA) rats and in Zucker fatty (ZF) rats. The STZ-NA rats were prepared at 8 weeks of age. At 9 weeks of age, the combination study was conducted by oral glucose tolerance test (OGTT). At 13 weeks of age, ZF rats were dosed orally with dapagliflozin once daily up to the 22(nd) day. At days 15 and 22, the combination study was conducted by OGTT. In 2 different animal models, plasma glucose levels were strongly suppressed by the combination of mitiglinide and dapagliflozin as compared with either drug alone. The urinary glucose excretion was drastically elevated in the dapagliflozin group, but the combination with mitiglinide suppressed it about 50%. In STZ-NA rats, the plasma insulin secretion by the combination of both drugs was about at the same level as in the mitiglinide group. In ZF rats, the plasma insulin secretion by the combination of both drugs was less than mitiglinide group. Thus, in 2 different animal models, the combination of mitiglinide and dapagliflozin showed stronger antihyperglycemic action accompanied by less insulin secretion than mitiglinide alone, and reduced the urinary glucose excretion as compared with dapagliflozin used alone. These results indicate that the combination of mitiglinide and dapagliflozin can be a promising combination for the treatment of diabetic patients.

Profiling of differentially expressed microRNA and the bioinformatic target gene analyses in bovine fast- and slow-type muscles by massively parallel sequencing

MicroRNA (miRNA) are highly conserved, noncoding small RNA involved in post-transcriptional gene regulation in a variety of biological processes. To elucidate roles of miRNA in bovine muscle type specification and maintenance, we sought to determine differentially expressed miRNA between semitendinosus (STD) and masseter (MS) muscles from 3 Japanese black cattle by massively parallel sequencing. Differential gene expression of myosin heavy chain (MyHC) isoforms confirmed that STD and MS were MyHC-2x- and MyHC-1-abundant muscles, respectively. In total, 192 known miRNA and 20 potential new bovine miRNA were obtained from the sequencing. The differentially expressed miRNA with more than 2-fold difference in each muscle were identified. In particular, miR-196a and miR-885 were exclusively expressed in STD muscle, which was validated by quantitative reverse transcription-PCR (P=0.045 and P<0.001, respectively), whereas a slow type-directing miR-208b was highly expressed in MS compared with STD (false discovery rate<0.05). In addition, 16 potential novel miRNA were mapped and confirmed for their precursor structures by computational analyses. The results of functional annotation combined with in silico target analysis showed that the predicted target genes of miR-196a/b and miR-885 enriched gene ontology (GO) terms related to skeletal system development and regulation of transcription, respectively. Moreover, GO terms enriched from predicted targets miRNA suggested that STD-abundant- and MS-abundant-miRNA were associated with embryonic body planning and organ/tissue pattern formation, respectively. The present results revealed that the differentially expressed miRNA between the STD and MS muscles may play key roles to determine muscle type-specific tissue formation and maintenance in cattle thorough attenuating putative target genes involved in different developmental events.

ERK2 dependent signaling contributes to wound healing after a partial-thickness burn

Burn healing is a complex physiological process involving multiple cell activities, such as cell proliferation, migration and differentiation. Although extracellular signal-regulated kinases (ERK) have a pivotal role in regulating a variety of cellular responses, little is known about the individual functions of ERK isoform for healing in vivo. This study investigated the role of ERK2 in burn healing. To assess this, Erk2(+/-) mice generated by gene targeting were used. The resultant mice exhibited significant delay in re-epithelization of partial-thickness burns in the skin in comparison to wild-type. An in vitro proliferation assay revealed that keratinocytes from Erk2(+/-) mice grew significantly slower than those prepared from wild-type. These results highlight the importance of ERK2 in the process of burn healing.

Effects of mitiglinide on glucose-induced insulin release into the portal vein and fat-induced triglyceride elevation in prediabetic and diabetic OLETF rats

OBJECTIVE

The effect of single-dose mitiglinide on glucose and lipid metabolism was examined in OLETF rats with spontaneous type 2 diabetes in which the early insulin response following glucose challenge is known to diminish over time and become lost with aging.

METHODS

(1) With catheters inserted into the portal veins, 12-wk-old prediabetic OLETF rats were given an OGTT of 1 g/kg after 17 h of fasting. Eight rats each were orally given mitiglinide 1 mg/kg, nateglinide 50 mg/kg, or glibenclamide 1 mg/kg, vs 0.5% carboxymethylcellulose (CMC) as control, and were given an OGTT immediately afterward. Following oral administration of mitiglinide, nateglinide, glibenclamide, or 0.5% CMC, the 24-wk-old overt-diabetic OLETF rats were immediately given an OGTT of 1g/kg. (2) After 17 h of fasting, 24-wk-old OLETF rats were subjected to a fat-loading test. Eight rats each were given mitiglinide 3 mg/kg, glibenclamide 1 mg/kg, or glimepiride 1 mg/kg, vs 0.5% CMC, and were given soy oil 2 g/kg immediately afterward. They were also given mitiglinide orally and examined for LPL mRNA expression in their adipose tissue.

RESULTS

(1) After OGTT, mitiglinide produced a significant increase in portal insulin levels 15 min after its administration, as well as a significant decrease in peripheral glucose levels 15-120 min after its administration in the OLETF rats. Likewise, nateglinide produced an increase in portal insulin levels and a decrease in peripheral glucose levels shortly after its administration in these rats. Glibenclamide increased portal insulin levels for an extended time after its administration, and significantly decreased peripheral glucose levels in the rats 120-300 min after its administration in the rats. In contrast, as in the 12-wk-old rats, a precipitous rise in insulin secretion was seen in the portal vein of 24-wk-old rats given mitiglinide, which peaked 15 min after mitiglinide administration, but the insulin levels continued to increase for 120 min or longer in the 24-wk-old rats given glibenclamide. In addition, as in the 12-wk-old rats, a significant decrease in glucose levels in peripheral blood was noted 30 and 60 min after mitiglinide administration and 300 min after glibenclamide administration in the 24-wk-old rats. (2) Mitiglinide increased LPL mRNA expression 120 min after its administration, and significantly decreased peripheral TG and chylomicron- TG levels after fat challenge in the 24-wk-old OLETF rats.

CONCLUSION

Mitiglinide exhibited fast-onset and short-acting insulin-secretagogic effects, inhibiting post-glucose challenge increases in glucose levels and post-fat challenge increases in TG levels.

Left atrial appendage dysfunction in chronic nonvalvular atrial fibrillation is significantly associated with an elevated level of brain natriuretic peptide and a prothrombotic state

The study tested the hypothesis that left atrial appendage (LAA) dysfunction in nonvalvular atrial fibrillation (NVAF) correlates with a prothrombotic state, and investigated whether the plasma natriuretic peptides are marker of LAA dysfunction in NVAF. Sixty-seven patients underwent transthoracic and transesophageal echocardiography. The left ventricular fractional shortening, left atrial diameter (LAD), LAA flow velocity and the grade of spontaneous echo contrast (SEC) were determined. The plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), D-dimer, and thrombin-antithrombin III complex (TAT) were measured. The patients were divided into 2 groups according to LAA flow velocity: group I (LAA velocity <20 cm/s) and group II (LAA velocity > or = 20cm/s). The SEC score, D-dimer, TAT, BNP and LAD were significantly increased in group I. Based on simple linear regression analysis, SEC score (r=-0.638), LAD (r=-0.493), D-dimer (r = -0.485), BNP (r = -0.463), TAT (r = -0.455) and age (r = -0.314) were inversely correlated with LAA flow velocity. Multivariate analysis showed that SEC score (p = 0.0014) and plasma BNP level (p=0.0075) were independent negative predictors for LAA flow velocity. In conclusion, LAA dysfunction is associated with a prothrombotic state, and the plasma BNP concentration may serve as a determinant of LAA function in NVAF.

Functional role and angioarchitectural arrangement of the filiform and fungiform papillae on the medial-dorsal surface of the beagle dog tongue

A scanning electron microscopic study has been performed on the three-dimensional morphological structure and functional arrangement in microvascular cast specimens (MVCS) of the filiform (FiP) and fungiform papillae (FuP) of the entire medial-dorsal surface of the caudal portion of the beagle dog tongue. The characteristics and functional arrangements of each FiP and FuP were as follows: The FiPs densely and geometrically covered the entire medial-dorsal surface. The outer structure of the FiPs was composed of both the main process (mp) and accessory process (ap). These were formed by both the ascending and descending branches and originating in their tributaries was a spoon-like capillary micronetwork structure with a sharp arrowhead-like top. The mp inclined posteriorly and the ap anteriorly. On the other hand, the outer structure of the FuPs was a rounded papillary body composed of a capillary microvascular network consisting of the ascending and descending branches just as the FiPs. They were distributed sporadically along the oblique eines of FiPs in a V running from both peripheral edges in the posterocentral direction. It has been conjectured that the FiPs play a concentric functionally important role in transporting food and liquid from both the peripheral edges to the postero-central part or towards the pharynx, and on the other hand the FuPs play an assisting role in receiving gustatory sensations from the masticated food and liquid on the medial-peripheral and central-dorsal surface of the caudal portion of the beagle dog tongue.

Effect of KAD-1229, a nonsulfonylurea hypoglycemic agent, on plasma glucose and insulin in streptozotocin-induced diabetic dogs

Hypoglycemic agents with a rapid onset and short duration of action should be useful for controlling postprandial hyperglycemia. Our aim was to establish a diabetes mellitus model in dogs, and then during an oral glucose tolerance test to compare the hypoglycemic effect and insulinotropic action of KAD-1229, a new hypoglycemic agent, with that of gliclazide, a conventional sulfonylurea. In this model, KAD-1229 reduced the increase in plasma glucose level without producing hypoglycemia. Gliclazide had a weaker effect on reduction of the glucose increase and caused hypoglycemia via a significantly raised insulin secretion in the late phase. A rapid insulinotropic action of KAD-1229 was clearly observed in the portal venous blood. The results suggest that in type 2 diabetes caused by, at least, insulin deficiency, KAD-1229 may improve impaired insulin secretion in the early phase and attenuate hyperglycemia without causing a sustained hypoglycemia.

Functional and angioarchitectural structure and classification of lingual papillae on the postero-dorsal surface of the beagle dog tongue

A scanning electron microscopic study was done of the three-dimensional, morphological structure and classification by means of microvascular cast specimens (MVCS) of the filiform (FiP), fungiform (FuP) and circumvallate papillae (CvP) on the postero-centro-peripheral, and conical papillae (CoP) on the posteroperipheral-dorsal surface of the caudal portion of the beagle dog tongue. The characteristics and functional arrangement of each lingual papilla were as follows: the FiP densely and geometrically covered the entire postero-centro-peripheral dorsal surface. The outer structure of the FiP, consisting of both the ascending and descending branches from their tributaries, was a spoon-like capillary micro-network structure with a sharp arrowhead-like top inclined posteriorly. On the other hand, the outer structure of the FuP, appearing sporadically on the oblique lines of the FiP, was of round form consisting of a capillary microvascular network structure. The FuP, consisting of ascending and descending branches similar to the FiP, were distributed sporadically and geometrically on oblique lines in a V-form running from both peripheral sides to postero-central direction on the FiP A group of three CvPs were arranged on oblique lines in a V form from the peripheral to the postero-central region on the postero-dorsal surface. The outer shape of the microvascular network structure of the CvP was a round fence-like structure surrounding the papillary body and the papillary body consisted of an inner semi-spherical microvascular network structure. The CoP densely covered the entire postero-peripheral-dorsal surface. The exterior figure of the conical micro-network structure, consisting of both the ascending and descending branches of the CoP, was a cone-like capillary network structure, and the sharp tops were inclined posteriorly. They were classified into three types: large (L-CoP), medium (M-CoP) and small (S-CoP) according to the morphological characteristics in shape, size and the distributive position. It was conjectured that the FiP play a concentric functionally important role in transporting food and liquid from both sides in a postero-central direction towards the pharynx. And, on the other hand, the FuPs play an assistant role in receiving gustatory sensations from the masticated food and liquid on the central dorsal surface. The CoP play a functionally important role on the postero-peripheral-dorsal surface, in transporting food and liquid towards the pharynx and a complementary role of the CvP is to receive gustatory sensations from masticated food and liquid on the postero-peripheral-dorsal surface of the caudal portion of the beagle dog tongue.

Functional and positional difference and classification of the fungiform papillae on the rabbit tongue seen in microvascular cast specimens by means of scanning electron microscope

The relationships between the functional and morphological characteristics, the positional difference and classification seen in microvascular cast specimens (MVCS) of the fungiform papillae (FuP) on the anterodorsal surface and both sides of the intermolar eminence (IME) of the rabbit tongue were examined and compared by means of scanning electron microscopy (SEM). The small fungiform papillae (S-FuP), scattered sporadically among the numerous small filiform papillae (SfP), were found to be distributed irregularly over the anterodorsal surface. The large fungiform papillae (L-FuP), distributed in a length-wise line in the anterior to the posterior direction among the SfP, were found to be distributed on both peripheral sides of the IME. FuPs consisted of the ascending and descending capillary loops, forming the central hole on the top of the FuP, resembling a carnation, the petals of which numbered eight to twelve, and were wider and more complex in shape and size than SfPs were morphologically different. S-FuPs can be classified into three types: type I (consisting of eight petals), type II (ten petals) and type III (twelve petals) according to the shape of the FuP and the number of petals, L-FuPs, were larger and wider than S-FuPs and of a more complex shape, classified into two types: type I (consisting of ten petals) and type II (twelve petals) according to the shape of the FuP and the number of petals in the MVCS of FuPs as seen in SEM. These results suggest that the petals in the ascending and descending capillary loops of the FuP expand into flower-like figures, increase on the surface and play an effective role in receiving the taste sense from foods and liquids on the antero-dorsal surface and both peripheral sides of the IME.

Functional angioarchitectural comparison of the fungiform papillae of rat, rabbit, cat in scanning electron microscopic specimens

The aim of this study was to compare the functional angioarchitectural fungiform papillae (FuP) of three kinds of mammalia, rat, rabbit and cat, with microvascular cast specimens (MVCS) utilizing the corrosive resin cast method in scanning electron microscopy (SEM). FuP distributed geometrically on the dorsal surface of the tongues of the three mammals with different eating habits were of various kinds of form based on their functional and microvascular structure. The basic form of the capillary loop of FuP in the three mammals consisted of the ascending and descending branches of the capillary bed. The basic form of the loop microstructure in rat FuP was a cylindrical or bamboo-basket-like loop structure. In the rabbit, FuPs consisted of a carnation-like structure and in the cat FuP consisted of a half oval fishnet ball-like structure. It can be said conclusively that from this detailed investigation of the intracapillary microvascular architecture of the three mammals, FuP are effective as a sensory organ receiving the taste of foods and liquids by the expansion of the surface area in various functional and microvascular formations in the rat (cylindrical or bamboo-basket-like loop structure), rabbit (carnation-like) and cat (half oval fishnet-ball-like) respectively.

Distinct families of Z-line targeting modules in the COOH-terminal region of nebulin

To learn how nebulin functions in the assembly and maintenance of I-Z-I bands, MYC- and GFP- tagged nebulin fragments were expressed in primary cultured skeletal myotubes. Their sites of incorporation were visualized by double staining with anti-MYC, antibodies to myofibrillar proteins, and FITC- or rhodamine phalloidin. Contrary to expectations based on in vitro binding studies, none of the nebulin fragments expressed in maturing myotubes were incorporated selectively into I-band approximately 1.0-micrometer F-alpha-actin-containing thin filaments. Four of the MYC/COOH-terminal nebulin fragments were incorporated exclusively into periodic approximately 0.1-micrometer Z-bands. Whereas both anti-MYC and Rho-phalloidin stained intra-Z-band F-alpha-actin oligomers, only the latter stained the pointed ends of the polarized approximately 1.0-micrometer thin filaments. Z-band incorporation was independent of the nebulin COOH-terminal Ser or SH3 domains. In vitro cosedimentation studies also demonstrated that nebulin SH3 fragments did not bind to F-alpha-actin or alpha-actinin. The remaining six fragments were not incorporated into Z-bands, but were incorporated (a) diffusely throughout the sarcoplasm and into (b) fibrils/patches of varying lengths and widths nested among normal striated myofibrils. Over time, presumably in response to the mediation of muscle-specific homeostatic controls, many of the ectopic MYC-positive structures were resorbed. None of the tagged nebulin fragments behaved as dominant negatives; they neither blocked the assembly nor induced the disassembly of mature striated myofibrils. Moreover, they were not cytotoxic in myotubes, as they were in the fibroblasts and presumptive myoblasts in the same cultures.

Comparative angioarchitectural formation seen in microvascular cast specimens of the fungiform papillae in the weaning period and adult rat tongue

The purpose of this study was an attempt to identify the functional and comparative angioarchitectural differences between the sexes, and the developmental processes seen in microvascular cast specimens (MVCS) of the formation of the fungiform papillae (FuP) geometrically and regularly distributed on the anterodorsal surface in the weaning period and in the adult rat tongue. The basic microvascular structure seen in the MVCS of FuP of both the weaning and adult rat tongue consisted of several ascending (As. b) and descending branches (Ds. b) and a loop structure (L. st), and the cylindrical network structure of the L. st made up of the open-hole formation of the C form of the upper and lower microvascular structures. In the lateral view, the MVCS of FuP has a bamboo basket-like shape, and by means of the three-dimensional expansion of the surface area, effectively plays an assistant functional role in receiving the taste of foods and liquids. There were obviously no sex and morphological differences in the developmental process as to shape, but there was some difference between the weaning period and the adult rat in size in the MVCS of FuP.

Preparation, solubility, and cytocompatibility of zinc-releasing calcium phosphate ceramics

Zinc is an essential trace element with stimulatory effects on bone formation. Therefore, zinc was doped into beta-tricalcium phosphate to develop zinc-releasing biomaterials to promote bone formation. The zinc-doped beta-tricalcium phosphate, beta-tricalcium phosphate, and hydroxyapatite powders were mixed at a (Ca+Zn)/P molar ratio of 1.60, followed by sintering into a dense body at 1100 degrees C for 1 h. The sintered body was a composite ceramic consisting of zinc-doped beta-tricalcium phosphate and hydroxyapatite phases. The composite ceramic contained zinc oxide when the zinc content was higher than 1.20 wt %. The composite ceramic released zinc under pseudophysiological conditions. However, the release of calcium and phosphate decreased with an increase in zinc content in a range higher than 0.12 wt % owing to a decrease in solubility of the zinc-doped beta-tricalcium phosphate phase. Proliferation of osteoblastic MC3T3-E1 cells was significantly increased on the composite ceramic with a zinc content from 0.6 to 1.20 wt %, compared with those without zinc. When the zinc content was higher than 1.20 wt %, release of zinc from the zinc oxide caused cytotoxicity. Therefore, the zinc content of the composite ceramic must be <1.20 wt %.

Stimulatory effect of zinc-releasing calcium phosphate implant on bone formation in rabbit femora

Although hydroxyapatite (HAP) and tricalcium phosphate (TCP) are currently used as bone graft substitutes or coatings on metallic prostheses because of their excellent biocompatibility and osteoconductivity, they do not stimulate bone formation or inhibit bone resorption. Zinc, an essential trace element in many animals, has a direct specific proliferative effect on osteoblastic cells and has a potent and selective inhibitory effect on osteoclastic bone resorption in vitro. Therefore, zinc-containing beta-tricalcium phosphate (ZnTCP) ceramics and composite ceramics of ZnTCP and HAP (ZnTCP/HAP) were implanted in the femora of New Zealand White rabbits for 4 weeks to promote bone formation. The implants were sintered ceramics with zinc contents of 0 (control), 0.063, 0.316 and 0.633 wt %. Histological and histomorphometrical investigation of the undecalcified sections revealed an increase by 51% (p =.0509) in the area of newly formed bone around the ZnTCP/HAP implants of 0. 316 Zn wt % compared with the control. Plasma zinc concentration was unchanged. An increased bone resorption on the endosteal surface was observed when ZnTCP and ZnTCP/HAP of 0.633 Zn wt % were implanted. To promote bone formation, the optimum zinc content of the calcium phosphate ceramics was therefore 0.316 wt %.