The optimal intravesical maintenance chemotherapy scheme for the intermediate-risk group non-muscle-invasive bladder cancer.

OBJECTIVE: Although the current European Association of Urology(EAU) guideline recommends that patients with intermediate-risk non-muscle-invasive bladder cancer (NMIBC) should accept intravesical chemotherapy or Calmette-Guerin (BCG) for no more than one year after transurethral resection of bladder tumor(TURBT), there is no consensus on the optimal duration of chemotherapy. Hence, we explored the optimal duration of maintenance intravesical chemotherapy in patients with intermediate-risk NMIBC. SUBJECTS AND METHODS: This was a real-world single-center retrospective cohort study. In total 158 patients with pathologically confirmed intermediate-risk NMIBC were included, who were divided into 4 subgroups based on the number of instillations given. We used Cox regression analysis and survival analysis chart to explore the 3-yr recurrence outcomes of tumor.The optimal duration was determined by receive operating characteristic curve (ROC). RESULTS: The median follow-up was 5.2 years. Compared with instillation for 1-2 months, the Hazard Ratios(HR) values of instillation for less than 1 month, maintenance instillation for 3-6 months and > 6 months were 3.57、1.57 and 0.22(95% CI 1.27-12.41;0.26-9.28;0.07-0.80, P = 0.03;0.62;0.02, respectively). We found a significant improvement in 3-yr relapse-free survival in intermediate-risk NMIBC patients who maintained intravesical instillation chemotherapy for longer than 6 months, and the best benefit was achieved with 10.5 months of maintenance chemotherapy by ROC. CONCLUSIONS: In our scheme, the optimal duration of intravesical instillation with pirrubicin is 10.5 months. This new understanding provides valuable experience for the precise medical treatment model of intermediate-risk NMIBC.

Inverse centrifugal effect induced by collective motion of vortices in rotating thermal convection.

When a fluid system is subject to strong rotation, centrifugal fluid motion is expected, i.e., denser (lighter) fluid moves outward (inward) from (toward) the axis of rotation. Here we demonstrate, both experimentally and numerically, the existence of an unexpected outward motion of warm and lighter vortices in rotating thermal convection. This anomalous vortex motion occurs under rapid rotations when the centrifugal buoyancy is sufficiently strong to induce a symmetry-breaking in the vorticity field, i.e., the vorticity of the cold anticyclones overrides that of the warm cyclones. We show that through hydrodynamic interactions the densely distributed vortices can self-aggregate into coherent clusters and exhibit collective motion in this flow regime. Interestingly, the correlation of the vortex velocity fluctuations within a cluster is scale-free, with the correlation length being proportional ( ≈ 30%) to the cluster length. Such long-range correlation leads to the counterintuitive collective outward motion of warm vortices. Our study brings insights into the vortex dynamics that are widely present in nature.

Applying MRI Intensity Normalization on Non-Bone Tissues to Facilitate Pseudo-CT Synthesis from MRI.

This study aimed to facilitate pseudo-CT synthesis from MRI by normalizing MRI intensity of the same tissue type to a similar intensity level. MRI intensity normalization was conducted through dividing MRI by a shading map, which is a smoothed ratio image between MRI and a three-intensity mask. Regarding pseudo-CT synthesis from MRI, a conversion model based on a three-layer convolutional neural network was trained and validated. Before MRI intensity normalization, the mean value ± standard deviation of fat tissue in 0.35 T chest MRI was 297 ± 73 (coefficient of variation (CV) = 24.58%), which was 533 ± 91 (CV = 17.07%) in 1.5 T abdominal MRI. The corresponding results were 149 ± 32 (CV = 21.48%) and 148 ± 28 (CV = 18.92%) after intensity normalization. With regards to pseudo-CT synthesis from MRI, the differences in mean values between pseudo-CT and real CT were 3, 15, and 12 HU for soft tissue, fat, and lung/air in 0.35 T chest imaging, respectively, while the corresponding results were 3, 14, and 15 HU in 1.5 T abdominal imaging. Overall, the proposed workflow is reliable in pseudo-CT synthesis from MRI and is more practicable in clinical routine practice compared with deep learning methods, which demand a high level of resources for building a conversion model.

Vortices as Brownian particles in turbulent flows.

Brownian motion of particles in fluid is the most common form of collective behavior in physical and biological systems. Here, we demonstrate through both experiment and numerical simulation that the movement of vortices in a rotating turbulent convective flow resembles that of inertial Brownian particles, i.e., they initially move ballistically and then diffusively after certain critical time. Moreover, the transition from ballistic to diffusive behaviors is direct, as predicted by Langevin, without first going through the hydrodynamic memory regime. The transitional timescale and the diffusivity of the vortices can be collapsed excellently onto a master curve for all explored parameters. In the spatial domain, however, the vortices exhibit organized structures, as if they are performing tethered random motion. Our results imply that the convective vortices have inertia-induced memory such that their short-term movement can be predicted and their motion can be well described in the framework of Brownian motions.

A rare life-threatening disease: unilateral kidney compressed by huge chronic spontaneous retroperitoneal hemorrhage.

OBJECTIVES: To study an uncommon life-threatening disease, spontaneous retroperitoneal and perirenal hemorrhage. CASE DESCRIPTIONS: A 69-year-old male presented with pain in the left waist and back of 1 month duration. The renal abscess was suspected by magnetic resonance imaging before operation. The perirenal hematoma was cleaned by operation. In another case, the patient had a functional solitary left kidney compressed by a huge retroperitoneal mass and uropenia appeared. RESULTS: The first patient died of adult respiratory distress syndrome after surgery. The second patient died of cardiac insufficiency and pulmonary embolism on the second day after evacuation of retroperitoneal hematoma. CONCLUSION: Conservative surgery, such as selective arterial embolization, is a reasonable approach in patients with chronic spontaneous retroperitoneal and perirenal space hemorrhage and with poor general condition. We strongly recommend drainage or interventional therapy, but not a major surgery, in patients with poor condition.

Inflammatory myofibroblastic tumor with extensive involvement of the bladder in an adolescent: a case report.

Inflammatory myofibroblastic tumor (IMT) is a rare lesion of unclear pathogenesis that shows a wide, highly variable spectrum of clinical behavior. We describe the case of a 17-year-old boy with a large IMT that infiltrated the bladder, ileocecal junction, peritoneum and pelvic retroperitoneal space. The tumor was associated with extensive toughening and thickening of the bladder, and, although it showed a tendency for invasive growth, it affected mainly the bladder and adjacent tissue. To the best of our knowledge, this case report is the first to describe an IMT involving the entire bladder and several adjacent pelviabdominal organs. The bladder wall was tough and could hardly be cut by scalpel. Levels of inflammatory response markers such as C-reactive protein fell after surgery.