Ex vivo human testes as a practical model to simulate ultrasound-guided testicular cell transplantation for human fertility restoration.

OBJECTIVE: To develop an ex vivo model to practice ultrasound-guided injection of cellular material into human seminiferous tubules to simulate testicular cell transplantation (TCT). DESIGN: Simulated TCT injections were performed in human testes removed during orchiectomy. The rete testis was the target site of injection. Successful retrograde infiltration of injected material into the lumen of the seminiferous tubules was detected using ultrasound and confirmed with histology. SETTING: Single academic surgical center. PATIENT(S): Adult patients undergoing orchiectomy for nononcologic indications. INTERVENTION(S): The testes were injected with sonographic contrast (Optison), methylene blue, and fluorescent-labeled cells. MAIN OUTCOME MEASURE(S): A characteristic streaming pattern of sonographic contrast in the testis was used to define sonographic success, and the presence of methylene blue and fluorescent-labeled cells within the seminiferous tubules confirmed histologic success. RESULT(S): We performed simulated TCT injections in 30 testes obtained from 16 patients undergoing orchiectomy. We were able to achieve sonographic success in 57% of injections and confirmed that sonographic success is correlated with histologic success. CONCLUSION(S): Testicular cell transplantation injections can be practiced using human testes. As there appears to be a learning curve associated with this procedure, developing this infrastructure to practice these skills is critical before implementation in patients.

Myosin IIB and F-actin control apical vacuolar morphology and histamine-induced trafficking of H-K-ATPase-containing tubulovesicles in gastric parietal cells.

Selective inhibitors of myosin or actin function and confocal microscopy were used to test the role of an actomyosin complex in controlling morphology, trafficking, and fusion of tubulovesicles (TV) containing H-K-ATPase with the apical secretory canaliculus (ASC) of primary-cultured rabbit gastric parietal cells. In resting cells, myosin IIB and IIC, ezrin, and F-actin were associated with ASC, whereas H-K-ATPase localized to intracellular TV. Histamine caused fusion of TV with ASC and subsequent expansion resulting from HCl and water secretion; F-actin and ezrin remained associated with ASC whereas myosin IIB and IIC appeared to dissociate from ASC and relocalize to the cytoplasm. ML-7 (inhibits myosin light chain kinase) caused ASC of resting cells to collapse and most myosin IIB, F-actin, and ezrin to dissociate from ASC. TV were unaffected by ML-7. Jasplakinolide (stabilizes F-actin) caused ASC to develop large blebs to which actin, myosin II, and ezrin, as well as tubulin, were prominently localized. When added prior to stimulation, ML-7 and jasplakinolide prevented normal histamine-stimulated transformations of ASC/TV and the cytoskeleton, but they did not affect cells that had been previously stimulated with histamine. These results indicate that dynamic pools of actomyosin are required for maintenance of ASC structure in resting cells and for trafficking of TV to ASC during histamine stimulation. However, the dynamic pools of actomyosin are not required once the histamine-stimulated transformation of TV/ASC and cytoskeleton has occurred. These results also show that vesicle trafficking in parietal cells shares mechanisms with similar processes in renal collecting duct cells, neuronal synapses, and skeletal muscle.