Gonadotropin-stimulated expansion of the mouse cumulus oocyte complex (COC) in vitro, measured with a quantitative videographic method, is comparable to that observed to occur in vivo when medium is supplemented with porcine follicle stimulating hormone (pFSH), 10% fetal bovine serum (FBS), and 2.5 mM glucosamine or optimal concentrations of glutamine and glucose. In the absence of glucosamine, the volumetric expansion of COCs in vitro is never more than 25% of that occurring in its presence. The addition of 6-diazo-5-oxo-1-norleucine (DON), an inhibitor of glucosamine synthesis to medium supplemented with glutamine and glucose, completely inhibits cumulus expansion in vitro. This system was utilized to examine the relationship between cumulus expansion and fertilization rates, and the maintenance of fertilizability in culture. Successful fertilization (as determined by development to the 2-cell stage) was correlated with the quantity and quality of the expanded cumulus mass, and conversely, the spontaneous loss or mechanical removal of the cumulus was correlated with a loss of fertilizability following additional incubation in culture medium. In addition, the i.p. injection of DON inhibited cumulus expansion within the intact follicle and suppressed ovulation.

Mechanics-based models of concentric tube continuum robots have recently achieved a level of sophistication that makes it possible to begin to apply these robots to a variety of real-world clinical scenarios. Endonasal skull base surgery is one such application, where their small diameter and tentacle like dexterity are particularly advantageous. In this paper we provide the medical motivation for an endonasal surgical robot featuring concentric tube manipulators, and describe our model-based design and teleoperation methods, as well as a complete system incorporating image-guidance. Experimental demonstrations using a laparoscopic training task, a cadaver reachability study, and a phantom tumor resection experiment illustrate that both novice and expert users can effectively teleoperate the system, and that skull base surgeons can use the robot to achieve their objectives in a realistic surgical scenario.

The application of a quantitative videographic technique has provided an opportunity to compare the quantitative volumetric expansion of cultured oocyte complexes (COCs) to quantitative changes in gap junction down-regulation and hyaluronic acid synthesis and to investigate the effects of physiological agents that influence these processes. Results of these experiments support the idea that the down-regulation of cumulus gap junctions is required for the initial phase of cumulus cell disaggregation and confirm earlier reports that hyaluronic acid synthesis plays a major role in additional expansion of the cumulus. These studies also provide evidence that the degree of expansion observed in culture lacking substrates of hyaluronic synthesis is significantly attentuated when compared with expansion occurring in vivo and that the failure of cultured complexes to expand maximally can be overcome by the addition of substrates of hyaluronic acid synthesis to the culture medium.

The direct interaction of hyaluronic acid (HA) and proteins of the inter-␣-inhibitor family plays a critical role in organization and stabilization of the expanding cumulus extracellular matrix (cECM) following an ovulatory stimulus. Despite similarities in the morphology of cumulus oocyte complexes (COCs) expanding in vivo and in vitro, we find that the cECM of COCs which expand within intact follicles are more elastic and resistant to shear stress than the cECM of those stabilized in vitro. Western blot analysis shows that only the heavy chains of inter-␣-inhibitor are incorporated into the cECM and appears to be covalently linked to HA after stabilization in vivo while intact inter-␣-inhibitor is bound to the HA-enriched cECM by a non-covalent mechanism in in vitro stabilized COCs. However, purified pre-␣-inhibitor and HA can form covalent linkage in the presence of granulosa cells or with granulosa cellconditioned medium. In addition, COCs resistance to shear stress is also enhanced by coincubation with granulosa cells. Upon formation of the apparent covalent linkage between heavy chains and HA in culture medium, the light chain (bikunin) is concomitantly released into the medium as a complex with chondroitin sulfate moieties of inter-␣-inhibitor supporting the possibility that HA may replace the chondroitin sulfate linkage to the heavy chains. We speculate that a factor(s) secreted by granulosa cells within the follicle may catalyze a transesterification reaction resulting in an exchange of chondroitin sulfate with HA at the heavy chain/chondroitin sulfate junction followed by release of chondroitin sulfate-bikunin into the follicular fluid. It is also possible that the consequent further stabilization of the cECM through the covalent interaction of HA and heavy chains of inter-␣-inhibitor may play an important role in the process of ovulation.In most mammalian species (including mouse, rat, and human), cumulus-oocyte complexes (COCs) 1 of pre-ovulatory follicles undergo a dramatic change following an ovulatory stimulus. The tightly packed cumulus cells first disaggregate and then synthesize and secrete large amounts of hyaluronic acid (HA) into their extracellular matrices (ECMs). The ECM, cumulus cells, and oocyte are thus integrally bound within an expanded mucoid complex which is about 20 to 40 times larger (volume) dependent upon the species (1). This process of cumulus expansion is required for ovulation and may also facilitate the process of fertilization (2-4).We have previously identified a serum factor (proteins of the inter-␣-inhibitor family), critical in organizing and stabilizing the expanding cumulus matrix (5). This protein factor appears to be excluded from follicular fluid until the ovulatory gonadotropin surge and then quickly diffuses into the follicular fluid where it becomes integrated within the cumulus ECM (5, 6). Two major forms of this factor, pre-␣-inhibitor (P␣I) and inter-␣-inhibitor (I␣I), exist in mammalian species including mouse, bovine, and human (7,8). They each include a ...

Neurohistochemical techniques were used to determine the distribution of adrenergic and cholinergic nerves in the human placenta and the umbilical cord adjacent to the chorion. These morphologic studies demonstrate the absence of neural elements in these sites. The significance of these findings to the placental innervation controversy is discussed.