LacZ-expressing olfactory ensheathing cells do not associate with myelinated axons after implantation into the compressed spinal cord.

Studies have shown that implanting olfactory ensheathing cells (OECs) may be a promising therapeutic strategy to promote functional recovery after spinal cord injury. Several fundamental questions remain, however, regarding their in vivo interactions in the damaged spinal cord. We have induced a clip compression injury at the T10 level of the spinal cord in adult rats. After a delay of 1 week, OECs isolated from embryonic day 18 rats were implanted into the cystic cavity that had formed at the site of injury. Before implantation, OECs were infected with a LacZ-expressing retrovirus. At 3 weeks after implantation, LacZ-expressing OECs survived the implantation procedure and remained localized to the cystic cavity. At the electron microscopic level, the cystic cavity had clusters of LacZ-expressing OECs and numerous Schwann cells lacking LacZ expression. Although labeled OECs made no direct contact with axons, unlabeled Schwann cells were associated with either a single myelinated axon or multiple unmyelinated axons. Positively labeled OEC processes often enveloped multiple Schwann cell-axon units. These observations suggest that the role of OECs as the primary mediators of the beneficial effects on axon growth, myelination, and functional recovery after spinal cord injury may require re-evaluation.

Olfactory ensheathing cells: historical perspective and therapeutic potential.

Olfactory ensheathing cells (OECs) are the glial cells that ensheath the axons of the first cranial nerve. They are attracting increasing attention from neuroscientists as potential therapeutic agents for use in the repair of spinal cord injury and as a source of myelinating glia for use in remyelinating axons in demyelinating diseases such as multiple sclerosis. This review mainly addresses the cell biological aspects of OECs pertinent to addressing two questions. Namely, where do OECs fit into the groupings of central nervous system (CNS)/peripheral nervous system (PNS) glial cells and should OECs be viewed as a clinically relevant alternative to Schwann cells in the treatment of spinal cord injury? The evidence indicates that OECs are indeed a clinically relevant alternative to Schwann cells. However, much more work needs to be done before we can even come close to answering the first question as to the lineage and functional relationship of OECs to the other types of CNS and PNS glial cells.

Challenging generally accepted contraindications to vaginal hysterectomy.

OBJECTIVE: A number of preexisting clinical conditions are generally accepted as contraindications to vaginal hysterectomy. The purpose of this study was to evaluate the validity of this concept. STUDY DESIGN: The study vaginal hysterectomy group consisted of 250 consecutive patients undergoing vaginal hysterectomy. These patients (1) had a large uterus (>180 g), (2) either were nulliparous or had no previous vaginal delivery, or (3) had a previous cesarean delivery or pelvic laparotomy. Three control groups used for comparison underwent (1) laparoscopically assisted vaginal hysterectomy, (2) vaginal hysterectomy, or (3) abdominal hysterectomy. The records for all patients were analyzed for age, weight, parity, primary diagnosis, uterine size, operative time, blood loss, analgesia, hospital stay, resumption of diet, incidence of morcellation, and surgical complications. Sample size calculations were based on previous studies of complications associated with vaginal hysterectomy (alpha =.05; beta =.20). RESULTS: Hysterectomy was successfully completed by the intended vaginal route in all study patients. Major and minor complications (3.2%) were significantly less (P <.001) than in the other groups as follows: vaginal hysterectomy, 10.4%; laparoscopically assisted vaginal hysterectomy, 11.6%; and abdominal hysterectomy, 13.6%. The decrease in hematocrit was 5.7% in the study vaginal hysterectomy group compared with 6.2% for vaginal hysterectomy, 6.5% for abdominal hysterectomy (P =.009), and 6.6% for laparoscopically assisted vaginal hysterectomy (P =.002). Hospital stay was shorter for the study group (2.1 days) than for vaginal hysterectomy (2.3 days; P <.001) and abdominal hysterectomy (2.7 days; P <.001). Operative time was shorter in the study vaginal hysterectomy group (49 minutes) than with laparoscopically assisted vaginal hysterectomy (76 minutes; P <.001) or abdominal hysterectomy (61 minutes; P <.001), although morcellation was carried out more frequently in the study group (34%) than with vaginal hysterectomy (4%) or laparoscopically assisted vaginal hysterectomy (11%). CONCLUSION: Our data indicate that a large uterus, nulliparity, previous cesarean delivery, and pelvic laparotomy rarely constitute contraindications to vaginal hysterectomy.

The role of vaginal apex excision in the management of persistent posthysterectomy dyspareunia.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of vaginal apex excision in the treatment of patients with posthysterectomy dyspareunia. STUDY DESIGN: This was a case series with an independent third-party survey of patients with posthysterectomy dyspareunia managed at the University of Utah Pelvic Pain Clinic. Thirteen patients were first treated with local injections of anesthetics into localized vaginal pain foci. Further evaluation included formal psychometric testing and a diagnostic spinal block. Nine patients underwent surgical excision of the vaginal apex. An independent interviewer who did not know the patients assessed the effects of this procedure on dyspareunia and coital frequency at a mean of 36.4 +/- 3.7 months after the operation. RESULTS: The mean coital verbal analog pain score (1-10 scale) decreased from 9.22 +/- 0.27 before excision of the vaginal apex to 3.11 +/- 0.84 after the operation (P <.001), and coital frequency improved from 5.22 +/- 2.02 episodes per month before surgery to 11.11 +/- 1.82 episodes per month after surgery (P =.02). Of the 9 patients, 5 essentially had the dyspareunia cured. Dyspareunia was decreased and coital frequency was markedly increased in all but 1 of the other 4 cases. CONCLUSION: Excision of the vaginal apex is an effective treatment for carefully selected patients with posthysterectomy dyspareunia.

Dyspareunia and recurrent stress urinary incontinence after laparoscopic colposuspension with mesh and staples. A case report.

BACKGROUND: A laparoscopic colposuspension technique using hernia staples and polypropylene mesh has been introduced for the treatment of stress urinary incontinence but is not without hazards. CASE: A 32-year-old woman developed recurrent stress urinary incontinence and dyspareunia approximately one year after undergoing laparoscopic colposuspension with hernia staples and polypropylene mesh. Metal staples palpated vaginally corresponded with the area of maximal tenderness, and the bladder neck was hypermobile. Upon surgical exploration of the space of Retzius, four staples were found in the bladder wall, and polypropylene mesh densely adherent to the bladder wall had eroded into the muscularis. CONCLUSION: Laparoscopic colposuspension with hernia staples and polypropylene mesh may be associated with early recurrence of incontinence and dyspareunia.

Is fruit juice a "no-no" in children's diets?

In addition to milk and other beverages, juices in reasonable quantities (12 fl oz/day or less) provide nutrients infants need while keeping sugar and food energy intakes adequate.

Differential expression of Hoxa-2 protein along the dorsal-ventral axis of the developing and adult mouse spinal cord.

We have used synthetic oligopeptides derived from the coding sequence of the murine Hoxa-2 protein to produce polyclonal antibodies that specifically recognize the Hoxa-2 recombinant protein. Immunohistochemical studies reveal a distinct pattern of spatial and temporal expression of Hoxa-2 protein within the mouse spinal cord which is concomitant with the cytoarchitectural changes occurring in the developing cord. Hoxa-2 protein is predominantly detected in the nuclei of cells in the ventral mantle region of 10-day-old mouse embryos. Islet-1, a marker for motor neurons was also shown to be co-localized with Hoxa-2 in nuclei of cells in this region. As development progresses from 10-days to 14-days of gestation, Hoxa-2 protein expression gradually extends to the dorsal regions of the mantle layer. The Hoxa-2 protein expression pattern changes at 16-days of embryonic development with strong expression visible throughout the dorsal mantle layer. In 18-day-old and adult mouse spinal cords, Hoxa-2 protein was expressed predominantly by cells of the dorsal horn and only by a few cells of the ventral horn. Double labeling studies with an antibody against glial fibrillary acidic protein (GFAP, an astrocyte-specific intermediate filament protein) showed that within the adult spinal cord, astrocytes rarely expressed the Hoxa-2 protein. However, Hoxa-2 and GFAP double-labeled astrocytes were found in the neopallial cultures, although not all astrocytes expressed Hoxa-2. Hoxa-2 expressing oligodendrocyte progenitor cells were also identified after double-labeling with O4 and Hoxa-2 antibodies; although cells in this lineage that have begun to develop a more extensive array of cytoplasmic processes were less likely to be Hoxa-2 positive. The early pattern of Hoxa-2 protein expression across transverse sections of the neural tube is temporally and spatially modified as each major class of neuron is generated. This congruence in the expression of the Hoxa-2 protein and the generation of neurons in the cord suggests that the Hoxa-2 protein may contribute to dorsal-ventral patterning and/or to the specification of neuronal phenotype. Dev Dyn 1999;216:201-217.

Managing organizational challenge and change: closing an inpatient unit.

The effects of a turbulent health care delivery market have impacted the day-to-day reality of acute care hospitals. One effect is that the supply of acute care hospital beds currently exceeds the demand, a trend that is expected to continue to the year 2000 and beyond. Nursing administrators at St. Marys Hospital Medical Center made the decision to close an inpatient unit in order to better match acute care bed supply to existing demand. Decision support for closure, organizational change, and lessons learned from the closure process are discussed.

Immunohistochemical localization of laminin, fibronectin and collagen type IV in the nerve fiber layer of the olfactory bulb.

When the olfactory nerve is injured in adult mammals, the axons grow across the PNS-CNS transitional zone and re-innervate their synaptic contacts within the olfactory bulb. Some years ago, Liesi [Liesi P. (1985) Laminin-immunoreactive glia distinguish regenerative adult CNS systems from non-regenerative ones. EMBO J. 4, 2505-2511] reported the presence of laminin in non-basal lamina locations within the nerve fiber layer (NFL) of the olfactory bulb of adult rats and suggested that this molecule may facilitate olfactory axonal growth into and within the CNS. The purpose of the present study was to compare the expression of laminin, fibronectin, and collagen type IV in: (a) the NFL of developing and adult rats; and (b) the NFL rostral and caudal to a stab wound in the olfactory bulb of adult rats. Numerous punctate deposits of immunofluorescence were seen in the NFL of the E18 (Theiler stage 23) bulb when antisera to laminin, fibronectin or collagen type IV were used. There was a dramatic drop-off in staining at the border between the NFL and the presumptive glomerular layer. The staining pattern was similar in the newborn bulb, although the immunofluorescence was not as strong. In the unoperated adult rats, only laminin was present consistently as punctate deposits within the NFL, whereas all three antisera stained numerous punctate deposits within the NFL during the first week after a stab wound. Although there was a partial recapitulation of the expression pattern for laminin, fibronectin and collagen type IV in the lesioned adult NFL, it never reached the extent found in the E18 or newborn bulbs and its expression returned to normal levels prior to the re-innervation of the bulb during the second and third weeks after surgery. The results suggest that the molecular requirements for the successful growth of olfactory axons may differ during development to growth in adult animals.

Implantation of olfactory ensheathing cells in the adult rat brain following fimbria-fornix transection.

Ensheathing cells from fetal rat olfactory bulb were implanted into th e damaged adult rat brain to assess whether these cultured cells would survive in nonolfactory CNS areas and support the regrowth of nonolfactory axons. Cultures of primary ensheathing cells prelabeled with WGA-Au were embedded in a collagen matrix and implanted into a lesion cavity immediately following ablation of the fimbria-fornix in adult rats; the animals were sacrificed 4 weeks after surgery. Labeled ensheathing cells were observed only within the graft and not in the adjacent neural tissue. Immunostaining for p75 neurotrophin receptor revealed two characteristic morphologies of ensheathing cells within the graft; slender, spindle-shaped cells and larger, flattened cells. Although GFAP immunostaining revealed an intense glial reaction around the margin of the wound with host astrocytes sending cytoplasmic processes into the collagen matrices, no immunoreactive cells were found within the grafts. Histochemical detection of AChE revealed numerous reactive fibers confined to the regions of the grafts possessing ensheathing cells. Axons within the grafts were also immunoreactive for GAP-43. These initial experiments provide encouraging data concerning the survival of ensheathing cells for a minimum of 4 weeks following implantation into the adult rat brain and their ability to support the growth of new axons.

Comparison of laparoscopically assisted vaginal hysterectomy with abdominal and vaginal hysterectomy.

OBJECTIVE: To define the advantages and disadvantages of laparoscopically assisted vaginal hysterectomy (LAVH). STUDY DESIGN: The first 70 cases of LAVH performed in a community hospital were compared with 70 cases of abdominal and 70 cases of vaginal hysterectomy performed by the same physicians during the same period. RESULTS: The mean operating time was 80 minutes for LAVH, 50 for abdominal hysterectomy and 40 for vaginal hysterectomy. The incidence of complications was low for all groups. Although the total mean hospital charges were higher with LAVH, those patients required the least postoperative analgesia, resumed a regular diet earlier, required the shortest hospital stay, and returned to regular activity and work earlier than the other two groups. CONCLUSION: LAVH offers specific benefits for properly selected patients.

Olfactory ensheathing cells do not require L-ascorbic acid in vitro to assemble a basal lamina or to myelinate dorsal root ganglion neurites.

Ensheathing cells reside within both the PNS and CNS portions of the primary olfactory pathway and provide a glial covering and support for the unmyelinated olfactory axons. In vivo, these ensheathing cells express a mixture of astrocyte-specific and Schwann cell-specific phenotypic features. When grown in vitro in the presence of DRG neurons however, these ensheathing cells were observed to myelinate DRG neurites. The purpose of the present study was to determine whether ensheathing cells, like Schwann cells, require the addition of ascorbic acid to the medium in order to assemble a basal lamina and a myelin sheath. Our findings indicate that ensheathing cells can myelinate DRG neurites regardless of whether ascorbic acid is included in the growth medium and that these glial cells can assemble a basal lamina in the absence of added ascorbic acid. It appears from these results that Schwann cells and ensheathing cells have different growth media requirements for the assembly of a basal lamina.

Olfactory ensheathing cells: potential for glial cell transplantation into areas of CNS injury.

Ensheathing cells are the glial cells that ensheath olfactory axons within both the PNS and CNS portions of the primary olfactory pathway. These glial cells express a mixture of astrocyte-specific and Schwann cell-specific phenotypic features, support axonal growth by olfactory as well as by non-olfactory neurons, and survive transplantation into injured areas of the CNS. This review article focuses on those phenotypic features that are expressed by ensheathing cells that make them ideal candidates for transplantation into wound cavities in the damaged spinal cord of humans. Although much work remains to be done before such a therapeutic approach can be tried, the likelihood that ensheathing cells could simultaneously perform the roles of both astrocytes and Schwann cells following transplantation is the justification for developing such a therapeutic approach using animal models of spinal cord injury.

Elevated intracellular levels of cAMP induce olfactory ensheathing cells to express GAL-C and GFAP but not MBP.

The primary olfactory pathway contains non-myelinating glial cells, called ensheathing cells, that exhibit a variety of phenotypes depending on their immediate environment. In vivo, these cells normally possess a mixture of astrocyte- and Schwann cell-specific phenotypic features. When co-cultured with dorsal root ganglion neurons, their phenotype can become more like that of a myelinating Schwann cell. The objective of this study was to determine whether ensheathing cells would express a myelinating phenotype in culture in the absence of neurons but in the presence of cAMP analogues that are known to induce the expression of myelin associated molecules in Schwann cell cultures. The ensheathing cell cultures were initiated using the nerve fiber layers of Theiler stage 23 rat olfactory bulb primordia and were fed for 1 day to 3 weeks with serum containing (1% or 10% FBS) or serum-free media to which was added different concentrations of dBcAMP (0.1 to 1 mM) or forskolin (10 microM). These cultures were double-labelled with a rabbit polyclonal antibody to S100 in combination with mouse anti-GAL-C (O1 and BRD1 hybridomas) or anti-MBP monoclonal antibodies. The remaining cultures were double-labeled with a rabbit polyclonal antibody to GFAP in combination with the BRD1 antibody. Treatment with dBcAMP or forskolin failed to induce ensheathing cells to express MBP regardless of the concentration. On the other hand, the treatment induced approximately one tenth of the cells to express GAL-C, and virtually all of the cells to express GFAP. These results indicate that although ensheathing cells can synthesize myelin associated molecules, the cAMP second messenger system appears to play a lesser role in controlling the expression of a myelinating phenotype in ensheathing cells than it does in Schwann cells.

The development of glial fibrillary acidic protein-positive cells and the appearance of laminin-like immunoreactivity in fetal olfactory bulb transplants.

Embryonic rat olfactory bulbs were transplanted into the site vacated by aspiration of an olfactory bulb from a neonatal rat. This paper presents our findings related to the development of glial fibrillary acidic protein (GFAP) positive (+ve) glial cells and the appearance of laminin-like immunoreactivity in these transplants. The GFAP+ve glial cells formed perivascular end-feet on the invading vasculature and formed a glia limitans along the pial surface of the transplant. This reconstituted glia limitans was continuous with that of the host brain, there being no glia limitans at the donor-host interface. Thus, the donor tissue was well-integrated with that of the host brain.

Media that support the growth and differentiation of oligodendrocytes do not induce olfactory ensheathing cells to express a myelinating phenotype.

The glial cells that ensheath olfactory axons are referred to as ensheathing cells. In vivo, these non-myelinating glial cells express a mixture of astrocyte-specific and Schwann cell-specific phenotypic features with the former cellular phenotype predominating, but in vitro can assemble a myelin sheath when co-cultured with dorsal root ganglion neurons. Thus, certain in vitro conditions induce ensheathing cells to express a phenotype more like that of a myelinating Schwann cell. The present study addresses whether ensheathing cells will express a myelinating phenotype in neuron-free cultures when fed for 1 to 5 weeks with media shown to promote the growth and differentiation of oligodendrocyte progenitor cells. The ensheathing cell cultures were initiated using the nerve fiber layers (NFL) of rat olfactory bulb primordia. Oligodendrocyte cultures were established from newborn rat neopallium and from the tissue that remained after removing the NFL from the developing olfactory bulb (i.e., the OB-NFL). The cultures were double-labelled with rabbit polyclonal antibodies to S100 or glial fibrillary acidic protein in combination with the mouse monoclonal antibodies O4, BRD1 [anti-galactocerebroside (anti-GAL-C)], and anti-myelin basic protein (MBP). In some experiments the ensheathing cells were labelled with PKH26 prior to being co-cultured with oligodendrocytes of the OB-NFL. None of the media induced ensheathing cells to express either GAL-C or MBP. However, when 0.5 mM dibutyrylcyclic-AMP (dBcAMP) was added to the medium, ensheathing cells became GAL-C + ve, but remained MBP-ve. The molecular mechanisms that regulate the expression of a myelinating phenotype by ensheathing cells appear to be different from those that operate in oligodendrocytes.

Medical therapy for recurring catamenial pneumothorax following pleurodesis.

BACKGROUND: Catamenial pneumothorax, a rare complication of systemic endometriosis, has been difficult to treat successfully. Successful medical therapy is associated with amenorrhea. CASE: A 44-year-old white woman with recurring catamenial pneumothorax underwent thoracotomy and abrasive pleurodesis. Following the procedures, pneumothorax occurred again and she was treated with the GnRH analogue leuprolide acetate, 3.75 mg monthly intramuscularly. After 6 months, her therapy was changed to continuous hormonal suppression with norethindrone, 0.7 mg/day. After 6 months of this therapy and into the third episode of vaginal bleeding, the patient had another recurrent pneumothorax. CONCLUSION: Leuprolide acetate followed by continuous hormonal suppression with norethindrone was successful for 1 year in resolving recurring postsurgical catamenial pneumothorax, but the problem recurred with the resumption of vaginal bleeding during progestin therapy. Successful medical therapy requires amenorrhea.

Glial progenitor cells of the nerve fiber layer of the olfactory bulb: effect of astrocyte growth media.

There are two morphologically distinct types of glial cells (i.e., ensheathing cells and astrocytes) in the nerve fiber layer (NFL) of the adult mammalian olfactory bulb. Ensheathing cells provide ensheathment for olfactory axons, whereas astrocytes occupy the interfascicular spaces of the olfactory NFL. During embryonic development, however, only one type of glial cell is found in this layer of the olfactory bulb, namely, the ensheathing cell. Even though ensheathing cells take up residence within the CNS, they are actually derived from the olfactory placode. Far less is known about the developmental origin of interfascicular astrocytes, which arise either from the glial progenitor cells that give rise to ensheathing cells or from astrocyte precursor cells that migrate into the NFL from deeper layers of the bulb primordium. In the present study, enriched populations of ensheathing cells were grown in vitro in media known to promote the growth and differentiation of astrocytes to determine whether ensheathing cell progenitors could differentiate into astrocytes. These media failed to induce the appearance of astrocytes in the ensheathing cell cultures. It was concluded that the astrocytes of the NFL most likely arise from progenitor cells that migrate into this layer from deeper parts of the developing bulb.

Glial cells in the nerve fiber layer of the main olfactory bulb of embryonic and adult mammals.

This article provides a detailed description of the glial cell types in the nerve fiber layer of the main olfactory bulb during embryonic development, in adult mammals, and at the nerve entry zone of the first cranial nerve. In adult mammals, the glial cell types of the olfactory nerve fiber layer include intrafascicular ensheathing cells, which have the exclusive role of ensheathing the olfactory axons in both the PNS and CNS, and interfascicular astrocytes, which occupy the spaces between adjacent olfactory fascicles. The ensheathing cells are particularly interesting because they possess a mixture of Schwann cell and astrocytic phenotypic features, are more likely to be of placodal than of CNS origin, and have the exclusive role of forming the glia limitans at the PNS-CNS transitional zone. It is proposed that one important function of ensheathing cells is to modulate the growth of olfactory axons within the CNS; this modulation is probably mediated by selective cell adhesion molecules, extracellular matrix molecules, and chemotropic agents.

Olfactory ensheathing cells myelinate dorsal root ganglion neurites.

The objective of this study was to determine whether olfactory ensheathing cells (from E18 rat embryos) could myelinate dorsal root ganglion neurites in vitro. By four weeks many of the S100-positive ensheathing cells were Gal-C+ and MBP+ and had begun to myelinate the larger axons, as visualized with the electron microscope. We conclude that olfactory ensheathing cells can form a myelin sheath if given the opportunity to ensheath neurites of a proper size.