Symptomatic improvement after mesh removal: a prospective longitudinal study of women with urogynaecological mesh complications.

OBJECTIVE: To compare clinical characteristics and outcomes in patients undergoing excision of polypropylene urogynaecological mesh for pain, mesh exposure or both. DESIGN: Prospective, longitudinal cohort. SETTING: Academic tertiary referral centre. POPULATION: Women undergoing complete vaginal mesh excision for mesh exposure and/or pain. METHODS: Clinical and patient-reported outcomes assessing pain (visual analog scale, VAS), bother (Pelvic Floor Distress Inventory, PFDI) and functional impact (Pelvic Functional Impact Questionnaire, PFIQ) were collected at baseline, 6, 12 and 24 months after complete mesh excision. Outcomes were compared by mesh type (sling, prolapse [transvaginal or sacrocolpopexy mesh], both) and complication (pain, exposure, both). MAIN OUTCOME MEASURES: 'Much better' or 'Very much better' on Patient Global Impression of Improvement (PGI-I) up to 2 years after removal. RESULTS: Of 173 women, 48 underwent removal for pain, 27 for exposure and 98 for exposure plus pain. 'Moderate to severe' baseline symptoms were reported by 75%; the most prevalent and severe symptom was dyspareunia. Patients with pain alone were most bothered (PFDI median 234.2, interquartile range 83, P = 0.02) and had the highest functional impact (PFIQ median 181, interquartile range 138, P < 0.001). After excision, only 33.3% of women with pain alone reported 'improved' symptoms (PGI-I), versus 73.9% with exposure, 58.3% with exposure plus pain (P = 0.03) with no differences in PGI-I by mesh type. VAS scores decreased in all groups, but PFDI and PFIQ did not improve in pain patients. CONCLUSIONS: In women experiencing a pain complication after urogynaecological mesh insertion, mesh removal often does not improve symptoms. TWEETABLE ABSTRACT: Only 33% of women with pain complications have improved symptoms after urogynaecological mesh removal.

The impact of prolapse mesh on vaginal smooth muscle structure and function.

OBJECTIVE: To evaluate the impact of prolapse meshes on vaginal smooth muscle structure (VaSM) and function, and to evaluate these outcomes in the context of the mechanical and textile properties of the mesh. DESIGN: Three months following the implantation of three polypropylene prolapse meshes with distinct textile and mechanical properties, mesh tissue explants were evaluated for smooth muscle contraction, innervation, receptor function, and innervation density. SETTING: Magee-Womens Research Institute at the University of Pittsburgh. POPULATION: Thirty-four parous rhesus macaques of similar age, parity, and pelvic organ prolapse quantification (POP-Q) scores. METHODS: Macaques were implanted with mesh via sacrocolpopexy. The impact of Gynemesh(™)  PS (Ethicon; n = 7), Restorelle(®) (Coloplast; n = 7), UltraPro(™) parallel and UltraPro(™) perpendicular (Ethicon; n = 6 and 7, respectively) were compared with sham-operated controls (n = 7). Outcomes were analysed by Kruskal-Wallis ANOVA, Mann-Whitney U-tests and multiple regression analysis (P < 0.05). MEAN OUTCOME MEASURES: Vaginal tissue explants were evaluated for the maximum contractile force generated following muscle, nerve, and receptor stimulation, and for peripheral nerve density. RESULTS: Muscle myofibre, nerve, and receptor-mediated contractions were negatively affected by mesh only in the grafted region (P < 0.001, P = 0.002, and P = 0.008, respectively), whereas cholinergic and adrenergic nerve densities were affected in the grafted (P = 0.090 and P = 0.008, respectively) and non-grafted (P = 0.009 and P = 0.005, respectively) regions. The impact varied by mesh property, as mesh stiffness was a significant predictor of the negative affect on muscle function and nerve density (P < 0.001 and P = 0.013, respectively), whereas mesh and weight was a predictor of receptor function (P < 0.001). CONCLUSIONS: Mesh has an overall negative impact on VaSM, and the effects are a function of mesh properties, most notably, mesh stiffness. TWEETABLE ABSTRACT: Prolapse mesh affects vaginal smooth muscle.

Deterioration in biomechanical properties of the vagina following implantation of a high-stiffness prolapse mesh.

OBJECTIVE: To define the impact of prolapse mesh on the biomechanical properties of the vagina by comparing the prototype Gynemesh PS (Ethicon) to two new-generation lower stiffness meshes, SmartMesh (Coloplast) and UltraPro (Ethicon). DESIGN: A study employing a nonhuman primate model. SETTING: University of Pittsburgh, PA, USA. POPULATION: Forty-five parous rhesus macaques. METHODS: Meshes were implanted via sacrocolpopexy after hysterectomy and compared with sham. Because its stiffness is highly directional, UltraPro was implanted in two directions: UltraPro Perpendicular (less stiff) and UltraPro Parallel (more stiff), with the indicated direction referring to the position of the blue orientation lines relative to the longitudinal axis of the vagina. The mesh-vaginal complex (MVC) was excised in toto after 3 months. MAIN OUTCOME MEASURES: Active mechanical properties were quantified as the contractile force generated in the presence of 120 mmol/l KCl. Passive mechanical properties (a tissue's ability to resist an applied force) were measured using a multiaxial protocol. RESULTS: Vaginal contractility decreased by 80% following implantation with the Gynemesh PS (P = 0.001), 48% after SmartMesh (P = 0.001), 68% after UltraPro Parallel (P = 0.001) and was highly variable after UltraPro Perpendicular (P = 0.16). The tissue contribution to the passive mechanical behaviour of the MVC was drastically reduced for Gynemesh PS (P = 0.003), but not for SmartMesh (P = 0.9) or UltraPro independent of the direction of implantation (P = 0.68 and P = 0.66, respectively). CONCLUSIONS: Deterioration of the mechanical properties of the vagina was highest following implantation with the stiffest mesh, Gynemesh PS. Such a decrease associated with implantation of a device of increased stiffness is consistent with findings from other systems employing prostheses for support.

Vaginal degeneration following implantation of synthetic mesh with increased stiffness.

OBJECTIVE: To compare the impact of the prototype prolapse mesh Gynemesh PS with that of two new-generation lower stiffness meshes, UltraPro and SmartMesh, on vaginal morphology and structural composition. DESIGN: A mechanistic study employing a nonhuman primate model. SETTING: Magee-Womens Research Institute at the University of Pittsburgh. POPULATION: Parous rhesus macaques, with similar age, weight, parity and Pelvic Organ Prolapse-Questionnaire scores. METHODS: Following Institutional Animal Care Use Committee approval, 50 rhesus macaques were implanted with Gynemesh PS (n = 12), UltraPro with its blue line perpendicular to the longitudinal axis of vagina (n = 10), UltraPro with its blue line parallel to the longitudinal axis of vagina (n = 8) or SmartMesh (n = 8) via sacrocolpopexy following hysterectomy. Sham-operated animals (n = 12) served as controls. MAIN OUTCOME MEASURES: The mesh-vagina complex was removed after 12 weeks and analysed for histomorphology, in situ cell apoptosis, total collagen, elastin, glycosaminoglycan content and total collagenase activity. Appropriate statistics and correlation analyses were performed accordingly. RESULTS: Relative to sham and the two lower stiffness meshes, Gynemesh PS had the greatest negative impact on vaginal histomorphology and composition. Compared with sham, implantation with Gynemesh PS caused substantial thinning of the smooth muscle layer (1557 ± 499 µm versus 866 ± 210 µm, P = 0.02), increased apoptosis particularly in the area of the mesh fibres (P = 0.01), decreased collagen and elastin content (20%, P = 0.03 and 43%, P = 0.02, respectively) and increased total collagenase activity (135%, P = 0.01). Glycosaminoglycan, a marker of tissue injury, was highest with Gynemesh PS compared with sham and other meshes (P = 0.01). CONCLUSION: Mesh implantation with the stiffer mesh Gynemesh PS induced a maladaptive remodelling response consistent with vaginal degeneration.

Relaxin is essential for renal vasodilation during pregnancy in conscious rats.

Marked vasodilation in the kidney and other nonreproductive organs is one of the earliest maternal adaptations to occur during pregnancy. Despite the recognition of this extraordinary physiology for over four decades, the gestational hormone responsible has remained elusive. Here we demonstrate a key role for relaxin, a member of the IGF family that is secreted by the corpus luteum in humans and rodents. Using a gravid rodent model, we employ two approaches to eliminate relaxin or its biological activity from the circulation: ovariectomy and administration of neutralizing antibodies. Both abrogate the gestational elevation in renal perfusion and glomerular filtration, as well as preventing the reduction in myogenic reactivity of isolated, small renal arteries. Osmoregulatory changes, another pregnancy adaptation, are also abolished. Our results indicate that relaxin mediates the renal vasodilatory responses to pregnancy and thus may be important for maternal and fetal health. They also raise the likelihood of a role for relaxin in other cardiovascular changes of pregnancy, and they suggest that, like estrogen, relaxin should be considered a regulator of cardiovascular function.

Alternatively spliced glucocorticoid receptor messenger RNAs in glucocorticoid-resistant human multiple myeloma cells.

Glucocorticoids are highly effective chemotherapeutic agents used in the treatment of hematological malignancies including multiple myeloma. However, the clinical usefulness of this class of drugs is limited by the problem of resistance. In the following study, we have isolated two alternatively spliced transcripts of the glucocorticoid receptor from a complementary DNA library generated from the glucocorticoid-resistant myeloma cell line MM.1Re. In each of the clones, specific exons of the hormone binding domain are precisely deleted. Our data implicate alternate splicing as a mechanism by which a cell generates different receptor isoforms and as a consequence evades the effects of hormone.

A variant glucocorticoid receptor messenger RNA is expressed in multiple myeloma patients.

In multiple myeloma cells resistant to glucocorticoids, we have previously identified a variant glucocorticoid receptor (GR) transcript (P. A. Moalli et al., Cancer Res., 53: 3877-3879, 1993). Here, we report a reverse transcription-PCR assay to assess whether this aberrant GR transcript is present in myeloma patients. We detected both the wild-type and variant GR transcripts in the patient isolate that was the source of our myeloma cell lines, in patients refractory to steroid treatment, and in healthy control subjects. Simultaneous amplification of wild-type and variant GR mRNAs indicates that the variant GR is more highly expressed in cells that are resistant to glucocorticoids. We hypothesize that the variant GR is a normal mRNA transcript that acts to modulate glucocorticoid responsiveness, and increased expression contributes to a resistant phenotype.

Glucocorticoid receptors and resistance to glucocorticoids in hematologic malignancies.

Glucocorticoids are highly effective in inducing the cytolysis of cells of lymphocytic origin. This property has resulted in their incorporation into chemotherapy regimens used in the treatment of hematologic malignancies. Studies at the molecular and cellular levels have demonstrated that the hormone-induced cytolytic response is mediated through a highly specific cytoplasmic glucocorticoid receptor (GR). The GR has been cloned and sequenced and found to be organized into a discrete series of domains which mediate the receptor functions of hormone binding, nuclear translocation, DNA binding and transcriptional modulation. Thus, the binding of glucocorticoids by the GR induces a series of cellular events which result in the activation or repression of a network of glucocorticoid responsive genes and produces a specific cellular response. Prolonged exposure to glucocorticoids ultimately causes resistance to develop; thereby limiting the usefulness of this class of drugs. Studies addressing the mechanism of resistance have shown that the GR is the primary target of genetic alterations that lead to resistance to cytolysis. Using mouse and human cell lines as model systems, it has been shown that the vast majority of glucocorticoid resistant mutants express low levels or altered forms of the GR. Similarly, in vivo studies on patients have suggested that low GR levels are associated with a poor response to glucocorticoid based therapies. Recently, aberrant GR isolated from a patient with multiple myeloma resistant to glucocorticoids were found to harbor deletions in their hormone binding domains. Sequencing of the receptors suggested that each arose as a result of alternate splicing events. In both cases, the latter event produces a receptor unable to bind hormone leading to the speculation that alternate splicing may serve as a mechanism by which a cell evades the effects of glucocorticoids. The therapeutic implications for patients expressing aberrant receptors is discussed.

Acute injury and regeneration of the mesothelium in response to asbestos fibers.

The mesothelium is a target of the toxic and carcinogenic effects of asbestos fibers. Fibers greater than 8 mu in length and less than 0.25 mu in diameter have been found to be highly tumorigenic in rodents, while shorter asbestos fibers or spherical mineral particles have not been shown to produce mesotheliomas. For investigation of early mesothelial reactions associated with the development of mesotheliomas, C57BL/6 mice were given intraperitoneal injections of 200 micrograms of short or long crocidolite asbestos fibers, toxic silica particles, or nontoxic titanium dioxide particles. At intervals between 3 hours and 21 days after a single injection, the mesothelial surface of the diaphragm was examined by stereomicroscopy, scanning electron microscopy, and autoradiography. Within 6 hours after injection of asbestos fibers, mesothelial cells in the lacunar regions of the diaphragm retracted opening stomata 10.7 +/- 2.3 mu in diameter leading to the submesothelial lymphatic plexus. Short asbestos fibers (90.6% less than or equal to 2 mu in length), silica, or titanium dioxide particles (less than or equal to 5 mu in diameter) were cleared through these stomata without provoking an inflammatory reaction or mesothelial injury. In contrast, long asbestos fibers (60.3% greater than or equal to 2 mu in length) were trapped at the lymphatic stomata in the lacunar regions on the peritoneal surface of the diaphragm. At these sites, an intense inflammatory reaction developed with accumulation of activated macrophages and a 5.5-fold increase in albumin recovered in the peritoneal lavage fluid after 3 days. As early as 12 hours after injection of long asbestos fibers, the adjacent mesothelial cells were unable to exclude trypan blue and lost their surface microvilli, developed blebs, and detached. Recovery of lactate dehydrogenase activity in the peritoneal lavage fluid was increased 5.8-fold after 3 days and returned to normal levels after 14 days. Regenerating mesothelial cells appeared at the periphery of asbestos fiber clusters 3 days after injection. Maximal incorporation of 3H-thymidine by mesothelial cells occurred after 7 days, followed by partial restoration of the mesothelial lining after 14-21 days. As late as 6 months after a single injection of crocidolite asbestos fibers, clusters of fibers remained in the lacunar regions, partially covered by mesothelium but surrounded by macrophages and regenerating mesothelial cells. The anatomic distribution and size of lymphatic stomata on the peritoneal surface of the diaphragm account for the selective accumulation of long asbestos fibers in these regions.(ABSTRACT TRUNCATED AT 400 WORDS)

A mechanism of resistance to glucocorticoids in multiple myeloma: transient expression of a truncated glucocorticoid receptor mRNA.

Despite their widespread use, little is known of either the mechanism of action of glucocorticoids in the treatment of multiple myeloma or why patients ultimately become resistant to their therapeutic effects. Here, we address these issues by examining the direct effects of the glucocorticoid dexamethasone (DEX) on a hormone-sensitive clone (MM.1S) of a human multiple myeloma line and compare them with those of its hormone-resistant counterpart (MM.1R). MM.1S expresses approximately 50,000 glucocorticoid receptors (GR) per cell, the full-length 7.1-kb GR mRNA at high levels, and is lysed by DEX. DEX-induced cytolysis is effectively blocked by the glucocorticoid antagonist, RU 486, indicating the specificity of this response for the GR. In contrast to MM.1S, MM.1R is not lysed by hormone, has little hormone-binding activity, and expresses the 7.1-kb GR mRNA at low levels. Interestingly, we have found that two distinct phenotypes emerge from MM.1R with increasing periods of growth in culture. The first or "early" form, MM.1Re, expresses high levels of a variant GR mRNA of 5.5 kb that has a deletion in its 3' end. With further growth in the presence or absence of selective media, the expression of this transcript is repressed, resulting in the second or "late" phenotype characteristic of MM.1RL. No discernible differences in the organization of the genomic GR sequence in DEX-sensitive and -resistant cells were detectable by Southern analysis, suggesting that no gross deletions, rearrangements, or allelic variations in the genomic sequence account for the resistant phenotypes of MM.1R.

Impact of menopause on collagen subtypes in the arcus tendineous fasciae pelvis.

OBJECTIVE: The arcus tendineous fasciae pelvis (ATFP) provides support to the anterior vagina. The objective of this study was to determine the impact of menopause on the structural components of the ATFP. STUDY DESIGN: Biopsy specimens of the ATFP were obtained from 10 premenopausal, 5 postmenopausal, and 12 postmenopausal women on hormone therapy. Scanning confocal microscopy of fluorescent micrographs was used to define the amount of collagen subtypes, smooth muscle, and elastin. Collagen fiber orientation was determined by scanning electron microscopy. RESULTS: The ATFP is comprised primarily of parallel bundles of type III collagen fibers (84%), an intermediate amount of elastin (13%), and very little smooth muscle. The ratio of collagen I/(III+V) was decreased in postmenopausal not on hormones relative to premenopausal women (P=.04) due to a 75% decrease in collagen I (P=.046). The decrease in collagen I and change in collagen ratios was not present in women on hormone therapy. Comparison of the amounts of elastin and smooth muscle showed no difference in the ATFP of premenopausal and postmenopausal women. CONCLUSION: Menopause in the absence of hormone therapy is associated with a decrease in quantity of collagen I in the ATFP resulting in a decrease in the ratio of collagen I/(III+V). This may compromise the tensile strength and an increase susceptibility to anterior vaginal wall prolapse.