Prevention of genital prolapse following Burch colposuspension: comparison between two surgical procedures

 Our objective was to evaluate the efficacy of cul-de-sac obliteration in preventing pelvic floor anatomical defects formation following Burch colposuspension. We evaluated 441 patients who had undergone Burch colposuspension. The patients were divided into two groups: group A (132 patients) who underwent Burch colposuspension only, and group B (309 patients) who had had a concomitant cul-de-sac obliteration. Cul-de-sac obliteration was performed using two different techniques, the Moschocowitz procedure in 131 patients, and approximation of the sacrouterine ligaments in 178 patients. The follow-up period was 8.6 years (range 3–16). In total we found 43/441 (9.7%) postoperative anatomical defects. Obliteration of the cul de sac significantly (P<0.0001) reduced the formation of anatomical defects compared to Burch colposuspension. In a comparison of the two surgical procedures for cul-de-sac obliteration, the approximation of the sacrouterine ligaments was significantly more effective than either the Moschcowitz procedure (P<0.001) or the Burch colposuspension alone (P<0.001). The Moschcowitz procedure reduced the formation of anatomical defects to 15/131 (11.4%) compared to Burch colposuspension only (25/132; 18.9%), but statistically the difference was insignificant. The time of anatomical defect detection was significantly reduced after cul-de-sac obliteration: 2 years 6/25 (24%) in group A compared to 1/8 (5.5%) in group B (P<0.01). After 5 years the detection rate was 64% (16/25) and 22.2% (4/18) respectively (P<0.01). It was concluded that cul-de-sac obliteration using approximation of the sacrouterine ligaments significantly reduced the incidence of anatomical defect formation following Burch colposuspension. A long follow-up period is needed to evaluate the truce incidence. Received: 2 October 2002 / Accepted: 2 July 2002     

Identification of functional GRP-preferring bombesin receptors on human melanoma cells

Bombesin was originally isolated from amphibian skin, wherease its mammalian counterpart, gastrin-releasing peptide (GRP), was first identified in the nervous system of the gastrointestinal tract. Whether GRP is present in the human skin is not known. Bombesin-like peptides are also known to modulate growth. We therefore investigated whether human melanoma cell lines express functional GRP-preferring bombesin receptors and whether they alter growth or other specific cellular functions of these tumour cells. GRP receptor mRNA was found in HBL, D-10, Me-28 and A375-6 cell lines, but only A375-6 cells express a large number of high-affinity binding sites for [¹²⁵I]-[Tyr⁴] bombesin ( K _d 0.31 ± 0.04 nmol L⁻¹, 3880 ± 429 binding sites per cell). Bombesin dose-dependently increased cytosolic calcium, but did not alter interleukin (IL) 1β-induced reduction of cell viability or IL-6 secretion, both A375-6-specific cell functions. Growth of A375-6 cells was not altered by bombesin or the specific GRP receptor antagonist BIM26226 as measured by [³H]-thymidine incorporation or methylene blue assay, whereas insulin alone or in combination with other potential growth factors dose-dependently stimulated growth of these cells. The newly characterized GRP-preferring bombesin receptors on highly malignant human melanoma cells could initiate studies of growth effects on solid tumours or in vivo scanning using radiolabelled tracers.     

Charge of a quasiparticle in a superconductor

Nonlinear charge transport in superconductor–insulator–superconductor (SIS) Josephson junctions has a unique signature in the shuttled charge quantum between the two superconductors. In the zero-bias limit Cooper pairs, each with twice the electron charge, carry the Josephson current. An applied bias V_SD leads to multiple Andreev reflections (MAR), which in the limit of weak tunneling probability should lead to integer multiples of the electron charge ne traversing the junction, with n integer larger than 2Δ/eV_SD and Δ the superconducting order parameter. Exceptionally, just above the gap eV_SD ≥ 2Δ, with Andreev reflections suppressed, one would expect the current to be carried by partitioned quasiparticles, each with energy-dependent charge, being a superposition of an electron and a hole. Using shot-noise measurements in an SIS junction induced in an InAs nanowire (with noise proportional to the partitioned charge), we first observed quantization of the partitioned charge q = e*/e = n, with n = 1–4, thus reaffirming the validity of our charge interpretation. Concentrating next on the bias region eV_SD ～ 2Δ, we found a reproducible and clear dip in the extracted charge to q? ～ 0.6, which, after excluding other possibilities, we attribute to the partitioned quasiparticle charge. Such dip is supported by numerical simulations of our SIS structure.Excitations in superconductors (Bogoliubov quasiparticles) can be described according to the Bardeen–Cooper–Schrieffer (BCS) theory (1) as an energy-dependent superposition of an electron with amplitude u(ε), and a hole with amplitude v(ε), where the energy ε is measured relative to the Fermi energy (2). Evidently, the expectation value of the charge operator (applied to the quasiparticle wave function), which we address as the quasiparticle charge e* = q(ε)e, is smaller than the charge of an electron, q(ε) = |u(ε)|² ? |ν(ε)|² (3). Solving the Bogoliubov–de Gennes equations, one finds that |u(ε)|2=1/2[1+(ε2−Δ2/ε)] and |v(ε)|2=1/2[1−(ε2−Δ2/ε)], with the expected charge evolving with energy according to q(ε)=ε2−Δ2/ε––vanishing altogether at the superconductor gap edges (3). Note, however, that the quasiparticle wave function is not an eigenfunction of the charge operator (3, 4). Properties of quasiparticles, such as the excitation spectra (5), lifetime (6–10), trapping (11), and capturing by Andreev bound states (12, 13), had already been studied extensively; however, studies of their charge are lagging. In the following we present sensitive shot-noise measurements in a Josephson junction, resulting in a clear observation of the quasiparticle charge being smaller than e, q(eV_SD∼2Δ) < 1, and evolving with energy, as expected from the BCS theory.To observe the BCS quasiparticles in transport we study a superconductor–insulator–superconductor (SIS) Josephson junction in the nonlinear regime. The overlap between the wave functions of the quasiparticles in the source and in the drain is expected to result in a tunneling current of their effective charge. This is in contrast with systems which are incoherent (14, 15) or with an isolated superconducting island, where charge conservation leads to traversal of multiples of e – Coulomb charge (16). As current transport in the nonlinear regime results from “multiple Andreev reflections” (MAR), it is prudent to make our measurements credible by first measuring the charge in this familiar regime.In short, the MAR process, described schematically in Fig. 1, carries a signature of the shuttled charge between the two superconductors (SCs), being a consequence of n traversals through the junction (as electron-like and hole-like quasiparticles), with n an integer larger than 2Δ/eV_SD. A low transmission probability t (via tunneling through a barrier) in the bias range 2Δ/n < eV_SD < 2Δ/(n ? 1) assures dominance of the lowest order MAR process (higher orders are suppressed as tⁿ), with the charge evolving in nearly integer multiples of the electron charge. Although there is already a substantial body of theoretical (3, 17–23) and experimental (24–29) studies of the MAR process, charge determination without adjustable parameters is still missing. An important work by Cron et al. (27) indeed showed a staircase-like behavior of the charge using “metallic break junctions;” however, limited sensitivity and the presence of numerous conductance channels some of which with relatively high transmission probabilities did not allow exact charge quantization. Our shot-noise measurements, performed on a quasi-1D Josephson junction (single-mode nanowire) allowed clear observation of charge quantization without adjustable parameters. To count a few advantages: (i) the transmission of the SIS junction could be accurately controlled using a back-gate; (ii) this, along with our high sensitivity in noise measurements, enabled us to pinch the junction strongly (thus suppressing higher MAR orders); and (iii) with the Fermi level located near the 1D channel van Hove singularity, a rather monoenergetic distribution could be injected (SI Appendix, section S7).Open in a separate windowFig. 1.MAR. Illustrations of the leading processes contributing to the current as function of bias. In general, for 2Δ/(n ? 1) > eV_SD > 2Δ/n the leading charge contribution to the current is ne. An electron-like quasiparticle is denoted by a full circle, whereas a hole-like quasiparticle is denoted by an empty circle. (A) When the bias is larger than the energy gap, eV_SD > 2Δ, the leading process is a single-path tunneling of single quasiparticles from the full states (Left) to the empty states (Right). This current is proportional to the transmission coefficient t. Higher-order MAR process (dashed box), being responsible for tunneling of Cooper pairs, is suppressed as t². (B) For 2Δ > eV_SD > Δ, the main charge contributing to the current is 2e with probability t². (C) For Δ > eV_SD > 2Δ/3, the main charge contributing to the current is 3e with probability t³.     

Maternal Adnexal Torsion in Pregnancy Is Associated with Significant Risk of Recurrence

Study ObjectivesTo investigate the phenomenon of recurrent adnexal torsion during the same pregnancy, describe its risk factors, and suggest possible management of this entity.DesignRetrospective case-control study (Canadian Task Force classification II-3).SettingGynecologic endoscopy unit in a university hospital.Patients and interventionsPregnant women with surgically proved adnexal torsion were retrospectively identified from 1993 to 2007. Details of clinical presentation, method of conception, preoperative ultrasound findings, and operative findings were analyzed.InterventionComparison of characteristics of patients with recurrent episodes of adnexal torsion during the same pregnancy vs a single episode of torsion.Measurements and Main ResultsThirty-three pregnant women with 38 episodes of adnexal torsion were included in the study. Seventeen pregnancies (51.5%) were spontaneously conceived. Twenty-eight women had a single episode of torsion, and 5 women (15.1%) had recurrent episodes of torsion during the same pregnancy. No significant differences were found between the 2 groups in age, method of conception, and gestational age at time of torsion. However, ultrasound studies demonstrated that multicystic ovaries were significantly more common in women with recurrent torsion compared with women with a single episode of torsion (80% vs 25%; p = .02). The interval between the first and second episodes of torsion ranged from 1 to 4 weeks.ConclusionPregnant women are at risk for recurrent torsion, especially when the ovaries are enlarged and ultrasound studies demonstrate multiple cysts. Cyst aspiration may prevent recurrent torsion during the same pregnancy.     

Effects of induced menopause on Burch colposuspension for urinary stress incontinence.

The clinical and urodynamic short term results after colposuspension for urinary stress incontinence has been studied in a group of young patients in whom menopause was induced surgically and compared with a similarly treated group who did not undergo surgical castration. Clinically, no differences were found in the incidence of diurnal frequency, nocturia, urgency, urge incontinence or stress incontinence between the groups. No urodynamic changes in the cystometric, uroflowmetry and urethral pressure profile measurements were found post-operatively between the two groups. It is concluded that surgically induced menopause in the absence of aging has no effect on the results of colposuspension for urinary stress incontinence in the short term.     

Methotrexate local injection for unruptured tubal pregnancy: an alternative to laparotomy?

Fifty-nine women with early unruptured tubal pregnancy were treated by a single local injection of methotrexate at laparoscopy. All 59 patients underwent the procedure without any adverse reaction, 47 (80%) of them needing no laparotomy. Twelve patients required a laparotomy for reasons such as rising beta-hCG levels and abdominal pain with or without rising levels of beta-hCG. Only one patient ruptured the tube. None of the women needed a blood transfusion. We found tubal patency in 19 out of 21 patients at follow up hysterosalpingography. Eleven pregnancies were subsequently reported, one of them tubal. The appearance of the injected tube was absolutely normal in three patients, one at cesarean section and two at repeated laparoscopy. No peritubal adhesions were observed. We suggest that this new technique is a safe and effective alternative to laparotomy in a patient with an early unruptured tubal pregnancy.     

Colposuspension for urinary stress incontinence in premenopausal and postmenopausal women

Sixty-nine premenopausal and 53 postmenopausal women had a colposuspension operation for urinary stress incontinence. A significant postoperative reduction (p less than 0.001) of symptoms of frequency, nocturia, urgency and urge incontinence was obtained in both groups. Postoperatively, 88.4 per cent of the premenopausal women were found to be dry compared with 66 per cent in the postmenopausal group (p less than 0.01). No differences were found preoperatively and postoperatively in the cystometric values or in the urethral pressure profiles at rest in both groups and between the groups. The pressure transmission ratios were significantly improved postoperatively in both groups. The postoperative transmission ratios in the premenopausal women were found to be significantly higher than those in the postmenopausal group, at the middle two-quarters of the urethra. Although surgical treatment for urinary stress incontinence in postmenopausal women results in lower cure rates than in younger women, it should be considered.