The current role of the artificial urinary sphincter for the treatment of urinary incontinence

PURPOSE: The introduction of the artificial urinary sphincter (AUS) in 1972 was heralded as a revolution for the treatment of genuine stress incontinence. Initial enthusiasm was tempered by disappointment as complications occurred. The device has now been in routine clinical use for more than 30 years, and the indications and surgical principles involved in its use along with short-term and long-term outcomes are more clearly defined. Hence, we reviewed the literature to clarify the role of the AUS and offer a possible solution to its problems in the guise of a new sphincter. MATERIALS AND METHODS: A MEDLINE search was performed and all articles relating to the role of the AUS for the treatment of urinary incontinence were reviewed. RESULTS: The AMS 800 (American Medical Systems, Minnetonka, Minnesota) provides urinary continence in 73% of cases (range 61% to 96%) and it has a complication rate of 12% (range 3% to 33%) for mechanical failure, 4.5% to 67% for early infection/erosion, 15% for late erosion and 7% for delayed recurrent incontinence. The literature supports the role of the AUS as an important and reliable treatment modality for stress urinary incontinence and intrinsic sphincter deficiency. However, it is not suitable in all patients and its use for the management of hypermobility is controversial. Hence, careful patient selection according to indication is required with full preoperative counseling. CONCLUSIONS: Despite its reliability for achieving urinary continence the AMS 800 is not perfect. Newer devices, such as that being developed at our institution, may offer improved outcomes and decreased complication rates.     

负压吸宫术前口服和阴道放置米索前列醇及米非司酮对宫颈扩张作用的比较

目的:比较终止早期妊娠负压吸宫术前口服和阴道放置米非司酮及米索前列醇对宫颈的扩张作用,观察副反应、手术时间及术中出血量。方法:将停经6～8周要求手术终止妊娠的130名妇女随机分为4组,A组(口服米非司酮)34例、B组(阴道放置米非司酮)32例、C组(口服米索前列醇)36例、D组(阴道放置米索前列醇)28例。阴道用药组于用药后12h,口服组于用药后24h行负压吸宫术。记录观察对象的宫颈扩张度、用药后副反应及术中出血量和手术时间。结果:宫颈扩张程度,D组与其他各组相比,差异有显著性(P<0.05),其余各组之间差异无显著性;D组的手术时间较B组明显缩短(P<0.05);D组无一例出现胃肠道反应,与其他各组相比,差异有显著性(P<0.05),术前阴道出血发生率较其他各组高(P<0.01),下腹痛的发生率较A组、B组高(P<0.01)。结论:负压吸宫术前口服或阴道放置米索、米非司酮均可扩张宫颈,但阴道放置米索前列醇效果好,且胃肠道反应发生率低,更适合有早孕反应的妇女。     

Scanning Electron Microscopic Evaluation of the Surfaces of Artificial Hearts

This Report summarizes the surface changes seen in artificial hearts implanted in calves for periods up to four months. Fabrication defects as well as degradation resulting from wear are identified. SEM evaluation of the blood contacting surface as well as the surface of the diaphragm associated with the drive mechanism has revealed potential problems with current heart designs and methods of fabrication. Materials evaluation of implanted hearts is crucial for a clinically useful system to evolve.     

Histochemical and morphometric changes in the adrenal cortex during acute vascular insufficiency

Artificial hypotension for 5 h produced in cats by intravenous injection of Arfonad is accompanied by depression of adrenal function. Insufficiency of the adrenals, especially of their glucocorticoid function, in established acute vascular insufficiency can be interpreted as adaptation aimed specifically at maintaining homeostasis.Department of Pathological Anatomy, S. M. Kirov Leningrad Postgraduate Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 615–616, May, 1977.     

Prostaglandins in the fetal circulation following maternal ingestion of a prostaglandin synthetase inhibitor during mid-pregnancy

To assess the possible effect upon the fetus of maternal ingestion of the prostaglandin synthetase inhibitor, mefenamic acid, taken during mid-pregnancy (15-22 weeks) to prevent spontaneous abortion, samples of fetal blood were collected at fetoscopy from 13 treated and 14 untreated control cases. Mefenamic acid levels in the fetus were 32-54% of those in the mothers in the treated group, while prostaglandins E2 (PGE2), 6-oxo-PGF1 alpha and PGFM were all slightly but not significantly lower in those patients given 500 mg mefenamic acid 40-180 min prior to sampling than in untreated controls. Results indicate that the prostaglandin synthetase inhibitor crosses the placenta at this early gestation and may possibly suppress fetal prostaglandin production.     

Electronic Pacemaker Models of Parasystole

This study deals with a method of analysis of artificial pacemaker function which can be used to understand the electrocardiographic manifestations of some spontaneous rhythms. The modes of operation of 11 normally-functioning QRS-inhibited (VVI) pacemakers resembled those of spontaneous automatic nonprotected (nonparasystolic) rhythms. The function of 11 continuous asynchronous (fixed rate or VOO) pacemakers was similar to that of continuous-parasystolic rhythms. In 12 patients with malfunctioning QRS-inhibited (VVI) pacemakers, an abnormally-prolonged pacemaker refractory period was equivalent to intermittent parasystole with phase 3 protection; and non-sensing during the terminal portions of the cycle was the iatrogenic counterpart of intermittent parasystole with phase 4 protection. Premature beats occurring within the periods of phase 3 and phase 4 protection were "encompassed" by ectopic intervals equalling the ectopic cycle length, or twice the ectopic cycle length. Therefore, they were manifested differently from the "decelerating" and "accelerating" phases of modulation since premature beats occurring during the letter phases may be encompassed by ectopic intervals which are longer and shorter, respectively, than the ectopic cycle length. Because in previous reports the search for these phenomena was based on premises established "a priori," future studies should be designed to analyze tracings of "group beating" where no previous conclusions have been reached.     

Preconception peripheral natural killer cell activity as a predictor of pregnancy outcome in patients with unexplained infertility

PROBLEM: Preconception high peripheral natural killer (NK) cell activity in women with recurrent spontaneous abortion can predict subsequent miscarriages. We have examined prospectively, for the first time, the pregnancy rate in patients with unexplained infertility by measuring the peripheral NK activity. METHOD OF STUDY: We tested the peripheral NK activity of 94 infertile women who despite treatment were unable to conceive for 6 or more months (mean; 2.4 years). Peripheral NK activity was measured by a chromium-51 release cytotoxicity assay. Women were followed for 2 years and assessed. RESULTS: In 77 patients who were followed for 2 years, 28 had conceived but 49 did not. The peripheral NK activity of the group that became pregnant (mean +/- S.D.; 34.5 +/- 13.8%) was significantly lower than that of non-conception group (42.3 +/- 13.3%, P = 0.017). CONCLUSIONS: Our finding suggests that elevated peripheral NK activity in patients with unexplained infertility is a risk factor for attaining pregnancy success.     

Offer and demand: proliferation and survival of neurons in the dentate gyrus

The proliferation and survival of new cells in the dentate gyrus of mammals is a complex process that is subject to numerous influences, presenting a confusing picture. We suggest regarding these processes on the level of small networks, which can be simulated in silico and which illustrate in a nutshell the influences that proliferating cells exert on plasticity and the conditions they require for survival. Beyond the insights gained by this consideration, we review the available literature on factors that regulate cell proliferation and neurogenesis in the dentate gyrus in vivo. It turns out that the rate of cell proliferation and excitatory afferents via the perforant path interactively determine cell survival, such that the best network stability is achieved when either of the two is increased whereas concurrent activation of the two factors lowers cell survival rates. Consequently, the mitotic activity is regulated by systemic parameters in compliance with the hippocampal network's requirements. The resulting neurogenesis, in contrast, depends on local factors, i.e. the activity flow within the network. In the process of cell differentiation and survival, each cell's spectrum of afferent and efferent connections decides whether it will integrate into the network or undergo apoptosis, and it is the current neuronal activity which determines the synaptic spectrum. We believe that this framework will help explain the biology of dentate cell proliferation and provide a basis for future research hypotheses.     

Glycinergic neurons expressing enhanced green fluorescent protein in bacterial artificial chromosome transgenic mice

Although glycine is a major inhibitory transmitter in the mammalian CNS, the role of glycinergic neurons in defined neuronal circuits remains ill defined. This is due in part to difficulties in identifying these cells in living slice preparations for electrophysiological recordings and visualizing their axonal projections. To facilitate the morphological and functional analysis of glycinergic neurons, we generated bacterial artificial chromosome (BAC) transgenic mice, which specifically express enhanced green fluorescent protein (EGFP) under the control of the promotor of the glycine transporter (GlyT) 2 gene, which is a reliable marker for glycinergic neurons. Neurons expressing GlyT2-EGFP were intensely fluorescent, and their dendrites and axons could be visualized in great detail. Numerous positive neurons were detected in the spinal cord, brainstem, and cerebellum. The hypothalamus, intralaminar nuclei of the thalamus, and basal forebrain also received a dense GlyT2-EGFP innervation, whereas in the olfactory bulb, striatum, neocortex, hippocampus, and amygdala positive fibers were much less abundant. No GlyT2-EGFP-positive cell bodies were seen in the forebrain. On the subcellular level, GlyT2-EGFP fluorescence was colocalized extensively with glycine immunoreactivity in somata and dendrites and with both glycine and GlyT2 immunoreactivity in axon terminals, as shown by triple staining at all levels of the neuraxis, confirming the selective expression of the transgene in glycinergic neurons. In slice preparations of the spinal cord, no difference between the functional properties of EGFP-positive and negative neurons could be detected, confirming the utility of visually identifying glycinergic neurons to investigate their functional role in electrophysiological studies.