Genetic structure of northwestern Spanish brown trout (Salmo trutta L.) populations, differences between microsatellite and allozyme loci

Genetic variation in nine wild brown trout (Salmo trutta L.) populations was studied by means of allozyme and microsatellite markers. All brown trout populations were clearly separated into two clusters that represented the Sil and Duero basins. Although both markers revealed a strong genetic differentiation between basins, microsatellite loci resulted much more accurate when population structure at the intrabasin level was analysed. Also pairwise multilocus FST estimates and assignment tests of individual fish to the set of sampled populations demonstrated a much higher efficiency of microsatellites compared to allozymes. The analysis of both markers provides new insights in defining the conservation units at this local area and confirms the existence of a recognized sub-lineage in the Duero basin. The management implications of these findings are discussed and changes in trout release activity are recommended to avoid mixing of trout gene pools mainly in the Sil basin.

Prostate brachytherapy--the community hospital experience

One of the options for treating localized carcinoma of the prostate includes the implantation of radioactive seeds under ultrasound guidance (brachytherapy). A community hospital-based prostate brachytherapy program was started in 1992. The overall survival and disease-free survival figures for the initial 100 patients treated in this program seem comparable to patients treated by radical prostatectomy or brachytherapy in larger series. The main side effects of brachytherapy included nocturia, daytime urinary frequency, dysuria, and proctitis. These side effects were transient and decreased to less than 10% by 12 to 24 months following implantation. Prostate brachytherapy can be effectively and safely provided in a community hospital setting.

A new temporary catheter (ContiCath) for the treatment of temporary, reversible, postoperative urinary retention

OBJECTIVES

To describe the initial experience of a newly designed temporary urethral catheter, ContiCath, as an aid in the management of postoperative or temporary outflow obstruction. In patients with normal detrusor and sphincter function, this catheter allows volitional voiding while maintaining an open prostatic urethra.

METHODS

In a pilot study, 64 nonconsecutive patients with postoperative or temporary urinary retention, at eight clinical trial sites, were enrolled for the placement of this temporary catheter. Three patients did not have the catheter placed because of placement failure because of either a large median lobe or a urethral stricture. The remaining 61 patients were divided into three groups: those with non-neuropathic causes of retention and retention for 1 week or less (37 patients), those with non-neuropathic causes of retention and retention for longer than 1 week (19 patients), and those with neuropathic causes of retention and retention for longer than 1 week (5 patients). The ContiCath is placed in the office setting, in the same fashion as a Foley catheter. A blue prolene tether extends from the bulbar urethra to the meatus to assist in the removal of the device. Patients were then reassessed at 3 hours, and at 7, 14, 21, and 28 days, at which point the device was removed.

RESULTS

In patients with a neuropathic cause for their retention (5 patients) and those with non-neuropathic causes of retention and retention for longer than 1 week (19 patients), only 3 patients were able to void after the catheter was placed. Of the 37 patients with a non-neuropathic cause and retention 1 week or less, controlled voiding was seen in 33 patients (89%). Controlled voiding was defined as the patient's volitional ability to initiate and stop his urinary stream. There were no complications with catheter placement; however, 8 patients (24.2%) had minor adverse experiences of frequency/urgency (n = 3), incontinence (n = 3), migration of the catheter (n = 1), and pain (n = 1).

CONCLUSIONS

ContiCath offers an alternative to an indwelling Foley catheter in men with temporary bladder outlet obstruction and urinary retention.

Uncommon complications of permanent stents

The UroLume endoprosthesis has been used for recurrent bulbar urethral strictures, benign prostatic hyperplasia, and detrusor-external sphincter dyssynergia. Complications of the UroLume have been described by the North American Multicenter Trial as migration, encrustation, hyperplastic tissue growth, in addition to pain and irritative voiding symptoms. Generally, complications have been minimal, and few of the stents required removal. Patients with bulbar strictures were felt to be at relatively greater risk of hyperplastic tissue reaction if their stricture was secondary to trauma or if they had a prior urethroplasty. On the other hand, patients with benign prostatic hyperplasia were at risk of developing complications if they had median lobe enlargement or a short (<2.5 cm) prostatic urethra. We describe two cases in which off-label compassionate use of UroLumes in the anterior urethra and in an irradiated urethra led to adverse reactions such as stent separation, poor epithelialization, hyperplastic tissue growth, encrustation, or obstruction necessitating removal.

Epithelialization of permanent stents

The permanent Urolume Wallstent has been used for the relief of bladder outlet obstruction (BOO), detrusor-external sphincter dyssnergia (DESD), and recurrent bulbar urethral strictures. Because of its woven construction, it allows ingrowth of urothelial tissue, resulting in complete epithelialization by 6 to 12 months. Certain risk factors are associated with poor epithelialization that may lead to hyperplastic tissue growth and occlusion of the urethral lumen. We review the literature and discuss the 5-year results of the North American Multicenter Urolume Trial with regard to epithelialization, hyperplastic tissue growth, and treatment of hyperplastic growth.

Dopaminergic influence on the cardiovascular response to exercise in normotensive and hypertensive subjects

Fourteen subjects (normotensive, hypertensive) were studied at the Vargas Hospital of Caracas. They were treated with placebo (2 periods), domperidone, a peripheral dopaminergic blocker, at the daily oral dose of 40 mg, and metoclopramide, a central and peripheral dopaminergic blocker, at the daily oral dose of 40 mg. All placebo and active drug periods lasted 1 week. Cardiovascular hemodynamic parameters (blood pressure, heart rate) were measured before, during and after submitting subjects to treadmill exercise according to the Bruce's protocol. Metoclopramide decreased significantly heart rate before and during exercise stress and systolic blood pressure during stage 1 exercise in normotensive subjects. Domperidone decreased significantly heart rate before and during exercise stress, and systolic blood pressure during stage 3 exercise in hypertensive subjects. Neither heart rate nor blood pressure were changed significantly after 8 minutes resting period post exercise. Our results suggest the existence of an excitatory modulatory influence of dopaminergic influence during exercise over the sympathetic activity.