Laparoscopic donor nephrectomy: an increasingly common cause for testicular pain and swelling

INTRODUCTION

Laparoscopic donor nephrectomy (LDN) is now a well established method for kidney procurement from living donors. In our centre, LDN is currently offered only to donors suitable for a left nephrectomy. The aim of this study was to investigate the incidence of testicular pain and swelling following LDN.

METHODS

A total of 25 left-sided LDN male patients were assessed in a prospective structured interview together with a control cohort of 25 male patients who had undergone left-sided open donor nephrectomy (ODN).

RESULTS

Data were collected on testicular pain, swelling, numbness, urinary symptoms and sexual dysfunction from all 50 patients (100% response rate). Of the 25 LDN patients, 11 (44%) experienced ipsilateral testicular pain and/or swelling. In most instances, pain was of immediate onset, mild to moderate in severity, lasted for a few days to several weeks and was associated with testicular swelling (10 of 11 cases). However, testicular pain and/or swelling were not apparent in ODN patients, with only 2 of 25 (8%) experiencing mild testicular pain, 1 of whom also had swelling.

CONCLUSIONS

Testicular pain and swelling following LDN is a common problem. It is underreported in the literature and should be included in the differential diagnoses of testicular pain and swelling. Further investigation is required to confirm our findings.

The efficacy of a range of contact media as coupling agents in extracorporeal shockwave lithotripsy

OBJECTIVE

To determine if the nature of the coupling agent normally used between the lithotripter and the patient affects the stone fragmentation rate during extracorporeal shock wave lithotripsy.

MATERIALS AND METHODS

A jig designed to hold 'phantom' 10-mm stones at the focal point was fixed against the shock wave delivery point of an electromagnetic lithotripter (Dornier Compact, Germany). A layer of either petroleum jelly (Vaseline, Cheeseborough-Ponds Ltd, London, UK) ultrasonography jelly, a eutectic mixture of local anaesthetic (EMLA) cream, Instillagel (Farco-Pharma, Cologne, Germany) or a commercial water-soluble lubricating jelly was placed between the jig and shockwave head, and the number of shock waves required to fragment the stones was recorded.

RESULTS

Significantly more shock waves were required to fragment stones when petroleum jelly was used as the coupling agent than with all the other agents under test, whereas significantly fewer shock waves were required when using Instillagel or lubricating jelly than for all other agents.

CONCLUSION

The coupling agent used in water-free lithotripsy can affect the stone fragmentation rate and should not be considered inert. Ultrasonography jelly is probably the optimum agent available for use as a lithotripsy coupling agent.

The interaction of nitric oxide and prostaglandins in the control of corporal smooth muscle tone: evidence for production of a cyclooxygenase-derived endothelium-contracting factor

OBJECTIVE

To investigate the interaction of endothelium-derived nitric oxide (NO) and prostaglandins (PGs) in regulating corporal smooth muscle tone in vitro. Materials and methods Strips of rabbit corpus cavernosum were mounted in organ chambers for the measurement of isometric tension. Strips were submaximally contracted with noradrenaline and concentration-response curves (CRCs) to acetylcholine (ACh) were constructed before and after treatment with 5 micromol/L atropine, 20 micromol of the cyclooxygenase inhibitor indomethacin and 10 micromol of the PGH2/thromboxane A2 receptor antagonist SQ29548. The NO synthase (NOS) inhibitors L-NG-monomethyl arginine (L-NMMA) and L-NG-nitroarginine (L-NOARG) were added to strips at tonic tension in the presence and absence of indomethacin, and after this CRCs to ACh were constructed.

RESULTS

The addition of ACh to strips produced a concentration-dependent relaxation which was inhibited by atropine. Indomethacin, but not SQ29548, significantly increased relaxation to ACh. Relaxation to ACh was impaired by L-NMMA, but adding ACh to strips treated with L-NOARG resulted in contractile responses, whilst both effects were reversed by indomethacin. L-NMMA and L-NOARG led to increases in tonic tone which were unaffected by indomethacin.

CONCLUSIONS

In rabbit corpus cavernosum there is a tonic release of NO which does not appear to be inhibited by a vasoconstrictor prostanoid. Endothelium-dependent relaxation to ACh results in the dual production of NO and a cyclooxygenase-derived endothelium contracting factor which acts in opposition to NO; this factor is unlikely to act on PGH2/TXA2 receptors.

Nitric oxide-mediated corpus cavernosal smooth muscle relaxation is impaired in ageing and diabetes

OBJECTIVE

To examine nitric-oxide (NO)-mediated relaxation in cavernosal smooth muscle in a rat model of diabetes, as previous experiments showed that HbA1c (an isoform of glycosylated haemoglobin and a marker of long-term diabetic control) impaired NO-mediated relaxation of normal corpus cavernosal tissue through the generation of superoxide anions.

MATERIALS AND METHODS

Eight weeks after the induction of diabetes, male Wistar rats were killed and cavernosal tissue obtained. Strips were contracted with 1 micromol/L noradrenaline before applying acetylcholine or electrical field stimulation (EFS) or sodium nitroprusside (SNP). Relaxation responses were repeated in the presence of L-arginine (100 micromol/L), indomethacin (10 micromol/L) or superoxide dismutase (SOD, 120 IU/mL). Young and age-matched control animals were examined in the same way.

RESULTS

Eight weeks of uncontrolled diabetes caused a significant impairment in mean relaxation responses to acetylcholine (P < 0.05) and to EFS (P < 0.05), but not to SNP, compared with young and age-matched controls, respectively. L-arginine, indomethacin and SOD had no significant effect on this impairment. Ageing caused a lesser but significant impairment in EFS-mediated cavernosal smooth muscle relaxation (P < 0.05).

CONCLUSION

Diabetes impairs endothelial and neuronal NO-mediated cavernosal smooth muscle relaxation in rats in vitro. This effect is not mediated by an alteration in the intracellular action of NO, the availability of NO, superoxide anion inactivation of NO or the generation of constrictor prostanoids. It is possible that cholesterol or advanced glycation end products are responsible for the effect of diabetes on penile smooth function.

Advanced glycation end-products are responsible for the impairment of corpus cavernosal smooth muscle relaxation seen in diabetes

OBJECTIVE

To determine if advanced glycation end-products (AGEs) are responsible for the lower neuronal and endothelial-derived nitric oxide (NO)-mediated relaxation of corpus cavernosum in tissue in diabetic rats than in control rats.

MATERIALS AND METHODS

Diabetes was induced in male Wistar rats by an intraperitoneal injection with streptozotocin (60 mg/kg). One group of diabetic rats was given free access to water and standard diet. A second group was given standard diet and aminoguanidine with their water (50 mg/100 mL) from the initiation of diabetes. Two groups of rats that were not diabetic acted as age-matched controls. After 8 weeks animals were killed by cervical dislocation, corpus cavernosal tissue strips harvested and mounted in an organ bath to measure isometric tension. After 90 min of equilibration at optimal resting tension and contraction with 1 micromol/L noradrenaline, the response to either acetylcholine or electrical field stimulation (EFS) after adding guanethidine (5 micromol/L) and atropine (1 micromol/L) was determined for each group.

RESULTS

There was no difference between the baseline characteristics of all the experimental groups. After 8 weeks the mean body mass and glycosylated haemoglobin (HbA1c) were significantly greater in the diabetic than in control animals. Aminoguanidine had no effect on the recorded body mass or HbA1c. The in vitro relaxation response to the application of acetylcholine or EFS of tissue strips from age-matched control animals fed a standard diet and those supplemented with aminoguanidine were the same. The administration of aminoguanidine to diabetic animals for 8 weeks reversed the expected impaired relaxation response to acetylcholine; the response to EFS was similar.

CONCLUSION

AGEs are more prevalent in erectile tissue from diabetic than in control animals. Aminoguanidine reversed the impairment in neuronal and endothelial NO-mediated penile smooth muscle relaxation seen in diabetes. As aminoguanidine prevents AGE formation, erectile dysfunction in diabetes is probably caused partly by the generation of AGEs.

Endothelial and neuronal-derived nitric oxide mediated relaxation of corpus cavernosal smooth muscle in a rat, in vitro, model of erectile function

We set out to establish a simple, reproducible, rat in vitro model of erectile function and to use this to demonstrate the functional importance of both neuronal- and endothelial-derived nitric oxide within this animal. Two corpora cavernosal smooth muscle strips were harvested from sexually mature male Wistar rats and mounted in an organ bath for measurement of isometric tension. Following contraction with noradrenaline the strips were relaxed by the addition of either acetylcholine or sodium nitroprusside. Electrical field stimulation was performed in the presence of atropine and guanethidine. Relaxation responses were repeated in the presence of methylene blue, L-arginine, L-NNA and haemoglobin +/- L-arginine. Methylene blue abolishes the relaxation to acetylcholine and EFS; L-NNA and haemoglobin cause a significant impairment in the relaxation response. L-arginine reverses the effect of haemoglobin. In conclusion, the inhibitory, relaxant stimulus of rat corpora cavernosa is due to both neuronal nitric oxide and endothelial-derived nitric oxide released in response to cholinergic stimulation.

Impairment of corpus cavernosal smooth muscle relaxation by glycosylated human haemoglobin

OBJECTIVE

To examine the effect of HbA1c, an isoform of glycosylated haemoglobin (GHb, a product of non-enzymatic reactions between elevated blood glucose and haemoglobin), on nitric oxide-mediated corpus cavernosal smooth muscle relaxation, and to categorize the mechanisms involved.

MATERIALS AND METHODS

Corpus cavernosal tissue from Wistar rats (300-350 g body weight) was prepared for the measurement of isometric tension. After equilibration in Krebs solution gassed with 95% O2/5% CO2 at 37 degrees C for 90 min, optimal resting tension was applied. Tissue was precontracted with 1 micromol/L noradrenaline (NAd) and either relaxed with incremental doses of acetylcholine (ACh) or sodium nitroprusside (SNP). After washout, strips were again precontracted with NAd and then incubated with pyrogallol (100 micromol/L), 100 microL of haemoglobin or 100 microL of GHb in the presence of either L-arginine (100 micromol/L), indomethacin (10 micromol/L), allopurinol (100 micromol/L), deferoxamine (100 micromol/L), catalase (600 IU/mL), or superoxide dismutase (SOD) (120 IU/mL) before ACh- or SNP-induced relaxation responses were repeated.

RESULTS

Haemoglobin and GHb significantly impaired the relaxation of rat corpus cavernosum to ACh in a dose-dependent manner. L-arginine reversed the impairment caused by Hb, but not GHb. A donor of superoxide anions, pyrogallol, mimicked this impairment to ACh when added to control strips. Catalase, deferoxamine, indomethacin and allopurinol had no significant effect on the impaired relaxation response to ACh, whilst L-arginine partially reversed it. SOD completely reversed the GHb-induced impaired relaxation; GHb did not alter the relaxation response to SNP.

CONCLUSION

GHb significantly impairs endothelial NO-mediated corpus cavernosal relaxation in the rat, in vitro. This effect is caused partly by the generation of superoxide anions and the extracellular inactivation of NO.

A randomized double-blind placebo-controlled crossover trial of the efficacy of L-arginine in the treatment of interstitial cystitis

OBJECTIVES

To determine, in a double-blind placebo-controlled crossover study, whether L-arginine improves the symptoms of interstitial cystitis (IC), a chronic condition in which nitric oxide (NO) may be important, as previous open pilot studies suggested that L-arginine reduced the pain and frequency associated with IC.

PATIENTS AND METHODS

Patients fulfilling the standard diagnostic criteria for IC were randomized to receive L-arginine (2.4 g/day) or placebo for one month. After a 2-week 'washout' period they received the other medication. Patients were assessed at each stage using a validated symptom index, a voiding diary, urine analysis and records of adverse events. Patients were asked about overall efficacy at the close of the study. The results were compared using a t-test, with significance indicated at P<0.05.

RESULTS

Sixteen (16) patients (mean age 51.3 years) were enrolled; the mean duration of IC was 5.4 years, the IC symptom index score 29.1, their nocturnal frequency 3.5 (voided volume 182 mL) and daytime frequency 12.7 (124 mL). Patients on placebo showed no differences in any recorded variable over the baseline values. L-arginine caused a statistically significant reduction in the overall symptom score of 2.2 over baseline, but there was no difference in voided volume, frequency or nocturia. As there was no significant difference for any variable between L-arginine and placebo, this reduction in score should be regarded with caution. Three patients withdrew because of side-effects (severe headaches, night sweats and flushing).

CONCLUSION

Oral L-arginine produces a statistically significant improvement in the IC symptom index in patients with IC, but the effect is small. This effect may not be clinically significant as there were no improvements in the other variables assessed and no significant difference between the response to L-arginine and placebo. From these results the use of L-arginine cannot be recommended for treating IC.

The stability of free and bound prostate-specific antigen

OBJECTIVE

To determine if the assay for free prostate specific antigen (fPSA) and the calculated ratio of fPSA to total PSA (f/tPSA) is stable in conditions likely to be met in routine clinical practice.

MATERIALS AND METHODS

Two blood samples were obtained from 27 patients attending a routine urology clinic. Sample 1 was centrifuged immediately, assayed for fPSA and tPSA, and the f/tPSA calculated. This sample was then stored at 4 degrees C for 24 h, 48 h and 1 week, or at -20 degrees C for 24 h, 1 week and 1 month before the assays for fPSA and tPSA were repeated. The second sample was left at room temperature for 24 h before assay and processing, as for sample 1.

RESULTS

tPSA is a highly stable analyte; if whole blood samples are processed immediately, fPSA is stable for 24 h at 4 degrees C and 1 month at -20 degrees C. There was a significant reduction in the calculated f/tPSA in samples stored for >/=24 h at 4 degrees C (P<0.01); if the sample was stored at -20 degrees C the calculated f/tPSA was stable. After 24 h storage at room temperature, fPSA decreased by 6.3% and f/tPSA by 6.4%. Subsequent storage of serum at 4 degrees C for 1 week resulted in a 25% decrease from the baseline value. After 1 month at -20 degrees C the fPSA value was 13% lower than the baseline value.

CONCLUSION

These results indicate that if there is to be confidence in the accuracy of the f/tPSA value, then blood samples must be handled and processed correctly. Total PSA is sufficiently stable to permit whole blood samples to remain at room temperature for 24 h before serum is separated. If fPSA is to be determined accurately then the whole blood sample must be centrifuged promptly. As the fPSA values in blood samples left at room temperature for 24 h are up to 25% lower than those on immediate assay, and the subsequent f/tPSA 29% lower, then for the optimum use of this test, these samples should also be handled appropriately.