Epinephrine reduces the severity of catheter-induced urethral inflammation by action at the alpha 2-adrenoceptors.

We have studied the contribution of epinephrine to experimentally induced urethral inflammation in the rat. Inflammation was induced by inserting latex strips into the urethra. The effects of various experimental procedures were assessed according to a 4-point scale based on histological findings. The results showed that 0.5 mg/kg epinephrine decreased the severity of catheter-induced urethral inflammation. This effect was blocked by the alpha 2-adrenergic agonist, yohimbine, but not by alpha 1 (prazosin), beta 1 (M32 MTC), or beta 2 (butoxamine) antagonists. The results suggest that the suppressive effect of epinephrine is mediated by action at the alpha 2 adrenergic receptor.

Interstitial cystitis: correlation with nerve fibres, mast cells and histamine.

Interstitial cystitis (IC) is a painful condition in the urinary bladder of unknown aetiology and pathogenesis. To assess the contribution of the nervous system to IC a biopsy was taken from 6 patients with IC and from a control group of 6 patients with non-ulcerative IC. Mast cells were counted and histamine measured in bladder washings from all patients. There were significantly more nerve fibres within the sub-urothelium and detrusor muscle in chronic IC than there were in non-ulcerative IC. The bladder washings from all patients with IC contained mast cells and histamine, while only occasional mast cells and traces of histamine were found in washings from patients with non-ulcerative IC. There was a good correlation between the number of nerve fibres and number of mast cells as well as between the number of nerve fibres and the amount of histamine.

The contribution of epinephrine to experimentally induced urethral inflammation in the rat.

We have studied the effect of the adrenal medulla and epinephrine on experimentally induced urethral inflammation in the rat. Urethral inflammation was induced by inserting latex strips into the urethra. The effects of different experimental procedures were assessed by using a 4-graded inflammation scale based on histological findings. Adrenal medullectomy significantly reduced experimentally induced urethral inflammation. This effect was reversed if the rats were treated repeatedly with epinephrine or salbutamol. On the other hand high doses of epinephrine reduced the experimentally induced urethral inflammation.

The role of sensory nerves in catheter-induced urethral inflammation.

We have studied the contribution of the nervous system on experimentally induced urethral inflammation in the rat. Urethral inflammation was produced by inserting latex strips into the urethra. The effects of different experimental procedures were assessed by using a 4-grade inflammation scale based on histological findings. Attenuation of urethral inflammation was produced by administration of capsaicin at birth. A more complete attenuation was produced by infusion of capsaicin prior to application of the latex strip. These data taken together indicate that sensory innervation of the urethral mucosa is involved in the inflammatory reaction and that infusion of the urethra with capsaicin may be tried to prevent catheter-induced urethral inflammation.

Role of the autonomic nervous system in catheter-induced urethral inflammation.

We have studied role of the autonomic nervous system on experimentally induced urethral inflammation in the rat. Urethral inflammation was produced by inserting latex strips into the urethra. The effects of different experimental procedures were assessed by using a 4-grade inflammation scale based on histological findings. Rats pretreated with the nonspecific catecholamine depletors reserpine or quanethidine had a significantly less severe urethral inflammation than vehicle-treated controls. The severity of urethral inflammation was increased in spontaneous hypertensive rats, which have an increased sympathetic tone as compared to the normotensive rats. Propranolol, a nonselective beta-adrenergic receptor antagonist reduced and butoxamine, a beta 2-antagonist, significantly reduced the urethral inflammation. Neither phenoxybenzamine (nonselective) nor prazosin (alpha 1) or yohimbine (alpha 2), alpha-adrenergic receptor antagonists, affected the degree of urethral inflammation. These data taken together indicate that the autonomic innervation of the urethral mucosa is critically involved in the inflammatory reaction and that the use of beta 2-antagonist may be a treatment alternative in the future for the treatment of catheter-induced inflammation.

Influence of the nervous system on experimentally induced urethral inflammation.

We have studied the contribution of the nervous system on experimentally induced urethral inflammation in the rat. Urethral inflammation was induced by inserting latex strips into the urethra. The effects of different experimental procedures was assessed by using a 4-graded inflammation scale based on the histological findings. Attenuation of urethral inflammation was produced by administration of capsaicin at birth. A more complete attenuation was produced by sympathectomy prior to application of the latex strip. Urethral inflammation was also severe in the spontaneous hypertensive rat. Injection of morphine into the third ventricle of the brain significantly reduced the experimentally induced urethral inflammation. These data taken together indicate that the sensory and postganglionic innervation of the urethral mucosa as well as the central nervous system is critically involved in the inflammatory reaction of the urethra following exposure to latex strips.

Silver alloy coated catheters reduce catheter-associated bacteriuria.

The tendency of indwelling catheters to cause urinary tract infection was evaluated in a randomised clinical study of 223 patients. A Foley catheter coated with silver alloy on both inner and outer surfaces was used in 60 patients; 60 others received a Teflonised latex Foley's catheter and the remaining 103 patients were excluded because of antibiotic treatment, diabetes, etc. There was a statistically significant difference in the incidence of catheter-associated bacteriuria (greater than 10(5) organisms/ml) in the 2 groups after 6 days' catheterisation: 6 patients with the silver coated catheter developed bacteriuria compared with 22 who had the Teflonised latex catheter. This suggests that the silver impregnated urethral catheters reduce the incidence of catheter-associated urinary tract infection.

Refinements in the coating of urethral catheters reduces the incidence of catheter-associated bacteriuria. An experimental and clinical study.

The tendency to develop bacteriuria during the use of various forms of indwelling catheters was evaluated in a randomized trial in 90 patients. A silver alloy and hydrogel-coated Foley catheter (SHC) was compared to a non-coated catheter (NC) and a catheter coated only with hydrogel (HC). Three patients (10%) with SHC catheters, 10 (33%) patients with HC catheters, and 15 (50%) patients with NC catheters developed bacteriuria (greater than 10(5) organisms/ml). The difference in the rate of bacteriuria after 5 days of catheterization was statistically significant between the SHC catheter and the NC catheter (p less than 0.002). There was no significant difference between the SHC catheter and the HC catheter, nor was there a significant difference between the HC catheter and the NC catheter. The toxic effects, as estimated by the IC50 value, of the urinary catheter material used was elucidated in an experimental fibroblast model. The IC50 value for the NC catheter was 33.9%, HC catheter 72.2% and for the SHC catheter 98.1%.

Pseudomonas aeruginosa: adherence to and growth on different urinary catheter coatings.

Discs of urinary catheters with different coatings were exposed to a flow of artificial urine containing cells of Pseudomonas aeruginosa. Within 10 h an adherent biofilm consisting of the bacteria and their exopolysaccharide products had developed on those discs coated with latex, teflon, and silicon. In contrast, on the silver alloy-coated catheter discs no biofilm of Pseudomonas aeruginosa had developed.

Silver coating of urinary catheters prevents adherence and growth of Pseudomonas aeruginosa.

Discs of urinary catheter material were exposed to the flow of artificial urine containing cells of Pseudomonas aeruginosa. Within 10 h an adherent biofilm composed of the bacteria and of their exopolysaccharide products had developed on the uncoated catheter material. On the silver-coated catheter material no biofilm of Pseudomonas aeruginosa had developed.

Catheter induced urethral inflammatory reaction and urinary tract infection. An experimental and clinical study.

Urinary tract infections accounts for over 40% of all nosocomial infections, and almost all these infections are associated with indwelling catheters. The acquisition of urinary tract infections following urinary bladder catheterizations are associated with nearly a threefold increase in mortality among hospitalized patients. The economic impact of nosocomial urinary infections is difficult to assess. An estimate of the cost of these infections have shown that patients with hospital-acquired urinary tract infections secondary to indwelling catheters, spent an average of 2.4 additional days in the hospital. Bearing this in mind, even a marginal decrease in urinary tract infections may be cost-effective. In two randomized prospective clinical studies we have shown that coating urinary catheters with silver significantly reduces the infection rate during short-term catheterization (less than 7 days). We also showed that silver coating of urinary catheters prevented adherence and growth of Pseudomonas aeruginosa on the catheter material. Another risk from using indwelling catheters is an inflammatory reaction of the urethral mucosa leading to stricture formation. Several aetiological factors whereby indwelling catheters may cause a urethral stricture have been discussed. During the last years much attention has been paid to the catheter material as such, especially latex, and its role in stricture formation. Urinary catheters are made from a variety of materials combined with different chemicals. It seems as if these chemical substances can dissolve from the catheter material, causing inflammatory reactions. Using a cell culture technique with a mouse fibroblast cell line (BALBc/3T3), and an animal model with implantation of catheter material into the urethra, we assessed both in vitro cytotoxicity (IC50) and inflammatory reactions in vivo from different catheter materials. The studies confirmed that especially latex materials do not have both cytotoxic effects and cause considerable inflammation within the urethral mucosa. By coating the catheters with silver, the cytotoxicity could be significantly reduced as compared with pure latex and hydrogel coated latex catheters. Several studies have demonstrated a cytotoxic effect from catheter materials, indicating that this may be of importance in urethral inflammation. However, the exact mechanisms behind this phenomenon is not known. In an attempt to explain the inflammatory reaction within the urethra secondary to an indwelling catheter, we investigated the influence of the nervous system on experimentally induced urethral inflammation. Our findings indicate that an important part in catheter induced inflammation is played by neurogenic reactions.

Assessment of silver-coated urinary catheter toxicity by cell culture.

The toxicity of silver-coated urinary catheters was assessed using a cell culture technique. The inhibitory effect of catheter extracts on the uptake of 3H-labelled thymidine by mouse fibroblasts was measured. The results show that silver-coating had no toxic effect whereas silvernitrate and silversulphate coating did have a toxic effect.

Calf muscle atrophy and muscle function after non-operative vs operative treatment of achilles tendon ruptures.

Fifteen operatively and eight non-operatively treated subcutaneous achilles tendon ruptures were randomly selected from 120 surgically and 35 non-surgically treated patients. Their calf muscle function was studied three to five years after treatment. Non-operatively treated patients were found to have a significantly impaired dynamic muscle function of the calf muscles when tested in a specially constructed heel-raise test device. Operatively treated patients did not show any significant impairment of their muscle function. Measurement of muscle area with CT-scanning showed a significant reduction of the calf muscle in the non-operatively treated patient while no such difference could be found in the operatively treated patients. Isokinetic muscle torque did not differ in the two groups of patients, thus Cybex-measurements do not seem to be a discriminating method in studying muscle function after achilles ruptures. On the basis of our findings we recommend that all athletes with achilles tendon ruptures be treated surgically. In non-athletes and older patients non-operative treatment might be considered.