Chonghe Jiang

Intravesical Electrical Stimulation—An Experimental Analysis of The Mechanism of Action

The working mechanism of intravesical electrical stimulation (IVES) was evaluated in alpha-chloralose anaesthetized cats and rats. IVES involved a direct activation of bladder mechanoreceptor afferents of the A delta type and as a consequence a central reflex activation of the detrusor. The detrusor response was abolished by bilateral transection of the S1-S3 dorsal roots and by intravesical instillation of lidocaine. The optimal stimulation frequency was 20 Hz. The results offer a theoretical rationale for the use of IVES as treatment of weak detrusor contractility in man.

The C fibre reflex of the cat urinary bladder

1 Reflexes evoked in bladder parasympathetic neurones by electrical stimulation of bladder C afferent fibres were studied in cats anaesthetized with α‐chloralose. The responses were compared with the ordinary micturition reflex evoked by low‐threshold Aδ afferents from bladder mechanoreceptors and mediated by a spino‐ponto‐spinal reflex pathway. 2 The bladder was catheterized for fluid instillations and pressure recordings. Efferent reflex discharges were recorded from the cut central end of a small distal bladder branch of the pelvic nerve. The remaining bladder pelvic nerve branches were stimulated electrically close to the bladder. 3 Stimulation at C afferent intensity evoked a late reflex discharge in bladder pelvic efferents in all animals. The response was centrally mediated, had a latency of 150−250 ms, and was much weaker after stimulation on the contralateral nerve. 4 The bladder C fibre reflex differed in several functional aspects from the ordinary Aδ micturition reflex. It could be evoked at a low rate of stimulation, with an empty bladder and no background activity from bladder mechanoreceptors. In this situation, the normal Aδ micturition reflex is not elicited. The C fibre reflex also survived an acute spinalization at a low thoracic level. 5 The C fibre reflex was strongly inhibited by dorsal clitoris or dorsal penis nerve stimulation, an effect that was maintained after spinalization. It was facilitated by bladder or urethra exposure to cold and menthol, stimuli that activate specific cold‐sensitive receptors associated with unmyelinated C afferents. 6 It is concluded that the central pathway of the C fibre reflex is spinal and partly separate from that of the ordinary micturition reflex. These observations are in keeping with the clinical finding that a bladder cooling reflex can be elicited in patients with disturbed descending control of the bladder.

Comparison of experimental nerve injury caused by ultrasonically activated scalpel and electrosurgery

Iatrogenic nerve injury caused by heat from dissection instruments is a significant problem in many areas of surgery. The aim of the present study was to compare the risk of nerve injury for three different dissection instruments: monopolar and bipolar electrosurgery (ES) and an ultrasonically activated (US) instrument.

Comparison of lycopene and fluvastatin effects on atherosclerosis induced by a high-fat diet in rabbits

OBJECTIVE We evaluated the antiatherogenic effect of lycopene in rabbits fed a high-fat diet. METHODS Forty adult male rabbits were divided into five groups that were fed a standard diet, a high-fat diet, a high-fat diet plus 4 mg/kg of lycopene, a high-fat diet plus 12 mg/kg of lycopene, and a high-fat diet plus 10 mg/kg of fluvastatin, respectively. Lycopene and fluvastatin were administered intragastrically. The level of serum total cholesterol, total triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total antioxidant capacity, and malondialdehyde were measured before and after 4 and 8 wk of experimental treatment. In addition, plasma levels of lycopene, oxidized low-density lipoprotein, serum nitric oxide, and interleukin-1 were measured after the experiment. The area of atherosclerotic plaque and pathologic changes of the aorta were evaluated. RESULTS Compared with the control, levels of total cholesterol, total triacylglycerol, low-density lipoprotein cholesterol, malonaldehyde, oxidized low-density lipoprotein, and interleukin-1 were increased and total antioxidant capacity and nitric oxide were decreased in the animals with a high-fat diet (P < 0.05). Intragastric administration of lycopene counteracted the change in these parameters (P < 0.05). In this case, the data showed that lycopene in the used dose was better than the fluvastatin intervention. Morphologic analysis revealed that lycopene and fluvastatin markedly reduced the formation of atherosclerotic plaques in the aorta compared with the situation in rabbits on a high-fat diet alone. CONCLUSION Lycopene, like fluvastatin, significantly attenuated atherogenesis in rabbits fed a high-fat diet.

Prolonged increase in micturition threshold volume by anogenital afferent stimulation in the rat

To determine whether induced bladder contractions influence the modulation by intravesical electrical stimulation (IVES) of the micturition reflex in anaesthetized rats, and to identify the optimal IVES frequency and duration.

Modulation of the micturition reflex pathway by intravesical electrical stimulation: An experimental study in the rat

Intravesical electrical stimulation (IVES) is used clinically to improve bladder evacuation in patients with inadequate micturition contractions. The procedure involves field stimulation of Aδ bladder mechanoreceptor afferents resulting in a prolonged enhancement of the micturition reflex. The aim of the present experimental study in the rat was to identify the site for this neuromodulation, whether it was due to sensitization of bladder mechanoreceptors, to enhancement of transmission in the central micturition reflex pathway, or to improved effectiveness of the peripheral motor system of the bladder. The experiments were performed on female rats, anesthetized by α‐chloralose. Multi‐unit afferent or efferent activity was recorded from bladder pelvic nerve branches during repeated cystometries before and after IVES. The specific antagonist CPPene was used to block central glutaminergic receptors of NMDA type. Micturition threshold volume decreased significantly after IVES. The afferent threshold volume, peak response, and pressure sensitivity were unchanged as were the peak efferent activity and bladder contractility. There was no efferent activity until just before the micturition contraction. The IVES‐induced decrease in micturition threshold was blocked by prior administration of the NMDA (N‐methyl‐d‐aspartic acid) antagonist CPPene (3‐(2‐carboxypiperazin‐4‐yl)‐1‐propenyl‐1‐phosphonic acid). The findings indicate that the IVES‐induced modulation of the micturition reflex is due to an enhanced excitatory synaptic transmission in the central micturition reflex pathway. The observed modulation may account for the clinical beneficial effect of IVES treatment. Neurourol. Urodynam. 17:543–553, 1998.

Intravesical Electrical Stimulation Induces a Prolonged Decrease in Micturition Threshold Volume in the Rat

PURPOSE Intravesical electrical stimulation (IVES) has been used clinically to treat patients with voiding disorders. The aim of the present experimental study was to obtain objective evidence of a modulation of the micturition reflex by intravesical electrical stimulation (IVES). MATERIALS AND METHODS Forty-one female rats, anesthetized by alpha-chloralose were used for the experiments. Intravesical electrical stimulation was given by a catheter electrode in the bladder (5 minutes of continuous stimulation at 20 Hz, 7 to 11 mA). The effect was evaluated by the change in cystometric micturition threshold volume. RESULTS The threshold volume of the micturition reflex decreased significantly to 82% of controls after IVES (p<0.001; n=31). The effect was reversible and lasted for about 1 hour. The decrease was prevented by a transient blockade of the bladder nerves during IVES. CONCLUSIONS Intravesical electrical stimulation induced a prolonged modulation of the micturition reflex in anesthetized rats. The effect was due to activation of bladder mechanoreceptor afferents and remained long after the period of stimulation. It is proposed that the modulation was due to a prolonged enhancement of excitatory synaptic transmission in the central micturition reflex pathway. Such a modulation may underlie the curative effect of IVES in certain voiding disorders.

Clinical Significance of IL-2, IL-10, and TNF-α in Prostatic Secretion of Patients With Chronic Prostatitis

OBJECTIVES To explore the clinical significance of interleukin-2 (IL-2), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-alpha) in expressed prostatic secretions (EPS) of patients with different types of chronic prostatitis (CP). METHODS Fifty-seven CP patients and 12 healthy males (controls) were investigated. The CP patients were evaluated through routine examination of urine, EPS, 2 glasses urine culture, and the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score and classified by the NIH prostatitis diagnostic criteria. The levels of cytokines TNF-alpha, IL-10, and IL-2 in the EPS were measured by two-antibody enzyme-linked immunosorbent assay. RESULTS CP patients fell into 3 groups: type II (n = 10), type IIIa (n = 26), and type IIIb (n = 21). EPS TNF-alpha and IL-10 levels were significantly higher in type II and type IIIa than in type IIIb and control groups. The levels of IL-2 were lower than control in all CP groups, but only type II was statistically different from the controls. In the CP patients, the level of TNF-alpha was positively related to the white blood cell counts (r = .77; P <.01), and the level of IL-10 was positively related to the NIH-CPSI scores (r = .55; P <.01). CONCLUSIONS Determination of variety expression of TNF-alpha, IL-10, and IL-2 in the EPS of CP patients may provide a potential indicator for clinical diagnosis classification and an indicator to evaluate the effect of treatment of CP.

Roles of stem cell factor on loss of interstitial cells of Cajal in bladder of diabetic rats.

OBJECTIVE To explore the roles of stem cell factor (SCF) on the loss of interstitial cells (ICCs) in the bladder of diabetic rats, which have not been investigated. METHODS The rats were assigned to 3 groups: normal control rats, diabetic rats, and SCF-treated diabetic rats. The diabetic rat model was created using a streptozotocin (60 mg/kg) intraperitoneal injection. The SCF and c-kit levels in bladder tissue were determined using reverse transcriptase-polymerase chain reaction and Western blot analysis. The quantity of ICCs as represented by c-kit-positive cells was examined by image analysis of immunofluorescence staining. RESULTS Compared with the control rats, the diabetic rats exhibited a significant decrease in the SCF levels and c-kit expression and number of ICCs in the bladder tissues. All these impaired parameters were effectively restored to the control level after exogenous SCF treatment. CONCLUSION These findings suggest that the loss of ICCs in the bladder tissue of diabetic rats can be attributed to a deficiency in endogenous SCF. The beneficial effect of exogenous SCF on diabetic depletion of ICCs could provide a theoretical rationale for the use of SCF as a potential therapeutic drug in treating patients with diabetes-related voiding dysfunction.

Transurethral Endoscopy Technique with a Ureteroscope for Diagnosis and Management of Seminal Tracts Disorders: A New Approach

PURPOSE To apply a transurethral endoscopic technique for examining and managing suspicious distal seminal tracts disorders with a ureteroscope. PATIENTS AND METHODS Sixteen patients with distal seminal tracts disorders underwent transurethral endoscopy through the distal seminal tracts using a semirigid ureteroscope. Of the 16 patients, 6 had suspected hemospermia, 4 spermatocele, and 6 male infertility. RESULTS The ejaculatory duct, seminal vesicle, and ampulla of the vas deferens were observed under direct vision with the ureteroscope. The vas deferens was investigated by cannulation with a guidewire or an epidural anesthesia catheter. Four patients received a diagnosis of spermatocele, four seminal vesiculitis, and three vas deferens obstruction. All patients received appropriate treatment. The remaining five patients had no anatomic disorders. All patients received careful postoperative observation and treatment, and were monitored for at least 3 months. Three patients had postoperative discomfort in the perineal region. There were no further complications. CONCLUSIONS This new technique with the ureteroscope enables diagnosis and management of distal seminal tracts disorders through the normal anatomic tract. This endoscopic technique can be performed easily with minimal complications.