Acute Changes in Left Atrial and Left Ventricular Diameters After Physiological Pacing

The present study examined alterations in left atria! diameter (LAD) and diastolic left ventricular diameter (LVDd) in 37 patients (72.2 ± 9.8 years old) who received physiological pacemakers; 22 with atrioventricular (AV) block and 15 with sick sinus syndrome (SSS). After pacemaker implantation, LAD and LVDd were serially measured using echocardiography, and their diameters ware expressed per body surface area (LADI and LVDdl; mm/m). Pulmonary capillary wedge pressure (PCWP) and cardiac output (CO) were measured in ten patients with SSS and ten with AV block during both right ventricular and AV sequential pacing. After AV sequential pacing, CO increased in 19 of 20 patients (3.2 ± 0.9 L/min to 3.9 ± 1.0 L/min: P < 0.001). LADI decreased from 24.9 ± 4.2 mm/m² to 21.8 ± 4.4 mm/m² (P < 0.001) in 22 patients with AV block and from 24.1 ± 3.4 mm/m² to 20.4 ± 3.8 mm/m² (P < 0.001) in 15 SSS patients. However, LVDdl did not change significantly in either group of patients. The changes in LAD after the implantation of a physiological pacemaker occurred rapidly, i.e. LAD began to decrease within 1 minute after the procedure, and then reached a plateau. This plateau phase continued for at least 7 days during physiological pacing. There was a positive correlation between the changes in LADI after pacemaker implantation and those in PCWP observed during the AV sequential pacing performed prim- to the implantation (r = 0.86; P < 0.001). The reduction in LAD following pacemaker implantation was rapid and seemed to be accompanied by improvement of cardiac function. Thus, it is suggested that the serial measurement of LADI is useful to predict the efficacy of physiological pacemaker implantation.     

Intraoperative electrical stimulation of cavernous nerves with monitoring of intracorporeal pressure to confirm nerve sparing during radical prostatectomy: Early clinical results

BACKGROUND: We performed intraoperative cavernous nerve stimulation with an intracavernous pressure (ICP) monitoring system to confirm nerve sparing during radical pelvic surgery and assessed the results. METHODS: Nineteen cases of radical prostatectomy and three of radical cystoprostatectomy were examined. Electrical stimulation of the site where the neurovascular bundle (NVB) was determined to run was performed and changes in ICP were measured before and after prostate removal. RESULTS: Of the 22 patients, bilateral NVBs were preserved in six patients while unilateral NVB was preserved in 16. Before dissection, all NVBs examined exhibited positive responses (ICP changes of>5 mmHg) to nerve stimulation. After removal of the prostate, positive responses were observed in 22 (79%) of 28 macroanatomically preserved NVBs. Of 16 sides on which the NVB was not preserved, there were positive responses in five (31%). In these patients, some nerve fibers were macroscopically observed lateral to the original site of NVB. Finally, bilateral or unilateral nerve sparing was confirmed electrophysiologically in 20 (91%) of the 22 patients. CONCLUSION: Intraoperative stimulation of the NVB while monitoring ICP changes is a simple and reliable method of accurately evaluating the preservation of cavernous nerves. This system may provide further insight into the mechanism of postoperative erectile dysfunction.     

Ablation of eosinophils with anti-IL-5 antibody enhances the survival of intracranial worms of Angiostrongylus cantonensis in the mouse

Effects of depressed eosinophilia on the development of Angiostrongylus cantonensis in the mouse were studied using monoclonal rat anti-mouse-interleukin-5 antibody (anti-IL-5). The administration of anti-IL-5 strongly depressed peripheral, cerebrospinal fluid (CSF) and medullary eosinophilic responses in mice infected with A. cantonensis, when compared with groups treated with phosphate-buffered saline solution (PBS) alone or isotype-matched rat IgG. There was no significant difference in A. cantonensis antigen specific IgG and IgE antibody responses between rat IgG treated and anti-IL-5 treated mice. Intracranial worm recovery in anti-IL-5 treated mice was consistently high throughout the course of the study and some worms migrated from the brain to the lungs. By contrast, almost all the intracranial worms in the mouse groups treated with PBS alone or rat IgG died before day 32. These data clearly indicate that IL-5 is essential for eosinophil responses in A. cantonensis infected mice and also that eosinophils serve as a potential effector cell in the killing of the intracranial worms in mice.     

Modulation of Bladder Afferent Activity by Propiverine and its Active Metabolites (M‐1 and M‐2) in Rats

Objectives: To evaluate the effects of propiverine and its active metabolites (M‐1 and M‐2) on bladder function through modulation of afferent activity in rats. Methods: Cystometry was performed in urethane anesthetized female rats. We examined the effects of intravesical administration of propiverine, M‐1 and M‐2 on bladder overactivity induced by oxotremorine‐M (Oxo‐M; non‐selective mAChR agonist). Results: Intravesical administration of Oxo‐M (200 µM) elicited bladder overactivity as evidenced by decreased intercontraction interval (ICI) and pressure threshold (PT) without changing maximum voiding pressure or baseline pressure. These effects were blocked by intravesical administration of propiverine (30 µM) or M‐2 (300 µM). Intravesical administration of M‐1 (30 µM) alone increased ICI and PT, but did not prevent Oxo‐M‐induced decreases in ICI and PT. Conclusion: These results suggest that propiverine and M‐2 have anticholinergic effects on bladder afferent activity and that M‐1 has an inhibitory effect through the mechanism other than muscarinic receptor modulation. Thus, clinical benefits of propiverine in patients with overactive bladder could be mediated by multiple actions of propiverine and its active metabolites.