Junji Takatani

Olprinone reduces ischemia/reperfusion-induced acute renal injury in rats through enhancement of cAMP.

Activated leukocytes are implicated in development of ischemia/reperfusion (I/R)-induced organ injuries. Phosphodiesterase 3 inhibitors have anti-inflammatory effects by preventing cyclic adenosine monophosphate (cAMP) degradation. We examined the effects of olprinone, a specific phosphodiesterase 3 inhibitor, on I/R-induced acute renal injury model in rats. Forty-five minute renal I/R was induced in uni-nephrectomized rats. Rats were divided into a vehicle group, an olprinone group, and a dibutyril (DB) cAMP group. Olprinone (0.2 μg/kg/minute) infusion began 30 min after reperfusion and continued for 3 h. DBcAMP (5 mg/kg), a stable analog of cAMP, was intraperitoneally administered 5 min after reperfusion to clarify the effect of cAMP in our model. Olprinone reduced the I/R-induced increases in serum levels of blood urea nitrogen and creatinine, and improved histological changes, including acute tubular necrosis in the outer medulla. Hemodynamic status was not affected by olprinone. I/R-induced a decrease in renal tissue blood flow, an increase in renal vascular permeability, and an enhancement of leukocyte activation, reflected by renal tissue levels of myeloperoxidase activity, and the tissue levels of cytokine-induced neutrophil chemoattractant (an equivalent of human interleukin 8) and tumor necrosis factor-α were all significantly decreased by olprinone. Olprinone also increased the renal tissue and plasma levels of cAMP in rats subjected to renal I/R. DBcAMP showed similar effects. Our results indicated that olprinone reduced the I/R-induced acute renal injury, probably by inhibiting leukocyte activation. The effects of olprinone could be explained through its action on cAMP levels.

Evaluation of the therapeutic results of epiduroscopic adhesiolysis for failed back surgery syndrome

BACKGROUND No data for patients with failed back surgery syndrome (FBSS) based on the location of adhesions separated by epiduroscopic adhesiolysis have been reported. METHODS We performed epiduroscopic adhesiolysis on 28 FBSS patients to examine the impact of differences in the locations of the separated regions on the treatment results. We performed fluoroscopic imaging through the sacral hiatus to assess the condition of adhesions in the epidural space during the post-adhesiolysis observation period. RESULTS In patients in whom only the epidural space was separated by adhesiolysis, there was a significant improvement in the Roland-Morris disability questionnaire (RDQ) score until 12 weeks after adhesiolysis, but the score gradually returned to the preoperative value thereafter. Among patients in whom the nerve root responsible for radicular pain was separated, there was a long-term improvement in the RDQ, Oswestry disability index 2.0 (ODI), and Japanese Orthopedic Association Assessment of Treatment (JOA) scores. Among patients in whom both the epidural space and the nerve root responsible for pain were separated, there was a 12 week improvement in the RDQ score and 24 week improvements in the ODI and JOA scores. CONCLUSIONS Progressive epidural imaging after adhesiolysis suggested that pain was caused by re-adhesion around the nerve root. Since re-adhesion of the nerve root required some time, the effect of adhesiolysis was maintained for extended periods in these cases. We suggest that epiduroscopic adhesiolysis is an effective therapy for FBSS patients, and that adhesiolysis of the nerve root may exhibit the long-term (24 weeks) efficacy in patients with pain.

Use of Imaging Agent to Determine Postoperative Indwelling Epidural Catheter Position

Background Epidural anesthesia is widely used to provide pain relief, whether for surgical anesthesia, postoperative analgesia, treatment of chronic pain, or to facilitate painless childbirth. In many cases, however, the epidural catheter is inserted blindly and the indwelling catheter position is almost always uncertain. Methods In this study, the loss-of-resistance technique was used and an imaging agent was injected through the indwelling epidural anesthesia catheter to confirm the position of its tip and examine the migration rate. Study subjects were patients scheduled to undergo surgery using general anesthesia combined with epidural anesthesia. Placement of the epidural catheter was confirmed postoperatively by injection of an imaging agent and X-ray imaging. Results The indwelling epidural catheter was placed between upper thoracic vertebrae (n = 83; incorrect placement, n = 5), lower thoracic vertebrae (n = 123; incorrect placement, n = 5), and lower thoracic vertebra-lumbar vertebra (n = 46; incorrect placement, n = 7). In this study, a relatively high frequency of incorrectly placed epidural catheters using the loss-of-resistance technique was observed, and it was found that incorrect catheter placement resulted in inadequate analgesia during surgery. Conclusions Although the loss-of-resistance technique is easy and convenient as a method for epidural catheter placement, it frequently results in inadequate placement of epidural catheters. Care should be taken when performing this procedure.

Ultrasound visibility of regional anesthesia catheters: an in vitro study

Background Ultrasound subjective visibility of in-plane needles is correlated with the intensity difference between the needle surface and the background. Regional anesthesia catheters are difficult to visualize by an ultrasound. In the present study, we investigated the ultrasound visibility of the catheters. Methods Six catheters were placed at 0° and 30° relative to and at a depth of 1 cm below the pork phantom surface. Ultrasound images of in-plane catheters were evaluated, subjectively and objectively. Outer and inner objective visibilities were defined as the difference in the mean pixel intensity between the catheter surface and adjacent background, and between the surface and the center of the catheter, respectively. Evaluations were made based on the portion of the catheters. A P value < 0.05 was considered significant. Results Subjective visibility was more strongly correlated with the inner objective visibility than with the outer objective visibility at both angles. Metallic 19-gauge catheters were more subjectively visible than the non-metallic 20-gauge catheters at 30° degrees (P < 0.01). Subjective, and outer and inner objective visibility were significantly lower at 30° than at 0° (P < 0.01, P < 0.01, P = 0.02). Perifix ONE at 0° and Perifix FX at 30° were the most visible catheters (P < 0.01 for both). Conclusions Subjective visibility of catheters can not be evaluated in the same manner as that of the needles. For the best possible visualization, we recommend selecting a catheter with a structure that enhances the dark at the center of catheter, rather than basing the catheter selection on the bore size.

A case of perineal pain related to interstitial cystitis which was supposed to be relieved with gabapentin

alleviation of her symptoms for several days, her symptoms recurred. Two months after the cystoscopy, she visited our pain clinic. At that time, her visual analogue scale (VAS) score for pain was 100. We diagnosed her with bladder pain syndrome related to IC, and started oral administration of a combination of paroxetine, etodolac, acetaminophen, and clonazepam. However, these medications had no effect on her symptoms, and she was admitted to our department for nerve block treatment. For this treatment, an epidural catheter was advanced at the L4-5 interspace, and the tip was placed at L3. The pain related to IC almost disappeared after the epidural administration of 5 ml of 1% lidocaine (Fig. 1). She was scheduled to receive 5 ml of 1% lidocaine administered through the epidural catheter periodically, four times a day. However, the epidural administration of 5 ml of 1% lidocaine induced hypotension. Therefore, the dose of 1% lidocaine was decreased to 4 ml. As a result of the decrease in epidural lidocaine administration, the pain related to IC increased. Therefore, oral gabapentin was started, at a dose of 200 mg· day and gradually increased. After the epidural catheter was removed, the superior hypogastric plexus was blocked with 0.75% ropivacaine as a trial. The pain was diminished for a few days after the superior hypogastric plexus blockade. However, she declined permanent block with alcohol because of A case of perineal pain related to interstitial cystitis which was supposed to be relieved with gabapentin

New Anthranilic Acid Derivative, EAntS-GS, Attenuates Freund’s Complete Adjuvant-Induced Acute Pain in Rats

BACKGROUND Acute and chronic pain commonly accompany various clinical conditions such as contusion, fracture, osteoarthritis, peripheral neuropathy, and postherpetic neuralgia. Recent studies have found that antioxidative drugs can have analgesic effects. The present study tested the hypothesis that a new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects on inflammatory pain in a rat model. METHODS We induced subacute pain with a plantar injection of Freunds complete adjuvant (FCA) in Sprague-Dawley rats. EAntS-GS (1 mg/kg subcutaneous injection or 1% application) was administered every 12 h beginning 24 h after FCA administration, and the plantar test was used to determine its effect on pain. Levels of myeloperoxidase, inducible nitric oxide synthase (iNOS), and protease activated receptor 2 (PAR2) were measured to elucidate the mechanism of action of EAntS-GS. RESULTS EAntS-GS significantly reduced FCA-induced pain and myeloperoxidase, iNOS, and PAR2 levels. Our findings suggest that the new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects, and that the mechanism involves iNOS and PAR2. CONCLUSION We conclude that EAntS-GS should be considered a new therapeutic tool to treat acute and chronic pain.

Effects of high peak airway pressure on the expression of heat shock protein 70 in rat lungs: a preliminary study

Background:  Heat shock protein 70 (HSP70) is induced by a wide variety of stresses in addition to hyperthermia. Recent studies have clarified that mechanical stretching and pressure overload can induce HSP70 in some tissues and cells. However, it remains unclear whether HSP70 is induced in stretch‐subjected lungs, such as those under mechanical ventilation. This study was designed to investigate the effects of high peak airway pressure (PAP) ventilation on HSP70 expression in intact rat lungs.