Bupivacaine Treatment Research Articles

Optimization of Naked DNA Delivery for Interferon Subtype Immunotherapy in Cytomegalovirus Infection.

Type I interferon (IFN) gene therapy modulates the immune response leading to inflammatory heart disease following cytomegalovirus (CMV) infection in a murine model of post-viral myocarditis. Efficacy of different immunisation protocols for the IFN constructs was influenced by the dose of DNA, subtype choice, combination use, pre-medication, and timing of DNA administration. Optimal efficacy was found with bupivacaine treatment prior to DNA inoculation of 200mg IFN DNA 14 days prior to virus challenge. Maximal antiviral and antimyocarditic effects were achieved with this vaccination schedule. Furthermore, inoculation of synergistic IFN subtypes demonstrated enhanced efficacy when delivered either alone or with CMV gB DNA vaccination in the CMV model. Thus naked DNA delivery of IFN provides an avenue of immunotherapy for regulating herpesvirus-induced diseases.

Differential effects of bupivacaine enantiomers, ropivacaine and lidocaine on up-regulation of cell surface voltage-dependent sodium channels in adrenal chromaffin cells

In cultured bovine adrenal chromaffin cells, (±)-bupivacaine inhibited veratridine-induced 22Na + influx (IC 50 6.8 μM). The IC 50 of (+)-bupivacaine (2.8 μM) was 6.2-, 7.4-, and 17.1-fold lower than those of (−)-bupivacaine (17.3 μM), (−)-ropivacaine (20.6 μM), and lidocaine (47.8 μM). Chronic (i.e. 3-h) treatment of cells with (±)-bupivacaine increased cell surface [ 3H]saxitoxin ([ 3H]STX) binding capacity by 48% (EC 50 of 233 μM; t 1/2=7.4 h), without changing the K d value. Treatment for 24 h with either (+)- or (−)-bupivacaine, or (−)-ropivacaine elevated [ 3H]STX binding, whereas 24-h treatment with lidocaine had no effect. The rise of [ 3H]STX binding by (±)-bupivacaine was prevented by cycloheximide, an inhibitor of protein synthesis, or brefeldin A, an inhibitor of cell surface vesicular exit from the trans-Golgi network; however, (±)-bupivacaine did not increase Na + channel α- and β 1-subunit mRNA levels. In cells subjected to (±)-bupivacaine treatment (1 mM for 24 h) followed by 3-h washout, veratridine-induced 22Na + influx was enhanced, even when measured in the presence of ouabain, an inhibitor of Na +,K +-ATPase. Ptychodiscus brevis toxin-3 potentiated veratridine-induced 22Na + influx by 2.3-fold in the (±)-bupivacaine-treated cells, as in non-treated cells. These results suggest that lipophilic bupivacaine enantiomers or (−)-ropivacaine acutely inhibit Na + channel gating, whereas its chronic treatment up-regulates cell surface expression of Na + channels via translational and externalization events.

Skeletal muscle regeneration after insulin-like growth factor I gene transfer by recombinant Sendai virus vector.

We scrutinized the applicability and efficacy of Sendai virus (SeV) vectors expressing either LacZ or human insulin-like growth factor-I (hIGF-I) in gene transfer into skeletal muscle. Seven days after the intramuscular injection of LacZ/SeV X-gal labeled myofibers were demonstrated in rat anterior tibialis muscle with/without bupivacaine treatment and the transgene expression persisted up to 1 month after injection. Recombinant hIGF-I was detected as a major protein species in culture supernatants of a neonatal rat myoblast cell line L6 and thus induced the cells to undergo myogenetic differentiation. The introduction of hIGF-I/SeV into the muscle showed a significant increase in regenerating and split myofibers which were indicative of hypertrophy, and also an increase in the total number of myofibers, in comparison to that seen in the LacZ/SeV-treated control muscle. These results demonstrate that SeV achieves high-level transgene expression in skeletal muscle, and that hIGF-I gene transfer using SeV vector may therefore have great potential in the treatment of neuromuscular disorders.

Expression of Myostatin Gene in Regenerating Skeletal Muscle of the Rat and Its Localization

The expression of myostatin mRNA was examined in regenerating skeletal muscle of the rat. Skeletal muscle regeneration was induced by injecting bupivacaine or hypertonic saline solution into the femoral muscle, and the tissues were collected 48 h after the treatment. In situ hybridization analysis revealed that the cells positive for myostatin message were localized in the regenerating area of the bupivacaine-treated tissues, where a numerous number of mononucleated cells were present. The myostatin-positive mononucleated cells contained both myogenic and nonmyogenic cells, as revealed by immunohistochemical staining for desmin and vimentin. Bupivacaine treatment to the testes resulted in no myostatin message expression in the testicular vimentin-positive cells, suggesting that the expression of myostatin message in vimentin-positive cells is a skeletal muscle-specific phenomenon. Furthermore, crushed muscle extract prepared from regenerating skeletal muscle had induced myostatin mRNA expression in skeletal muscle-derived fibroblasts in a dose-dependent manner. These results indicated that myostatin is expressed during skeletal muscle regeneration both in myogenic and nonmyogenic cells, and suggested that some factor(s) capable of inducing myostatin expression in fibroblasts are present in regenerating skeletal muscle.

BUPIVACAINE INFILTRATION INTO THE NEUROVASCULAR BUNDLE OF THE PROSTATIC NERVE DOES NOT IMPROVE POSTOPERATIVE PAIN OR RECOVERY FOLLOWING TRANSVESICAL PROSTATECTOMY

Purpose We assessed the effect of intraoperative bupivacaine infiltration into the neurovascular bundle of the prostatic nerve on postoperative pain and patient outcome. Materials and Methods The study included 40 American Society of Anesthesiologists physical status I to III patients undergoing transvesical prostatectomy. Following surgical resection of the prostate the neurovascular bundle of the prostatic nerve was infiltrated with either 10 ml. bupivacaine 0.5% or saline. Postoperative pain intensity was assessed using a patient generated 100 mm. visual analog scale and a patient controlled analgesia device. Additional analgesic requirements, time to ambulation, length of hospitalization and return to normal activity were also recorded. Results There were no differences in visual analog scale for pain, patient controlled analgesia demands or actual morphine delivered. Similarly, saline versus bupivacaine infiltration did not influence ambulation time (21.3 +/− 2.7 versus 25.0 +/− 11.8 hours, respectively), length of hospitalization (7.06 +/− 0.8 versus 7.11 +/− 0.6 days, respectively), return to normal activity (14.4 +/− 8.8 versus 14.2 +/− 8.2 days, respectively) or patient satisfaction. On postoperative days 1 and 2 more patients in the saline treatment group requested additional oral analgesia compared to the bupivacaine treatment group. However, no statistical difference was demonstrated. Conclusions Following transvesical prostatectomy, prostatic nerve blockade has no beneficial effects on postoperative pain or patient outcome.

Suppression of acetylcholine-induced relaxation by local anesthetics and vascular NO-cyclic GMP system.

Local anesthetics have been demonstrated to attenuate acetylcholine-induced relaxation of vascular smooth muscle, but the mechanism responsible has not been elucidated. The present study was undertaken to ascertain whether this effect of local anesthetics is due to suppression of the vascular nitric oxide (NO)-cyclic GMP (cGMP) system. Isolated rat aortae were cut into helical strips and mounted in bathing solution to measure isometric tension changes. They were precontracted with phenylephrine (0.3 microM) then exposed to cumulative concentrations of relaxants including acetylcholine, sodium nitroprusside (SNP) and papaverine, in the absence or presence of local anesthetics. Aortae for cGMP measurements were cut longitudinally into pairs of strips and bathed in the solution without tension. In the absence or presence of anesthetics, they were stimulated with acetylcholine or SNP, and the cGMP content of each strip was radioimmunoassayed. Acetylcholine-induced, endothelium-dependent relaxation of phenylephrine-precontracted aortae was attenuated by lidocaine (30-300 microM), tetracaine (10-30 microM), bupivacaine (10-100 microM) and ropivacaine (30-100 microM). SNP-induced relaxation was attenuated by lidocaine (300 microM), tetracaine (30 microM), bupivacaine (10-100 microM) and ropivacaine (30-100 microM). Papaverine-induced relaxation was attenuated by lidocaine (300 microM), bupivacaine (30-100 microM) and ropivacaine (30-100 microM), and augmented by tetracaine (30 microM). Cyclic GMP levels in acetylcholine-stimulated aortae were reduced significantly by lidocaine (300 microM), tetracaine (100 microM) and bupivacaine (300 microM) treatment, but not by ropivacaine (300 microM). SNP-stimulated cGMP levels were reduced by tetracaine (100 microM) but not by any other anesthetics at the concentrations tested. We conclude that lidocaine, tetracaine and bupivacaine suppress acetylcholine-stimulated formation of cGMP. However, the attenuation of acetylcholine-induced relaxation by local anesthetics is not totally ascribable to reduced cGMP levels.

Intra-articular morphine and/or bupivacaine in the management of pain after total knee arthroplasty

The purpose of this study was to determine if intra-articular injection of morphine or bupivacaine significantly decreased postoperative pain as well as the use of intravenous narcotics for pain relief in patients undergoing total knee arthroplasty (TKA). In a prospective, double-blind, randomized fashion, 105 patients undergoing TKA were divided into the following 4 groups defined by the intra-articular injection they received: group 1 (n = 27) received saline solution, group 2 (n = 26) received morphine sulfate (5 mg), group 3 (n = 24) received bupivacaine (50 mg), and group 4 (n = 28) received a combination of morphine sulfate and bupivacaine. The injections were administered immediately after wound closure by the Hemovac drainage tubing that remained clamped for 45 minutes after surgery to allow for absorption. Before surgery and at 2, 4, 6, 24, and 48 hours after surgery, pain intensity was recorded using a visual analog scale. Postoperative supplemental intravenous morphine and/or meperidine was administered via a patient-controlled analgesia device, and 24-hour drug usage was tabulated. Results were suggestive of a modest short-term reduction in pain scores in the morphine and bupivacaine treatment groups compared with placebo (saline); however, results were statistically significant only at 4 hours because of the great variability in the pain score data. The total amount of postoperative pain medication used in the first 24 hours after surgery was not statistically significant between the 4 treatment groups. Thus, the results put into question the benefit of postoperative intraarticular administration of morphine or bupivacaine in patients undergoing TKA.

Appearance of complex branched fibers following repetitive muscle trauma in normal rat skeletal muscle.

To examine whether the complex branched fibers observed in mdx mutant mice were formed in normal skeletal muscles, long-term repetitive muscle trauma was applied to muscle of normal Wistar male rats. Three kinds of artificial muscle trauma--crush injury, bupivacaine hydrochloride treatment, and forced stretching of contracting muscle (eccentric contraction)--were performed once a week for 10 weeks to achieve a state of repetitive degeneration and regeneration in the muscles. Two weeks after the final treatment, numerical, histochemical, and three-dimensional analyses by scanning electron microscopy were performed. Mean numbers of total branched fibers of the three groups were increased compared with normal control values, especially in the bupivacaine treatment group (three- to fivefold greater than in the other two groups). Aggregations of fibers of the same type which usually appear in mdx mice were observed in various parts of histological sections of the bupivacaine treatment group and only in a part of the crush injury group. No aggregations were observed in sections of the forced stretching group. In the three-dimensional analysis, complex branched fibers appearing as an "anastomosing syncytial reticulum" were observed only in the bupivacaine treatment group. These findings suggest that the formation of an anastomosing syncytial reticulum is one of the adaptation mechanisms of normal skeletal muscle rather than a specific event in mdx mutant mice, and long-term repeated trauma of the same fiber is necessary for this formation. Adaptive changes in the muscles with the three different types of muscle trauma are discussed.

Initiation of satellite cell replication in bupivacaine-induced myonecrosis.

To determine how and when the satellite cells are stimulated to replicate in muscle regeneration, the rat soleus muscle was examined chronologically after bupivacaine-induced myonecrosis. Bromodeoxyuridine and desmin-positive mononuclear cells, indicating the start of satellite cell replication, were seen 25 h after bupivacaine treatment when macrophages had already invaded the sarcoplasm of necrotic fiber. These findings suggest that muscle regeneration starts as early as the time at which macrophages begin to scavenge necrotic material. Proliferating myoblasts increased in number, reaching a maximum at 49 h after myonecrosis, and decreased in number 3 days after the myoblasts fused with each other form myotubes. The satellite cell proliferation after bupivacaine-induced myonecrosis began at almost the same time as in crush injury, and earlier than after muscle transplantation using whole intact or minced muscle fragments. The earlier beginning and more rapid regenerating process probably resulted from the preservation of intact satellite cells, blood vessels and peripheral nerves in the bupivacaine-induced myonecrosis.

Thoracic epidural analgesia with bupivacaine and fentanyl for postoperative thoracotomy pain

This study was designed to evaluate the potential fentanyl-sparing effect of a dilute local anesthetic, bupivacaine, administered in fixed combinations with fentanyl for post-thoracotomy analgesia via a continuous thoracic epidural infusion. Forty adult patients scheduled for thoracotomy were randomly allocated in a double-blind fashion to receive an epidural infusion containing 0, 0.03, 0.06, or 0.125% bupivacaine in combination with fentanyl (4 μg/mL). The epidural infusions were initiated in the operating room at 10 mL/hr. During the first 24 hours, there were no between-group differences in pain scores. Total fentanyl use was significantly decreased 24% to 33% in all bupivacaine treatment groups. However, fentanyl plasma levels at 24 hours were not significantly different between groups. Arterial blood gas measurements performed on the morning after surgery revealed significant reductions in PaCO 2 values, 38 ± 4, 36 ± 4, 37 ± 4 mmHg for 0.03, 0.06, and 0.125% bupivacaine groups respectively, versus 44 ± 6 for the plain fentanyl group. Arterial pH values were significantly higher in all bupivacaine treatment groups. These findings suggest that the combination of dilute bupivacaine with fentanyl for thoracic epidural analgesia for post-thoracotomy pain may have beneficial effects on pulmonary gas exchange.

Gene Transfer in Regenerating Muscle

We have compared the efficiency of direct gene transfer in normal and regenerating rat skeletal muscle. Muscle necrosis and regeneration was induced by intramuscular injection of bupivacaine in the soleus muscle of adult rats. Plasmids containing beta-galactosidase (beta-gal) or chloramphenicol acetyltransferase (CAT) genes driven by viral promoters were injected 3 days after bupivacaine treatment into the regenerating and the contralateral uninjured muscles. Expression of CAT activity was > 80-fold higher in regenerating compared to control muscles at 7 days post-transfection, but decreased at 30 and 60 days. Southern blot analysis showed that the predominant form of CAT DNA was episomal in transfected muscles; however, CAT activity measurements performed on the same transfected muscles showed no precise correlation between enzymatic activity and amount of plasmid DNA. Expression of beta-gal was detected in numerous regenerating fibers of the injured soleus muscles at 7 days post-transfection; in contrast, only rare positive fibers were found in control muscles. Focal infiltrates of mononuclear cells, which surround and invade selectively beta-gal-positive fiber segments, were observed at 30 days post-transfection, suggesting that immune mechanisms are implicated in the progressive loss of transgenes with time. The finding that regenerating muscle fibers display a higher efficiency of transfection may be relevant to gene therapy of Duchenne muscular dystrophy, because regenerating fibers are numerous in the early stages of the disease.

Improved gene transfer by direct plasmid injection associated with regeneration in mouse skeletal muscle

Gene transfer into skeletal muscle via simple plasmid injection in vivo has many potential uses but these are severely constrained by the low efficiency of this technique. Muscle regeneration, induced by the myotoxic local anaesthetic bupivacaine, significantly increased gene expression following plasmid injection 3–7 days after bupivacaine treatment. Much of this effect can be attributed to uptake and expression of the plasmid by a greater number of muscle fibres, up to 9% of the mouse tibialis anterior muscle. A similar significant increase in expression was observed in the naturally regenerating muscle of the dystrophic mdx mouse when compared to the control C57B1/10 strain.

Coordinated expression of phosphorylase kinase subunits in regenerating skeletal muscle.

The developmental expression of the alpha, beta, and gamma subunits of skeletal muscle phosphorylase kinase has been examined in regenerating muscle. Rat extensor digitorum longus (EDL) muscles, treated with bupivacaine, promptly undergo a rapid degeneration of the muscle, followed by regeneration and recovery of essentially normal morphology and physiology by 3-4 weeks post-treatment (Hall-Craggs, E. C. B., and Seyan, H. S. (1975) Exp. Neurol. 46, 345-354). Phosphorylase kinase activity dropped to approximately 10% of control within 3 days of bupivacaine treatment and remained at this low level for several days but had attained at least 60% of normal levels by day 21. The pH 6.8/8.2 activity ratio was unusually high during the period of low activity, suggesting that the catalytic activity was not under normal regulation at this time. The subunit mRNAs were readily detected in control EDL but were undetectable at day 3 post-bupivacaine treatment. Very small amounts of message for all three subunits were evident by day 6 and began to approach normal levels by day 12-15. The mRNA for both the alpha and alpha' subunits of phosphorylase kinase exhibited a similar pattern of recovery, as did also the mRNA for phosphorylase. In contrast to both phosphorylase kinase and phosphorylase, actin mRNA exhibited a quite a different pattern, with a nearly full recovery of message levels by day 6 post-bupivacaine. These data indicate that synthesis of phosphorylase and the alpha, beta, and gamma subunits of phosphorylase kinase appears to be coordinately regulated at the level of message accumulation and that the expression of phosphorylase kinase activity is likely to be also regulated post-transcriptionally.

Inhibition of peritonitis by amide local anesthetics.

Peritonitis was induced in rats by exposing the peritoneal surface to 0.1 M hydrochloric acid (HCl). Peritonitis was quantified by extraction of Evans blue-bound albumin from the tissue exposed to HCl and analyzed by a spectrophotometric technique. In the first set of experiments, one group of rats had the peritoneal surface exposed to HCl following local pretreatment with isotonic saline; a second group of rats had the peritoneum exposed to HCl after topical pretreatment with an equal volume of lidocaine 1%, whereas in a third group the peritoneal surface was exposed only to saline without HCl. The experimental design in the second set of experiments was similar to that of the first set except that bupivacaine 0.5% was used instead of lidocaine in the second group. Results show a significant inhibition of peritonitis in the groups pretreated with lidocaine (P less than 0.01) and bupivacaine (P less than 0.05) compared with rats in the saline pretreated group. In the lidocaine-pretreated group Evans blue-albumin extravasation did not differ significantly from the rats not receiving HCl, whereas the bupivacaine-pretreated group showed a slightly but significantly (P less than 0.05) more pronounced peritonitis than control rats not exposed to HCl. In the third set of experiments the peritoneum was topically treated with either lidocaine 1%, bupivacaine 0.5%, or isotonic saline after first having exposed the peritoneal surface to HCl. A significant inhibition of albumin extravasation was seen following lidocaine (P less than 0.001) or bupivacaine (P less than 0.001) treatment compared with treatment with isotonic saline.(ABSTRACT TRUNCATED AT 250 WORDS)

Maturation, dystrophic changes and the continuous production of fibers in skeletal muscle regenerating in the absence of nerve.

To investigate how much skeletal muscle depends on influences coming from peripheral nerve, we studied muscle regeneration induced by bupivacaine in the permanently denervated soleus muscle of adult rats. Using light and electron microscopy, we studied the extent of maturation attained by regenerated myofibers and their ability to regenerate again after repeated bupivacaine injury. Morphometric analyses showed that within the first two weeks after injury, the regenerated denervated fibers increased in diameter, matured and then became atrophic. By electron microscopy the morphological characteristics of mature fibers are evident, but final differentiation into adult fiber types is not attained. This is in keeping with previously reported biochemical results. A new phase of massive regeneration occurred when bupivacaine treatment was repeated, thus demonstrating that regenerated myofibers devoid of innervation keep their intrinsic ability to regenerate after injury. Spontaneous though scanty regeneration also occurred in denervated regenerated muscle at late stages, when atrophy and dystrophy of fibers became prominent. Concomitantly the relative number of myosatellite cells remained high. These morphological observations further support the hypothesis that fiber regeneration participates in the maintenance of chronically denervated muscles.

Effects of repeated bupivacaine administration on sciatic nerve and surrounding muscle tissue in rats.

The effects of repeated administration of 0.5% bupivacaine or saline into the sciatic notch of rats were studied by light microscopy, electron microscopy and a neurophysiological technique. Very severe myositis, including local necrosis, developed in six of 12 rats treated twice daily with 1 ml bupivacaine for either 3 or 7 days. A 3-h infusion of 1.5 ml 0.5% bupivacaine resulted in minor injury to muscle tissue. A marked degree of disruption and vacuolization of myelin sheaths was evident in nerves exposed to bupivacaine for 3 days. Lymphocyte accumulation was confined to the area surrounding the nervous tissue in 7 of 10 of the preparations from rats treated for 3 days or by a 3-h infusion. No histological changes were detected in nerve and muscle tissue from the opposite extremity exposed to saline. After a recovery period of 3 weeks, no differences in the nerve or muscle histology were seen between samples from bupivacaine- or saline-treated animals. The amplitude of the compound action potential of sciatic nerves was, however, significantly lower after bupivacaine treatment (7 days, 1 ml twice daily). Thus, impaired function may continue despite the lack of histological intraneural injury.