Water-diluted local anesthetic for trigger-point injection in chronic myofascial pain syndrome: evaluation of types of local anesthetic and concentrations in water.

BACKGROUND AND OBJECTIVES: We have recently demonstrated that a mixture of 1% lidocaine with water in a 1:3 ratio has less injection pain and is more effective than unaltered 1% lidocaine in treating chronic myofascial pain syndromes. Yet, the most suitable local anesthetic and the most effective dilution in water have not been evaluated. METHODS: Various mixtures of local anesthetics and water or saline were injected intramuscularly into the shoulder of 40 female volunteers, and pain scores on injection were evaluated in a randomized and double-blinded manner. In another portion of the study, 0.25% or 0.2% lidocaine in water were injected randomly into 1 side of 21 outpatients with chronic neck, shoulder, or lumbar myofascial pain to the same degree in both sides. The other solution was injected into the other side of the same patients. RESULTS: Less injection pain was experienced with the water-diluted 0.25% lidocaine and water-diluted 0.25% mepivacaine than the saline-diluted 0.25% lidocaine and water-diluted 0.0625% bupivacaine. Also, less injection pain was experienced with the water-diluted 0.25% and 0.2% lidocaine than the water-diluted 0.3% and 0.15% lidocaine. In the other study, there were no differences in either the effectiveness or duration of analgesia between the 0.25% and 0.2% water-diluted lidocaine. CONCLUSIONS: The suitable type of local anesthetic may be lidocaine or mepivacaine, and the most effective water-diluted concentration is considered to be 0.2% to 0.25%.

Interaction of drugs and Chinese herbs: pharmacokinetic changes of tolbutamide and diazepam caused by extract of Angelica dahurica.

The inhibitory effects of Angelica dahurica root extract on rat liver microsomal cytochrome P450 and drug-drug interactions were studied. The 2alpha- and 16alpha-hydroxylase activity of testosterone were most strongly inhibited, with 17.2% and 28-5% of their activity remaining, respectively, after oral administration of A. dahurica extract at a 1 g kg(-1) dose. 6beta-Hydroxylase activity was also inhibited, with 70% of its activity remaining, under the same conditions. In addition, treatment with the extract inhibited the metabolism of tolbutamide, nifedipine and bufuralol. These results showed that the extract inhibited the various isoforms of cytochrome P450 such as CYP2C, CYP3A and CYP2D1. The A. dahurica extract delayed elimination of tolbutamide after intravenous administration at a 10 mg kg(-1) dose to rats. Thus, the extract altered the liver intrinsic clearance. It had little effect, however, on the pharmacokinetic parameters of diazepam after intravenous administration at 10 mg kg(-1). Since diazepam showed high clearance, it underwent hepatic blood flow rate-limited metabolism. Therefore, the change of intrinsic clearance had little effect on hepatic clearance. However, the Cmax value after oral administration of diazepam with extract treatment was four times that with non-treatment. It was suggested that the first-pass effect was changed markedly by the extract. High-dose (1 g kg(-1)), but not low dose (0.3 g kg(-1)), administration of A. dahurica extract increased significantly the duration of rotarod disruption following intravenous administration of diazepam at 5 mg kg(-1). It was concluded that administration of A. dahurica extract has the potential to interfere with the metabolism, by liver cytochrome P450, of other drugs.

cDNA cloning of an alternative splicing variant of protein kinase C delta (PKC deltaIII), a new truncated form of PKCdelta, in rats.

Recently, an alternative splicing variant of mouse protein kinase C delta (PKC deltaII, GenBank Accession No. AB011812) has been reported which has a 78 bp (26 amino acid) insertion at the caspase-3 recognition sequence in the V3 region of PKC delta (PKC deltaI). We isolated a cDNA encoding a new variant of PKC delta (PKC deltaIII, AF219629), which has a 83 bp insertion at the same site in the V3 region, by RT-PCR using rat testis RNA as a template. In rats, the 83 bp insertion causes inframe termination, and rat PKC deltaIII protein is expressed as a truncated form, having only the regulatory domain without a catalytic domain. Genomic DNA analysis revealed that the difference between mouse PKC deltaII and rat PKC deltaIII is derived from the different sequence at the 5'-splicing donor sites. To investigate the potential functions of the truncated form of PKC delta, rat PKC deltaIII fused to green fluorescent protein (GFP) was expressed in CHO-K1 cells. PKC deltaIII-GFP was localized in the cytoplasm with dot-like accumulation and highly expressed on the plasma membrane, whereas PKC deltaI-GFP is localized homogeneously throughout the cytoplasm, including the nucleoplasm. Stimulation by phorbol ester caused weak translocation of deltaIII-GFP from the cytosol to the plasma membrane. These results suggest that PKC deltaIII may show a dominant negative effect against PKC deltaI, and that the modulation of signal transduction by alternative splicing variant may play a crucial role in the physiological and/or pathological conditions, and the pathogenesis of disease.

Changes in calcium, PTH and 1,25(OH)2 vitamin D3 during tail-suspension in ovariectomized rats: effects of estrogen administration.

It is well known that estrogen deficiency results in osteoporosis in human and experimental animals. However, how its deficiency affects the development of disuse atrophy is not well understood. We thus investigated how estrogen deficiency caused by ovariectomy and estrogen supplements affect serum levels of calcium, parathyroid hormone (PTH), and 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in tail-suspended rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups. One group received an intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received the vehicle alone (OVX group). After the third injection, the rats were subjected to tail-suspension in metabolic cages for 1, 3, 5 or 7 days. In the OVX group, urinary excretion of deoxypyridinoline (D-Pyr) tended to increase on day 1 after tail-suspension. In the OVX-E2 group, basal excretion was lower than that in the OVX group, and no increase was observed after the suspension. Serum concentrations of ionized calcium significantly increased on day 1 after the suspension in both groups. However, in the OVX-E2 group, the level tended to be higher than those in the OVX group from day 0 to day 3. Serum PTH tended to decrease on day 1 after suspension in the OVX group. In the OVX-E2 group, it did not change during the suspension, but the levels were higher than those in the OVX group during the experiment. Serum 1,25(OH)2D3 transiently and significantly increased on day 1 after suspension in both groups. However, in the OVX group, the level was significantly higher than that in the OVX-E2 group. These data indicate that estrogen treatment of ovariectomized rats modifies the changes in calcium metabolism induced by tail-suspension.

Differential catalytic properties in metabolism of endogenous and exogenous substrates among CYP3A enzymes expressed in COS-7 cells.

The catalytic properties of CYP3A7 in the metabolism of endogenous and exogenous substrates were compared with those of CYP3A4 and CYP3A5 using COS-7 expressing enzymes. The highest activities of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone 3-sulfate (DHEA-S) 16alpha-hydroxylase were observed in COS-7 cells expressing CYP3A7. In contrast, the activity of testosterone 6beta-hydroxylase of CYP3A7 expressed in COS-7 cells was much less than that of CYP3A4 expressed in COS-7 cells. The rate of carbamazepine 10, 11-epoxidation was the greatest in COS-7 cells expressing CYP3A4, followed by CYP3A5 and CYP3A7. On the other hand, the formation of reductive metabolite of zonisamide was the highest in COS-7 cells expressing CYP3A4, followed by CYP3A7 and CYP3A5. Furthermore, the addition of triazolam resulted in a decrease in 6beta-hydroxylation catalyzed by CYP3A7, but not by CYP3A4, whereas the pretreatment of microsomes with triacetyloleandomycin (TAO) resulted in a decrease in the reaction catalyzed by CYP3A4, but not by CYP3A7. Together with these results, it was suggested that CYP3A7 exerts differential catalytic properties not only in metabolism of endogenous substrates but also in drug metabolism compared to CYP3A4 and CYP3A5.

Administration of bisphosphonate prevents disuse bone atrophy induced by tail suspension.

We recently demonstrated that osteopenia induced by rat tail-suspension was associated with an initial increase in bone resorption. To study the significance of the increase in early bone resorption for osteopenia, we investigated whether administration of YH529, a third-generation bisphosphonate, prevents the development of osteopenia as evidenced by increased wet weight of the femur, together with its calcium and phosphorus contents, when compared with those of tail-suspended rats treated with the vehicle alone. These results suggested that the initial increase in bone resorption plays an important role in the development of osteopenia induced by tail suspension.

Effect of estrogen on the development of disuse atrophy of bone and muscle induced by tail-supension in rats.

Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.

Changes in urinary excretion of pyridinium cross-links during Spacelab-J.

In SLJ-1 we proposed to study three major objectives. They were; 1. hormonal changes associated with fluid and electrolyte metabolism, 2. the effect of space flight on the circadian rhythms of endocrine and metabolic systems, 3. the changes in the indices of the bone and muscle metabolism during space flight. In this report, the changes in the bone metabolism during Spacelab-J will be presented with a special emphasis on urinary excretion of pyridinium cross-links. Timed urine samples from three Japanese payload specialists were obtained for 3 days from May 19 to 21, 1991 (one year before the launch = L-1 year). Immediately before the launch (L-3 to L-0), urine samples were obtained from a payload specialist who was on board the Space Shuttle Endeavor (PS). During the inflight period (flight from September 3 to 10 in 1992), urine samples from the PS were collected by using Urine Monitoring System (UMS). After the landing, they were obtained from the PS for three days (R+0-R+2). Various parameters related to bone metabolism such as hydroxyproline, pyridinium cross-links and calcium were determined. It was noted that excretion of hydroxyproline decreased during the preflight periods when compared with that in the control L-1 year period. The average excretory rate during control period was 846.2 +/- 198.7 milligrams/hour (mean +/- SD), while those in the preflight 474.6 +/- 171.1 milligrams/hour, suggesting the diminished collagen intake during the preflight period. Average excretion rate of pyridinium cross-links during the first 4 mission days (MD0-MD3) was similar to that of preflight and control L-1 year period. However, it was significantly increased during the last 4 mission days (MD4-MD7). It returned to the preflight level during postflight days (R+0-R+2). Increased urinary excretion of calcium during the last 4 mission days were also observed. These results suggest that increase in bone resorption could occur during relatively short stay in microgravity.

Effects of bisphosphonate on bone metabolism in tail-suspended rats.

Our previous studies demonstrated that tail suspension causes early, transient increases in osteoclastic activity, followed by a decrease in osteoblastic activity in the hind limbs of rats. To assess whether this early increase in bone resorption is important in the development of disuse atrophy, the effect of YH529, a third generation bisphosphonate, was studied on hind limb atrophy in rats subjected to tail suspension. YH529 (YH group) or PBS (control group) were administered subcutaneously in 5-week-old male Wistar rats suspended for 7 days. In the control group, wet weight, calcium and phosphorus contents decreased significantly in the femur but they did not change in the humerus. In the YH group, however, these parameters did not change significantly in the femur, but both calcium and phosphorus increased significantly in the humerus. These results indicate that the inhibition of bone resorption by YH529 prevents the development of disuse atrophy induced by tail suspension. It is thus suggested that early increases in bone resorption are important for the development of disuse bone atrophy.

Pharmacologically active components from a Peruvian medicinal plant, huira-huira (Culcitium canescens H. & B.).

The methanol extract of Huira-Huira (Culcitium canescens) showed analgesic effects in acetic acid-induced writhing and tail pressure tests, and it also produced potent prolongation of hypnosis induced by pentobarbital. The latter activity was used as an isolation-guide to determine the active components which were identified as dehydrocacalohastine, cacalohastine and cacalonol.

Analgesic component of Notopterygium incisum Ting.

Notopterol was identified as the analgesic component of Notopterygium incisum TING by using the acetic acid-induced writhing method. Notopterol also indicated an anti-inflammatory activity by its inhibitory effect in the vascular permeability test. The intensive prolongation of pentobarbital-induced hypnosis was possibly caused by its inhibitory effect on the drug metabolism in liver. Pharmacological differences between the analgesic components of N. incisum, Aralia cordata and Angelica pubescens were also discussed.

Simple and sensitive determination of methylglyoxal in biological samples by gas chromatography with electron-capture detection.

Methylglyoxal was allowed to react with 4,5-dichloro-1,2-phenylenediamine, and the 6,7-dichloro-2-methylquinoxaline formed was determined by gas chromatography with electron-capture detection. The standard curve of the quinoxaline was linear up to 160 pmol/ml. The recoveries of methylglyoxal from coffee and rat liver homogenate were 84.1 and 77.6%, respectively. This procedure was very selective and so sensitive that as little as 9 fmol of the quinoxaline could be measured in biological and food samples.

Fluorometry of nanogram amounts of selenium in biological samples.

For fluorometry of selenium in human blood, hair, and liver and in leaves, we wet-ashed the samples with conventional nitric and perchloric acids, and then extracted piazselenol (complex of Se and 2,3-diaminonaphthalene) in cyclohexane. Selenium was back-extracted from the cyclohexane into nitric acid to remove the fluorometric interferences of trace amounts of organic compounds. This fluorometric method is rapid and suitable for routine analysis. We applied the method to human hair samples and compared it with the data for non-destructive neutron activation analysis of the hair.