Managing delayed-onset muscle soreness: lack of effect of selected oral systemic analgesics

OBJECTIVE

To investigate the efficacy of commonly available analgesics in the management of delayed-onset muscle soreness over an 11-day period.

DESIGN

Double-blind, placebo-controlled randomized trial.

SETTING

University laboratory.

PARTICIPANTS

Sixty healthy volunteers (30 men, 30 women) with no current arm pain or pathology completed the experimental procedure.

INTERVENTIONS

Subjects were randomly allocated to one of five experimental groups: control; placebo; aspirin (900 mg); codeine (60 mg); and paracetamol (1000 mg) (n = 12 in all groups). Delayed soreness was induced in the nondominant elbow flexors using a standardized exercise protocol of repeated eccentric contractions.

MAIN OUTCOME MEASURES

Pain (visual analogue scale; McGill pain questionnaire [MPQ]), range of extension, flexion and resting angle (universal goniometer), and mechanical pain threshold (pressure algometer). Measurements were taken before and after drug administration each day, except for the MPQ, which was completed on the first and third days of the experiment.

RESULTS

Analysis of results using repeated-measures analysis of variance and relevant post hoc tests provided no evidence of the effectiveness of any of the preparations.

CONCLUSION

There is no beneficial effect from the medications, at least at the doses stated, in the management of delayed-onset muscle soreness.

Failure to demonstrate any hypoalgesic effect of low intensity laser irradiation (830nm) of Erb's point upon experimental ischaemic pain in humans

BACKGROUND AND OBJECTIVE

This study assessed the putative analgesic effect of low intensity, near-infrared laser irradiation (830nm; 1.5 & 9.0J/cm2; continuous wave).

STUDY DESIGN/MATERIALS AND METHODS

The current study was completed under double-blind conditions using a standardised form of the submaximal effort tourniquet technique. Healthy naive female volunteers (n = 48) attended on two occasions for pain induction in the non-dominant upper limb, the first during which baseline data were obtained and on a second occasion during which subjects were randomly allocated to either control, placebo, or one of two treatment groups. In the treatment groups, irradiation was applied to ten points on the ipsilateral Erb's point immediately prior to the pain induction procedure at the parameters stated: For the placebo condition, sham "irradiation" was delivered by applying the laser unit without activating the probe. Pain was measured using computerised visual analogue scales and McGill Pain Questionnaires to assess "current pain intensity" and "worst pain experience," respectively.

RESULTS

Whereas analysis of variance and appropriate posthoc tests showed a trend toward hypoalgesia at a radiant exposure of 1.5J/cm2, no significant effects of laser therapy were found.

CONCLUSIONS

These results do not provide convincing evidence for the clinical potential of low intensity laser irradiation as a pain relieving modality, at least at the parameters used. Further work is thus necessary to provide objective quantifiable data on the putative clinical efficacy of this modality and the relevance (if any) of irradiation parameters.

Human sphingosine kinase: molecular cloning, functional characterization and tissue distribution

Sphingosine-1-phosphate (SPP), the product of sphingosine kinase, is an important signaling molecule with intra- and extracellular functions. The cDNA for the mouse sphingosine kinase has recently been reported. In this paper we describe the cloning, expression and characterization of the human sphingosine kinase (huSPHK1). Sequence analysis comparison revealed that this kinase is evolutionarily very conserved, having a high degree of homology with the murine enzyme, and presenting several conserved regions with bacteria, yeast, plant, and mammalian proteins. Expressed huSPHK1 cDNA specifically phosphorylates D-erythro-sphingosine and, to a lesser extent, D, L-erythro-dihydrosphingosine, and not at all the 'threo' isoforms of dihydrosphingosine; hydroxy-ceramide or non-hydroxy-ceramide; diacylglycerol (DAG); phosphatidylinositol (PI); phosphatidylinositol-4-phosphate (PIP); or phosphatidylinositol-4, 5-bisphosphate (PIP(2)). huSPHK1 shows typical Michaelis-Menten kinetics (V(max)=56microM and K(m)=5microM). The kinase is inhibited by D,L-threo-dihydrosphingosine (K(i)=3microM), and by N, N-dimethyl-sphingosine (K(i)=5microM). Northern blots indicate highest expression in adult lung and spleen, followed by peripheral blood leukocyte, thymus and kidney, respectively. It is also expressed in brain and heart. In addition, database searches with the stSG2854 sequence indicate that huSPHK1 is also expressed in endothelial cells, retinal pigment epithelium, and senescent fibroblasts.

Pituitary adenylyl cyclase-activating peptide activates multiple intracellular signaling pathways to regulate ion channels in PC12 cells

Pituitary adenylyl cyclase-activating peptide (PACAP) stimulates calcium transients and catecholamine secretion in adrenal chromaffin and PC12 cells. The PACAP type 1 receptor in these cells couples to both adenylyl cyclase and phospolipase C pathways, but although phospolipase C has been implicated in the response to PACAP, the role of adenylyl cyclase is unclear. In this study, we show that PACAP38 stimulates Ca(2+) influx in PC12 cells by activating a cation current that depends upon the dual activation of both the PLC and adenylyl cyclase signaling pathways but does not involve protein kinase C. In activating the current, PACAP38 has to overcome an inhibitory effect of Ras. Thus, in cells expressing a dominant negative form of Ras (PC12asn17-W7), PACAP38 induced larger, more rapidly activating currents. This effect of Ras could be overidden by intracellular guanosine-5'-O-3-(thio)triphosphate (GTPgammaS), suggesting that it was mediated by inhibition of downstream G proteins. Ras may also inhibit the current through a G protein-independent mechanism, because cAMP analogues activated the current in PC12asn17-W7 cells, provided GTPgammaS was present, but not in PC12 cells expressing wild type Ras. We conclude that coupling of PACAP to both adenylyl cyclase and phospholipase C is required to activate Ca(2+) influx in PC12 cells and that tonic inhibition by Ras delays and limits the response.

1,3,5-Trialkyl-2,4,6-triiodobenzenes: novel X-ray contrast agents for gastrointestinal imaging

Examination of the gastrointestinal (GI) tract has been performed for decades using barium sulfate. Although this agent has many recognized limitations including extreme radiopacity, poor intrinsic affinity for the GI mucosa, and very high density, no alternative contrast agents have emerged which produce comparable or better contrast visualization. In fact, the various techniques of the GI radiologic examination (i.e., single contrast, double contrast, biphasic) were developed to compensate for its limitations. Each of these techniques requires complex patient manipulation to achieve adequate mucosal coating or compression to overcome the marked radiopacity of barium sulfate in order to obtain a diagnostically useful examination. A series of novel radiopaque oils, the 1,3, 5-trialkyl-2,4,6-triiodobenzenes, was designed to improve the efficacy, stability, and safety of barium formulations. These substances were prepared in two steps from 1,3,5-trichlorobenzene. Compound 17 (1,3,5-tri-n-hexyl-2,4,6-triiodobenzene), formulated as an oil-in-water emulsion, was found to be well-tolerated in rodents (mice, hamsters, rats) following acute oral and/or intraperitoneal administrations at 4 times the anticipated human clinical dose. No metabolism of 17 was detected in rat, hamster, dog, monkey, or human hepatic microsomes, suggesting the lack of oral toxicity was a consequence of poor absorption. In imaging experiments in dogs, emulsions of 17 have demonstrated excellent mucosal coating and improved radiodensity relative to barium sulfate suspensions. On the basis of the preliminary imaging and toxicity data, compound 17 was selected as a potential development candidate.

Study of the effects of various transcutaneous electrical nerve stimulation (TENS) parameters upon the RIII nociceptive and H-reflexes in humans

Despite over two decades of clinical use, the neurophysiological and anti-nociceptive effects of transcutaneous electrical nerve stimulation (TENS) have yet to be definitively described. The current study was designed to examine the effect of TENS on the RIII nociceptive reflex elicited in healthy human subjects; the H-reflex was measured concomitantly to monitor changes in alpha-motoneuron excitability. Following approval from the university's ethical committee, 50 healthy human volunteers (25 male and 25 female) participated in the study. The subjects ranged in age from 18 to 30 years (mean 22, SD 3). Subjects were randomly allocated equally to a control group or one of four TENS groups. In the TENS groups, stimulation was applied for a total of 15 min over the sural nerve in the left leg. Ipsilateral RIII and H-reflexes were recorded five times during the 45 min experimental period. In addition, subjects also rated pain associated with the RIII reflex using a computerized visual analogue scale (VAS). Statistical analysis using two-way repeated-measures ANOVA showed no differences between groups for H-reflex, RIII reflex nor VAS data. These results suggest that TENS does not significantly affect either of the two reflexes, at least using the parameters and application time in the current study.

Repeat transduction in the mouse lung by using adeno-associated virus vectors with different serotypes

Vectors derived from adeno-associated virus type 2 (AAV2) promote gene transfer and expression in the lung; however, we have found that while gene expression can persist for at least 8 months in mice, it was reduced dramatically in rabbits over a period of 2 months. The efficiency and persistence of AAV2-mediated gene expression in the human lung have yet to be determined, but it seems likely that readministration will be necessary over the lifetime of an individual. Unfortunately, we have found that transduction by a second administration of an AAV2 vector is blocked, presumably due to neutralizing antibodies generated in response to the primary vector exposure. Here, we have explored the use of AAV2 vectors pseudotyped with capsid proteins from AAV serotypes 2, 3, and 6 for readministration in the mouse lung. We found that an AAV6 vector transduced airway epithelial and alveolar cells in the lung at rates that were at least as high as those of AAV2 pseudotype vectors, while transduction rates mediated by AAV3 were much lower. AAV6 pseudotype vector transduction was unaffected by prior administration of an AAV2 or AAV3 vector, and transduction by an AAV2 pseudotype vector was unaffected by prior AAV6 vector administration, showing that cross-reactive neutralizing antibodies against AAV2 and AAV6 are not generated in mice. Interestingly, while prior administration of an AAV2 vector completely blocked transduction by a second AAV2 pseudotype vector, prior administration of an AAV6 vector only partially inhibited transduction by a second administration of an AAV6 pseudotype vector. Analysis of sera obtained from mice and humans showed that AAV6 is less immunogenic than AAV2, which helps explain this finding. These results support the development of AAV6 vectors for lung gene therapy both alone and in combination with AAV2 vectors.

Improved adeno-associated virus vector production with transfection of a single helper adenovirus gene, E4orf6

Recent advances in adeno-associated virus (AAV) vector production have eliminated the need for adenovirus infection by transfection of plasmids encoding the adenovirus E2A, E4orf6, and VA RNA transcription units. We report here the generation of significantly higher AAV vector titers with transfection of the single adenovirus gene, E4orf6, when used in conjunction with the split AAV packaging plasmids MTrep and CMVcap. Transduction in a murine lung model with these higher titer vector stocks was greater than that observed with traditional preparation methods. The generation of higher titer AAV vector stocks with fewer adenovirus gene products and free of replication-competent AAV will enhance the potential for AAV in clinical applications.

Endocytosis and vesicular trafficking of immune complexes and activation of phospholipase D by the human high-affinity IgG receptor requires distinct phosphoinositide 3-kinase activities

FcgammaRI, the human high-affinity IgG receptor, is responsible for the internalization of immune complexes and their subsequent targetting to the lysosomes for degradation. We show here that aggregation of FcgammaRI by surface immune complexes in interferon-gamma-primed U937 cells causes the transient appearance of swollen vacuolar structures, probably swollen late endosomes, which disappear as the immune complexes are degraded. Wortmannin and LY294002, specific inhibitors of phosphoinositide 3-kinases (PI 3-kinases), delay the disappearance of these structures and also correspondingly inhibit degradation of FcgammaRI-mediated immune complexes. In addition these inhibitors delay the initial phase of FcgammaRI-mediated endocytosis of immune complexes and block the activity of FcgammaRI-stimulated phospholipase D, an enzyme that has previously been implicated in membrane-trafficking events. p85 is the regulatory subunit of PI 3-kinase. A p85-dependent PI 3-kinase was shown to be involved in the initial phase of FcgammaRI-mediated endocytosis, but not in the trafficking of immune complexes for degradation or the activation of phospholipase D. The results presented here show a role for a p85-independent PI 3-kinase in regulating the trafficking of FcgammaRI-mediated immune complexes, either directly or as a result of the activation of phospholipase D, and a distinct role for a p85-dependent PI 3-kinase isoform in the initial phases of FcgammaRI-mediated internalization of immune complexes.

Persistent, therapeutically relevant levels of human granulocyte colony-stimulating factor in mice after systemic delivery of adeno-associated virus vectors

Adeno-associated virus (AAV) vectors have been shown to preferentially transduce hepatocytes after systemic administration in adult mice and to provide long-term expression of introduced genes. One application of this technology would be for the production of granulocyte colony-stimulating factor (G-CSF), which increases mature neutrophil numbers in humans and in animals, and has therapeutic effects in disorders featuring chronic neutropenia, including cyclic, severe congenital, and idiopathic neutropenia, and glycogen storage disease type Ib. We have treated mice by tail vein injection of AAV vectors encoding human G-CSF, and have detected high G-CSF levels and marked elevation of neutrophil counts for at least 5 months. A therapeutically relevant amount of G-CSF production was obtained when the liver-specific mouse albumin promoter-enhancer was used to drive G-CSF expression. In mice receiving higher amounts of vector, plasma levels of human G-CSF gradually increased over 3 weeks to high concentrations, whereas for lower amounts human G-CSF remained at initial, low levels. The previously observed effect of gamma irradiation, to increase AAV transduction rates, was diminished when large amounts of vector were used. Absolute neutrophil counts increased 10- to 50-fold for the period of observation to levels that would be therapeutic in the treatment of cyclic neutropenia. In conclusion, gene therapy with AAV vectors synthesizing G-CSF shows promise for the treatment of disorders featuring neutropenia.

Comparative analgesic effects of H-wave therapy and transcutaneous electrical nerve stimulation on pain threshold in humans

OBJECTIVE

To assess the comparative analgesic efficacy of H-wave therapy (HWT) and transcutaneous electrical nerve stimulation (TENS) using a mechanical model of pain threshold measurement.

STUDY DESIGN

Forty-eight healthy human volunteers (24 women, 24 men) were recruited and randomly assigned into one of six experimental groups; control, HWT (placebo, 2Hz, or 60Hz), or TENS (placebo or 110Hz). For each subject, mechanical pain threshold (MPT) measurements were recorded at three standardized recording points marked on the dorsal web space of the dominant hand. Two MPT measurements were recorded at each point at the following time intervals: before treatment was initiated (baseline), after each of three consecutive 10-minute periods of stimulation (HWT or TENS), and at four intervals within 30 minutes after stimulation. In the control and placebo groups MPT measurements were recorded at similar time intervals.

RESULTS

Difference scores, calculated from patients' baseline values, were analyzed by ANOVA for each of the three recording points. Although results showed a significant increase in MPT levels in all three stimulation groups when compared with their relative placebo (indicating a hypoalgesic effect), no differences were observed between the different modalities or HWT frequencies. Significant hypoalgesia continued for 5 minutes after stimulation.

CONCLUSION

The findings showed that HWT and TENS provided localized hypoalgesia during stimulation and for up to 5 minutes after it. No frequency- or modality-specific effects were observed between the groups.

FcgammaRI activation of phospholipase Cgamma1 and protein kinase C in dibutyryl cAMP-differentiated U937 cells is dependent solely on the tyrosine-kinase activated form of phosphatidylinositol-3-kinase

The human high affinity receptor for immunoglobulin G, FcgammaRI, in dibutyryl cyclic AMP (dbcAMP)-differentiated U937 cells, is coupled to the activation of phospholipase C (PLC) and the conventional protein kinase C (PKC) isoforms, alpha, beta, and gamma. Here we demonstrate that aggregation of FcgammaRI activates the tyrosine-kinase regulated form of phosphatidylinositol-3-kinase (PI-3-kinase) and that an increase of phosphatidylinositol trisphosphate (PIP3) is essential for the activation and translocation of PLCgamma1 in these cells. In addition, activation of the PKC isoforms was ablated by specific inhibitors of PI3-kinase or by overexpression of a dominant negative p85 subunit of PI3-kinase. The findings reported here demonstrate that PLCgamma1 and PKC activation by FcgammaRI are downstream of PI3-kinase, and that in contrast to cytokine primed cells, only the tyrosine-kinase activated isoform of PI3-kinase is coupled to FcgammaRI in dbcAMP-differentiated cells.

The human high-affinity immunoglobulin G receptor activates SH2-containing inositol phosphatase (SHIP)

On cytokine-primed U937 cells, aggregation of the human high-affinity immunoglobulin receptor, FcgammaRI, initiates signal transduction cascades which lead to the release of calcium from intracellular stores and no significant calcium influx. In these cells, aggregation of FcgammaRI results in no significant increase in inositol trisphosphate production, but rather phospholipase D is activated. Here we show that, in interferon-gamma (IFN-gamma)-primed cells, the SH2 containing inositol 5' phosphatase, SHIP, is constitutively associated with the membrane fraction. Following aggregation of FcgammaRI, SHIP is rapidly and transiently tyrosine phosphorylated and becomes associated with the adapter molecule Shc. Shc also becomes tyrosine phosphorylated and translocates from the cytoplasm to the membrane fraction concomitant with the association between Shc and SHIP. Further, SHIP and Shc appear to be recruited to membrane-associated immune complexes following FcgammaRI aggregation. As no immunoreceptor inhibitory motif has been demonstrated to associate with FcgammaRI, these data suggest that SHIP may be recruited to the receptor through an SH2 domain interaction with Shc.

Biosynthesis of straight-chain ester volatiles in red delicious and granny smith apples using deuterium-labeled precursors

Biosynthesis of straight-chain ester volatiles by Granny Smith and Red Delicious apples was investigated using deuterium-labeled fatty acids, C-6 aldehydes, and alcohols. Perdeuterated saturated and monounsaturated fatty acids were metabolized to hexyl-d(11), hexanoate-d(11), heptanoate-d(13), and octanoate-d(15) esters, whereas perdeuterated linoleic acid produced only hexyl-d(11) and hexanoate-d(11) esters. Exposure of fruit to vapors of deuterated 3Z-hexenal, 2E-hexenal, and hexanal identified the following biosynthetic processes: (1) isomerization between 3E, 3Z, and 2E-hexenals; (2) reduction to 3E, 3Z, and 2E-hexenyl esters; (3) reduction to hexanol and hexyl esters; (4) oxidation to hexanoic acid and formation of hexanoate esters; (5) beta-oxidation of hexanoic acid leading to butyl and butanoate esters; and (6) alpha-oxidation of hexanoic acid leading to pentyl and pentanoate esters. Unsaturated straight-chain ester volatiles appear to arise only by the lipoxygenase pathway and may be useful indicators of lipoxygenase activity in fruit.

Biosynthesis of straight-chain ester volatiles in red delicious and granny smith apples using deuterium-labeled precursors

Biosynthesis of straight-chain ester volatiles by Granny Smith and Red Delicious apples was investigated using deuterium-labeled fatty acids, C-6 aldehydes, and alcohols. Perdeuterated saturated and monounsaturated fatty acids were metabolized to hexyl-d(11), hexanoate-d(11), heptanoate-d(13), and octanoate-d(15) esters, whereas perdeuterated linoleic acid produced only hexyl-d(11) and hexanoate-d(11) esters. Exposure of fruit to vapors of deuterated 3Z-hexenal, 2E-hexenal, and hexanal identified the following biosynthetic processes: (1) isomerization between 3E, 3Z, and 2E-hexenals; (2) reduction to 3E, 3Z, and 2E-hexenyl esters; (3) reduction to hexanol and hexyl esters; (4) oxidation to hexanoic acid and formation of hexanoate esters; (5) beta-oxidation of hexanoic acid leading to butyl and butanoate esters; and (6) alpha-oxidation of hexanoic acid leading to pentyl and pentanoate esters. Unsaturated straight-chain ester volatiles appear to arise only by the lipoxygenase pathway and may be useful indicators of lipoxygenase activity in fruit.

Management of nonspecific low back pain by physiotherapists in Britain and Ireland. A descriptive questionnaire of current clinical practice

STUDY DESIGN

A descriptive questionnaire of chartered physiotherapists.

OBJECTIVE

To investigate current physiotherapeutic management of low back pain throughout Britain and Ireland.

SUMMARY OF BACKGROUND DATA

Physiotherapists play a key role in low back pain management. Although clinical guidelines for best practice have been developed recently, there has been no large-scale attempt to describe current physiotherapeutic treatment approaches within Britain or Ireland.

METHODS

After semi-structured interviews (n = 6) and two pilot studies (n = 77) were done, postal questionnaires were distributed to four regional cluster samples of the membership of two physiotherapy professional organizations (n = 2654). After two mailings, a random sample of 90 nonresponders were followed up. Data were analyzed using the Statistical Package for the Social Sciences (SPSS Ltd., Woking, Surrey, UK), and precision of the survey estimates was assessed by calculation of sampling errors and intraclass correlation coefficients for cluster sampling.

RESULTS

Results were received from 1548 therapists (total response rate, 58.3%); of these, 813 reported that they were practicing in settings in which they treated patients with low back pain. Analysis of the results indicated the overall popularity of the Maitland mobilization and McKenzie approaches among physiotherapists. Although exercise per se was mentioned frequently by respondents, a marked difference in opinion among therapists regarding the optimal type of exercise for low back pain was obvious. Little evidence was demonstrated of the use of manipulation, fitness programs, or multidisciplinary efforts involving behavioral and physical aspects of treatment. Commonly used methods of electrotherapy were interferential therapy, ultrasound, pulsed short-wave diathermy, and transcutaneous electrical nerve stimulation.

CONCLUSIONS

The results of this study emphasize the need to evaluate further and improve the dissemination of findings regarding the effectiveness of specific physiotherapy approaches for low back pain management.

Nicotinamide-inhibited vasoconstriction: lack of dependence on agonist signalling pathways

Previously, we have shown that nicotinamide inhibits both high [K+]- and phenylephrine-induced constrictions in a dose-dependent manner in rat tail arteries. We have now investigated the effect of nicotinamide on intracellular signalling pathways in vascular smooth muscle. Nicotinamide (8.2 mM) reduced the response to phenylephrine- and [Arg8]vasopressin-induced constrictions by means of 72.9+/-6.9 and 51.8+/-5.7%, respectively. It also blocked phenylephrine-induced constrictions in the absence of a functional endothelium (P < 0.0136). In addition, pre-treatment of the artery with nifedipine (10 mM) also failed to inhibit nicotinamide's activity (P < 0.0178). Moreover, nicotinamide significantly reduced the sensitivity to phenylephrine in Ca2+-free Krebs' solution (P < 0.0152). Continuous perfusion of maximal concentrations of ryanodine or thapsigargin significantly inhibited the response to phenylephrine; the addition of nicotinamide (8.2 mM) caused a significant additional inhibition when compared to the effect of ryanodine (P < 0.0006) or thapsigargin (P<0.037) alone. In addition, beta-escin (0.02%) permeabilisation and Ca2+ (2.5 mM)-mediated constriction was also significantly attenuated by nicotinamide (P < 0.0001). However, phorbol ester-induced constriction was not attenuated by nicotinamide. This would suggest that nicotinamide directly inhibits vascular smooth muscle cell contraction and is unlikely to act via blockage of external Ca2+ entry or release of Ca2+ from intracellular stores.

Effect of cholesterol feeding on DNA damage in male and female Syrian hamsters

Cholesterol oxides are cytotoxic and have been implicated in many disease processes; however, it has been proposed that cholesterol oxides result from cholesterol acting as a sacrificial antioxidant. In this study, the effect of dietary cholesterol on DNA damage, assessed by the alkaline comet assay, was examined in male and female Syrian hamsters. Animals were fed ad libitum a modified AIN-76 diet (control) or a diet with 0.5% cholesterol for 10 weeks. Following the 10-week feeding period, there was no significant difference in body weight between cholesterol-fed and control animals. Cholesterol feeding resulted in significant liver hypertrophy, and increased plasma total and HDL cholesterol in both male and female animals compared with controls. There was no difference in liver cell DNA damage levels as measured by the comet assay. Heart cells from cholesterol-fed hamsters, however, showed a significant decrease in tail DNA (p = 0.050) indicating decreased damage compared with controls and a possible protective effect of cholesterol against DNA damage.

Differentiation-dependent switch in protein kinase C isoenzyme activation by FcgammaRI, the human high-affinity receptor for immunoglobulin G

Aggregation of receptors for the constant region (Fc) of immunoglobulin G on myeloid cells results in endocytosis or phagocytosis and cellular activation. Previous work has shown, using the cell line U937, that the high-affinity immunoglobulin G receptor, FcgammaRI, activates alternate intracellular signalling pathways depending on the cell differentiation state, which results in a marked change in the nature of calcium transients within the cell. Here, we show that protein kinase C (PKC) is activated in both interferon-gamma (IFN-gamma) -primed and dibutyryl cyclic AMP (dbcAMP) -differentiated cells but that the nature of the particular isoenzymes recruited differs. Thus, in IFN-gamma-primed U937 cells, FcgammaRI aggregation results in an increase of PKC activity which is essentially calcium independent resulting from the translocation to the membrane of the novel PKCs, delta and epsilon, together with the atypical PKC zeta. However, in cells differentiated to a more macrophage phenotype, all PKC enzyme activity after receptor aggregation is calcium dependent. Consistent with this finding, the isoenzymes translocated to the nuclear-free membrane fraction are the conventional PKCs alpha, beta and gamma; results consistent with our previous finding that FcgammaRI couples to phospholipase C in such dbcAMP-differentiated cells. Thus, the nature of PKC isoenzyme activated following FcgammaRI aggregation is defined by differentiation. The calcium dependence of the PKC isoenzyme is consistent with the duration of calcium transients previously reported in the two differentiation states.

Delayed onset muscle soreness: lack of effect of therapeutic ultrasound in humans

OBJECTIVE

To investigate the effects of two dosages of pulsed ultrasound therapy (1 MHz, spatial averaged peak intensity 0.8 W/cm2, mark space ratio of 1:4) on acute-stage delayed onset muscle soreness (DOMS).

DESIGN

Double-blind, placebo-controlled, randomized trial.

SETTING

Laboratory of a university physiotherapy department.

PARTICIPANTS

Forty-eight healthy volunteers (24 men, 24 women) with no arm pathology or pain at the time of the study.

INTERVENTIONS

Subjects were randomly allocated to one of four treatment groups: control, placebo (sham insonation), low-dosage pulsed ultrasound (mean dosage 172.8 J), or high-dosage pulsed ultrasound (mean dosage 345.6 J). DOMS was induced in the nondominant elbow flexors in a standardized fashion through repeated eccentric exercise until exhaustion.

MAIN OUTCOME MEASURES

Elbow extension, flexion, and resting angles (universal goniometer), pain (visual analogue scale), mechanical pain threshold/tenderness (pressure algometer), and a McGill pain questionnaire. Measurements were taken before and after treatment each day except for the McGill pain questionnaire, which was completed at the end of the trial.

RESULTS

Significant differences were seen between groups in relation to range of flexion (p = .0032), with the control group losing least range of flexion. There were no other significant differences between the groups.

CONCLUSION

No convincing evidence was found to support the use of pulsed ultrasound therapy in the management of DOMS at the parameters discussed here.

Improved gene transfer into baboon marrow repopulating cells using recombinant human fibronectin fragment CH-296 in combination with interleukin-6, stem cell factor, FLT-3 ligand, and megakaryocyte growth and development factor

We have used a competitive repopulation assay in baboons to develop improved methods for hematopoietic stem cell transduction and have previously shown increased gene transfer into baboon marrow repopulating cells using a gibbon ape leukemia virus (GALV)-pseudotype retroviral vector (Kiem et al, Blood 90:4638, 1997). In this study using GALV-pseudotype vectors, we examined additional variables that have been reported to increase gene transfer into hematopoietic progenitor cells in culture for their ability to increase gene transfer into baboon hematopoietic repopulating cells. Baboon marrow was harvested after in vivo administration (priming) of stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF). CD34-enriched marrow cells were divided into two equal fractions to directly compare transduction efficiencies under different gene transfer conditions. Transduction by either incubation with retroviral vectors on CH-296-coated flasks or by cocultivation on vector-producing cells was studied in five animals; in one animal, transduction on CH-296 was compared with transduction on bovine serum albumin (BSA)-coated flasks. The highest level of gene transfer was obtained after 24 hours of prestimulation followed by 48 hours of incubation on CH-296 in vector-containing medium in the presence of multiple hematopoietic growth factors (interleukin-6, stem cell factor, FLT-3 ligand, and megakaryocyte growth and development factor). Using these conditions, up to 20% of peripheral blood and marrow cells contained vector sequences for more than 20 weeks, as determined by both polymerase chain reaction and Southern blot analysis. Gene transfer rates were higher for cells transduced on CH-296 as compared with BSA or cocultivation. In one animal, we have used a vector expressing a cell surface protein (human placental alkaline phosphatase) and have detected 10% and 5% of peripheral blood cells expressing the transduced gene 2 and 4 weeks after transplantation as measured by flow cytometry. In conclusion, the conditions described here have resulted in gene transfer rates that will allow detection of transduced cells by flow cytometry to facilitate the evaluation of gene expression. The levels of gene transfer obtained with these conditions suggest the potential for therapeutic efficacy in diseases affecting the hematopoietic system.

Transcutaneous electrical nerve stimulation: effect on peripheral nerve conduction, mechanical pain threshold, and tactile threshold in humans

OBJECTIVES

To investigate the effect of different transcutaneous electrical nerve stimulation (TENS) parameters on nerve conduction in the human superficial radial nerve and on peripheral mechanical pain threshold (MPT) and tactile threshold (TT), and to further the current knowledge of the neurophysiologic effects of TENS.

STUDY DESIGN

Fifty healthy human subjects were randomly allocated in equal numbers to a control group or one of four TENS groups to receive electrical stimulation consisting of four combinations of TENS pulse durations (50microsec and 200microsec) and frequencies (4Hz and 110Hz). In the TENS groups, TENS was applied under double-blind conditions for 15 minutes over the superficial radial nerve in the dominant forearm. Over a 1-hour period, compound action potentials, MPT readings, and TT readings were recorded bilaterally.

RESULTS

Only one combination of TENS parameters (110Hz, 200microsec) effected consistent changes in all of the variables assessed, ie, TENS produced a significant increase in negative peak latency while simultaneously increasing both MPT and TT.

CONCLUSION

The findings from this study suggest that at least part of TENS-mediated hypoalgesia is a consequence of a direct peripheral effect of TENS, although a "central" effect may not be excluded.

Team assessment utilizing a many-facet Rasch model

As organizations begin to implement work teams, their assessment will ultimately reflect compensation strategies that move away from individual assessment. This will involve not only using multiple raters, but also the use of multiple criteria. Team assessment using multiple raters and multiple criteria is therefore necessitated; however, this can produce differences in ratings due to the leniency or severity of the individual team raters. This study analyzed the ratings of individual members on 31 different teams across 12 different criteria of team performance. Utilizing the many-facet Rasch model, statistical differences between the teams and 12 criteria were calculated.