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Muscle Pain (muscle + pain)

Distribution by Scientific Domains

Medical Sciences	76%
Life Sciences	24%

Distribution within Medical Sciences

Neurology	21%
Pharmacology & Pharmaceutical Medicine	15%

Selected Abstracts

Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects

THE JOURNAL OF PHYSIOLOGY, Issue 1 2009
A. R. Burton
Human studies conducted more than half a century ago have suggested that superficial pain induces excitatory effects on the sympathetic nervous system, resulting in increases in blood pressure (BP) and heart rate (HR), whereas deep pain is believed to cause vasodepression. To date, no studies have addressed whether deep or superficial pain produces such differential effects on muscle sympathetic nerve activity (MSNA). Using microneurography we recorded spontaneous MSNA from the common peroneal nerve in 13 awake subjects. Continuous blood pressure was recorded by radial arterial tonometry. Deep pain was induced by intramuscular injection of 0.5 ml hypertonic saline (5%) into the tibialis anterior muscle, superficial pain by subcutaneous injection of 0.2 ml hypertonic saline into the overlying skin. Muscle pain, with a mean rating of 4.9 ± 0.8 (s.e.m.) on a 0,10 visual analog scale (VAS) and lasting on average 358 ± 32 s, caused significant increases in MSNA (43.9 ± 10.0%), BP (5.4 ± 1.1%) and HR (7.0 ± 2.0%) , not the expected decreases. Skin pain, rated at 4.9 ± 0.6 and lasting 464 ± 54 s, also caused significant increases in MSNA (38.2 ± 12.8%), BP (5.1 ± 2.1%) and HR (5.6 ± 2.0%). The high-frequency (HF) to low-frequency (LF) ratio of heart rate variability (HRV) increased from 1.54 ± 0.25 to 2.90 ± 0.45 for muscle pain and 2.80 ± 0.52 for skin pain. Despite the different qualities of deep (dull and diffuse) and superficial (burning and well-localized) pain, we conclude that pain originating in muscle and skin does not exert a differential effect on muscle sympathetic nerve activity, both causing an increase in MSNA and an increase in the LF : HF ratio of HRV. Whether this holds true for longer lasting experimental pain remains to be seen. [source]

The effects of experimental muscle and skin pain on the static stretch sensitivity of human muscle spindles in relaxed leg muscles

THE JOURNAL OF PHYSIOLOGY, Issue 11 2008
Ingvars Birznieks
Animal studies have shown that noxious inputs onto ,-motoneurons can cause an increase in the activity of muscle spindles, and it has been proposed that this causes a fusimotor-driven increase in muscle stiffness that is believed to underlie many chronic pain syndromes. To test whether experimental pain also acts on the fusimotor system in humans, unitary recordings were made from 19 spindle afferents (12 Ia, 7 II) located in the ankle and toe extensors or peronei muscles of awake human subjects. Muscle pain was induced by bolus intramuscular injection of 0.5 ml 5% hypertonic saline into tibialis anterior (TA); skin pain was induced by 0.2 ml injection into the overlying skin. Changes in fusimotor drive to the muscle spindles were inferred from changes in the mean discharge frequency and discharge variability of spindle endings in relaxed muscle. During muscle pain no afferents increased their discharge activity: seven afferents (5 Ia, 2 II) showed a decrease and six (4 Ia, 2 II) afferents were not affected. During skin pain of 13 afferents discharge rate increased in one (Ia) and decreased in two (1 Ia, 1 II). On average, the overall discharge rate decreased during muscle pain by 6.1% (P < 0.05; Wilcoxon), but remained essentially the same during skin pain. There was no detectable correlation between subjective pain level and the small change in discharge rate of muscle spindles. Irrespective of the type of pain, discharge variability parameters were not influenced (P > 0.05; Wilcoxon). We conclude that, contrary to the ,vicious cycle' hypothesis, acute activation of muscle or skin nociceptors does not cause a reflex increase in fusimotor drive in humans. Rather, our results are more aligned with the pain adaptation model, based on clinical studies predicting pain-induced reductions of agonist muscle activity. [source]

Isoprostane 8-epi-PGF2, is frequently increased in patients with muscle pain and/or CK-elevation after HMG-Co-enzyme-A-reductase inhibitor therapy

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2001
H. Sinzinger
Background:,Muscle pains with or without CK-elevation are among the most frequently observed side-effects in patients with hyperlipoproteinemia on various statins. The pathophysiological background, however, remains obscure. Methods:,We examined isoprostane 8-epi-PGF2,, a marker of in-vivo oxidation injury, in plasma, serum and urine in these patients at baseline, when muscle problems manifested and different time intervals after withdrawing the respective statin. A healthy control group and a group of untreated patients with hyperlipoproteinemia were run as controls. Results:,The majority of patients with muscular side-effects show elevated 8-epi-PGF2, in plasma and urine, whereas serum values were elevated only to a lesser extent. Stopping statin therapy or successfully changing to another member of this family of compounds resulted in a normalization of the values in all patients. Conclusion:,These findings indicate a significant involvement of oxidative injury in the muscular side-effects of statins in patients suffering from hyperlipoproteinemia. [source]

Evaluation of sympathetic vasoconstrictor response following nociceptive stimulation of latent myofascial trigger points in humans

ACTA PHYSIOLOGICA, Issue 4 2009
Y. Kimura
Abstract Aim:, Myofascial trigger points (MTrPs) are a major cause of musculoskeletal pain. It has been reported that stimulation of a latent MTrP increases motor activity and facilitates muscle pain via activation of the sympathetic nervous system. However, the magnitude of the sympathetic vasoconstrictor response following stimulation of MTrP has not been studied in healthy volunteers. The aims of this study were to (1) evaluate the magnitude of the vasoconstrictor response following a nociceptive stimulation (intramuscular glutamate) of MTrPs and a breath-hold manoeuvre (activation of sympathetic outflow) and (2) assess whether the vasoconstrictor response can be further modulated by combining a nociceptive stimulation of MTrPs and breath-hold. Methods:, Fourteen healthy subjects were recruited in this study. This study consisted of four sessions (normal breath group as control, breath-hold group, glutamate MTrP injection group and glutamate MTrP injection + breath-hold group). Skin blood flow and skin temperature in both forearms were measured with laser Doppler flowmetry and infrared thermography, respectively, in each session (before the treatment, during the treatment and after the treatment). Results:, Glutamate injection into MTrPs decreased skin temperature and blood flow in the peripheral area. The magnitudes of the reduction were comparable to those induced by the breath-hold manoeuvre, which has been used to induce sympathetic vasoconstrictor response. Conclusion:, The combination of glutamate injection into latent MTrPs together with the breath-hold manoeuvre did not result in further decrease in skin temperature and blood flow, indicating that sympathetic vasoconstrictor activity is fully activated by nociceptive stimulation of MTrPs. [source]

Phosphoglycerate kinase deficiency in two brothers with McArdle-like clinical symptoms

EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2000
J. Aasly
Phosphoglycerate kinase (PGK) catalyses the transfer of the acylphosphate group of 1,3-diphosphoglycerate to ADP with formation of 3-phosphoglycerate and ATP in the terminal stage of the glycolytic pathway. Two young brothers are presented who both experienced muscle pain, cramps and stiffness shortly after beginning heavy exercise. After these episodes they noticed that the urine was dark brown, indicating rhabdomyolysis and myoglobinuria. The neurological examinations were without remarks. There was no lactate increase in the ischaemic forearm exercise test. Both had very low PGK levels in muscle, erythrocytes, leukocytes and fibroblasts. This is the first family with more than one affected case of PGK deficiency and exercise-induced stiffness, myalgia and rhabdomyolysis. The clinical manifestations may resemble myophosphorylase deficiency (McArdle's disease: glycogenosis Type V) and muscle phosphofructokinase deficiency (Tarui's disease: glycogenosis Type VII). PGK deficiency is inherited as an X-linked trait and may show other features such as mental retardation and/or haemolytic anaemia. [source]

Effects of prolonged gum chewing on pain and fatigue in human jaw muscles

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2001
Mauro Farella
Gum chewing has been accepted as an adjunct to oral hygiene, as salivary stimulant and vehicle for various agents, as well as for jaw muscle training. The aim of this study was to investigate the effects of prolonged gum chewing on pain, fatigue and pressure tenderness of the masticatory muscles. Fifteen women without temporomandibular disorders (TMD) were requested to perform one of the following chewing tasks in three separate sessions: chewing a very hard gum, chewing a soft gum, and empty-chewing with no bolus. Unilateral chewing of gum or empty chewing was performed for 40 min at a constant rate of 80 cycles/min. In each session, perceived muscle pain and masticatory fatigue were rated on visual analog scales (VAS) before, throughout, and after the chewing task. Pressure pain thresholds (PPTs) of masseter and anterior temporalis muscles were assessed before and immediately after the chewing tasks, and again after 24 h. The VAS scores for pain and fatigue significantly increased only during the hard gum chewing, and after 10 min of recovery VAS scores had decreased again, almost to their baseline values. No significant changes were found for PPTs either after hard or soft gum chewing. The findings indicate that the jaw muscles recover quickly from prolonged chewing activity in subjects without TMD. [source]

Psychosocial Impact of Headache and Comorbidity with Other Pains among Swedish School Adolescents

HEADACHE, Issue 8 2002
Åsa Fichtel MSc
Background.,The psychosocial impact of headache combined with other pains has previously been insufficiently investigated. Objective., The present study examined the prevalence of headache, its comorbidity with other pains and psychosocial impact among adolescents. Methods., 793 adolescents in a sample recruited from 8 schools in the middle of Sweden were assessed. Results.,Forty-five percent of the adolescents reported ongoing pain during assessment and more than half of the adolescents reported at least one frequent pain during the previous 6 months. The most common pain among girls was headache (42%), but for boys muscle pain (32%) was most prevalent. Number of pains and perceived pain disability were also higher among girls than boys. One-third of the headache sufferers had headache only, while one-third reported one other frequent pain and the others had at least two other frequent pains. Overall, adolescents with frequent headaches had higher levels of anxiety or depressive symptoms, in addition to functional disability and usage of analgesic medication. Frequent headache sufferers reported more problems in everyday life areas than those with infrequent headaches. Conclusions.,It is recommended that adolescents suffering from recurrent headaches routinely should be asked about the presence of other pains, anxiety and depressive symptoms, medication usage, in addition to psychosocial consequences in their everyday life activities. Longitudinal research is also needed to delineate causal relationships between psychosocial factors and recurrent pains, in particular regarding possible sex differences. [source]

Rheumatological presentations of anticoagulation related hemorrhages

INTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 2 2003
S. R. Cox
Abstract Background: Joint, back and muscle pain are common in patients referred to a rheumatology unit. Acute pain due to hemorrhage may be difficult to distinguish from more common causes of pain in these patients. This article describes a small case-series of patients who presented acutely with hemarthroses, spinal hemorrhage or muscle hematomas while receiving anticoagulant treatment. Methods: Case notes of nine patients were reviewed retrospectively. The demographic characteristics, indication for anticoagulation, international normalized ratio, and management were evaluated. Results: The majority of hemorrhages occurred when the INR was within the therapeutic range. Anticoagulation was held in all cases. Joint aspiration was performed in all cases of hemarthrosis. Surgical intervention was required in management of the spinal epidural bleed and also in one case of muscle hematoma. Conclusion: Cases described represent major hemorrhages in anticoagulated patients. There is little literature on specific treatment and prognosis, particularly with respect to hemarthrosis, and further studies are needed. [source]

Isoprostane 8-epi-PGF2, is frequently increased in patients with muscle pain and/or CK-elevation after HMG-Co-enzyme-A-reductase inhibitor therapy

Chronic fatigue syndrome: assessment of increased oxidative stress and altered muscle excitability in response to incremental exercise

JOURNAL OF INTERNAL MEDICINE, Issue 3 2005
Y. JAMMES
Abstract. Objectives., Because the muscle response to incremental exercise is not well documented in patients suffering from chronic fatigue syndrome (CFS), we combined electrophysiological (compound-evoked muscle action potential, M wave), and biochemical (lactic acid production, oxidative stress) measurements to assess any muscle dysfunction in response to a routine cycling exercise. Design., This case,control study compared 15 CFS patients to a gender-, age- and weight-matched control group (n = 11) of healthy subjects. Interventions., All subjects performed an incre-mental cycling exercise continued until exhaustion. Main outcome measures., We measured the oxygen uptake (Vo2), heart rate (HR), systemic blood pressure, percutaneous O2 saturation (SpO2), M-wave recording from vastus lateralis, and venous blood sampling allowing measurements of pH (pHv), PO2 (PvO2), lactic acid (LA), and three markers of the oxidative stress (thiobarbituric acid-reactive substances, TBARS, reduced glutathione, GSH, and ascorbic acid, RAA). Results., Compared with control, in CFS patients (i) the slope of Vo2 versus work load relationship did not differ from control subjects and there was a tendency for an accentuated PvO2 fall at the same exercise intensity, indicating an increased oxygen uptake by the exercising muscles; (ii) the HR and blood pressure responses to exercise did not vary; (iii) the anaerobic pathways were not accentuated; (iv) the exercise-induced oxidative stress was enhanced with early changes in TBARS and RAA and enhanced maximal RAA consumption; and (v) the M-wave duration markedly increased during the recovery period. Conclusions., The response of CFS patients to incremental exercise associates a lengthened and accentuated oxidative stress together with marked alterations of the muscle membrane excitability. These two objective signs of muscle dysfunction are sufficient to explain muscle pain and postexertional malaise reported by our patients. [source]

Evaluation of minimum interdental threshold ability in dentate female temporomandibular disorder patients

JOURNAL OF ORAL REHABILITATION, Issue 5 2010
E. M. KOGAWA
Summary, Minimum interdental threshold is the smallest thickness that can be detected between teeth during an occlusion and has an influence on the occlusal force and on the control of mandibular movements. The aim of this study was to assess the possible association of the signs and symptoms of temporomandibular disorders (TMD) with the ability to detect a minimum interdental threshold. Two hundred women were equally divided into four groups: asymptomatic (control), subjects with masticatory muscle pain, with articular [temporomandibular joint (TMJ)] pain and mixed (muscular and articular pain). Evaluation of the ability to detect a minimum interdental threshold was performed using aluminium foils with 0·010, 0·024, 0·030, 0·050, 0·080 and 0·094 mm of thickness in the premolar region. A total of 20 tests with each thickness for each patient were performed, starting with the thickest foil (0·094 mm) and ending with the thinnest one. The myogenic pain and articular groups presented significantly higher threshold values (0·020 and 0·022 mm, respectively), when compared to the control. Both groups reached the level of certain perceptiveness only at 0·030 mm. No significant correlation was found between minimum interdental threshold and age. These results suggest that discrimination of thicknesses can be disturbed as a consequence of TMD manifestations and not the cause of it. Clinicians should, therefore, be aware that changes on muscles and TMJ can secondarily lead to occlusion changes. The mechanisms involved in this process, however, are not well understood and warrant further investigation. [source]

Evaluation of maximal bite force in temporomandibular disorders patients

JOURNAL OF ORAL REHABILITATION, Issue 8 2006
E. M. KOGAWA
summary, The aim of this study was to evaluate the maximum bite force in temporomandibular disorders (TMD) patients. Two hundred women were equally divided into four groups: myogenic TMD, articular TMD, mixed TMD and control. The maximum bite force was measured in the first molar area, on both sides, in two sessions, using an IDDK (Kratos) Model digital dynamometer, adapted to oral conditions. Three-way anova, Tukey and Pearson correlation tests were used for the statistical analysis. The level of statistical significance was given when P , 0·05. The maximal bite force values were significantly higher in the control group than in the experimental ones (P = 0·00), with no significant differences between sides. Higher values were obtained in the second session (P = 0·001). Indeed, moderate negative correlation was found between age and bite force, when articular, mixed groups and all groups together were evaluated. A moderate negative correlation was also detected between TMD severity and the maximal bite force values for myogenic, mixed and all groups together. Authors concluded that the presence of masticatory muscle pain and/or TMJ inflammation can play a role in maximum bite force. The mechanisms involved in this process, however, are not well understood and deserve further investigation. [source]

The influence of hot pack therapy on the blood flow in masseter muscles

JOURNAL OF ORAL REHABILITATION, Issue 7 2005
K. OKADA
summary The purpose of this study was to clarify whether hot pack therapy can change the blood flow of human masseter muscles. Thirty-two healthy subjects with no history of muscle pain in the masticatory system participated and were divided into two groups. One group underwent proper hot pack therapy (hot pack group) and the other underwent sham hot pack therapy (control group). Continuous and non-invasive measurements of haemoglobin volumes and oxygen saturation levels (StO2) were determined with a near-infrared spectroscope. The blood flow parameters were total haemoglobin volume (THb), oxygenated haemoglobin volume (OXHb), deoxygenated haemoglobin volume (deOXHb) and oxygen saturation level (StO2). In hot pack group, results showed that the THb, OXHb and StO2 after the hot pack application were significantly larger than those before the hot pack. In control group, the THb, OXHb, deOXHb, StO2 and heart rates showed no significant differences between the values before and after the sham hot pack application. The THb, OXHb and StO2 after the hot pack application in hot pack group were significantly larger than those in control group, while the deOXHb after the hot pack was significantly smaller than that in control group. The heart rates showed no significant differences between the groups. The results suggest that hot pack therapy can increase regional blood flow of human masseter muscles and creates an advantageous condition for aerobic energy metabolism in the muscles. [source]

Craniomandibular pain, oral parafunctions, and psychological stress in a longitudinal case study

JOURNAL OF ORAL REHABILITATION, Issue 8 2004
M. K. A. van Selms
summary, In a single case study, the most frequently suggested contributing factors to craniomandibular pain, viz., oral parafunctions and psychological stress, were studied in more detail. During a 13-week study period, questionnaires were completed, in which, among others, jaw muscle pain, bruxism behaviour, and experienced/anticipated stress were noted. During about 40% of the nights, nocturnal masticatory muscle activity (NMMA) was recorded, using single-channel electromyography (EMG). The number of NMMA events per recorded hour was scored, using a detection threshold of 10% of the maximum voluntary contraction level. This threshold was established in a separate study, in which EMG was compared with polysomnography. Stepwise regression analyses indicated, that morning jaw muscle pain could be explained by evening jaw muscle pain for 64% and by alcohol intake for another 2%. In turn, evening jaw muscle pain was explained by daytime clenching for 56% and by vacuum sucking of the tongue for an additional 6%. Finally, daytime clenching was significantly explained by experienced stress for 30%. Data of the recorded nights showed, that variations in NMMA did not contribute to variations in morning jaw muscle pain. This case study corroborates the paradigm that experienced stress may be related to daytime clenching and, in turn, to evening and morning jaw muscle pain. [source]

Exercise tolerance and daily life in McArdle's disease

MUSCLE AND NERVE, Issue 5 2005
Karen Ollivier MSc
Abstract McArdle's disease is a common disorder of muscle metabolism and is due to myophosphorylase deficiency. The major complaint of patients with this disease is effort intolerance. Although the clinical features of affected patients are well known, their daily lifestyle is not well documented. The main objective of this work was to assess their mean daily energy expenditure (DEE) and compare it with control subjects. Thirty patients and 87 control subjects completed a questionnaire. A 3-day self-record of daily physical activities was used to estimate the mean DEE for patients and control subjects. A separate section of the questionnaire was used to assess patients' clinical features and daily lifestyle. The DEE of patients (44.1 ± 6.9 kcal/kg) was not significantly different from control subjects (44.5 ± 5.6 kcal/kg). Half of the patients with McArdle's disease performed a daily physical leisure activity as sport, sometimes at a high level (17%). Despite large individual variation, physical abilities and patients' symptoms were negatively correlated. Physical leisure activity significantly decreased the sensation of muscle pain (P < 0.03). These findings show that patients with McArdle's disease do not have a strictly sedentary lifestyle. Moreover, physical exercise appears to have positive effects on the main clinical features, such as effort intolerance. Thus, regular, moderate physical activity may be beneficial in McArdle's disease. Muscle Nerve, 2005 [source]

Classic pyomyositis of the extremities as an unusual manifestation of Blastomyces dermatitidis: a report of two cases

MYCOSES, Issue 4 2010
Michael Y. Lin
Summary Pyomyositis is an infection of skeletal muscle that, by definition, arises intramuscularly rather than secondarily from adjacent infection. It is usually associated with bacterial infection, particularly Staphylcococcus aureus. Fungi are rare causes, and Blastomyces dermatitidis has not been reported previously. In this case series, we report two cases of pyomyositis caused by B. dermatitidis. Cases were prospectively identified through routine clinical care at a single academic referral hospital. Two patients with complaints of muscle pain and subacute cough were treated at our hospital in 2007. Both patients were found to have pyomyositis caused by B. dermatitidis, in the quadriceps muscles in one patient, and in the calf muscle in another , by radiological imaging and fungal culture. Both were also diagnosed with pneumonia caused by B. dermatitidis (presumptive in one, confirmed in the other). There was no evidence of infection of adjacent structures, suggesting that the route of infection was likely direct haematogenous seeding of the muscle. A review of the literature confirmed that although B. dermatitidis has been described as causing axial muscle infection secondary to adjacent infection such as vertebral osteomyelitis, our description of isolated muscle involvement (classic pyomyositis) caused by B. dermatitidis, particularly of the extremity muscles, is unique. We conclude that B. dermatitidis is a potential cause of classic pyomyositis. [source]

Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects

The effects of experimental muscle and skin pain on the static stretch sensitivity of human muscle spindles in relaxed leg muscles

Myotonic dystrophy type 2 found in two of sixty-three persons diagnosed as having fibromyalgia

ARTHRITIS & RHEUMATISM, Issue 11 2008
Satu Auvinen
Because of its high prevalence, fibromyalgia (FM) is a major general health issue. Myotonic dystrophy type 2 (DM2) is a recently described autosomal-dominant multisystem disorder. Besides variable proximal muscle weakness, myotonia, and precocious cataracts, muscle pain and stiffness are prominent presenting features of DM2. After noting that several of our mutation-positive DM2 patients had a previous diagnosis of FM, suggesting that DM2 may be misdiagnosed as FM, we invited 90 randomly selected patients diagnosed as having FM to undergo genetic testing for DM2. Of the 63 patients who agreed to participate, 2 (3.2%) tested positive for the DM2 mutation. Their cases are described herein. DM2 was not found in any of 200 asymptomatic controls. We therefore suggest that the presence of DM2 should be investigated in a large sample of subjects diagnosed as having FM, and clinicians should be aware of overlap in the clinical presentation of these 2 distinct disorders. [source]

Acute heavy-resistance exercise,induced pain and neuromuscular fatigue in elderly women with fibromyalgia and in healthy controls: Effects of strength training

ARTHRITIS & RHEUMATISM, Issue 4 2006
Heli Valkeinen
Objective To examine heavy-resistance exercise,induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training. Methods Thirteen elderly women with FM (mean ± SD age 60 ± 2 years) and 10 healthy women (mean ± SD age 64 ± 3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale. Results The strength training led to large increases in maximal force and EMG activity of the muscles and contributed to the improvement in loading performance (average load/set) at week 21. The fatiguing loading sessions typically applied in strength training before and after the experimental period caused remarkable and comparable acute decreases in maximal force and increases in blood lactate concentration in both groups. Acute exercise-induced muscle pain increased similarly in both groups, and the pain level in women with FM was lowered after the 21-week training period. Conclusion The increased strength in women with FM improved high-load performance and also seemed to attenuate perceived pain. Acute exercise-induced neuromuscular changes and the time course of muscle pain in women with FM were comparable with findings in healthy controls, which suggests a typical fatiguing process and a similar trainability of the muscles in elderly women with FM. [source]

Reversal of acid-induced and inflammatory pain by the selective ASIC3 inhibitor, APETx2

BRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2010
Jerzy Karczewski
BACKGROUND AND PURPOSE Inflammatory pain is triggered by activation of pathways leading to the release of mediators such as bradykinin, prostaglandins, interleukins, ATP, growth factors and protons that sensitize peripheral nociceptors. The activation of acid-sensitive ion channels (ASICs) may have particular relevance in the development and maintenance of inflammatory pain. ASIC3 is of particular interest due to its restricted tissue distribution in the nociceptive primary afferent fibres and its high sensitivity to protons. EXPERIMENTAL APPROACH To examine the contribution of ASIC3 to the development and maintenance of muscle pain and inflammatory pain, we studied the in vivo efficacy of a selective ASIC3 inhibitor, APETx2, in rats. KEY RESULTS Administration of APETx2 into the gastrocnemius muscle prior to the administration of low pH saline prevented the development of mechanical hypersensitivity, whereas APETx2 administration following low-pH saline was ineffective in reversing hypersensitivity. The prevention of mechanical hypersensitivity produced by acid administration was observed whether APETx2 was applied via i.m. or i.t. routes. In the complete Freund's adjuvant (CFA) inflammatory pain model, local administration of APETx2 resulted in a potent and complete reversal of established mechanical hypersensitivity, whereas i.t. application of APETx2 was ineffective. CONCLUSIONS AND IMPLICATIONS ASIC3 contributed to the development of mechanical hypersensitivity in the acid-induced muscle pain model, whereas ASIC3 contributed to the maintenance of mechanical hypersensitivity in the CFA inflammatory pain model. The contribution of ASIC3 to established hypersensitivity associated with inflammation suggests that this channel may be an effective analgesic target for inflammatory pain states. [source]

Post-polio syndrome: epidemiologic and prognostic aspects in Brazil

ACTA NEUROLOGICA SCANDINAVICA, Issue 3 2009
M. T. R. P. Conde
Objectives,,, To describe the clinical and epidemiological aspects of post-polio syndrome (PPS) and identify predictors of its severity. Materials and methods,,, 132 patients with PPS were selected at the Neuromuscular Disease Outpatient Clinic of the Federal University of São Paulo. Descriptive analysis was carried out and predictors of PPS severe forms were investigated using an unconditional logistic regression. Results,,, The average age at onset was 39.4 years. The most common symptoms were fatigue (87.1%), muscle pain (82.4%) and joint pain (72.0%); 50.4% of the cases were severe. The following were associated with PPS severity: a ,4-year period of neurological recovery (OR 2.8), permanent damage in two limbs (OR 3.6) and residence at the time of acute polio in a city with more advanced medical assistance (OR 2.5). Conclusions,,, Health professionals should carefully evaluate polio survivors for PPS and be aware of the implications of muscle overuse in the neurological recovery period. [source]

Effect of vitamin C and zinc on osmotic fragility and lipid peroxidation in zinc-deficient haemodialysis patients

CELL BIOCHEMISTRY AND FUNCTION, Issue 2 2002
Ferda Candan
Abstract Peroxidation of the membrane lipid structure of red blood cell leads to haemolysis and anaemia in haemodialysis patients. Dietary constituents of antioxidant vitamins and trace elements may play an important role in protecting against oxidant damage. In this study, the effects of supplementation of vitamin C and zinc on osmotic fragility and lipid peroxidation of erythrocytes were investigated in 34 zinc-deficient haemodialysis patients. Sixteen sex- and age-matched normal volunteers acted as controls. Patients were randomized to receive vitamin C (250 mg day,1), zinc (20 mg day,1) or a placebo treatment for 3 months. The levels of vitamin C, zinc, malondialdehyde (MDA) and osmotic fragility were measured initially and 3 months after supplementation. Mean serum concentration of vitamin C and zinc increased significantly in the groups at the end of the respective study periods. Supplementation with vitamin C and zinc improved osmotic fragility, and decreased the level of MDA in the groups, but some side-effects (i.e. nausea, vomiting, fever, muscle pain, weakness) were observed during the zinc treatment. The results showed that the supplementation of both treatments decreased osmotic fragilty and MDA in zinc-deficient haemodialysis patients. However, vitamin C treatment was found to be safer than zinc supplementation. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Risks and benefits of continued aggressive statin therapy

CLINICAL CARDIOLOGY, Issue S3 2003
Antonio M. Gotto Jr. M.D., D.PHIL
Abstract The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, are a well-tolerated, effective class of medications for the reduction of low-density lipoprotein cholesterol (LDL-C) and total cholesterol levels. Extensive data from clinical trials demonstrate that these agents reduce fatal and nonfatal cardiovascular risk in primary and secondary prevention patients, including women and the elderly. A threshold value for LDL-C reduction below which there is no further clinical benefit has not yet been identified. In the Heart Protection Study (HPS), significant relative risk reduction occurred even among patients with LDL-C levels < 2.6 mmol/l (100 mg/dl). Statin therapy also produced reductions in cardiovascular disease in a wide range of high-risk patients regardless of baseline cholesterol levels. Rhabdomyolysis, typically defined as muscle pain or weakness associated with creatine kinase levels higher than 10 times the upper limit of normal and the presence of myoglobulinuria, is a rare but potentially serious complication of statins. Although dose-dependent transaminase elevations occur in 0.5 to 2% of cases, it has not been determined whether these elevations qualify as true drug-related hepatotoxicity. Management of myopathy and elevated transaminases is addressed in a joint publication from the American College of Cardiology (ACC), the American Heart Association (AHA), and the National Heart, Lung, and Blood Institute (NHLBI). Because statins have significant potential benefits and a low risk for serious adverse effects, aggressive therapy should be considered in patients at high risk for coronary heart disease. [source]