Objectives: Pathomechanisms of work-related myalgia are poorly understood. Myalgia is thought to be caused by excitation of nociceptors present in the muscular tissue but not in the muscle fiber itself. Muscle contraction in combination with hypoxia is known to excite nociceptors. Morphologic analysis can contribute to the knowledge of the excitation of nociceptors. This study thoroughly examines the morphology of the trapezius muscle's capillary supply and signs of disturbed oxidative metabolism to understand their role in work-related myalgia.Methods: Surgical trapezius muscle biopsies were obtained from 25 female cleaners with long-standing work-related myalgia, 25 female cleaners without trapezius myalgia, and 21 healthy teachers. Enzyme and immunohistochemical stainings were performed to highlight fibers with aberrant intermyofibrillar patterns, indicating a disturbed oxidative metabolism (also known as moth-eaten fibers) and a disturbed capillary supply of different fibers.Results: A significantly lower number of capillaries per fiber area in cleaners suffering from myalgia compared with cleaners without trapezius myalgia was found. Moth-eaten fibers were found in the 3 groups, but these fibers were significantly more prevalent in the groups of cleaners than in the healthy teacher group.Conclusion: This work indicates that the capillary supply of trapezius is affected in work-related trapezius myalgia. More studies are needed to understand possible mechanisms that would explain the occurrence of moth-eaten fibers.

The aim of this study was to evaluate a commercial tube prepared with boric acid, sodium formate and sorbitol (Hemogard Vacutainer tubes, Becton-Dickinson, HG tubes). Fourteen bacterial strains were incubated in urine in HG tubes and conventional tubes. During a 24-h period, most of the microorganisms grew readily in conventional tubes at room temperature, whereas the bacterial counts were comparatively unchanged when chilled or kept in HG tubes. The bacterial counts of Alcaligenes faecalis and lactobacilli decreased by two 10 logarithms in the HG tubes, at room temperature. Experiments were also performed with the addition of various antibiotics. Ciprofloxacin caused a decrease in E. coli counts regardless of type of tube used, while the HG tubes and the conventional tubes kept chilled conserved bacterial counts upon challenge with fosfomycin, trimethoprim or mecillinam. Bedside cultures from 154 outpatients were sampled and divided into three tubes. One conventional tube was sent to our laboratory by ordinary chilled transport. Another conventional tube and one HG tube were transported to the laboratory without chilling. Cultures were performed upon arrival at the laboratory and then 24, 48 and 72 h after primary sampling. Within 24 h of sampling, no significant differences in bacterial counts were observed between chilled conventional tubes and the HG tubes at room temperature. However, in the HG tubes a significant change in enterococcal counts was noted within 48 h.

With recent interest in sleep apnoea, oral devices have been proposed and used increasingly to treat patients suffering from snoring and obstructive sleep apnoea (OSA). Numerous case reports have been published and studies have been carried out to determine the efficiency and mechanism of action as well as evaluate side effects, complications and costs of different oral devices in the treatment of habitual snoring and OSA.A summary of the scientific basis and current opinions regarding oral devices in the treatment of habitual snoring and obstructive sleep apnoea is presented in this article. The selection of papers was based on a computerised search of published clinical and associated studies identified by MEDLINE from 1980 to November 2000.Although there is not yet enough scientific evidence for the clinician to determine which appliance is most likely to improve symptoms for a given patient, it appears from the literature that dental devices may have a place in the treatment of habitual snoring and mild and moderate cases of OSA. However, most of the studies are case series, raising questions on validity, and few studies use appropriate control groups. The general opinion is that these patients should not be treated without a sleep study as the OSA must be diagnosed before beginning treatment with oral devices to identify patients at risk and to provide a baseline to establish the effectiveness of the treatment.The main advantages of oral devices is the relative simplicity of the treatment, its reversibility and cost-effectiveness, and the fact that they can be used as an alternate treatment in patients who are unable to tolerate nasal continuous positive airway pressure (nCPAP) or who are poor surgical risks. Side effects occur in a significant proportion of patients using the MAD. In most cases these are minor and their importance must be balanced against the efficacy of the MAD in treating snoring and OSA. n.

In the literature enlarged/increased cross-sectional area (CSA) of type I muscle fibres has been reported as a morphological mark of work-related localised myalgia in the descending part of the trapezius muscle of women. These studies did not use enough subjects or lacked an adequate control group. The recording of surface electromyograms (EMG) is central to the research field of work-related myalgia. However, the influence of intrinsic muscle properties – such as the effect of muscle fibre distribution upon surface EMG – has to be better understood in order properly to evaluate this method as a possible diagnostic and preventive tool. This study had two aims. Firstly, it investigated the muscle fibre distribution and CSA in work-related myalgia in trapezius muscles. Secondly, the multivariate relationships among muscle morphology and histochemistry [ragged-red (RR) fibres, and cytochrome-c-oxidase-negative-fibre changes] EMG, perceived fatigue, and biomechanical output of shoulder flexions were analysed. The raw data have been presented in an earlier study. The participants in this study were 25 female cleaners with work-related myalgia of the trapezius muscle and 25 female cleaners not experiencing work-related myalgia of this muscle. The control group comprised 21 healthy female teachers who had not been exposed to highly repetitive work or static muscle work. Smaller CSA of type II fibres were found in cleaners compared to teachers. In this study the CSA of type I fibres of the trapezius muscles associated with myalgia were no greater than in muscles without myalgia. The prevalence of RR fibres together with age, fibre type proportions, CSA and working as a cleaner correlated with the ability to relax as recorded electromyographically. The relative mean frequency of the EMG of the trapezius muscle correlated with the prevalence of RR fibres, but it did not correlate with the proportions and CSA of different fibre types. Low biomechanical outputs and low signal amplitude increases of the EMG during the test were associated with high proportions of type IIB fibres. The smaller CSA of type II fibres in cleaners might have reflected a different muscle activation pattern due to different occupational demands in cleaners than in teachers. Morphological or histopathological variables can influence the three EMG variables investigated.

To investigate whether arbitrarily primed (AP)‐PCR and/or 16S rDNA sequencing could be used as rapid methods for epidemiological typing and species identification of clinical Burkholderia isolates from patients with cystic fibrosis (CF), a total of 39 clinical B. cepacia isolates, including 33 isolates from 14 CF patients, were fingerprinted. ERIC‐2 primer was used for AP‐PCR. The AP‐PCR clustering analysis resulted in 14 different clusters at a 70% similarity level. The AP‐PRC patterns were individual despite considerable similarities. To sequence rDNA, a broad‐range PCR was applied. The PCR product included four variable loops (V8, V3, V4 and V9) of the 16S ribosomal small subunit RNA gene. The multiple sequence alignment produced 12 different patterns, 5 of them including more than one isolate. Heterogeneity of the bases in the V3 region, indicating the simultaneous presence of at least two different types of 16S rRNA genes in the same cell, was revealed in 10 isolates. Most of the CF patients were adults who had advanced disease at follow‐up. Both the sequencing and the AP‐PCR patterns revealed genetic heterogeneity of isolates between patients. According to the results obtained, AP‐PCR could advantageously be used for epidemiological typing of Burkholderia, whereas partial species identification could effectively be obtained by sequencing of the V3 region of the 16S RNA gene.

The association of cytochrome c oxidase negative fibres (COX-negative) and ragged-red fibres (RR-fibres) with work related trapezius myalgia has been proposed. Hitherto studies have been small or without control groups. The aim of the present study was to investigate the prevalences of RR-fibres and COX-negative fibres in female cleaners with (n=25) and without (n=23) trapezius myalgia and in clinically healthy female teachers (n=21). The cleaners did mainly floor cleaning requiring monotonous loading on the trapezius muscle. A questionnaire covering background data and aspects of pain (prevalence, duration, intensity and influence on daily living) was answered. Biopsies were obtained from the trapezius muscle by an open surgical technique. The three groups did not differ in prevalence of COX-negative or COX-superpositive (i.e. type-I fibres with extremely strong brownish reaction in both the COX and SDH/COX stainings) fibres. The prevalence of COX-negative fibres was age dependent. Two subgroups of RR-fibres were present when stained for COX; COX-negative (73%) and COX-superpositive (26%) fibres. Forty-two percent of the COX-negative fibres were RR-fibres and 79% of the COX-superpositive were RR-fibres. A significantly (P=0.002) higher proportion of the COX-superpositive fibres in the cleaners were RR-fibres compared to the teachers. Multivariate regression analysis revealed that age, occupation as cleaner and a tender point in the trapezius were significantly associated with increased prevalences of RR-fibres; a cleaner with a tender point had a 4.35 higher prevalence of RR-fibres compared to a teacher without a tender point. No correlations between other pain related variables and prevalence of RR-fibres were noted. In conclusion, RR-fibres but not COX-negative or COX-superpositive fibres were correlated with cleaning work tasks and with a tender point in the trapezius.

The aim of the investigation was to evaluate the status and function of the temporomandibular joint (TMJ) and masticatory system in patients with habitual snoring and obstructive apnoea after 2 years nocturnal treatment with a mandibular advancement splint. Thirty-two patients participated in the study, ranging from 43.0 to 79.8 years of age (mean 54.4 years, SD 8.78) at the start of treatment. All patients had been referred from the ENT department for treatment with a mandibular advancement splint. The acrylic splint advanced the mandible 50-70 per cent of maximal protrusion, opened 5 mm vertically, and was used 6-8 hours per night and 5-7 nights per week. Overjet, overbite, and molar relationship were measured on dental casts. The patients were asked to answer a questionnaire concerning symptoms of craniomandibular dysfunction (CMD). They were also clinically examined in a standardized manner, including registration of range of mandibular movements, TMJ sounds, pain on movement, and palpatory tenderness of the TMJ and the masticatory muscles. None of the patients showed more than five symptoms of dysfunction either at the start of or after 2 years of treatment. A decrease in the frequency of headache was found for nine of those 18 patients that reported headache (P = 0.004). A minor, but significant decrease in overjet and overbite was found and the molar relationship was also changed. It was concluded that 2 years' treatment with a mandibular advancement splint had no adverse effects on the craniomandibular status and function, but the observed occlusal changes requires further evaluation.

Muscle biopsies of the descending portion of the trapezius muscle from female patients with chronic trapezius myalgia and from healthy women were analyzed with enzyme histochemical and immunohistochemical methods. Frequency, area, and capillarization of the muscle fiber types were determined. A biochemical analysis determined the lactate concentration of mixed muscle samples and the adenosine triphosphate (ATP) and phosphocreatine levels in single muscle fibers. The patients had larger type I fibers and a lower capillary:fiber area ratio for type I and type IIA fibers. The patients also exhibited lower levels of ATP and phosphocreatine in both type I and type II fibers. It is suggested that there might have been an imbalance between the capillary supply and the cross-sectional fiber area of type I and type IIA fibers in the patients. This imbalance might be of significance in the development of muscular fatigue and pain.

The human trapezius muscle has an origin that is more extensive than that of any other body muscle; it has a complex macroscopic structure with fibers running in different directions. Histochemical analysis of multiple samples, obtained from different parts of the trapezius muscle from five males, showed marked differences in the distribution and the cross-sectional fiber area of the fiber types among different parts of the muscle as well as among individuals. As revealed by the mATPase activity, after different levels of alkaline and acidic preincubations, the lower third of the descending portion, the transverse, and the ascending portions of the muscle had a predominance of type I fibers (low mATPase activity at pH 9.4), whereas the most superior parts of pars descendens had a higher frequency of type II fibers (high mATPase activity at pH 9.4). The fibers of the most superior parts of the muscle were considerably smaller compared with those in all the other parts. In sections stained for NADH-TR, moth-eaten fibers were observed within parts of the descending portion. Their location and their larger fiber area, compared with that of ordinary type I fibers, may be related to frequent and/or continuous use of these fibers. In conclusion, the differences in fiber type composition between the different parts of the muscle probably reflect different functional demands on the trapezius muscle in various head, neck, and shoulder movements. We suggest that the interindividual differences in muscle fiber composition are due, at least in part, to genetic factors.

Primary fibromyalgia syndrome (PFS) is a form of nonarticular rheumatism characterized by muscular pain and stiffness, commonly located in the neck-, shoulder-, back-, and pelvic regions. The most common finding in patients with mandibular dysfunction (MD) is pain or tenderness of the masticatory muscles, but tender and painful neck and shoulder muscles are also often found in relation to jaw muscle affection. Complaints presented by patients suffering from musculoskeletal conditions may overlap one another. Indeed, there may be some common causative factors for these complaints. To test the hypothesis that some complaints by PFS patients could be explained by mandibular dysfunction, we have investigated the subjective symptoms and the clinical state of the stomatognathic system in eight patients suffering from PFS. According to the Helkimo anamnestic dysfunction index, six patients were classified as having severe signs of MD. The Helkimo clinical dysfunction index revealed severe or moderate dysfunction in all patients. Recurrent headaches was reported by half of the patients. In conclusion, the present study shows that PFS patients also may suffer from mandibular dysfunction. Thus, an examination of the function of the stomatognathic system would be an important part in the investigation to elucidate possible etiological factors behind the reported complaints by PFS patients. PFS may also be of etiological importance for mandibular dysfunction.

In man, there are large differences in histochemical fibre-type composition, distribution and size between jaw and trunk muscles, probably related to the special functions of the human stomatognathic system. In the hedgehog, the influence of alkaline and acid pre-incubations on the reaction for myofibrillar ATPase was different from that in man, suggesting a different myosin structure; the fibre composition was different also. The masseter, the superficial portion of the temporal and the lateral pterygoid muscles all showed a homogeneous fibre type profile with almost 100 per cent alkali-stable fibres. In two animals, the deep temporal muscles showed an apparent heterogeneous fibre pattern with 81 per cent alkali-stable fibres, 4 per cent alkali-labile fibres and 15 per cent ATPase-intermediate fibres; in one animal 87 per cent alkali-stable fibres and 13 per cent ATPase-intermediate fibres. There was no difference in cross-sectional area between the three fibre types within each muscle, but the fibres of the lateral pterygoid were smaller than the alkali-stable and the alkali-labile fibres of the masseter and temporal muscles. The limb and trunk muscles showed reactions for myofibrillar ATPase similar to the jaw muscles, but had a heterogeneous fibre-type profile. There was no significant difference in cross-sectional fibre area between the jaw and the limb muscles. Thus the jaw and limb muscles of the hedgehog have similar fibre types and about equal fibre size.