The impact of gender of the examiner on orofacial pain perception and pain reporting among healthy volunteers.

OBJECTIVES: Pain on palpation of jaw muscles is a commonly used diagnostic criterion when examining patients with orofacial pain. It is not known, however, if pain reports are affected by the gender of the examiner. Our aim was to investigate if pressure pain threshold (PPT), pressure pain tolerance (PTol), and pain intensity assessed over the masseter muscles in healthy individuals are affected by the gender of the examiner. MATERIALS AND METHODS: Healthy, pain-free individuals were recruited on a voluntary basis. PPT and PTol were assessed using pressure algometry. At the PTol level, participants also rated pain intensity on a 0-10 numeric rating scale. Assessments of PPT and PTol were conducted with six repeated measurements performed twice, separately by one female and one male examiner, on each participant. RESULTS: In total, 84 participants (43 women; median age 24, IQR 6) were included. With a female examiner, women reported higher pain intensity than men (Mann Whitney U, p = 0.005). In the multivariable analysis, significantly higher PTol was predicted by male examiner. Also, a higher ratio between PTol and reported pain intensity was predicted by male examiner. CONCLUSIONS: The gender of the examiner influences pain reporting and perception in an experimental setting. This effect on pain perception related to gender of the examiner is probably related to normative gender behaviors rather than to biological alterations within the examined individual. CLINICAL RELEVANCE: In clinical and experimental settings, gender of the examiner may affect not only pain perception but also pain reporting, with potential implications for diagnostics in patients with pain.

Pre-oxygenation using high-flow nasal oxygen vs. tight facemask during rapid sequence induction.

Pre-oxygenation using high-flow nasal oxygen can decrease the risk of desaturation during rapid sequence induction in patients undergoing emergency surgery. Previous studies were single-centre and often in limited settings. This randomised, international, multicentre trial compared high-flow nasal oxygen with standard facemask pre-oxygenation for rapid sequence induction in emergency surgery at all hours of the day and night. A total of 350 adult patients from six centres in Sweden and one in Switzerland undergoing emergency surgery where rapid sequence induction was required were included and randomly allocated to pre-oxygenation with 100% oxygen using high-flow nasal oxygen or a standard tight-fitting facemask. The primary outcome was the number of patients developing oxygen saturations <93% from the start of pre-oxygenation until 1 min after tracheal intubation. Data from 349 of 350 patients who entered the study were analysed (174 in the high-flow nasal oxygen group and 175 in the facemask group). No difference was detected in the number of patients desaturating <93%, five (2.9%) vs. six (3.4%) patients in the high-flow nasal oxygen and facemask group, respectively (p = 0.77). The risk of desaturation was not increased during on-call hours. No difference was seen in end-tidal carbon dioxide levels in the first breath after tracheal intubation or in the number of patients with signs of regurgitation between groups. These results confirm that high-flow nasal oxygen maintains adequate oxygen levels during pre-oxygenation for rapid sequence induction.

Response of Gammarus pulex and Baetis rhodani to springtime acid episodes in humic brooks.

While chronic acidification of water bodies has been steadily decreasing, episodic acidification continues to affect stream biology by temporarily decreasing pH and mobilizing aluminum. These events are becoming more common as climate change renders more frequent and intense storms and flooding. Throughout Scandinavia, the effects of acidification have been mitigated by liming since the 1980s, but remediation efforts can now be reduced. While transient acidity may reduce fish populations, also other species in streams are affected. In this in-stream study, two macro-invertebrates (Gammarus pulex and Baetis rhodani), both known as salmonid prey organisms, were exposed to snowmelt in six humic brooks with a natural gradient of pH and inorganic monomeric Al (Al(i)). We hypothesize that acid toxicity thresholds can be defined using lethal (mortality) and sublethal (changes in body elemental content) metrics. Periodic observations were made of mortality and whole body concentrations of base cations (BC: Ca, Mg, Na and K) and metals (Al, Fe, Zn and Mn). Mortality increased dramatically at pH<6.0 and Al(i)>15 µg/L for G. pulex and at pH<5.7 and Al(i)>20 µg/L for B. rhodani. No accumulation of Al was found. The invertebrate body Na concentration decreased when pH dropped, suggesting that osmoregulation in both species was affected. In contrast to general BC pattern, Ca concentration in G. pulex and Mg concentration in B. rhodani increased when pH decreased. Although Al(i) strongly correlates to pH, the Al composition of soil and bedrock also influences Al availability, potentially contributing to toxic Al(i) episodes. The estimated values calculated in this study can be used to improve water quality criteria and as thresholds to adjust doses of lime compared to old recommendations in ongoing liming programs. Such adjustments may be critical since both Al(i) and pH levels have to be balanced to mitigate damage to recovering stream ecosystems.

Prolonged attenuation of acetylcholine-induced phosphorylation of extracellular signal-regulated kinase 1/2 following sevoflurane exposure.

BACKGROUND: Volatile anaesthetics are known to affect cholinergic receptors. Perturbation of cholinergic signalling can cause cognitive deficits. In this study, we wanted to evaluate acetylcholine-induced intracellular signalling following sevoflurane exposure. METHODS: Pheochromocytoma12 PC12 cells were exposed to 4.6% sevoflurane for 2 h. Subsequently, Western blotting was used to measure acetylcholine-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) 1/2 and basal Protein kinase B (AKT) phosphorylation. RESULTS: After exposure, acetylcholine-induced ERK 1/2 phosphorylation was reduced to 58 ± 8% [95% confidence interval (CI): 38-77%, P = 0.003] compared with non-exposed controls. At 30 min after the end of sevoflurane administration [at 0.7% sevoflurane (0.102 mM)], ERK 1/2 phosphorylation remained reduced to 57 ± 7% (95% CI: 39-74%, P = 0.001) and was at 120 min [0.02% (0.003 mM] still reduced to 63 ± 10% (95% CI: 37-88%, P = 0.01), compared with control. At 360 min after exposure, acetylcholine-induced ERK 1/2 phosphorylation had recovered to 98 ± 16% (95% CI: 45-152%, P = 0.98) compared with control. In contrast, immediately after sevoflurane exposure, basal AKT phosphorylation was increased by 228 ± 37% (95% CI: 133-324%, P = 0.02) but had returned to control levels at 30 min after exposure, 172 ± 67% (95% CI: 0-356%, P = 0.34). CONCLUSION: Sevoflurane exposure has differential effects on different intracellular signalling pathways. On one hand, we observed a prolonged attenuation of acetylcholine-induced ERK 1/2 phosphorylation that persisted even when sevoflurane concentrations close to detection level. On the other hand, basal AKT phosphorylation was increased twofold during sevoflurane exposure, with a rapid return to baseline levels after exposure. We speculate that the effects on acetylcholine-induced intracellular signalling observed in our in vitro model could be of relevance also for cholinergic signalling in vivo following sevoflurane exposure.

Reducing blood culture contamination by a simple informational intervention.

Compared to truly negative cultures, false-positive blood cultures not only increase laboratory work but also prolong lengths of patient stay and use of broad-spectrum antibiotics, both of which are likely to increase antibiotic resistance and patient morbidity. The increased patient suffering and surplus costs caused by blood culture contamination motivate substantial measures to decrease the rate of contamination, including the use of dedicated phlebotomy teams. The present study evaluated the effect of a simple informational intervention aimed at reducing blood culture contamination at Skåne University Hospital (SUS), Malmö, Sweden, during 3.5 months, focusing on departments collecting many blood cultures. The main examined outcomes of the study were pre- and postintervention contamination rates, analyzed with a multivariate logistic regression model adjusting for relevant determinants of contamination. A total of 51,264 blood culture sets were drawn from 14,826 patients during the study period (January 2006 to December 2009). The blood culture contamination rate preintervention was 2.59% and decreased to 2.23% postintervention (odds ratio, 0.86; 95% confidence interval, 0.76 to 0.98). A similar decrease in relevant bacterial isolates was not found postintervention. Contamination rates at three auxiliary hospitals did not decrease during the same period. The effect of the intervention on phlebotomists' knowledge of blood culture routines was also evaluated, with a clear increase in level of knowledge among interviewed phlebotomists postintervention. The present study shows that a relatively simple informational intervention can have significant effects on the level of contaminated blood cultures, even in a setting with low rates of contamination where nurses and auxiliary nurses conduct phlebotomies.

Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study.

RATIONALE: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity beta2-containing nicotinic receptors (beta2*nAChRs) are located. OBJECTIVES: We intend to see which brain circuits are activated when nicotine is given in animals naïve for nicotine and whether the beta2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. MATERIALS AND METHODS: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and beta2 knockout (KO) mice. RESULTS: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, beta2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via alpha7 nicotinic receptors. CONCLUSIONS: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on beta2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice.

Musculoskeletal discomfort of music teachers: an eight-year perspective and psychosocial work factors.

Musicians at all levels of performance, especially string players, are known to have a high prevalence of work-related musculoskeletal disorders. The disorders seem to be most common in the neck, shoulders and low back. In 1988, a survey of the work-related musculoskeletal disorders of 36 music teachers was carried out at a music school in northern Sweden. In 1996, the teachers were reinvestigated. The study also included an investigation of the psychosocial work environment according to the Karasek demand-control theory, as well as measurements of upper-arm elevation during a working day in five violin teachers. The results showed that music teachers, like other professional musicians, often experience discomfort in the neck, shoulders, and low back. The discomfort tended to be of long duration, increasing over the years. The psychosocial work environment was characterized by high psychological demands and low authority over decisions. This was compensated for through good social support. The work required skill and creativity but was monotonous. The measurements of upper-arm elevation indicated considerable variations in shoulder positions between teachers. There were also differences in the work done with the right and left arms, with repetitive motions more commonly involving the right arm. Approximately a fourth of the working day was spent with the arm elevated 30-90 degrees. The relationships between upper-arm movements and ratings of discomfort were moderate.

DNA recovery and PCR quantification of catechol 2,3-dioxygenase genes from different soil types.

With the objective of monitoring xenobiotic degrading bacteria in soil, a method for rapid extraction of DNA from soil, amenable to amplification by PCR, was developed. The method was based on lysis by freeze-thawing and subsequent addition of sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide and proteinase K. The extraction method required 2 h and was tested on six different soils differing in organic content, water holding capacity and pH, including ones from which DNA extraction is difficult. DNA yields from the soils ranged from 6.1 to 54.0 micrograms of DNA per g soil. The efficiency and reproducibility of the DNA extraction method were evaluated by competitive PCR. The organic content in the soils was a major factor affecting the amount of obtained DNA amenable for amplification by PCR. A PCR primer-pair was designed on the basis of the known nucleotide sequences of several catechol 2,3-dioxygenase genes. The specificity of the primer-pair was demonstrated on different sequenced catechol 2,3-dioxygenase genes and on site-specific bacterial isolates from polycyclic aromatic hydrocarbon (PAH)-contaminated soil. The concentration of catechol 2,3-dioxygenase DNA in PAH-contaminated sediment undergoing an ex situ compost process was quantified by competitive PCR over a period of 16 weeks. The concentration of PAHs and catechol 2,3-dioxygenase DNA in the soil samples, was found to correlate.

Influence of triacylglycerol biosynthesis rate on the assembly of apoB-100-containing lipoproteins in Hep G2 cells.

Apolipoprotein B-100 (apoB-100) appears in three forms in the endoplasmic reticulum of Hep G2 cells: (1) tightly bound to the membrane, ie, not extractable by sodium carbonate. This form is glycosylated but protease sensitive when present in intact microsomes, suggesting that it is only partially translocated to the microsomal lumen; (2) extractable by sodium carbonate and present on low-density lipoprotein-very-low-density lipoprotein (LDL-VLDL)-like particles. This form is glycosylated and secreted into the medium; and (3) extractable by sodium carbonate but having a higher density than the LDL-VLDL-like particles. This form, referred to as Fraction I, is glycosylated and protected against proteases when present in intact microsomal vesicles, indicating that it is completely translocated to the luminal side of the microsomal membrane. Fraction I is not secreted into the medium, but it disappears with time from the cell, suggesting that it is degraded. Oleic acid induced a 2.7-fold increase in the rate of the biosynthesis of triacylglycerol but not of phosphatidylcholine in Hep G2 cells. Incubation of the cells with oleic acid had no significant effect on the rate of initiation of the apoB-100-containing lipoproteins, nor did it influence the amount of apoB-100 that was associated with the membrane or the turnover of apoB-100 in the membrane. Instead, it increased the proportion of the nascent apoB polypeptides on initiated lipoproteins that was converted into full-length apoB-100 on LDL-VLDL-like particles, giving rise to an increased amount of these particles in the lumen of the secretory pathway. Pulse-chase experiments showed that incubation with oleic acid gave rise to an increased formation of LDL-VLDL-like particles on behalf of the formation of Fraction I. This effect of oleic acid could partially explain the protective effect of the fatty acid on apoB-100, preventing it from undergoing posttranslational degradation.

Plasma haemoglobin concentrations and other influx variables in blood in connection with transurethral resection of the prostate using distilled water as an irrigating fluid.

Eight patients undergoing transurethral resection of the prostate (TURP) using sterile distilled water as an irrigating fluid were studied. The concentrations of plasma haemoglobin, serum sodium, serum prostatic acid phosphatase protein (PAP) and plasma osmolality were determined as possible indicators of absorption of irrigating fluid. In 3 patients there was a marked increase in plasma haemoglobin immediately postoperatively with a maximum of 3.3 g haemoglobin/l plasma. In the remaining 5 patients the plasma haemoglobin level did not exceed 0.7 g/l immediately postoperatively. In all cases there was a fairly rapid return of the elevated plasma haemoglobin level to preoperative values. There was also a postoperative increase in the serum PAP level which was not correlated with the simultaneous increase in plasma haemoglobin concentration. There was no significant change in the sodium, potassium or albumin concentration in serum nor in plasma osmolality postoperatively. There was some decrease in the postoperative serum creatinine and uric acid levels. The preoperative serum creatinine concentration was within reference limits in 7 patients and borderline high in 1 patient. The haemoglobin binding plasma protein haptoglobin showed a slight non-significant increase immediately postoperatively and a significant decrease in concentration 2 hours postoperatively. The mean plasma haemoglobin concentration immediately postoperatively did not exceed the mean preoperative haemoglobin binding capacity of serum. The mean preoperative haemoglobin binding capacity was 1.2 g/l and the mean plasma haemoglobin level was 1.2 g/l immediately postoperatively. Two hours later the mean plasma haemoglobin level was 0.8 g/l. The mean serum haptoglobin concentration was 2.4 g/l preoperatively, 2.6 g/l immediately postoperatively and 2.0 g/l 2 hours later.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of various irrigation fluids on serum enzyme patterns following transurethral resection of the prostate.

Serum levels of a variety of enzymes were determined preoperatively and repeatedly postoperatively in a comprehensive biochemical study of 60 patients undergoing transurethral resection of the prostate (TURP). These patients were divided into four groups depending on the type of fluid used for irrigation during TURP. Prostatic acid phosphatase (PAP, analysed by radio-immunoassay) in serum showed a marked postoperative increase but wide inter-individual variation in all groups. It returned to normal within 24 to 48 hours. When water was used for irrigation, similar but less pronounced increases were observed for serum lactate dehydrogenase (LD, LD-1) and aminotransferases (ASAT, ALAT). This is interpreted as being due to an influx of irrigating fluid into the general circulation from the bladder through opened veins, by absorption from a perivesical accumulation or, in the case of PAP, also from the prostatic wound. The enzyme increases (other than PAP) may be due to their release from haemolysed red cells in the bladder or in a perivesical fluid accumulation, which conjecture is supported by the marked increase also seen in plasma haemoglobin. When iso-osmolar fluids were used for irrigation signs of haemodilution, such as a postoperative decrease in serum sodium, were observed. Several of the variables studied may be used as markers to indicate the quantity of irrigating fluid absorbed during resection. Plasma haemoglobin, serum LD (or LD-1) in connection with water irrigation, serum sodium in connection with iso-osmolar fluid irrigation and serum PAP, regardless of the type of irrigating fluid used, are some practical suggestions for such markers.