Vibration-induced white finger syndrome and carpal tunnel syndrome among Finnish metal workers

Objective  Officially 10–26 cases of vibration-induced white fingers (VWF) have been reported annually in Finland. It has been suggested that the numbers are underestimated. The purpose of the present study was to estimate the cumulative exposure to hand–arm vibration (HAV) and the prevalence of clinically diagnosed cases of VWF and carpal tunnel syndrome (CTS) in a population of Finnish metal workers and to determine the symptoms and clinical tests that would best predict the diagnosis. Methods  A questionnaire on vibration exposure at the workplace and symptoms of the upper extremities was sent to a sample (n = 530) of members of the local Metalworkers Union. Those who reported finger blanching, numbness or tingling of the fingers or symptoms of CTS were invited to take part in clinical examinations. Their cumulative lifelong exposure to HAV was evaluated. Those whose symptoms referred to VWF or CTS were given a cold provocation test with the measurement of finger systolic blood pressure and electroneuromyography of the upper arms. Results  Altogether 285 metal workers (54%) responded to the questionnaire, and 24 new cases of VWF (8.4%) and 12 cases of CTS (4.2%) were diagnosed. In the group of VWF patients, seven workers had both VWF and CTS. All of the workers diagnosed as having VWF also had numbness or tingling in their fingers. Consequently, questions concerning numbness and tingling, a two-point discrimination test, Phalen’s test, and Tinell’s test had a high predicting value for VWF. The exposure time of the VWF cases did not differ significantly from that of the study group as whole, but the cumulative exposure index was significantly higher. Conclusion  The results suggest that VWF is underdiagnosed in Finland. In screening for the health effects of HAV, sensorineural symptoms of hands should be carefully inquired about and examined in patients complaining of white fingers. More education on the recognition and evaluation of HAV exposure and its health effects is needed.     

Magnetic resonance imaging in occupational chronic solvent encephalopathy

Purpose  The aim of this study was to characterize the magnetic resonance imaging (MRI) findings in chronic solvent encephalopathy (CSE) patients and to study whether the findings are associated with solvent exposure indices. Methods  The brain MRI scans of 71 CSE patients were independently re-evaluated and rated by two experienced neuroradiologists. All the work tasks were analyzed and the chemical composition of lifetime exposure was categorized. Results  The MRI scans of 27/71 CSE patients (38%) were classified as abnormal. Brain atrophy in any brain area was found in 17/71 CSE patients (24%). Abnormal white matter hyperintensities (WMH) were found in 20/71 CSE patients (28%). Cerebral and cerebellar brain atrophy was associated with the duration of exposure in years, and vermian atrophy was associated with alcohol consumption. Periventricular and brainstem WMH were related to age. Conclusions  Slight brain atrophy is associated with CSE and there is a correlation between brain atrophy and the duration of exposure in years. However, all the MRI findings in CSE are non-specific and thus MRI is useful mainly in the differential diagnosis of CSE.     

An insight into molecular mechanisms of human T helper cell differentiation

Selective activation of T helper (Th) cell subsets plays an important role in immune response to pathogens as well as in the pathogenesis of human allergy and inflammatory diseases. Th1 cells along with the recently discovered Th17 cells play a role in the pathogenesis of autoimmune diseases. Th2 cytokines lead to series of inflammatory processes characteristic for asthma and other atopic diseases. To understand the pathogenesis of immune-mediated diseases it is crucial to dissect pathways and regulatory networks leading to the development of distinct Th subsets. Such knowledge may lead to better strategies for developing diagnostics and therapies for these diseases. The differentiation of Th1, Th2, and Th17 effector cells is driven by signals originating from T cell and costimulatory receptors as well as cytokines in the surroundings of activated naive T helper cells. There are several proteins involved in the regulation of this differentiation process. Most of the data on T helper cell differentiation have been acquired using mouse. In this review, we have summarized what is known about human T helper differentiation. In addition, selected differences between human and mouse will be discussed.     

Allergy in marathon runners and effect of Lactobacillus GG supplementation on allergic inflammatory markers

OBJECTIVE: We studied the prevalence of asthma and allergy in non-elite marathon runners and investigated the effects of probiotic supplementation on allergic inflammatory markers. METHODS: Asthma and allergies were surveyed by questionnaire, and blood eosinophils, serum eosinophil cationic protein (ECP), total IgE, and Phadiatop were measured in 141 Finnish marathon runners who took part in the Helsinki City Marathon. They were also randomized to receive either Lactobacillus GG (LGG) or placebo during the 3 months of the pollen season prior to the marathon. RESULTS: Lifetime prevalence of physician-diagnosed asthma was 4.3% (six out of 139 athletes), of allergic rhinitis 17.3% (24/139), of food allergy 5.0% (7/139), and of atopic eczema 4.3% (6/139). Prevalence of atopy was 31% (35/112), and 21% (24/112) of the athletes were sensitized to birch pollen. Asthma or allergy medication was used by 20% (28/139) of the athletes. During pollen season, serum ECP increased significantly in all athletes, and total IgE and Phadiatop in atopics. The marathon induced a significant eosinopenia but had no effect on serum ECP or total IgE. No differences in changes were seen between groups receiving LGG or placebo. CONCLUSION: Non-elite marathon runners have asthma and allergies similar to Finnish general population. LGG supplementation did not prevent the increase of allergic markers during the pollen season, or the eosinopenia induced by the marathon.     

Transplantation of human embryonic stem cell-derived neural precursor cells and enriched environment after cortical stroke in rats: cell survival and functional recovery

Cortical stem cell transplantation may help replace lost brain cells after stroke and improve the functional outcome. In this study, we transplanted human embryonic stem cell (hESC)-derived neural precursor cells (hNPCs) or vehicle into the cortex of rats after permanent distal middle cerebral artery occlusion (dMCAO) or sham-operation, and followed functional recovery in the cylinder and staircase tests. The hNPCs were examined prior to transplantation, and they expressed neuroectodermal markers but not markers for undifferentiated hESCs or non-neural cells. The rats were housed in either enriched environment or standard cages to examine the effects of additive rehabilitative therapy. In the behavioral tests dMCAO groups showed significant impairments compared with sham group before transplantation. Vehicle groups remained significantly impaired in the cylinder test 1 and 2 months after vehicle injection, whereas hNPC transplanted groups did not differ from the sham group. Rehabilitation or hNPC transplantation had no effect on reaching ability measured in the staircase test, and no differences were found in the cortical infarct volumes. After 2 months we measured cell survival and differentiation in vivo using stereology and confocal microscopy. Housing had no effect on cell survival or differentiation. The majority of the transplanted hNPCs were positive for the neural precursor marker nestin. A portion of transplanted cells expressed neuronal markers 2 months after transplantation, whereas only a few cells co-localized with astroglial or oligodendrocyte markers. In conclusion, hESC-derived neural precursor transplants provided some improvement in sensorimotor function after dMCAO, but did not restore more complicated sensorimotor functions.     

Contact allergy to aliphatic polyisocyanates based on hexamethylene-1,6-diisocyanate (HDI)

Background. Aliphatic polyisocyanates based on hexamethylene 1,6‐diisocyanate (HDI) are components of lacquers, coatings, and spray paints. They are mainly composed of HDI trimers, but also contain larger oligomers, and minute amounts of HDI monomers (<1%). HDI trimers occur as biuret, isocyanurate and asymmetrical types. Objectives. We report on 4 patients with allergic contact dermatitis/contact allergy resulting from HDI‐based polyisocyanates in polyurethane paints. Methods. The patients were examined at the Finnish Institute of Occupational Health in 2000–2009. The first two patients were diagnosed by testing with their own polyurethane hardeners and ingredients of the hardeners. In 2002, HDI isocyanurate (HDI‐IC) trimer was added to our isocyanate series, and the last two patients were screened with the series. Results. Patient no. 1 was exposed and sensitized to HDI biuret trimer, patient no. 2 to HDI‐IC trimer, and patient no. 4 to HDI asymmetrical trimer. Patient no. 3 was positive with HDI‐IC trimer. He had been handling several paint hardeners containing HDI‐based polyisocyanates, but the subtypes of the trimers remained unidentified. All 4 patients were negative with HDI monomer. Conclusions. HDI trimers are novel contact allergens in workers who handle polyurethane paints. The allergic reactions cannot be explained by sensitization to HDI monomer.     

Transients may occur in functional magnetic resonance imaging without physiological basis

Functional magnetic resonance imaging (fMRI) has revolutionized the study of human brain activity, in both basic and clinical research. The commonly used blood oxygen level dependent (BOLD) signal in fMRI derives from changes in oxygen saturation of cerebral blood flow as a result of brain activity. Beyond the traditional spatial mapping of stimulus–activation correspondences, the detailed waveforms of BOLD responses are of high interest. Especially intriguing are the transient overshoots and undershoots, often, although inconclusively, attributed to the interplay between changes in cerebral blood flow and volume after neuronal activation. While physically simulating the BOLD response in fMRI phantoms, we encountered prominent transient deflections, although the magnetic field inside the phantom varied in a square-wave manner. Detailed analysis and modeling indicated that the transients arise from activation-related partial misalignment of the imaging slices and depend heavily on measurement parameters, such as the time between successive excitations. The results suggest that some transients encountered in normal fMRI recordings may be spurious, potentially compromising the physiological interpretation of BOLD signal overshoots and undershoots.     

Sleep quality and aerobic training among menopausal women--a randomized controlled trial

Background

Menopause is associated with poor sleep quality and daytime sleepiness, which may lead to impaired quality of life and impaired functioning in daily activities.

Objective

To study whether exercise training improves sleep quality or decreases the amount of night time hot flushes among menopausal women with vasomotor symptoms.

Study design

A randomized controlled trial. Sedentary women (N = 176) aged 43–63 years with menopausal symptoms were randomized to a six-month unsupervised aerobic training intervention (50 min 4 times per week) or a control group. Both groups attended lectures on physical activity and health once a month.

Main outcome measures

Sleep quality and the amount of hot flushes disturbing sleep. The women reported daily via mobile phone whether hot flushes had disturbed their sleep and how they had slept (scale 1–5). Responses received by mobile phone over the 6-month period totaled on average 125 (5.2 per week) responses per participant.

Results

At baseline there was no difference between the groups in the demographic variables. Sleep quality improved significantly more in the intervention group than in the control group (OR 1.02; 95% CI = 1.0–1.05, p = 0.043). The odds for sleep improvement were 2% per week in the intervention group and a decrease of 0.5% per week in the control group. The amount of hot flushes related to sleep diminished (p = 0.004) by the end of the intervention.

Conclusions

Aerobic training for 6 months may improve sleep quality and reduce hot flushes among symptomatic menopausal women.