Intra-articular corticoid injection induces circulating glucocorticoid bioactivity and systemic immune activation in juvenile idiopathic arthritis.

OBJECTIVE: To study the systemic effects of intra-articular (IA) glucocorticoid (GC) injections in juvenile idiopathic arthritis (JIA). METHODS: The study group comprised 21 JIA patients being treated with IA methylprednisolone [MP (n = 15) or MP plus triamcinolone hexacetonide (THA) (n = 6)] prescribed on clinical indications. The systemic effect of MP was assessed by measuring circulating glucocorticoid bioactivity (GBA) with a recombinant cell transactivation assay 7 and 24 h after the IA injections, and after 2 months. The systemic immunological responses were studied with a novel assay for testing patient serum-induced changes in the secretion of interferon (IFN)-γ and interleukin (IL)-5 from target cells. RESULTS: Administration of IA GC induced serum GBA (p = 0.001) and suppressed circulating cortisol levels (p = 0.002) 7 h after the injection. Serum withdrawn 24 h after the IA injection induced less IL-5 secretion from mitogen-activated target cells when compared with pre-treatment sera (p = 0.036). This decrease in target cell T helper (Th)2 response (IL-5) was MP dose related (r = -0.550, p = 0.018). High IL-5 secretion from target cells prior to the IA injections was associated with good clinical outcome at 2 months, seen as a low number of active (p = 0.044) and restricted joints (p = 0.049). CONCLUSION: IA GC injections have systemic effects that are reflected in the serum as an immediate elevation of GBA, a decrease of endogenous cortisol as well as a suppressive effect of patient serum on target cell IL-5 secretion. These systemic effects may play a role in the attenuation of disease activity.

Plasma and tissue concentrations of melatonin after midnight light exposure and pinealectomy in the pigeon.

The effect of midnight light exposure and pinealectomy on plasma and tissue concentrations of immunoreactive melatonin was studied in the pigeon. Light exposure of 80 min reduced plasma melatonin by 85%. The melatonin concentration fell to 50% of the original value during 12 min. Pinealectomy reduced plasma melatonin so that at midnight about 36 h after the operations the melatonin concentration of pinealectomized pigeons was about 55% of that of sham-operated pigeons. Two weeks after the operations plasma melatonin of pinealectomized pigeons had increased to 64% of that of sham-operated birds. At midday, melatonin levels were unaffected by the operations. The light-dark rhythm of plasma melatonin was also observed in pinealectomized pigeons. In tissue determinations pinealectomy was found to reduce hypothalamic melatonin significantly, suggesting that the pineal is the main source of hypothalamic melatonin. In the Harderian glands a significant increase of melatonin concentrations was observed after pinealectomy. These glands may therefore be the compensatory organs, explaining the presence of circulating melatonin after pinealectomy.

Poor dental status increases acetaldehyde production from ethanol in saliva: a possible link to increased oral cancer risk among heavy drinkers.

Epidemiological data support evidence that poor dental status increases oral cavity cancer risk especially among heavy alcohol consumers, but the causality of this finding is unclear. The enzymatic conversion of ethanol by the physiological oral microflora may lead to an accumulation of the highly carcinogenic intermediate acetaldehyde. This study was conducted to evaluate the role of dental status on the microbial production of acetaldehyde from ethanol in saliva. The microbial acetaldehyde production from ethanol was related to the dental score in 132 volunteers. After adjustment for smoking, alcohol consumption, age and gender, poor dental status was shown to lead to an approximately twofold increase in salivary acetaldehyde production from ethanol (P=0.02). Our results could be an important factor underlying the role of poor dental hygiene and status in oral cancer risk associated with ethanol drinking.

Nocturnal hypothermia in fasting Japanese quail: the effect of ambient temperature.

Japanese quail were equipped with intraperitoneal transmitters for telemetric measurement of body temperature (Tb) and activity. Food deprivation at + 24 degrees C for four days induced a well-defined nocturnal hypothermic response. The normal day-night difference (about 1 degrees C) in Tb increased 1 degrees C per day, reaching 5 degrees C on the fourth night of fast. Nocturnal motor activity decreased during the fast, while daytime activity first increased and then returned to the original level by the end of the fasting period. A strong correlation between Tb and motor activity was found during scotophase (r = .91) but not during photophase (r = .02). At + 4 degrees C, where food was deprived for two days, the level of hypothermia was not different from that at + 24 degrees C, but birds fasting in the cold reached the hypothermic level more rapidly. In control birds, the decrease in Tb at the beginning of scotophase was independent of ambient temperature. In the combined data, the level of hypothermia correlated strongly with body mass loss (r = .90), which shows that quail can directly or indirectly sense the amount of body energy reserves. This is the first report of hypothermia in a fasting gallinaceous bird. The consistent level of hypothermia at varying ambient temperatures suggests that either nonenergetic costs or phylogenetic constraints prevent deeper hypothermia in cold. Accordingly, the regulation of hypothermia cannot be explained by using only energetic arguments.

Cooling-induced changes in muscular performance and EMG activity of agonist and antagonist muscles.

The effect of whole body cooling on the muscular performance and electromyographic (EMG) activity of agonist and antagonist muscles during dynamic exercise was studied. Eleven slightly clothed male subjects were exposed to ambient temperatures of 27 degrees C and 10 degrees C for 60 min. After the exposures the subjects performed an overhead ball throwing test. Five balls, weighing from 0.3 kg to 3.0 kg were thrown and the velocity of the balls was measured. The EMG activity of two agonist-antagonist muscle pairs (m. triceps brachii--m. deltoideus and m. rectus abdominis--m. erector spinae) were measured during throwing. Cooling decreased mean skin temperature by 6.3 +/- 0.5 degree C (mean +/- SE). The temperature of m. triceps brachii decreased by 4.0 +/- 1.6 degrees C and 1.8 +/- 0.6 degrees C from the depth of 20 and 30 mm underneath the skin surface, respectively. The corresponding values of m. deltoideus were 5.1 +/- 0.4 degrees C and 3.2 +/- 0.8 degrees C. The cooling-induced decrement in ball velocity varied from 9.4 +/- 3.3% (0.3-kg ball) to 5.6 +/- 2.8% (3.0-kg ball) (p < 0.001-0.01). After cooling, the time to reach the maximal level of integrated electromyographic (IEMG) activity in m. triceps brachii (agonist) was increased (30-42%, p < 0.05-0.001). Moreover, cooling decreased the mean IEMG activity m. triceps brachii, while the activity of m. deltoideus (antagonist) was increased. The alteration was significant (p < 0.05-0.001) with the three lightest balls.(ABSTRACT TRUNCATED AT 250 WORDS)

Simulated parachute descent in the cold: thermal responses and manual performance.

BACKGROUND: Ejection from a fighter aircraft can expose the pilot to extreme cold and windy conditions. Knowledge of the effects of such conditions on thermal responses and performance of the pilot is scarce. HYPOTHESIS: It is expected that the temperature of bare skin and fingers may decrease to the level where health and/or performance are hampered. METHODS: Seven fighter pilots performed a simulated parachute descent (SPD) at ambient temperature (Ta) of -35 degrees C and wind velocity of 10 m x s(-1). The 8-min SPD was followed by a 60-min cold exposure (CE) at Ta of -20 degrees C. Flight garments with or without immersion suit were used. During SPD the subjects performed basic survival tasks. Rectal and skin temperatures were measured and manual performance was tested. RESULTS: Thermal responses did not significantly differ between the clothing ensembles. Mean skin temperature was 28 degrees C and 27 degrees C at the end of SPD and CE, respectively. The cheek temperature was 9 degrees C (range 3.2-13.8 degrees C) at the end of SPD. Finger skin temperature was 7 degrees C and 9 degrees C at the end of SPD and CE, respectively. The subjects could perform the defined tasks during SPD while manual performance was slightly impaired during CE. CONCLUSIONS: Subjects could tolerate the 8-min SPD and the following CE in the studied conditions without a loss of vital performance in basic survival actions. However, the risk of frostbite on the uncovered skin area as well as numbness of the fingers may jeopardize pilots' health and performance during parachuting.

Stretch- and H-reflexes of the lower leg during whole body cooling and local warming.

BACKGROUND: This study was undertaken to evaluate if possible changes in stretch- and H-reflexes could be related to the changes in the EMG activity of the cooled lower leg muscles observed during a stretch-shortening cycle exercise. METHODS: Eight subjects wearing shorts and jogging shoes were exposed once to 27 degrees C and twice to 10 degrees C for 60 min each. During the second exposure to 10 degrees C, the subject's lower legs were kept warm (10 degrees Clw) with electrical pillows. After the exposures Achilles tendon reflex (stretch reflex) was induced and the EMG activity of the triceps surae was measured. Immediately after reflex measurements the EMG activity of the triceps surae and tibialis anterior during a drop-jump (stretch-shortening cycle) was measured. After similar thermal exposures electrically induced H-reflex from the calf was measured. RESULTS: During the preactivity and stretch phases the EMG activity of the triceps surae increased after the exposure to 10 degrees C, whereas during the shortening phase it decreased. During the shortening phase cooling, on the contrary, increased the activity of tibialis surae anterior. These changes disappeared at 10 degrees Clw. At 10 degrees C the maximum EMG-amplitude of triceps surae during stretch reflex decreased (p<0.05), reflecting suppressed muscle spindle activity. Suppressed spindle activity causes the agonist to be unfacilitated and the antagonist muscle contraction to be uninhibited, which was seen in the present study as decreased agonist and increased antagonist EMG activity during the shortening phase at 10 degrees C. The Hmax/Mmax-ratio, H-reflex latency and amplitude increased at 10 degrees C (p<0.05), reflecting increased motoneuron pool excitability. This in part may explain the increased EMG activity during the preactivity and stretch phases. CONCLUSION: Cooling-induced increase in the excitability of the motoneuron pool and suppression of muscle spindle activity seem to be responsible of the EMG activity changes during the stretch-shortening cycle, consequently decreasing muscular performance.

Predisposing factors and prevention of frostbite.

This review focuses on the physiological, behavioural and environmental factors which predispose to frostbite. Also prevention of frostbite is summarised. Predisposing factors may increase heat loss, decrease heat production, decrease the insulation of the clothing, make people especially susceptible to cold or make them to behave inadequately. Marked increase in convective or conductive heat loss is often the immediate reason for frostbite. Wind (as described by wind chill index) increases convective heat loss and touching of metal objects increases conductive cooling. Poor insulation of the clothing is also a common reason of frostbite. The insulation can be insufficient when clothing is wet, tight, permeable to wind or does not cover the cold sensitive body parts. Individual factors predisposing to frostbite are inadequate behaviour, low physical fitness, fatigue, dehydration, earlier cold injuries, sickness or poor circulation in peripheral parts of the body. Frostbite is often associated with the use of alcohol. To prevent frostbite, it is necessary to recognise cold risks, practise tasks in the cold, eat and drink well, have physical exercise, have sufficient clothing (also spare clothing), change into dry clothing if necessary and take care of companions. In the cold it is not advisable to get fatigued until exhaustion, sweat excessively, use tight and/or wet clothing, drink alcohol, smoke and expose oneself unnecessarily to wind, metals or fluids.

Effect of regular winter swimming on the activity of the sympathoadrenal system before and after a single cold water immersion.

This study deals with the adaptation of the sympathoadrenal responses to an acute cold water immersion in ordinary winter swimmers. Hormonal responses were determined at the beginning of the winter swimming period in the autumn and after regular swimming for one and three months. Water temperature in the river was 10 degrees C at the beginning and 4 degrees C after one and three months. The mean duration of the test immersion was 36 s. Plasma catecholamine levels determined before the test immersion decreased with the winter swimming period for one month (NA, p < 0.001, A, p < 0.01). The test immersion significantly increased noradrenaline levels (p < 0.001). Plasma adrenaline and serum cortisol levels were increased or decreased by the immersion. After 1 month's swimming the test immersion to 4 degrees C increased noradrenaline to a similar level than the immersion to 10 degrees C at the beginning. Regularly practiced winter swimming for three months led to diminished catecholamine levels measured immediately after the test immersion (p < 0.01). The results suggest that cold adaptation induced by winter swimming attenuates the catecholamine responses to cold water. Adrenaline responses are also affected by its level prior to the immersion.

Heat balance at -5 degrees C after cold water immersion.

Two different possible behaviors at -5 degrees C after cold water immersion were studied. A test subject wearing winter clothing walked (5 km/h) on a treadmill for 45 minutes at -5 degrees C and at a wind velocity of 3 m/s with dry clothing, immediately after a thorough immersion in 5 degrees C water, or after immersion and wringing, freezing, and beating of the clothing (to remove ice). A marked heat debt (ca. 1000 kJ) was measured at the end of the cold water immersion. Attempts to dry the clothing caused an additional heat debt of ca. 300 kJ. After 45 minutes walking, the difference in heat depth between the treatments was nearly the same as before the exercise. The difference in clothing weight was only 0.9 kg between the two treatments after walking. Beating frozen clothing items could remove ice corresponding to only 0.7% of the wet weight of the clothing. Results suggest that after cold water immersion in winter, the undressing procedure could not be recommended. Instead, after initially removing boots, mittens, and hat, the subject should start walking. The water accumulated in boots and mittens should be poured out when necessary.

Work ability of young adults.

This paper reviews the themes related to work ability of young adults. Premature working discapacity causes significant economical and social costs in Finland compared to other Nordic countries and has for that reason been studied most intensively there. Work ability is an interaction of social, environmental and individual factors such as physical fitness, coping skills, social support behaviour and health behaviour. Environmental factors influencing work ability can be concrete, like physical and chemical exposures or more abstract like unemployment. The work ability of ageing people has been studied intensively, while work ability of young adults has not been properly evaluated so far. The worsened economic situation in Finland has meant an excessive work load for those who still have work. At the same time the risk of permanent unemployment is increasing. This polarizationing affects especially the young because they may fail to enter the working life. Also factors related to childhood may affect and even determine work ability in adulthood.

Sequelae of moderate finger frostbite as assessed by subjective sensations, clinical signs, and thermophysiological responses.

The aim of the study was to investigate prevalence and qualities of sequelae following moderate finger frostbite. The study material comprised 30 subjects, who had suffered second-degree frostbite (73% contact frostbite) 4-11 years before this study. In clinical tests 66% of the subjects had an elevated tendency for vasospasm, yet only 20% suffered from white fingers. However, no marked traces of frostbite-related alterations were observed in systemic cardiovascular reflex tests or in X-ray examinations of the frostbite area. Subjective assessments revealed a high prevalence of sequelae (63%), although the primary frostbite was moderate and local. The sequelae in the frostbite area included hypersensitivity to cold (53%), numbness of fingers (40%), and declined sensitivity of touch (33%). Also working ability was lowered due to frostbite sequelae (13%). In cold air provocation tests, the skin temperature of the frostbitten areas decreased more quickly and reached lower values than in healthy control subjects. In conclusion the suffered frostbite was associated with an increased tendency for vasospasm. Subjective sensations of the frostbitten area were associated with thermophysiological changes. The sequelae were reported to worsen in the cold environment thus emphasizing the probable occupational limitations of even moderate cold injury.

Prediction of duration limited exposure for participants wearing chemical protective clothing in the cold.

The suitability of the IREQ (insulation required) index for predicting the thermal responses of 6 participants wearing chemical protective clothing was tested during exercise at -20 and -25 degrees C. IREQ was used to calculate duration limited exposure (DLE). Measured DLE correlated (r =0.899, p <0.001) with the predicted DLE. In exposures exceeding 40 min, however, the predicted DLE tended to be 10-20 min too short compared to the measured one. During short exposures the prediction was 5-20 min too long. The results show that IREQ overestimated the cold strain in participants wearing chemical protective clothing during cold exposures longer than 40 min. Nevertheless, predicted DLE never exceeded measured times and thus the prediction was always safe from the occupational point of view.

Prevalence of cold-related musculoskeletal pain according to self-reported threshold temperature among the Finnish adult population.

BACKGROUND: Exposure to cold reportedly increases musculoskeletal pains. We assessed the prevalence of such pain and self-reported threshold temperature (TT) at which the pain emerges. METHODS: A random sample of 6591 people in Finland, aged 25-74 years, answered a questionnaire on repeated cold-related musculoskeletal pain (CMP) and its TT. The response rate was 64%. We used quantile regression to quantify the effects of personal characteristics and region of residence on TT at various locations of its distribution. RESULTS: Of the participants, 1892 (30%) experienced CMP in at least one body site and 1692 reported TT. Ten percent of the participants who perceived CMP did so at -2 °C, 50% at -14 °C and 90% at -23 °C. Residence in the South elevated TT by 1-6 °C compared with residence in the North, depending on the proportion of participants reporting CMP at various temperatures. Joint disorders increased TT at milder temperatures, at which only 10% of all participants perceived CMP, whereas back disorders did so mainly at lower temperatures, at which 70% were affected. Overweight was associated with a 2 °C lower TT, and physical inactivity with a 1 °C higher TT, and TT increased by 1 °C per 10-year increase in age. The greatest model-estimated difference in median TT between subgroups was 12 °C. CONCLUSIONS: People suffering from musculoskeletal disorders and those living in the warmer areas of Finland need special advice to protect themselves against the cold. Our study provides preliminary information to support such advice.

Oral health in women with pregnancy and delivery complications.

Oral health was retrospectively studied in 207 women (mean age 30 years) in the Helsinki Womens' Hospital with the hypothesis that women with pregnancy complications and/or delivery complications would present poorer dental status than women without complications. Computerized dental records of the City of Helsinki Health Department were used with decayed, missing, filled index (DMF) and community periodontal index (CPI) scoring systems and a summary dental health index (DHI) was constructed for statistics. In 72%, the delivery was uncomplicated, while 18% had Caesarean section. Of the women, 8% had gestational diabetes, 7.1% had gestational hypertension, and 1.8% had preeclampsia. Fifteen (6.6%) preterm babies were born; eight (3.5%) babies weighed <2.500 g, seven (3.2%) received a 1-min Apgar point <7 indicating less than satisfactory state of the newborn. DMF was 12.9+/-6.6 in women without complications compared to 15.3+/-6.7 in women with complications (n.s.). CPI values did not differ between the groups. The mean DHI values were 2.07 in women with normal pregnancy complications and no delivery complications, 2.23 in those with pregnancy complications, and 2.13 in those with delivery complications, respectively. In logistic regression analysis, no oral health parameters associated with any complications. Thus, this study failed to show an association between poor dental health and pregnancy or delivery complications.

Temperature limit values for touching cold surfaces with the fingertip.

OBJECTIVES: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfaces. METHODS: Data were collected in four laboratories with a total of 20 males and 20 females performing a grand total of 1655 exposures. Each touched polished blocks of aluminium, stainless steel, nylon-6 and wood using the distal phalanx of the index finger with a contact force of 1.0, 2.9 and 9.8 N, at surface temperatures from +2 to -40 degrees C for a maximum duration of 120 s. Conditions were selected in order to elicit varying rates of skin cooling upon contact. Contact temperature (TC) of the fingertip was measured over time using a T-type thermocouple. RESULTS: A database obtained from the experiments was collated and analysed to characterize fingertip contact cooling across a range of materials and surface temperatures. The database was subsequently used to develop a predictive model to describe the contact duration required for skin contact temperature to reach the physiological criteria of onset of pain (15 degrees C), onset of numbness (7 degrees C) and onset of frostbite risk (0 degrees C). CONCLUSIONS: The data reflect the strong link between the risk of skin damage and the thermal properties of the material touched. For aluminium and steel, skin temperatures of 0 degrees C occurs within 2-6 s at surface temperatures of -15 degrees C. For non-metallic surfaces, onset of numbness occurs within 15-65 s of contact at -35 degrees C and onset of cold pain occurs within 5 s of contact at -20 degrees C. The predictive model subsequently developed was a non-linear exponential expression also reflecting the effects of material thermal properties and initial temperature. This model provides information for the protection of workers against the risk of cold injury by establishing the temperature limits of cold touchable surfaces for a broad range of materials, and it is now proposed as guidance values in a new international standard.

Finger blood pressure and rewarming rate for screening and diagnosis of Raynaud's phenomenon in workers exposed to vibration.

Both the finger systolic blood pressure (FSP) and the rewarming test of finger skin are measures of circulation in the finger; the first reflects the vasoconstriction phase and the second the vasodilatation phase. The combinations of the specificity and the sensitivity of these methods were evaluated by a receiver operating characteristic curve (ROC). The material included 37 vibration-induced white finger (VWF) cases, five primary Raynaud's cases, and 37 controls. The specificity of the FSP test was high with regard to the anamnesis of white finger and the test was useful for the diagnosis of Raynaud's phenomenon, but the sensitivity was too low for screening. The rewarming test was useful for screening primary Raynaud's case and possibly for screening disorders in peripheral vasodilative function. The connections between the rewarming test and VWF are not clear and according to the present study the rewarming test was not suitable for screening VWF.