Neonatal hip instability: a prospective comparison of clinical examination and anterior dynamic ultrasound

BACKGROUND

Ultrasound is increasingly being used to complement the clinical examination in assessing neonatal hip instability. The clinical examination, although highly sensitive in detecting hip instability, can lead to considerable overtreatment.

PURPOSE

To compare anterior dynamic ultrasound and clinical examination in the assessment of neonatal hip instability and regarding treatment rates.

MATERIAL AND METHODS

536 newborn infants (out of a population of 18,031) were selected, on the basis of a combination of risk factors, clinical signs of hip instability or ambiguous clinical findings, to undergo an anterior dynamic ultrasound examination of the hip, by a method developed by our group. This examination, performed by one out of seven experienced examiners, was compared with the standard clinical hip examination conducted by one of four pediatric orthopedic surgeons. The clinical examination was carried out both prior to and within a few hours after the ultrasound examination.

RESULTS

The clinical examination diagnosed 81.7% of the hips as normal, 14.5% as unstable, and 3.8% as dislocatable or dislocated. With the dynamic ultrasound method, the corresponding figures were 87.8%, 10.4%, and 1.8%, respectively. Use of the criteria of the clinical examination resulted in treatment of 147 infants. Using the dynamic ultrasound examination as a criterion meant that 87 infants would receive treatment. The calculated treatment rate was 0.85% when based on the clinical stress test and 0.49% when based on the dynamic ultrasound.

CONCLUSION

The dynamic ultrasound results reduced the treatment rate by over 40% when used as a basis for the decision regarding treatment.

Anterior dynamic ultrasound and Graf's examination in neonatal hip instability

BACKGROUND

Discrepancy between neonatal hip morphology and stability has been reported in the literature. Comparative ultrasound studies on this issue are limited.

PURPOSE

To compare neonatal hip instability, as assessed by dynamic ultrasound and clinical examination, with acetabular morphology, as assessed by Graf's method.

MATERIAL AND METHODS

536 newborn infants with clinical signs of hip instability, ambiguous findings at clinical hip examination, or positive risk factors for DDH were investigated with two ultrasound methods, the Graf method and anterior dynamic ultrasound, at an average age of 12 days. The hips were allocated to three groups according to the Graf result: A, normal (type Ia and b); B, borderline or immature (type IIa); and C, pathologic (type IIc and worse). Graf examination was compared with two diagnostic tests for instability, namely clinical examination by senior pediatric orthopedists and anterior dynamic ultrasound.

RESULTS

According to Graf's method, 77% of the hips were normal, 20% borderline/immature, and 3% pathologic. On clinical hip examination, 82% were stable, 14% unstable, and 4% dislocatable. The dynamic ultrasound outcome was 88% stable hips, 10% unstable, and 2% dislocatable. Of the hips considered unstable or dislocatable on dynamic ultrasound, 21% had normal (type I) and 66% immature acetabular morphology according to the Graf method. Of the hips that were stable on dynamic ultrasound, only one (0.1%) was dysplastic according to the Graf method. Graf's examination showed the smallest number of normal hips, but also the fewest pathologic hips, with many indeterminate results that needed follow-up.

CONCLUSION

Acetabular morphology correlated better to stability as assessed by dynamic ultrasound than to the clinical examination results, with fair to moderate agreement. Graf's examination resulted in a large number of indeterminate results that needed follow-up, but when used as the sole criterion for deciding treatment did not lead to a higher treatment rate than when the decision was based on clinical hip examination.

Metacarpophalangeal pattern profile analysis as a tool for early diagnosis of Turner syndrome

PURPOSE

To analyze the metacarpophalangeal pattern profile (MCPP) in a cohort of individuals with Turner syndrome (TS), and to assess its value as a tool for early diagnosis of TS.

MATERIAL AND METHODS

Medical records and radiological material were collected of 71 patients with TS aged between 3 and 21 years. Forty-six patients received growth hormone therapy (33-66 microg kg(-1) day(-1)) and 14 of these were also treated with the anabolic steroid oxandrolone (1.25-3.75 mg day(-1)). A total of 233 frontal hand radiographs were studied and pattern profiles were calculated. Profiles of the TS patients were compared with those of 70 normal females. Mean pattern profiles were calculated for different age groups and extrapolated profiles for newborns and infants were developed.

RESULTS

Our results confirm that patients with TS have a distinct MCPP which differs significantly from that of normal individuals. A bone-shortening gradient with increasing shortening from distal phalanges to metacarpals was demonstrated. We also showed that the MCPP in TS is a remarkably constant feature from 3 to 18 years. Pattern profiles did not differ significantly between the patients with 45,X and non-45,X karyotype. MCPP was not affected by treatment with growth hormone of growth hormone plus oxandrolone. Discriminant analysis yielded correct classification in 88%, of analyzed cases.

CONCLUSION

TS individuals have a distinct hand pattern profile that is not age-related. MCPP analysis can be applied at any age and may facilitate early diagnosis of TS. Our study showed that MCPP analysis is a specific and sensitive method that should be considered as a routinely used tool for early diagnosis of TS in girls with unexplained short stature.

Appendicitis in children--impact of US and CT on the negative appendectomy rate

BACKGROUND/PURPOSE

Ultrasonography (US) and computed tomography (CT) have proved useful for the evaluation of suspected appendicitis and were introduced as diagnostic tools at our institution about ten and five years ago, respectively. The aim of this study was to evaluate how the negative appendectomy and perforation rates have changed with increased use of US and CT.

METHODS

The medical records of 600 children who underwent appendectomy during years 1991, 1994, 1997, and 2000 were reviewed. Perforation in perforated appendicitis was considered to have occurred after admission if the time interval between the first health professional contact and surgery exceeded 12 hours.

RESULTS

The total number of appendectomies during the years 1991, 1994, 1997, and 2000 was 406, 334, 407, and 397, respectively. The negative appendectomy rate for the same years was 23%, 8.7%, 8.0%, and 4.0%, respectively. The overall rate of perforations and the perforation rate after admission was 32% and 12%, 34% and 7.3%, 34% and 13%, and 29% and 2.1%, respectively. The rate of patients who underwent US and CT during each period was 1.0% and 0.0%, 41% and 0.0%, 91% and 21% and 98% and 59%, respectively.

CONCLUSIONS

The negative appendectomy rate has been substantially reduced after the introduction of both US and CT. The rate of perforation after admission has not increased.

Acute health effects common during graffiti removal

OBJECTIVE

The aim of this study was to identify possible health effects caused by different cleaning agents used in graffiti removal.

METHODS

In 38 graffiti removers working 8-h shifts in the Stockholm underground system, the exposure to organic solvents was assessed by active air sampling, biological monitoring, and by interviews and a questionnaire. Health effects were registered, by physical examinations, porta7ble spirometers and self-administered questionnaires. The prevalence of symptoms was compared with 49 controls working at the underground depots, and with 177 population controls.

RESULTS

The 8-h time-weighted average exposures (TWA) were low, below 20% of the Swedish permissible exposure limit value (PEL) for all solvents. The short-term exposures occasionally exceeded the Swedish short-term exposure limit values (STEL), especially during work in poorly ventilated spaces, e.g. in elevators. The graffiti removers reported significantly higher prevalence of tiredness and upper airway symptoms compared with the depot controls, and significantly more tiredness, headaches and symptoms affecting airways, eyes and skin than the population controls. Among the graffiti removers, some of the symptoms increased during the working day. On a group basis, the lung function registrations showed normal values. However, seven workers displayed a clear reduction of peak expiratory flow (PEF) over the working shift.

CONCLUSIONS

Though their average exposure to organic solvents was low, the graffiti removers reported significantly higher prevalence of unspecific symptoms such as fatigue and headache as well as irritative symptoms from the eyes and respiratory tract, compared with the controls. To prevent adverse health effects it is important to inform the workers about the health risks, and to restrict use of the most hazardous chemicals. Furthermore, it is important to develop good working practices and to encourage the use of personal protective equipment.

Air and biological monitoring of solvent exposure during graffiti removal

OBJECTIVE

The principal aim of the study was to estimate the level of exposure to organic solvents of graffiti removers, and to identify the chemicals used in different cleaning agents. A secondary objective was to inform about the toxicity of various products and to optimise working procedures.

METHODS

Exposure to organic solvents was determined by active air sampling and biological monitoring among 38 graffiti removers during an 8-h work shift in the Stockholm underground system. The air samples and biological samples were analysed by gas chromatography. Exposure to organic solvents was also assessed by a questionnaire and interviews.

RESULTS

Solvents identified were N-methylpyrrolidone (NMP), dipropylene glycol monomethyl ether (DPGME), propylene glycol monomethyl ether (PGME), diethylene glycol monoethyl ether (DEGEE), toluene, xylene, pseudocumene, hemimellitine, mesitylene, ethylbenzene, limonene, nonane, decane, undecane, hexandecane and gamma-butyrolactone. The 8-h average exposures [time-weighted average (TWA)] were below 20% of the Swedish permissible exposure limit value (PEL) for all solvents identified. In poorly ventilated spaces, e.g. in elevators etc., the short-term exposures exceeded occasionally the Swedish short-term exposure limit values (STEL). The blood and urine concentrations of NMP and its metabolites were low. Glycol ethers and their metabolites (2-methoxypropionic acid (MPA), ethoxy acetic acid (EAA), butoxy acetic acid (BAA), and 2-(2-methoxyethoxy) acetic acid (MEAA)) were found in low concentrations in urine. There were significant correlation between the concentrations of NMP in air and levels of NMP and its metabolites in blood and urine. The use of personal protective equipment, i.e. gloves and respirators, was generally high.

CONCLUSIONS

Many different cleaning agents were used. The average exposure to solvents was low, but some working tasks included relatively high short-term exposure. To prevent adverse health effects, it is important to inform workers about the health risks and to restrict the use of the most toxic chemicals. Furthermore, it is important to develop good working procedures and to encourage the use of personal protection equipment.

Improved health after intervention in a school with moisture problems

In a school with floor moisture problems, the personnel had complaints consistent with the sick-building syndrome (SBS). Interventive measures including the laying of a ventilated floor were undertaken to eliminate the emissions. To examine if the intervention resulted in positive health effects, 34 personnel and 336 pupils were interviewed just before the intervention and also 7 months after. Also were interviewed 21 personnel and 224 pupils at an adjacent school serving as a control. Compared with the control school, the problem school showed more complaints, more general symptoms and more symptoms from the eyes, airways and skin, both among the personnel and the pupils. In the post-intervention examinations, the excess of symptoms among the personnel had almost disappeared. Among the pupils, the frequency of eye irritation was reduced but a general improvement of the other symptoms was not as obvious. However, after adjustment for a recent common cold, atopy and stress among the pupils, only one symptom ("stuffy nose") remained significantly elevated. In conclusion, the intervention was followed by positive health effects, supporting the hypothesis that emissions from building material had contributed to the excess of symptoms. A recent common cold was highly related to the symptoms and should be considered in future SBS studies.

Hypersensitivity to electricity: working definition and additional characterization of the syndrome

Those who believe that electric appliances trigger adverse symptoms have coined the label hypersensitivity to electricity. Scientific research has not been able to identify a direct link between electromagnetic fields and symptoms, and no diagnostic criteria exist. Groups with reported hypersensitivity are very heterogeneous. A need exists for an operational working definition and improved characterization of groups. We report an investigation of symptoms and risk indicators associated with reported hypersensitivity to electricity-based on a survey at a high-technology, multinational telecommunications corporation. Comparisons are also made with patients referred to a university department of occupational and environmental health. No association was found between specific psychosocial work characteristics nor personal traits and hypersensitivity to electricity. We present skin and neurovegetative symptom indices. Results indicate that skin, and not neurovegetative symptoms, characterize the syndrome, at least during the first years of illness. For characterization, we propose a set of dimensions, including triggering factors, behavior, and duration of symptoms.

The HD-Zip gene ATHB6 in Arabidopsis is expressed in developing leaves, roots and carpels and up-regulated by water deficit conditions

Homeodomain-leucine zipper (HD-Zip) proteins are transcription factors as yet found only in plants. We have characterized one HD-Zip gene, ATHB6, from Arabidopsis thaliana. ATHB6 was expressed constitutively in seedlings, but significantly up-regulated in seedlings subjected to water deficit, osmotic stress or exogenous treatment with abscisic acid (ABA), an induction being detectable within 30 min. The ATHB6 induction was impaired in the two ABA-insensitive mutants, abi1 and abi2, but unaffected in the abi3 mutation. The induction was ABA-dependent, since no increase in ATHB6 transcript was detected in the ABA-deficient mutant aba-3 subjected to drought treatment. These results suggest that ATHB6 may act downstream to both ABI1 and ABI2 in a signal transduction pathway mediating a drought stress response. A translational fusion of the ATHB6 promoter with the reporter gene GUS (ATHB6::GUS) in transgenic A. thaliana plants showed high-level expression in leaf primordia. Expression in developing cotyledons, leaves, roots and carpels was restricted to regions of cell division and/or differentiation. The expression in the cotyledons was detectable in the epidermis and high in the stomatal cells. In mature cotyledons and leaves the marker gene was expressed only in the vascular tissue. These expression data suggest ATHB6 to have a function related to cell division and/or differentiation in developing organs.

Mercury inductions in persons with subjective symptoms alleged to dental amalgam fillings

This study was carried out to determine whether health disturbances alleged to mercury release from dental amalgam fillings, i.e. "amalgam disease", may be caused by an increased sensitivity to mercury (Hg). In the form of a double-blind test, 39 volunteers who themselves suspected "amalgam disease" inhaled small doses of mercury vapour (0.6-10 microg) or pure air in a random sequence. After the induction procedure, the test persons assessed whether they reacted or not, i.e. experienced increased illness or not. The test persons also registered the daily intensity of their various symptoms. Calculated on the whole population, there was no statistically significant difference between the number of reactions after inhalation of mercury vapour compared with after inhalation of air. Two subjects, however, reacted significantly more often to mercury vapour than to air. The results do not support that short-term exposure to low doses of Hg vapour in general promotes clinical illness in subjects who themselves suspect "amalgam disease". The deviating reactions presented by two test persons, however, may support the theory that occasional individuals can be sensitive to very low doses of Hg.

Personal decontamination after exposure to stimulated liquid phase contaminants: functional assessment of a new unit

OBJECTIVE

To evaluate the efficacy of a decontamination station following exposure of volunteers to liquids with physical characteristics comparable to sarin and mustard gas.

DESIGN

Twenty-four volunteers participated in the experiment which was performed with all staff wearing personal protective equipment including respiratory protection. The clothes, skin, and hair of the volunteers were contaminated with the simulated liquid phase contaminants, ethyl lactate and methyl salicylate. Sulphur hexafluoride gas was used to confirm the ventilation efficacy. Decontamination followed guidelines using a two-stage procedure. In the first chamber, all volunteers received a 3-minute shower with water at 30 degrees C, and their clothes but not their respiratory masks were removed. In the second, they were twice washed thoroughly with soap and water. After decontamination, the volunteers entered a third chamber for first aid measures.

RESULTS

The air concentration of sulphur hexafluoride was reduced by 1:10,000 between the first and the third chambers. Ethyl lactate and methyl salicylate were measured in low concentrations in the third chamber. The capacity was 16 volunteers per hour with two-thirds on stretchers. After self-decontamination of the staff, the concentration of ethyl lactate increased significantly in the third chamber, consistent with residual ethyl lactate adsorbed by their underwear. This observation revealed a deficiency in the guidelines for self-decontamination.

CONCLUSION

The capacity of the decontamination unit was found to be 16 volunteers per hour. The ventilation system and guidelines of the decontamination unit were demonstrated to be effective under the conditions examined. The self-decontamination of the staff was not optimal.

Psychological patterns in patients with coronary heart disease, chronic pain and respiratory disorder

Patients with coronary heart disease (CHD), chronic pain and respiratory disorder were investigated for different patterns of psychological factors. Several psychological factors were measured: depression (using Beck's 'BDI'), anxiety (using Spielberger's 'STAI'), anger (Spielberger's 'AX'), and cynicism (Greenglass & Julkunen's 'CD'). The special psychological pattern in patients with CHD was characterized by an increase in suppressed anger, overall experienced anger, and cynicism. Patients with chronic pain did not show any comparable pattern of elevated psychological factors. The pattern in patients with respiratory disorder was characterized by increased cynicism and, in women, also clinical depression.

Violence toward health care workers. Prevalence and incidence at a large, regional hospital in Sweden

The aim of this study was to establish data for career prevalence and 1 year incidence of work-place violence for major categories of health care workers. Three consecutive work environment questionnaire studies at a large Swedish hospital provided the basis for the study. Prevalence and incidence rates of violence were age and gender adjusted to the Swedish working population. Prevalence of violence in the study population was compared to data from a national sample of Swedish registered nurses. Incidence of violence in each professional group was compared to that of the largest group of hospital employees, registered nurses. Standardized prevalence ratios for violence were significantly higher for all nursing personnel and physicians, and were highest for practical nurses (1.56). Standardized incidence rates ranged from 18/100 person years for physicians to 31/100 person years for practical nurses. The relative risk for violence at work over a 1 year period was significantly higher only for practical nurses (1.59) as compared to registered nurses. Nursing personnel and physicians were at considerable risk for workplace violence in the course of their careers. One year incidence rates were highest for practical nurses.

Hospital Anxiety and Depression Scale (HAD): some psychometric data for a Swedish sample

The Hospital Anxiety and Depression Scale (HAD) was evaluated in a Swedish population sample. The purpose of the study was to compare the HAD with the Beck Depression Inventory (BDI) and Spielberger's State Trait Anxiety Inventory (STAI). A secondary aim was to examine the factor structure of the HAD. The results indicated that the factor structure was quite strong, consistently showing two factors in the whole sample as well as in different subsamples. The correlations between the total HAD scale and BDI and STAI, respectively, were stronger than those obtained using the different subscales of the HAD (the anxiety and depression subscales). As expected, there was also a stronger correlation between the HAD and the non-physical items of the BDI. It was somewhat surprising that the factor analyses were consistently extracting two factors, 'depression' and 'anxiety', while on the other hand both BDI and STAI tended to correlate more strongly with the total HAD score than with the specific depression and anxiety HAD subscales. Nevertheless, the HAD appeared to be (as was indeed originally intended) a useful clinical indicator of the possibility of depression and clinical anxiety.

Stress and sensitization in children: a controlled prospective psychophysiological study of children exposed to international relocation

This controlled prospective study investigated the development of sensitization as a result of international relocation in children, using the analyzing system Phadiatop. The effects of climate and predisposition to allergy were also measured. Children were examined prior to and during their first year of living abroad. A control group living at home was also examined during the same period. Participants answered a questionnaire before and after 1 year abroad, and blood samples were collected to determine sensitization. Before going abroad, there were no significant differences in atopic sensitization between groups nor in other key variables. After 1 year abroad, the proportion of children showing sensitization had increased significantly as compared with the control group at home. The exposed group reported an increase in skin symptoms during the year abroad. This study suggests that unidentified factors associated with foreign relocation increase the risk of sensitization in predisposed children. Stress might be one factor.

Exposure to mercury vapor and impact on health in the dental profession in Sweden

Possible adverse effects of mercury exposure in dentistry have been discussed in several studies. The objective of the present study was to carry out detailed measurements of mercury exposure in the dental profession in Sweden, and to search for adverse health effects from such exposure. We examined 22 dentists and 22 dental nurses, working in teams, at six Swedish dental clinics. Measurements of air mercury, performed with personal, active air samplers, showed a median air Hg of 1.8 micrograms/m3 for the dentists, and 2.1 micrograms/m3 for the dental nurses. Spot measurements with a direct reading instrument displayed temporarily elevated air Hg, especially during the preparation and application of amalgam. The average concentration of mercury in whole blood (B-Hg) was 18 nmol/L, in plasma (P-Hg) 5.1 nmol/L, and in urine (U-Hg) 3.0 nmol/mmol creatinine. Possible effects on the central nervous system (CNS) were registered with three questionnaires: Q16, Eysenck Personality Inventory (EPI), and the Profile of Mood Scales (POMS). In the Q16, the number of symptoms was statistically significantly higher in the dentistry group compared with an age- and gender-matched control group (n = 44). The urinary excretion of albumin and urinary activity of the tubular enzyme N-acetyl-beta-glucose-aminidase (NAG) did not differ between the two groups. The results confirm that exposure to mercury in the dental profession in Sweden is low. The air Hg levels were mainly influenced by the method of amalgam preparation and inserting, and by the method of air evacuation during drilling and polishing.

Psychomotor development at 10 months as related to neonatal health status: the Stockholm Neonatal Project

The psychomotor development of 171 preterm very-low-birthweight (VLBW) infants (birthweight < or = 1500 g) at 10 months of corrected age was assessed by the Griffiths' Mental Developmental Scale. The developmental score was related to the prenatal and obstetric risk factors and to the neonatal health status of each infant. These results, in turn, were compared to findings for a reference group of full-term infants. This analysis revealed that prolonged ventilator treatment, patent ductus arteriosus, bronchopulmonary dysplasia, brain haemorrhage with ventricle dilatation, white matter lesions, low birthweight and low gestational age influenced psychomotor development in an unfavourable manner. Multiple regression analysis confirmed most of these correlations. Preterm birth per se (when children with risk factors were excluded) in general had no significant effect on psychomotor development. However, the early development of preterm infants with several neonatal risk factors was adversely affected.

The Arabidopsis homeobox gene ATHB-7 is induced by water deficit and by abscisic acid

Homeodomain-leucine zipper (HD-Zip) proteins are putative transcription factors encoded by a class of recently discovered homeobox genes as yet found only in plants. This paper reports on the characterization of one of these genes, ATHB-7, in Arabidopsis thaliana. ATHB-7 transcripts were present in all organs of the plant at low levels, but expression was induced several-fold by water deficit, osmotic stress as well as by exogenous treatment with abscisic acid (ABA), a response being detectable at 10(-8) M and reaching a maximum at 10(-6) M ABA. The ATHB-7 transcript was detected within 30 min after treatment with ABA and the transcript level was rapidly reduced after removal of the hormone. The induction of ATHB-7 was shown to be mediated strictly via ABA, since no induction of ATHB-7 was detectable in the ABA-deficient mutant aba-3 subjected to drought treatment. Induction levels in two ABA-insensitive mutants abi2 and abi3 were similar to the wild-type response. In the abi1 mutant, however, induction was impaired as 100-fold higher concentrations of ABA were required for a maximum induction as compared with wild-type. In this mutant the ATHB-7 response was reduced also after drought and osmotic stress treatments. These results indicate that ATHB-7 is transcriptionally regulated in an ABA-dependent manner and may act in a signal transduction pathway which mediates a drought response and also includes ABI1.

Application of a single-compartment model for estimation of styrene uptake from measurements of urinary excretion of mandelic and phenylglyoxylic acids after occupational exposure

In biological monitoring of styrene, the exposure is usually related to the urinary concentration of mandelic (MA) and/or phenylglyoxylic (PGA) acids in a urine sample taken after the workshift or on following morning. To study this relationship further, a single-compartment mathematical model was developed by which measured occupational repetitive uptake of styrene during a working day was related to measured excretion rates of the urinary metabolites. The model was used in practice to calculate the unknown uptake (dose) from MA and PGA excretion analyzed in urine samples. For comparison, a styrene limit dose was calculated from the exposure limit. Analytical results of samples from plastic boat builders were compared with the limit values.

Lung Function in Woodworking Teachers in Sweden

Work-related airways symptoms are common in woodworkers. To study possible work-related effects on lung function, 40 exposed woodworking teachers and 31 controls were examined by spirometry, diffusion-capacity and nitrogen-washout determinations, and methacholine challenge. Measured levels of total and respirable dust and terpene concentrations in the shops were below the Swedish threshold-limit values. Lung-function values on Monday morning were similar in the two groups. Slight obstructive impairments during the working week were found in both groups. In the woodworking teachers, small changes in lung function were related to measured total dust, use of process ventilation, and use of a broom to clean the benches. Their methacholine reactivity was slightly more pronounced compared with that of the controls, but the numbers of hyperreactive individuals (PC&inf20; < 8 mg/m(3)) were equal in the two groups. These facts might indicate small work-related effects on lung function, but some contradictory findings disturb this interpretation. The results are therefore inconclusive.

Serial nasal peak expiratory flow measurements in woodwork teachers

Serial nasal peak expiratory flow rate (PEFRN) recordings and symptom ratings were used on 39 woodwork teachers exposed mainly to wood dust and on 31 control subjects (other school personnel) during a working week. The objective was to study whether the peak flow method is useful for the assessment of work-related nasal obstructive symptoms. By comparison with the controls, the woodwork teachers reported a higher level of nasal blockage, with a pattern of gradual increase during the working week, over which period the PEFRN deteriorated gradually. The method is considered useful for detecting work-related nasal obstruction in groups with exposure to airborne irritants and can be recommended for such purposes. But because of the great variability of peak flow values, many measurements on a great number of individuals must be performed.

Work related impairment of nasal function in Swedish woodwork teachers

OBJECTIVE

To study the relation between exposure and nasal function in woodwork teachers.

METHODS

39 selected woodwork teachers employed full time and 32 control subjects (other school personnel) were examined at the beginning and at the end of a working week with symptom rating, nose and throat inspection, rhinomanometry, nasal mucociliary clearance test, and a smell identification test. During one working day of the same week climate, dust and terpene concentrations were measured in all 39 schools.

RESULTS

The ventilation rate was highest in rooms with mechanical ventilation. Range of total dust (personally sampled) was 0.12-1.18 mg/m3, respirable dust 0.02-0.21 mg/m3, and terpenes (area sampled) 0.02-6.8 mg/m3. In contrast to the control subjects, the woodwork teachers had more nasal symptoms on the Thursday afternoon than on the Monday morning, especially those working in rooms without mechanical ventilation. Their mucociliary clearance worsened during the week (mean increase 4 min, P < 0.001). A small impairment of olfactory function was also found, but their rhinomanometric values did not change significantly. Nasal symptoms correlated weakly with the percentage of respirable dust in the total dust. Otherwise there were no significant dose-effect relations between measured dust or terpene concentrations and nasal tests.

CONCLUSIONS

The woodwork teachers had mainly reversible nasal complaints, impaired nasal mucociliary clearance and olfactory function related to the work environment, with dust concentrations below the Swedish threshold limit value of 2 mg/m3.

Work-related respiratory problems in industrial arts teachers

Because of reports of respiratory complaints in Swedish industrial arts (IA) teachers, a cross-sectional study was performed on 130 IA teachers in Stockholm to study the relationship between the work environment and health, and especially the aforementioned complaints. One hundred and twelve other school employees served as control subjects. Sex, age, and smoking habit distribution were similar in the two groups. All subjects answered a questionnaire about their health problems, and the IA teachers answered questions about their work environment. The work environment consisted of many old and neglected workshops (hereafter called shops). Compared to the control subjects, the IA teachers had more complaints in respect of the skin, eyes, nose, throat, and lower airways--including chronic bronchitis (OR 12.4, 95% confidence interval 2.95-110.5). A higher occurrence of symptoms existed in shops with bad ventilation and dust-spreading machines and in shops where dust-spreading cleanup methods were used. A suspected interaction between smoking and work environment was noted for some symptoms, especially impaired smell and chronic bronchitis. In conclusion, several factors in the work environment were identified as risk factors for health. Identification of these risk factors should result in a program to reduce the health problems in the work environment.

Expression patterns of novel genes encoding homeodomain leucine-zipper proteins in Arabidopsis thaliana

A recently discovered class of genes in Arabidopsis thaliana encode putative transcription factors which contain a homeodomain closely linked to a leucine zipper motif. We have previously reported on the cloning and cDNA sequence of one gene of this class, Athb-3. In this article we show this gene to be expressed predominantly in the cortex of the root and the stem. Using the Athb-3 clone as a probe we have isolated cDNA clones corresponding to three novel homeodomain-leucine zipper proteins. These clones, Athb-5, Athb-6 and Athb-7, hybridized to transcripts that were relatively abundant in the leaf, but also present in other vegetative organs, as well as in the flower. Only weak hybridization was observed to seed pod samples. These observations indicate that these Athb genes have major functions in the mature plant, and therefore, in contrast to homeobox genes in other eukaryotes and to the kn-1 gene in maize, are unlikely to function in the primary control of developmental processes during embryogenesis or organogenesis. The deduced amino acid sequences of Athb-5, Athb-6 and Athb-7 are highly similar to the previously isolated Athb-1, Athb-2 and Athb-3 in the homeodomain and leucine-zipper parts of the proteins, whereas the similarities to homeodomain proteins from other eukaryotes are limited. The Athb proteins thus constitute a new and well defined class of homeodomain proteins, apparently unique to plants.

DMSA administration to patients with alleged mercury poisoning from dental amalgams: a placebo-controlled study

The present investigation was performed to determine the effect of 14-day oral administration of meso-2.3-dimercaptosuccinic acid (DMSA) on the urinary mercury excretion and the potential reduction of blood and plasma mercury concentrations, and also to relate these effects to possible decrease of symptoms, allegedly associated with amalgam fillings. Twenty subjects, relating their symptoms to mercury from amalgam fillings, received 20 mg/kg DMSA or placebo for 14 days. Their symptoms and mood states were recorded during the study and at a check-up 3 months later. Interpretation was based on intra-individual differences. DMSA-treatment resulted in an average increase in urinary mercury excretion by 65% and a decrease in blood mercury levels of 0.04 microgram/L/day. At the check-up after 3 months, urinary mercury excretion had returned to the pre-treatment level. No treatment effect of DMSA was apparent on subjective symptoms and mood state. One statistically significant treatment effect was noted-a decrease in fatigue-inertia in the DMSA-group-but there was no demonstrable correlation with increased urinary excretion or decreased blood concentration of mercury. Three subjects showed hypersensitive reactions, probably DMSA-specific, at the end of the treatment period. This placebo-controlled study provides no scientific support for diagnostic or therapeutic administration of DMSA for symptoms allegedly associated with chronic mercury exposition from dental amalgam fillings.

Effects of occupational exposure to mercury vapour on the central nervous system

Possible effects of mercury on the central nervous system (CNS) were examined in a group of chloralkali workers exposed to mercury (n = 89) and compared with a control group (n = 75), by registration of subjective symptoms, personality changes, forearm tremor, and performance on six computerised psychometric tests in the two groups. The groups were similar in age, education, verbal comprehension, and work tasks. In the chloralkali group, median blood mercury concentration (B-Hg) was 55 nmol/l, serum mercury concentration (S-Hg) 45 nmol/l, and urine mercury concentration (U-Hg) 14.3 nmol/mmol creatinine (25.4 micrograms/g creatinine). Corresponding concentrations in the control group were 15 nmol/l, 4 nmol/l, and 1.1 nmol/mmol creatinine (1.9 micrograms/g creatinine) respectively. The number of self reported symptoms, the scores for tiredness and confusion in the profile of mood states (POMS), and the degree of neuroticism in the Eysenck personality inventory (EPI), were significantly higher in the mercury exposed group compared with the controls. Performance on the psychometric tests and tremor frequency spectra did not differ significantly between the two groups. Dose-response calculations showed weak but statistically significant relations between symptom prevalence and current mercury concentrations in both blood and urine. The performance on three of the psychometric tests was negatively correlated with earlier peak exposures. The findings indicate a slight mercury induced effect on the CNS among the chloralkali workers.

Exposure to organic solvents. A cross-sectional epidemiologic investigation on occupationally exposed care and industrial spray painters with special reference to the nervous system

In the present epidemiologic study 80 car or industrial spray painters with long-term low level exposure to organic solvents were examined and compared with two matched reference groups of nonexposed industrial workers (80 persons in each group). The aim of the study was to investigate the possible effects of the solvent exposure on health. The investigation included psychiatric interviews, psychometric tests, neurological, neurophysiological and ophthalmologic examinations, and computed tomography of the brain. The painters' previous and present exposure was carefully assessed by interviews and on-the-job measurements both at modern places of work and in a reconstructed model of a workshop from 1955. On the basis of the psychiatric interviews the psychiatric symptoms were rated according to a specially designed scale of 46 different items, graded in seven steps of increasing severity. The psychological performance was assessed by a battery of 18 tests. The neurological and neurophysiological examinations comprised visual evoked responses (VER), electroencephalography (EEG), and computerized EEG analysis (SPA) for the central nervous system and electroneurography (ENeG), the estimation of vibration sense thresholds, and a quantified neurological examination for the peripheral nervous system. The ophthamologic examination concentrated on the condition of the lens. Statistically significant differences between the exposed individuals and referents were found for psychiatric items indicative of a slight cerebral lesion (ie, a neurasthenic syndrome). The psychometric tests revealed statistically significant differences between the groups with respect to reaction time, manual dexterity, perceptual speed, and short-term memory. No differences were found with respect to performance on verbal, spatial, and reasoning tests. Significant differences between the groups were also found for the majority of the neurophysiological parameters measuring peripheral nerve functions, the most pronounced occurring in the long, sensory fibers. Moreover EEG and VER showed some differences between the groups, as did the results of the ophthalmologic examination and the computed tomography. Finally, it should be emphasized that the exposure levels, as measured at modern places of work and in the reconstructed workshop from 1955, were found to be considerably lower than the valid threshold limit values in Sweden.