[Aggravating factors in teachers' work and fatigue]

BACKGROUND

Teachers are a occupational group in which, due to the type and specificity of work, it can be expected that the feeling of fatigue will be very intense. However, there has been little research into this problem. The aim of the research was to assess the level of fatigue after work and chronic fatigue in teachers, and to determine whether and to what extent it depends on occupational and non-occupational loads.

MATERIAL AND METHODS

The stratified sampling model was used to select the sample, where the layers were the type of school and its location (size of a town/city). All teachers from selected schools were invited to participate. Overall, 650 questionnaires were distributed and 403 teachers returned completed questionnaires. Fatigue after work was assessed on the basis of answers to the following question: "Do you feel tired after work?" and chronic fatigue using the Fatigue Assessment Scale. A special questionnaire was developed to assess other factors that might affect the level of fatigue. The Subjective Stress Assessment at Work Questionnaire, Cohen's Perceived Stress Scale, a part of the Questionnaire of Professional Loads of the Teacher and a list of additional factors disturbing the work were used.

RESULTS

The study involved 70 men aged 35-63 years and 333 women (24-64 years). The groups did not differ significantly in terms of mean age. The level of fatigue, regardless of gender, was mostly influenced by time pressure, rush, mismanagement of the pace of work to individual abilities, increasing workload, an excess of responsible tasks, a lack of support from superiors, a low prestige of the profession, a lack of pedagogical successes, a sense of the lack of meaning in work, and the negative impact of work on family life, as well as non-occupational loads and insufficient rest.

CONCLUSIONS

The conducted study allowed for determining the profile and frequency of occupational and non-occupational factors affecting the level of fatigue in teachers. Med Pr. 2021;72(3):283-303.

Acetabular shape and orientation of the spastic hip in children with cerebral palsy

AIM

To see if three-dimensional (3D) methods could bring new understanding to acetabular changes in shape and orientation in the spastic hip and in which direction(s) acetabular orientation might change, which is crucial for planning appropriate hip correction surgery.

METHOD

We performed a retrospective study of pelvic computed tomography (CT) examinations in 20 consecutive patients (10 females, 10 males). The mean age of patients was 12 years 9 months (SD 2y; range: 9-16y) at the time of the CT examination. The control group consisted of 18 consecutive pelvic CT examinations (36 acetabula) of deceased individuals (six females, 12 males) aged 4 to 17 years (mean age: 10y 6mo; SD 5y 2mo) whose whole-body CT scans were taken shortly after their death. We compared 3D CT reconstructions of 28 unstable and dislocated hips in children with bilateral cerebral palsy (Gross Motor Function Classification System levels IV and V) with the unaffected side and typically developing controls to assess spatial orientation (inclination, anteversion, and tilt), acetabular volume, and surface area. Additionally, we analysed the multiple factors that may lead to structural and spatial changes of the acetabulum.

RESULTS

Patients with dislocated and spastic hips had significantly lower anteversion (-3.2° and -1.4° respectively, p<0.001), increased inclination (85.2° and 85.3° respectively, p<0.001), and decreased tilt (24.6° [p=0.014] and 20.7° [p=0.013] respectively) compared with typically developing individuals. Regarding acetabular volume and surface area, dislocated and unstable hips had significantly lower volume (17.6ml vs 31.5ml respectively, p<0.001) and surface area (28.9cm² vs 36.2cm² respectively, p<0.001) than unaffected hips. Among several factors, only Reimer's migration index had an influence on acetabular orientation (i.e. anteversion, p=0.01), volume (p<0.001), and surface (p=0.004).

INTERPRETATION

Acetabula in patients with spastic hip disease were severely retroverted with increased steepness; acetabular orientation was distorted superoposteriorly. In rare cases, acetabular orientation was distorted only superiorly or superoanteriorly.

WHAT THIS PAPER ADDS

Acetabular orientation was distorted superoposteriorly in most patients with severe bilateral cerebral palsy. More pronounced acetabular changes were found in hips with a higher Reimer's migration index.

[The reaction of the circulatory system to stress and electromagnetic fields emitted by mobile phones - 24-h monitoring of ECG and blood pressure]

BACKGROUND

Experimental studies have shown cardiovascular effects of electromagnetic fields (EMF) emitted by mobile phones (e.g., prolonged QTc interval and abnormal blood pressure [BP] values). Also, stress may have an impact on the cardiovascular function. However, there are practically no data regarding the joint effect of exposure to stress and EMF, with both factors pertaining, e.g., to employees of mobile network operators.

MATERIAL AND METHODS

Out of 208 subjects who had taken part in survey research, 55 workers agreed to undergo resting ECG, 24-h ECG and ambulatory blood pressure monitoring (ABPM). Their health condition, occupational and life-stress levels and EMF exposure were also assessed.

RESULTS

Among the workers using mobile phones for more than 60 min daily, the systolic BP values in office measurement and at night-time in ABPM were significantly higher than among the workers spending less time talking on mobile phones (p = 0.04 and p = 0.036, respectively). The workers with the highest level of occupational stress showed significantly higher systolic 24-h BP (p = 0.007) and at day-time (p = 0.002), both during work (p = 0.010) and after work (p = 0.005), and higher diastolic BP values at day-time (p = 0.028). Cardiovascular response was strongly gender-related: males showed more BP abnormalities while females displayed more impairments in ECG records. The heart rate from 24 h was significantly correlated with the level of occupational stress, after adjusting for gender, life-stress and EMF.

CONCLUSIONS

The findings obtained thus far have indicated the need to conduct in-depth studies on the impact of stress and EMF emitted by mobile phones on the health effects, in order to clarify the observed gender-related differences in cardiovascular response to the combined exposure to stress and EMF. Med Pr. 2019;70(4):411-24.

Analysis of bus drivers reaction to simulated traffic collision situations - eye-tracking studies

OBJECTIVES

The aim of the study was to establish whether the driver's visual strategy may influence a driver's behavior to avoid a crash in a high-risk situation. Any published papers on drivers' visual strategies just before a crash were not found.

MATERIAL AND METHODS

Tests were performed using a high-tech driving bus simulator. Participants comprised 45 men drivers, aged 43.5±7.9 years old, seniority as a bus driver of 13.3±8.6 years. The tests were preceded by medical examinations: general, neurological and ophthalmological. Each participant drove the same city route for approximately 40 min (entire route - ER). In the final phase, a collision situation was simulated (a phantom car blocked the participant's right of way). Driver's visual strategy was analyzed using the FaceLab device with 2 cameras during ER and just before collision. The field-of-view covered by camera 1 was divided into 8 regions, by camera 2 into 10 regions. The distribution of gazes in regions was a criterion of visual strategy.

RESULTS

Thirty-five drivers completed the simulated driving test, 14 escaped the collision, 21 crashed. These groups differed only in resting systolic blood pressure before the test. The analysis of covariance, after adjusting to this factor, indicated that during the ER visual strategy recorded by camera 1 did not differ between groups, in camera 2 the drivers in the crash group fixed their gaze more frequently (p = 0.049) in region 3 (close part of the road in front of the windshield). Just before the collision drivers who escaped the collision fixed their gaze significantly more often in region 6 (left side of the road) in camera 1 and in region 6 (in front of the windshield,) and region 10 (right side) in camera 2.

CONCLUSIONS

The visual strategy has an impact on the road safety. The analysis of visual strategies may be a useful tool for the training of drivers. Int J Occup Med Environ Health. 2019;32(2):161-74.

Radial Extracorporeal Shockwave Therapy and Ultrasound Therapy in the Treatment of Tennis Elbow Syndrome

BACKGROUND

Both ultrasound and radial shockwave therapies are used to treat tennis elbow syndrome. The aim of this study was to compare the therapeutic efficacy of both therapies by assessing the reduction in pain intensity and frequency, restoration of mobility, and reduction in the need for pain medication.

MATERIAL AND METHODS

The study enrolled 60 people, who were randomly divided into two groups of 30 patients: those treated by radial shockwave therapy and those treated by ultrasound therapy. Radial shockwave therapy consisted of 3 sessions at weekly intervals. Ultrasound therapy consisted of 10 treatments performed daily. The clinical status of the patients before treatment, just after treatment, and after 8 weeks was assessed with the Leitinen questionnaire and a visual analogue scale (VAS).

RESULTS

Pain reduction, as assessed by VAS scores, was observed in both groups, who were not different at baseline (p=0.807). While both therapies were effective (p&lt;0.005), mean pain intensity assessed by VAS scores in patients treated by radial shockwave therapy was significantly lower compared to those treated by ultrasound therapy; this relationship was present just after treatment completion (p=0.001) and at 8 weeks after treatment completion (p=0.002).

CONCLUSIONS

1. Both radial shockwave and ultrasound therapies cause a reduction in the intensity and frequency of pain that persists for at least 8 weeks, reducing the need for pain medication and improving the function of the treated upper limb. 2. Ultrasound therapy is less effective than radial shockwave therapy.

[Prevention of cardiovascular diseases - Prophylactic program in a selected enterprise]

BACKGROUND

In Poland cardiovascular diseases (CVD), classified as work-related diseases, are responsible for 25% of disability and cause 50% of all deaths, including 26.9% of deaths in people aged under 65 years. The aim of the study was to analyze employee expectations regarding CVD- oriented prophylactic activities in the selected enterprise.

MATERIAL AND METHODS

A questionnaire, developed for this study, consists of: socio-demographic data, job characteristics, occupational factors, and questions about the respondents' expectations concerning the prevention program. The study group comprised 407 multi-profile company employees aged (mean) 46.7 years (standard deviation (SD) = 9.1), including 330 men (81.1%), mean age = 46.9 (SD = 9.2) and 77 women (18.9%), mean age = 45.9 (SD = 8.2) The study was performed using the method of auditorium survey.

RESULTS

Employees declared the need for actions related to physical activity: use of gym, swimming pool, tennis (56.5%), smoking habits - education sessions on quitting smoking (24.6%). A few people were interested in activities related to healthy diet. According to the majority of the study group, the scope of preventive examinations should be expanded. Based on our own findings and literature data CVD- -oriented preventive program, addressed to the analyzed enterprise was prepared. The program will be presented in another paper.

CONCLUSIONS

The results showed significant quantitative and qualitative differences in the classic and occupational CVD risk factors between men and women, as well as in preferences for participation in prevention programs. Therefore, gender differences should be taken into account when planning prevention programs. Med Pr 2017;68(6):757-769.

[Effect of stress and intesity of mobile phone using on the health and subjective symptoms in GSM workers]

BACKGROUND

There are no available data on the health consequences that may result from the synergistic effects of electromagnetic fields (EMF) and stress. Understanding the mechanisms of the simultaneous exposure will make it possible to develop procedures to minimize adverse health effects in professionals using mobile phones.

MATERIAL AND METHODS

A questionnaire survey was conducted in 600 randomly selected people to obtain data on their health status and the prevalence of subjective symptoms related to the mobile phones using. Among them, there were 208 GSM Network employees, to whom the Perceived Stress Scale and Assessment of Stress at Work Questionnaire were sent. Eighty-nine completed questionnaires were returned (response rate - 42.8%).

RESULTS

The mean age of respondents was 30.3 years (standard deviation (SD) = 7.7), time of occupational use of mobile phone - 4.1 years (SD = 1.7), the level of occupational stress - 95.3 (SD = 19.1). A significant percentage of people (62.8%) complained of the frequent difficulties in coping with problems of everyday life, and 57.4% had a fairly frequent problems with managing their own affairs. Significant differences in the life stress were detected between groups with different time of phone use (p = 0.03), and in occupational stress level, significant differences were noted between the 2 groups differing in the length of the conversation (p = 0.05). The risk of headache, associated (odds ratio (OR) = 4.2, p = 0.008) or not associated (OR = 2.97, p = 0.04) with calls on mobile phone, adjusted for stress, was significantly higher in people speaking via mobile more than 60 min/day than in those talking less.

CONCLUSIONS

The study indicates that both stressors acting at the same time (EMF from cell phone and stress) adversely affect the well-being of workers and increase the risk of subjective symptoms. Med Pr 2017;68(5):617-628.

Mobile phone use and risk for intracranial tumors and salivary gland tumors - A meta-analysis

Results of epidemiological studies on the association between use of mobile phone and brain cancer are ambiguous, as well as the results of 5 meta-analysis studies published to date. Since the last meta-analysis (2009), new case-control studies have been published, which theoretically could affect the conclusions on this relationship. Therefore, we decided to perform a new meta-analysis. We conducted a systematic review of multiple electronic data bases for relevant publications. The inclusion criteria were: original papers, case-control studies, published till the end of March 2014, measures of association (point estimates as odds ratio and confidence interval of the effect measured), data on individual exposure. Twenty four studies (26 846 cases, 50 013 controls) were included into the meta-analysis. A significantly higher risk of an intracranial tumor (all types) was noted for the period of mobile phone use over 10 years (odds ratio (OR) = 1.324, 95% confidence interval (CI): 1.028-1.704), and for the ipsilateral location (OR = 1.249, 95% CI: 1.022-1.526). The results support the hypothesis that long-term use of mobile phone increases risk of intracranial tumors, especially in the case of ipsilateral exposure. Further studies are needed to confirm this relationship. Int J Occup Med Environ Health 2017;30(1)27-43.

Health risk to medical personnel of surgical smoke produced during laparoscopic surgery

OBJECTIVES

During laparoscopic cholecystectomy, the removal of the gall bladder, pyrolysis occurs in the peritoneal cavity. Chemical substances which are formed during this process escape into the operating room through trocars in the form of surgical smoke. The aim of this study was to identify and quantitatively measure a number of selected chemical substances found in surgical smoke and to assess the risk they carry to medical personnel.

MATERIAL AND METHODS

The study was performed at the Maria Skłodowska-Curie Memorial Provincial Specialist Hospital in Zgierz between 2011 and 2013. Air samples were collected in the operating room during laparoscopic cholecystectomy.

RESULTS

A complete qualitative and quantitative analysis of the air samples showed a number of chemical substances present, such as aldehydes, benzene, toluene, ethylbenzene, xylene, ozone, dioxins and others.

CONCLUSIONS

The concentrations of these substances were much lower than the hygienic standards allowed by the European Union Maximum Acceptable Concentration (MAC). The calculated risk of developing cancer as a result of exposure to surgical smoke during laparoscopic cholecystectomy is negligible. Yet it should be kept in mind that repeated exposure to a cocktail of these substances increases the possibility of developing adverse effects. Many of these compounds are toxic, and may possibly be carcinogenic, mutagenic or genotoxic. Therefore, it is necessary to remove surgical smoke from the operating room in order to protect medical personnel.

[Neurological symptoms and syndromes in municipal transport drivers]

BACKGROUND

The way the municipal transport drivers perform their job contributes to varied burdens linked with the body posture at work, stress, shift work, vibration, noise and exposure to chemical agents. The aim of the study was to assess the condition of the nervous system (NS) in municipal transport drivers.

MATERIAL AND METHODS

The study covered 42 men, aged 43.4 years (standard deviation (SD): 8.3), employed as bus drivers in the municipal transport enterprise. The duration of employment was 11.8 years on average (SD: 8.6). The condition of the nervous system was assessed on the basis of clinical neurological examinations.

RESULTS

Chronic lumbosacral syndrome was found in 54.8% of the subjects. A significant relationship between the incidence of lumbosacral syndrome and the duration of employment (p=0.032) was observed; significantly higher in drivers employed for 11-15 years (90.9%) in comparison to the remaining groups. Nervous system functional disorders were characterized by the increased emotional irritability (47.6%), sleep disorders manifested by excessive sleepiness (33.3%) or insomnia (28.6%) and headaches (3%), mostly tension headaches. Excessive daytime sleepiness was significantly age-dependent (p=0.038).

CONCLUSIONS

The evidenced NS disorders indicate the need to undertake preventive measures tailored for the occupational group of bus drivers.

Testicular effect of a mixture of 2-methoxyethanol and 2-ethoxyethanol in rats

BACKGROUND

2-Methoxyethanol (ME) and 2-ethoxyethanol (EE) represent a large group of chemicals which are used separately or as mixtures. These compounds exert multidirectional toxic effects. The present studies aimed to demonstrate the effects of ME and EE alone and their mixture on the reproductive organs in the rats.

METHODS

Male Wistar rats were treated subcutaneously with ME and EE alone (1.25-5.0mM/kg/day) or with their mixture (1:1) for 4 weeks. After completion of the experiment, the testes, epididymides, and prostate were weighed. In post-mitochondrial supernatant of the testes, the level of total protein, non-protein and protein sulfhydryl groups, malondialdehyde, total antioxidant status, and glutathione peroxidase and glutathione reductase activities were determined.

RESULTS

Exposure to ME alone resulted in a dose-dependent decrease in the organ weights, the total protein, non-protein and protein sulfhydryl groups. EE alone led to less marked alterations. Co-exposure to ME and EE caused alterations similar as in the rats treated with ME alone.

CONCLUSIONS

Marked testicular atrophy, decrease in epididymis and prostate weights are predominant effects of the repeated exposure to relatively low doses of ME and EE. A decrease in the total protein level, and protein sulfhydryl groups may be responsible for testicular atrophy. A significant depletion of non-protein sulfhydryl groups and occasionally elevated glutathione peroxidase activity may indicate that ME and EE resulted in disturbances of pro-oxidant/antioxidant balance. The study suggests that testicular toxicity in male rats co-exposed to ME and EE is mainly caused by the former compound.

Hematological effects of exposure to mixtures of selected ethylene glycol alkyl ethers in rats

Exposure to various ethylene glycol monoalkyl ethers (EGAEs) is known to result in hemolytic effect caused by their metabolites, appropriate alkoxyacetic acids, generated via both alcohol dehydrogenase and aldehyde dehydrogenase. It has been shown in many studies that administration of single doses of EGAEs to rats lead to dose- and time-dependent hemolytic anemia. The repeated exposure to isopropoxyethanol (IPE), and butoxyethanol (BE), contrary to methoxyethanol (ME) and ethoxyethanol (EE), resulted in significantly less pronounced hematological changes. While the majority of hematological effects were dramatic at the beginning of the exposure, later these changes clearly regressed despite continued weekly exposure to these ethers. The gradual recovery from the hemolytic anemia may be associated with tolerance development to the hemolytic effect of IPE and BE. ME demonstrated high hematotoxicity, which increased progressively and reached a maximum at the end of 4 week exposure, whereas EE revealed moderate hematological effects. It might be suspected that ME and EE may modified of IPE hemolytic activity in rats simultaneously treated with these compounds. In the rats co-exposed to IPE and ME subcutaneously at a relatively low doses of 0.75 mM + 0.75 mM for 4 weeks, a significantly less pronounced hematological changes at the beginning of the exposure in comparison with animals treated with IPE (0.75 mM) alone were observed. At the later period, i.e., at the end of 4 weeks exposure, the hematological alterations in the same animals were markedly pronounced and progressively elevated with exposure time, except for mean corpuscular volume (MCV) values, which were significantly lower in comparison with IPE group. ME at the higher dose of 1.25 mM/kg and EE at both doses of 0.75 and 1.25 mM/kg did not modify the hematotoxicity of IPE (at doses of 0.75 mM and 1.25 mM) at the beginning of the exposure, whereas increased its harmful effects at the end of the treatment. The amelioration in the majority of the hematological parameters at the beginning of the exposure may be caused by inhibitory effect of ME on IPE metabolism. On the contrary, an accumulation of the methoxyacetic acid and ethoxyacetic acid, toxic metabolites of ME and EE, respectively, and no tolerance development to the hemolytic effect of these two chemicals may be responsible for elevated hematological alterations at the end of the exposure.

Oxidative DNA damage and oxidative stress in subjects occupationally exposed to nitrous oxide (N(2)O)

OBJECTIVES

Occupational exposure to nitrous oxide (N(2)O) and/or halogenated hydrocarbons has been suggested to induce damage of genetic material, but the underlying mechanisms remain obscure. This study investigated the role of oxidative processes in the genotoxicity associated with exposure to waste anaesthetic gases.

METHODS

The study was performed in 36 female nurses and in 36 unexposed female health care workers matched for age and employment duration. Genotoxic effects were examined by Comet test modification employing formamidopyrimidine glycosylase (FPG) that allows assessment of oxidative DNA damage. Reactive oxygen species (ROS) in leukocytes were investigated by fluorescence spectroscopy with 2',7'-dichlorofluorescin diacetate. Oxidative stress markers including 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)), thiobarbituric acid-reacive substances (TBARS), α-tocopherol, and glutathione peroxidise (GPX) activity were measured immuno- or colorimetrically. N(2)O, sevoflurane and isoflurane were monitored by gas chromatography and mass spectrometry.

RESULTS

The study documents for the first time the positive correlation between the oxidative DNA damage and the N(2)O levels in the ambient air. By contrast, no association was observed between genotoxic effects and sevoflurane or isoflurane. In addition, ROS generation and plasma and urine concentrations of TBARS and 8-iso-PGF(2α), respectively, were elevated, while GPX activity was reduced in nurses exposed to waste anaesthetic gases. Path analysis pointed to a causal relationship between N(2)O exposure, oxidative stress and DNA damage.

CONCLUSION

Occupational exposure to N(2)O is associated with increased oxidative DNA damage and the level of exposure plays a critical role in this regard. Increased oxidative stress may represent a mechanistic link between chronic N(2)O exposure and genotoxicity.

[Certain issues concerning medical certification and driving fitness assessment after craniocerebral traumas]

BACKGROUND

The incidence of craniocerebral traumas increases with a growing number of road accidents. It should be emphasized that it is rather difficult to determine precisely the craniocerebral traumas incidence rate, however, it is well known that road accidents are the major cause of these injuries.

MATERIAL AND METHODS

The study embraced 43 men (mean age: 47.1; SD: 11.4) after craniocerebral traumas. Of the 43 men, 23 drivers had driving license of the following classes: A, Al, A2, AM, B, B1 and BE without professional driving permit, and 20 men worked as professional drivers licensed according to the following classes: C, CE, C1, C1E, D, DE, D1 and DIE. The duration of drivers' employment ranged from 4 to 33 years (mean: 19 years; SD: 7.7). The clinical diagnosis was based on the patient's medical history, medical records, neurological examination complemented with other specialist examinations.

RESULTS

Posttraumatic encephalopathy diagnosed in 23 (53.5%) patients was characterized by varied clinical symptoms. Posttraumatic simple encephalopathy diagnosed in 13 patients was the most frequent contradiction to run motor vehicles. Posttraumatic epilepsy was a contradiction in 5 and posttraumatic subarachnoid haemorrhage in 2 patients (one with neurological deficiency hemiparesis, the other with frontal lobe syndrome. Following the treatment 46.5% of men under study did not show neurological deficits and were allowed to run motor vehicles.

CONCLUSIONS

The certification procedure in cases of past craniocerebral traumas should not follow the routine and careful examination of each individual case is required prior to assessing a driver's ability to run motor vehicles.

Semen quality in men from subfertile couples from the region of Łódź (Poland) according to the new reference values recommended by WHO 2010

The semen analysis is the main diagnostic tool for evaluating the male fertility potential. The standard semen analysis includes evaluation of the sperm concentration, motility, and their morphology. The most important question is whether the results from semen analysis may be accurate markers for male fertility. Therefore, we retrospectively studied sperm quality among men attending the infertility clinic due to reproductive problems consistent with the WHO manual from 1999, which were reassessed according to the manual from 2010. Semen results from 571 males from couples undergoing fertility investigation were analyzed. All subjects included in the study had no abnormalities during examination. In 64 samples (11.2%), a leukocyte count above 1 x 10⁶/ml was found and their semen volume (median 3.2 ml) was significantly lower in comparison with the group without leukocytes (3.6 ml; p <0.001). Normal semen parameters were found in 290 subjects (50.8%) according to the 1999 manual and in 362 men (63.4%) according to the 2010 manual. The normozoospermia group, according to the 2010 manual, had a significantly lower percentage of sperm with progressive motility, motile sperm concentration, and total number of motile sperm in comparison with the normozoospermia group according to the manual from 1999. It seems that routine semen analysis is not sufficient to estimate male fertility potential and some men with normal semen parameters may be subfertile. Further investigations are needed.

Headspace measurements of irradiated in vitro cultured cells using PTR-MS

A pilot study was performed to evaluate a new concept for a radiation biodosimetry method. Proton transfer reaction-mass spectrometry (PTR-MS) was used to find out whether radiation induces changes in the composition of volatile organic compounds (VOCs) in the headspace of in vitro cultured cells. Two different cell lines, retinal pigment epithelium cells hTERT-RPE1 and lung epithelium cells A-549, were irradiated with gamma radiation at doses of 4 Gy and 8 Gy. For measuring the cell-specific effects, the VOC concentrations in the headspace of flasks containing cells plus medium, as well as of flasks containing pure medium were analyzed for changes before and after irradiation. No significant radiation-induced alterations in VOC concentrations in the headspace could be observed after irradiation.

Discrimination of cancerous and non-cancerous cell lines by headspace-analysis with PTR-MS

Proton transfer reaction mass spectrometry (PTR-MS) has been used to analyze the volatile organic compounds (VOCs) emitted by in-vitro cultured human cells. For this purpose, two pairs of cancerous and non-cancerous human cell lines were selected:1. lung epithelium cells A-549 and retinal pigment epithelium cells hTERT-RPE1, cultured in different growth media; and 2. squamous lung carcinoma cells EPLC and immortalized human bronchial epithelial cells BEAS2B, cultured in identical growth medium. The VOCs in the headspace of the cell cultures were sampled: 1. online by drawing off the gas directly from the culture flask; and 2. by accumulation of the VOCs in PTFE bags connected to the flask for at least 12 h. The pure media were analyzed in the same way as the corresponding cells in order to provide a reference. Direct comparison of headspace VOCs from flasks with cells plus medium and from flasks with pure medium enabled the characterization of cell-line-specific production or consumption of VOCs. Among all identified VOCs in this respect, the most outstanding compound was m/z = 45 (acetaldehyde) revealing significant consumption by the cancerous cell lines but not by the non-cancerous cells. By applying multivariate statistical analysis using 42 selected marker VOCs, it was possible to clearly separate the cancerous and non-cancerous cell lines from each other.

The effects of low environmental cadmium exposure on bone density

Recent epidemiological data indicate that low environmental exposure to cadmium, as shown by cadmium body burden (Cd-U), is associated with renal dysfunction as well as an increased risk of cadmium-induced bone disorders. The present study was designed to assess the effects of low environmental cadmium exposure, at the level sufficient to induce kidney damage, on bone metabolism and mineral density (BMD). The project was conducted in the area contaminated with cadmium, nearby a zinc smelter located in the region of Poland where heavy industry prevails. The study population comprised 170 women (mean age=39.7; 18-70 years) and 100 men (mean age=31.9; 18-76 years). Urinary and blood cadmium and the markers of renal tubular dysfunction (beta(2)M-U RBP, NAG), glomerular dysfunction (Alb-U and beta(2)M-S) and bone metabolism markers (BAP-S, CTX-S) as well as forearm BMD, were measured. The results of this study based on simple dose-effect analysis showed the relationship between increasing cadmium concentrations and an increased excretion of renal dysfunction markers and decreasing bone density. However, the results of the multivariate analysis did not indicate the association between exposure to cadmium and decrease in bone density. They showed that the most important factors that have impact on bone density are body weight and age in the female subjects and body weight and calcium excretion in males. Our investigation revealed that the excretion of low molecular weight proteins occurred at a lower level of cadmium exposure than the possible loss of bone mass. It seems that renal tubular markers are the most sensitive and significant indicators of early health effects of cadmium intoxication in the general population. The correlation of urinary cadmium concentration with markers of kidney dysfunction was observed in the absence of significant correlations with bone effects. Our findings did not indicate any effects of environmental cadmium exposure on bone density.

[Evaluation of the relation between Doppler flow in maternal and fetal vessels and the risk of adverse neonatal outcome]

AIM

The study aimed at: 1. Analysis of the relationship between Doppler flow in the selected maternal and fetal vessels and the risk of adverse perinatal outcome (APO); 2. Multivariate logistic regression model for the assessment the risk of APA.

MATERIAL AND METHODS

The study population covered 216 pregnant women from Lodz and Kalisz between 2003-2006.

RESULTS

In univariate logistic regression model PI_UA significantly influenced the risk of APO. That risk was increasing 1.2 times, if the PI_UA value was 1/10th higher than the measured unit. Abnormal cardiotocography (CTG) pattern was related to 12-times higher risk of APO. In cases of abnormal PI_MCA, the risk of APO was 2.5 times higher than when PI_MCA was within the normal range. Abnormal PI_UA was related to 11.5-times higher risk of APO. Similarly when PIV_DV was abnormal, the risk of APO was 2.3-times higher. Low birth weight (LBW) was connected with the 6-times higher risk of APO. In multivariate logistic regression model, CTG and LBW were the risk factors significantly associated with APA. Abnormal CTG pattern was related to more than 6-times higher increase of the risk of APO, however LBW with nearly 4-times higher risk of APO.

CONCLUSION

Abnormal values of PI in UA and in MCA, abnormal flow in DV and abnormal CTG pattern, as well as low birth weight, had significant influence on the risk of APO. In multivariate analysis only abnormal CTG and low birth weight were the significant factors of APO.

[Comparison of Doppler flow in selected maternal and fetal vessels in pregnancies with fetal intrauterine growth restriction]

OBJECTIVES

The aim of the study was to compare Doppler flows in materno-fetal circulation in pregnancies with IUGR and small for gestational age (SGA) neonatal weight or normal weight, as well as in uncomplicated pregnancies.

MATERIAL AND METHODS

The study population comprised 216 pregnant women from Lodz and Kalisz between 2003-2006. In the group I we included 68 women with IUGR observed in prenatal ultrasound examination and SGA neonates, in the group II--29 women with IUGR observed in US but normal neonatal weight and in the group III--110 women with normal fetal and neonatal weight.

RESULTS

Mean fetal weight in the group II was (2035 g +/- 400 g) and in the group I (1947 g +/- 414 g) and it was lower than in the group III (2765 g +/- 543 g) (p<0.0005). Notch in UTA was found more often in the group I (39.7%), than in the groups III (8.4%) and II (10.3%), (p< 0.0005). The mean PI in the right UTA in the group I (0.957 +/- 0.440) was higher than in the groups II (0.718 +/- 0.259) and III (0.730 +/- 0.215), (p<0.001). Abnormal Doppler flows in MCA in the groups I (39.7%) and II (34.5%) were observed more often than in the group III (6.4%), (p<0.0005). Similarly abnormal Doppler examination in DV in the groups I (45.5%) and II (46.4%) were observed more often than in the group III (17.8%), (p<0.0005). PI in UA in the groups I (1.061+/- 0.325) and II (0.965 +/- 0.184) was higher than in the group III (0.848 +/- 0.166), (p<0.0005).

Hydrophilic olive cake extracts: characterization by physicochemical properties and Cu(II) complexation

Disposed olive cake generates hydrophilic components that can be mobilized in the aquatic environment. This paper deals with the characterization of such components, isolated by alkaline extraction. It is shown that these substances possess properties very much resembling humic acid, including a substantial inventory of proton exchanging groups. Extraction and purification of the hydrophilic components from the disposed olive cake was performed by the standard approach for isolation of humic acids from solid sources, i.e. alternating alkaline dissolution and acid flocculation, leaving the purified extract in the protonated form. The purified sample was characterized by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Fourier Transform Infra Red Spectroscopy (FTIR), UV-vis, Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Asymmetrical Flow Field-Flow Fractionation (AFFFF). The complex formation properties were investigated by potentiometry using Cu(II) ion selective electrode under atmospheric conditions at I=0.1M NaClO(4) (aqueous solution) and pH 6. The formation constant for the CuHA complex is found to be logbeta=5.3+/-0.4 which is close to the corresponding value (logbeta=5.2+/-0.4) obtained from similar investigations with the commercially available Aldrich humic acid (this study) and corresponding published values for various humic acids. Both, structural properties and complex formation data show that the olive cake extract has considerable similarities with humic acids from different sources, pointing towards potential similarities in environmental behavior and impact.

[Occupational diseases in Poland, 2008]

BACKGROUND

The aim of the paper was to present basic statistical data on occupational diseases diagnosed in 2008.

MATERIAL AND METHODS

The work was based on the data compiled from "Occupational Disease Reporting Forms" received by the Central Register of Occupational Diseases in 2008. The data comprised information on nosologic units, gender and age of patients, and duration of occupational exposure to harmful agents responsible for the development of specified pathologies. These data were further classified by sectors of the national economy and voivodeships. The incidence was specified in terms of the number of cases in relation to paid employees or to employed persons.

RESULTS

The number of occupational diseases diagnosed in 2008 accounted for 3546 cases. The incidence rate was 34.7 cases per 100,000 paid employees. The highest incidence rates were noted for infectious and parasitic diseases (9.4/100,000), chronic voice disorders (7.9) and pneumoconioses (6.8). As many as 77.9% of patients affected by occupational diseases had been exposed to harmful agents for longer than 20 years. In industrial sectors of the national economy, the highest incidence rate was noted in the coal mining industry (416.3 cases per 100,000). The highest incidence rates were recorded in the Lubelskie (75.5), Silesian (66.3) and Podlaskie (60.7) voivodeships.

CONCLUSIONS

An increase of 261 (7.9%) cases of occupational diseases and an increase of 3.6% in their incidence rate over the previous year were noted in 2008. The greatest increase was noted in infectious and parasitic diseases (of 285 cases, i.e. 42.5%) and chronic diseases of the locomotor system (of 22 cases i.e. 22.4%).

[Quantitative methods of cancer risk assessment in exposure to chemicals]

This is a methodology paper--it contains a review of different quantitative risk assessment methods and their comparison. There are two aspects of cancer risk modeling discussed here: 1. When there is one effective dose only. There were compared two models in this evaluation: one proposed by the Dutch Expert Committee on Occupational Standards and the other--a classical two-stage model. It was taken into account that in both models the animals were exposed for less than two years. An exposure period and a study period of animals were considered in the Dutch methodology. If we use as an exposure measure average lifespan dose estimated with different coefficients of exposure time in an experiment, we get two different dose-response models. And each of them will create different human risk models. There is no criterion that would let us assess which of them is better. 2. There are many models used in the BenchMark Dose (BMD) method. But there is no criterion that allows us to choose the best model objectively. In this paper a two-stage classical model and three BMD models (two-stage, Weibull and linear) were fit for particular data. Very small differences between all the models were noticed. The differences were insignificant because of uncertainties in the risk modeling. The possibility of choice of one model from a bigger set of models is the greatest benefit of this comparison. If the examined chemical is a genotoxic carcinogen, nothing more is needed than to estimate the threshold value.

Gestational diabetes mellitus - an analysis of risk factors

INTRODUCTION

Gestational diabetes mellitus (GDM) is associated with an increased frequency of gestational, perinatal and neonatal complications. The aim of the study was to evaluate risk factors for GDM and their predictive value.

MATERIAL AND METHODS

The group studied consisted of 510 pregnant women with GDM diagnosed according to World Health Organization (WHO) criteria (GDM). The controls were 1160 pregnant women with normal glucose tolerance (NGT). Multifactorial analysis was performed and odds ratios (OR) were calculated for each risk factor identified.

RESULTS

The GDM patients were significantly older than the NGT subjects (30.1 vs. 27.2 years; p < 0.0001), had a greater tendency towards obesity before pregnancy (BMI 25.0 vs. 21.6 kg/m2; p < 0.0001), more often had relatives with diabetes (40.0 vs. 25.7%; p < 0.01), had greater parity (third or subsequent pregnancy: 33.6 vs. 16.0%; p < 0.001) and more often experienced adverse perinatal outcomes (21.4 vs. 13.7%; p < 0.01). Multivariate analysis revealed the following risk factors for GDM: BMI > 25 kg/m2 (OR 4.14), a history of macrosomia (OR 2.72), being pregnant for the third time or more (OR 1.8), a family history of diabetes (OR 1.76) and age at gestation > 25 years (OR 1.34). No risk factors were present in 12% of GDM subjects, and at least one risk factor was found in 74.1% of subjects with NGT. No risk factor cluster was found which could be used easily in everyday practice to identify reliably subjects at increased risk of GDM.

CONCLUSIONS

Age, overweight and obesity, diabetes in the family, parity, macrosomia and a history of perinatal complications were identified as risk factors for GDM. As no reliable method of identifying subjects at increased GDM risk was found, we suggest that all pregnant women should undergo laboratory screening for GDM.

[Occupational diseases in Poland, 2007]

BACKGROUND

The aim of the paper was to present basic statistical data on occupational diseases diagnosed in 2007.

MATERIAL AND METHODS

The work was based on the data compiled from "Occupational Disease Reporting Forms" received by the Central Register of Occupational Diseases in 2006. The data comprised information on nosologic units, gender and age of patients, and duration of occupational exposure to harmful agents responsible for the development of specified pathologies. These data were further classified by sectors of the national economy and voivodships. The incidence was specified in terms of the number of cases in relation to paid employees or to employed persons.

RESULTS

In 2007, 3285 cases of occupational diseases were diagnosed. The incidence rate was 33.5 cases/100 000 paid employees. The highest incidence rates were noted for chronic voice disorders (8.1/100 000), pneumoconioses (7.1), infectious and parasitic diseases (6.8) and hearing loss (2.6). As many as 77.3% of patients affected by occupational diseases had been exposed to harmful agents for more than 20 years. In industrial sectors of the national economy, the coal mining industry showed the highest incidence rates (404.1 cases/100 000). The highest incidence rates were recorded in the Lubelskie (73.1), Silesian (68.4), Swietokrzyskie (66.5) and Małopolskie (60.7) voivodships.

CONCLUSIONS

Compared with 2006, the number of cases of occupational diseases increased by 156 cases (5%), the incidence rate increased by 2.1%. The greatest rise was noted in infectious and parasitic diseases (by 68 cases, 11.3%) and chronic diseases of peripheral nervous system (by 50 cases, 46.3%). At the same time the number of hearing loss cases apparently decreased (by 43 cases, 14.6%).

Expression of tumour necrosis factor-related apoptosis-inducing ligand and caspase-3 in relation to grade of inflammation and stage of fibrosis in chronic hepatitis C

AIM

To assess whether the distribution of the recently described proapoptotic ligand, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), and the apoptosis effector, caspase-3 alters with the degree of inflammation and fibrosis present in liver biopsy specimens from patients with chronic hepatitis C virus infection.

METHODS AND RESULTS

Expression of TRAIL and caspase-3 was assessed immunohistochemically in liver biopsy specimens obtained from 89 adults with chronic hepatitis C. Expression of TRAIL in hepatocytes correlated inversely with stage of fibrosis (P = 0.001), classified according to the Scheuer score; expression of caspase-3 in hepatocytes correlated with grade of inflammation (P = 0.012). Expression of TRAIL in hepatocytes was not correlated with grade of inflammation (P > 0.05); expression of caspase-3 was not correlated with stage of fibrosis (P > 0.05). Maximum expression of proapoptotic TRAIL protein was observed in cases with low grade inflammation (G0) and low stage fibrosis (S1). Maximum expression of caspase-3 in hepatocytes was observed in cases with high grade inflammation (G3-4) and high stage fibrosis (S3), but not with liver cirrhosis (S4).

CONCLUSIONS

There is a significant decrease in TRAIL expression with increasing grade of inflammation, whereas caspase-3 expression is significantly increased with advanced fibrosis, short of cirrhosis.

Expression of Bax, Bcl-xL and Bcl-2 proteins in relation to grade of inflammation and stage of fibrosis in chronic hepatitis C

AIMS

To determine the expression of regulators of apoptosis in chronic hepatitis C.

METHODS AND RESULTS

Expression of Bax, Bcl-xL and Bcl-2 proteins was assessed immunohistochemically in liver biopsy specimens obtained from 89 adults with chronic hepatitis C. Expression of Bax in hepatocytes correlated inversely with grade of inflammation (P < 0.001) and stage of fibrosis (P = 0.011), classified according to the Scheuer score; expression of Bcl-xL in hepatocytes did not correlate with grade of inflammation (P = 0.106) or stage of fibrosis (P = 0.078); maximum Bcl-xL expression was observed in grade 3 inflammation and stage 4 fibrosis. Expression of Bcl-2 protein in hepatocytes was present in only two cases (both with advanced disease); the expression of Bcl-2 protein in interlobular bile duct epithelial cells correlated with the grade of inflammation (P = 0.018), but not with stage of fibrosis (P = 0.154). The expression of Bcl-2 protein in lymphoid cells infiltrating portal zones and lobules did not correlate with grade of inflammation (P = 0.113) or stage of fibrosis (P = 0.815).

CONCLUSION

Major differences in expression of studied proteins were observed in relation to grade of inflammation and stage of fibrosis in chronic hepatitis C.

Does fecal diversion offer any chance for spontaneous closure of the radiation-induced rectovaginal fistula?

Analysis of the clinical course of patients with postirradiation rectovaginal fistula after fecal diversion. The studied group included 17 women with postirradiation rectovaginal fistula who underwent fecal diversion as a sole mode of treatment, between January 1987 and December 2002, in our department. All patients were subjected to radiotherapy due to cancer of the uterine cervix, administered 5-107 months before the fistula appearance (mean, 22.9 months). In 3 of 17 patients (18%), spontaneous closure of fistula was observed after 5, 6, and 9 months, respectively, from fecal diversion. Closure was confirmed by endoscopy. Length of follow-up after fecal diversion ranged from 0.5 to 122 months. The actuarial probability of spontaneous closure of postradiotherapy rectovaginal fistula was 0.24 at 9 months of follow-up and then remained stable thereafter. In conclusion, colostomy alone gives hardly a chance for closure of the postradiotherapy rectovaginal fistula. Additional surgical measures are necessary.

[Occupational diseases in Poland, 2006]

BACKGROUND

The aim of the paper was to present basic statistical data on occupational diseases diagnosed in 2006.

MATERIAL AND METHODS

The work was based on the data compiled from "Occupational Disease Reporting Forms" received by the Central Register of Occupational Diseases in 2006. The data comprised information on individual diseases, gender and age of patients, and duration of occupational exposure to harmful agents responsible for the development of specified pathologies. These data were further classified by sectors of the national economy and voivodships (provinces). The incidence was specified in terms of the number of cases per 100,000 paid employees and per 100,000 employed persons.

RESULTS

In Poland, the number of occupational diseases diagnosed in 2006 accounted for 3129 cases. The incidence rate was 32.8 cases per 100,000 paid employees. The highest incidence rates were noted for chronic disorders of the voice organ (8.0 per 100,000), pneumoconioses (7.0), contagious and parasitic diseases (6.3) and permanent bilateral hearing loss (3.1 per 100 000). As many as 75.8% of patients affected by occupational diseases had been exposed to harmful agents for longer than 20 years. In industrial sectors of the national economy, the highest incidence was noted among workers employed in the mining industry (309.1 cases per 100,000 paid employees), particularly in coal mining (366.8). The highest incidence rates were recorded in the Lubelskie (73.7), Silesian (70.2) and Swietokrzyskie (62.6) voivodships.

CONCLUSION

The incidence of occupational diseases in Poland continues to abate. A downward trend is primarily due to a lower number of cases of hearing loss, diseases of pleura or pericardium induced by asbestos dust, skin diseases, and intoxications with chemical substances. However, an increase in the number of cases of chronic diseases of the voice organ was revealed.

[Work-related stress and the Conservation of Resources Theory by Stevan Hobfoll]

BACKGROUND

The Conservation of Resources Theory by Stevan Hobfoll has grown in popularity, as a new theory of stress, since the 1980s. A general assumption of Hobfoll's theory is that an individual has some resources at his/her disposal which he/she greatly appreciates and is inclined to protect and never loose them. Stress is predicted to occur as a result of circumstances that represent: (1) a threat of resource loss, or (2) an actual loss of the resources required to sustain the individual, and (3) the lack of reasonable gain following resource investments. Hobfoll has developed the Conservation of Resources-Evaluation (COR-E) questionnaire as an instrument derived from his theory to measure the degree of lost and gained resources. The questionnaire has been adapted to Polish conditions. The aim of the study was to assess the usefulness of COR-E in the diagnosis of work-related stress. In the literature, we have found information on the relationship between COR-E results and depressive mood, anxiety and other stress effects. But it should be remembered that these effects are not caused only by stress. We would like to check whether COR-E results are correlated with the results of the stress at work questionnaire.

MATERIAL AND METHODS

The study group comprised 157 persons. Each person completed two questionnaires: COR-E (in Polish version) and Subjective Assessment of Work Characteristics. The later has been developed to measure stress at work according to the psychosocial factor approach.

RESULTS

There was no relationship between reported gains of resources and work stress, but we found very low correlation between reported lost resources and work stress (r = 0.16; p < 0.05). Item analyses revealed that the loss of some resources was correlated with work stress. However, much higher correlation was observed between the results of a subscale consisting of these items and work stress (r = 0.40; p < 0.01).

CONCLUSIONS

The COR-E questionnaire can be accepted as a new instrument to measure work stress, but further investigations are needed to cover other occupational groups.

Physiological reaction to work in cold microclimate

OBJECTIVES

In Poland, occupational exposure to cold microclimate is quite common (5.1 workers/1000 occupationally active people). Reports on health effects of this exposure are rather scarce. The aim of the study was to evaluate the physiological reaction in workers occupationally exposed to cold microclimate.

MATERIALS AND METHODS

Examinations were performed in a group of 102 workers (41 women and 61 men) employed at cold storage units. The mean age in the group was 39.1 +/- 9.9 years and the duration of employment under conditions of cold environment was over 12 years. The study population was divided into four groups, according to microclimate conditions (group I, ambient temperature -26 degrees C; group II, 10-14 degrees C; group III, 18-20 degrees C, control group; and group IV, 0-10 degress C). The workers underwent the following procedures: general medical examinations, cold pressor test, ambulatory blood pressure monitoring, and heart rate variability (HRV) analysis (time- and frequency-domain parameters).

RESULTS

The results were adjusted for confounding factors (age, smoking and drinking habits). The analysis of HRV parameters did not reveal any significant differences between the study groups. However, systolic and diastolic blood pressure (BP) in the daytime and at night was significantly higher in group IV compared to group II. Mean heart rate (HR) in the daytime and at night and the BP and HR day/night ratio did not differ between the groups. The analysis of BP by gender revealed that in women, systolic BP during the day and at night was significantly higher in group IV than in group II. In the group of workers with hypertension (18 men and 5 women), men reacted to the cold pressor test either by increased or decreased BP while all the women reacted by the increased BP.

CONCLUSIONS

Our findings indicated that in workers exposed to cold microclimate, the physiological reaction was dependent on gender and ambient temperature. Women seemed to be more sensitive to cold stress than men. However, this finding must be further investigated.

The role of the acetabulum in Perthes disease

The purpose of this study is to evaluate the changes in the shape of acetabulum from the onset of the disease to the skeletal maturity in Legg-Calvé-Perthes disease. The study population consisted of 243 patients with unilateral involvement who had reached skeletal maturity at last follow-up. All hips were treated by containment methods (which included bed rest and traction in abduction, Petri cast, brace, varus osteotomy, Salter osteotomy, and shelf acetabuloplasty). Necrosis of the femoral head was estimated according to the lateral pillar classification and late results according to the Stulberg classification. Changes in the shape of the acetabulum were divided into 3 groups: type I-normal, concave lateral acetabulum margin; type II-flat, horizontal lateral acetabulum margin; and type III-convex, sloping acetabular margin. Roentgenograms performed during the fragmentation stage revealed type I changes in 78 (32.1%) hips, type II in 136 (55.7%), and type III in 29 (12.2%). At the last follow-up, there were type I changes in 124 (51.2%) hips, type II in 81 (33.5%), and type III in 38 (15.3%). The statistical analysis revealed no significant statistical difference between the age at the onset and gender with regard to acetabular changes. There was significant statistical correlation between the lateral pillar classification, subluxation of the femoral head, the range of hip abduction, and the Stulberg classification with regard to acetabular changes. A type III was statistically associated with lateral pillar classification group C, major subluxation of the femoral head, limited hip abduction, and in Stulberg group 3, 4, or 5. Only surgical methods of treatment improved the acetabular shape at the last follow-up (P<0.05). In our opinion, the lateral acetabulum shape plays a very important role during the remodeling of the deformed proximal femoral epiphysis.

Neurovegetative disturbances in workers exposed to 50 Hz electromagnetic fields

OBJECTIVES

Since the circulatory and nervous systems are composed of electrically excitable tissues, it is plausible that they can be stimulated by electromagnetic fields (EMF). No clinical studies have as yet been carried out to explain whether and how occupational exposure to 50 Hz EMF can influence the neurovegetative regulation of the cardiovascular function. The present project was undertaken to assess the autonomic function in workers occupationally exposed to 50 Hz EMF, by analyzing the heart rate variability.

MATERIALS AND METHODS

The study group comprised 63 workers of switchyard substations, aged 22-67 years (39.2 +/- 10.0 years), and the control group 42 workers of radio link stations, aged 20-68 years (40.7 +/- 9.2 years), employed at workposts free from EMF exposure. The age range and employment duration in both groups did not differ significantly. To assess the neurovegetative regulation of the cardiac function, heart rate variability (HRV) analysis was made based on 512 normal heart beats recorded at rest. The analysis, performed using fast Fourier transformation, concerned the time- and frequency-domain HRV parameters. Power spectrum in the very low (VLF), low (LF) and high (HF) frequency bands was determined.

RESULTS

The relative risk of decreased HRV (STD R-R < 27 ms), calculated with use of a logistic regression model, was significantly higher in the exposed group than in controls (OR = 2.8). The VLF power spectrum was significantly higher in the exposed group and correlated with the exposure level. The percentage of subjects with dominant sympathetic function (LF/HF > 1) was significantly higher in the study group than in controls (65% vs. 47%).

CONCLUSIONS

It was concluded that occupational exposure to 50 Hz EMF could influence the neurovegetative regulation of the cardiovascular system.

Expression of Ki-67, transforming growth factor beta1, and B-cell lymphoma-leukemia-2 in liver tissue of patients with chronic liver diseases

BACKGROUND

The purpose of the present paper was to assess expression of proliferation, fibrosis and apoptosis markers in different phases of chronic liver diseases.

METHODS

Sixty-six adults with chronic liver diseases (chronic hepatitis C, n = 48; chronic hepatitis B, n = 10; alcohol chronic liver disease, n = 8) treated at the Department of Infectious Diseases and Hepatology from 1999 to 2001, composed the study group. Liver biopsy specimens were used for immunohistochemical assessment of expression of Ki-67, transforming growth factor beta1 (TGF-beta1) and B-cell lymphoma-leukemia-2 (Bcl-2). Grade of liver inflammation and stage of fibrosis were evaluated according to the Scheuer scale.

RESULTS

Expression of Ki-67 in hepatocytes was most intensive in patients with grade 2 and 3 inflammation. The expression in patients with grade 4 inflammation was low. The expression of Ki-67 in lymphocytes was most intensive in patients with grade 2 inflammation. Expression of TGF-beta1 in hepatocytes reached a maximum in patients with grade 2 or 3 inflammation and dropped in patients with grade 4 inflammation. There was a statistically significant correlation between stage of fibrosis and expression of TGF-beta1 in liver stromal cells. A very strong correlation was found between the expression of Bcl-2 in bile ductules epithelium and the grade of inflammation (P = 0.006). The expression of Bcl-2 in hepatocytes was observed only in patients with very intense liver inflammation (grade 3) and in patients with stage 3 or 4 fibrosis.

CONCLUSION

Processes of proliferation, fibrosis and apoptosis are not directly correlated to progression of liver disease. Expression of studied markers can be used for analysis of dynamics of these processes.

Proposed Criteria for Assessing Low Frequency Noise Annoyance in Occupational Settings

OBJECTIVES

The aim of the study was to recommend methods for assessing low frequency noise (LFN) in the occupational environment to prevent annoyance and its effects on work performance. Three different evaluating methods and corresponding admissible values were proposed: (i) method I--frequency analysis in 1/3-octave bands within the range of 10-250 Hz, (ii) method II--consisting in 1/3-octave band measurements and determination of low frequency equivalent-continuous A-weighted sound pressure level (SPL) in the frequency range of 10-250 Hz, and (iii) method III--based on equivalent-continuous A-weighted SPL corrected due to the presence of low frequencies and tonal character of LFN. Separate noise limits were recommended for workplaces in control rooms and office-like areas.

MATERIALS AND METHODS

The proposed criteria were verified in laboratory and field studies. The laboratory study included 55 volunteers, aged 21.8 +/- 2.1 years, with normal hearing (< 25 dB HL). The subjects listened to different noises at A-weighted SPL of 45-65 dB, and evaluated annoyance using a 100-score graphical rating scale. In the field study, 35 male workers, aged 40.1 +/- 7.2 years, exposed to LFN at A-weighted SPL of 48-61 dB, were asked to rate noise annoyance at their workplaces using a similar graphical scale. The subjective ratings of LFNs were compared to objective results from various assessing methods. The relations between annoyance and excesses of proposed limits were analyzed using Pearson's correlation coefficient (r).

RESULTS

Linear relationships between the subjective ratings and results from all proposed exposure criteria were observed (0.550 < or = r < or = 0.673; p < 0.001). In the field conditions, however, the highest correlation coefficient was found for method II (r = 0.673), while during the laboratory study for method I (r = 0.612) and criterion curves based on hearing threshold level (HTL).

CONCLUSIONS

All proposed criteria, especially the evaluation method based on the low frequency equivalent-continuous A-weighted sound SPL (method II) as well as the frequency analysis in 1/3-octave bands 10(20)-250 Hz (method I) and criterion curves based on HTL or A-weighting characteristics, seem to be able to quite well predict annoyance experienced from LFN at workplaces.

[Occupational diseases in Poland, 2005]

BACKGROUND

The aim of this paper was to present basic statistical data on occupational diseases diagnosed and certified in 2005.

MATERIALS AND METHODS

This work is based on the data compiled from "Occupational Disease Reporting Forms" received by the Central Register of Occupational Diseases in 2005. The data comprised information on individual diseases, gender and age of patients, and duration of occupational exposure to harmful agents responsible for the development of specified pathologies. These data were further classified by sectors of the national economy and voivodships (provinces). The incidence was specified in terms of the number of cases per 100,000 paid employees and per 100,000 employed persons.

RESULTS

In Poland, the number of occupational diseases diagnosed in 2005 accounted for 3249 cases. The incidence rate was 34.8 cases per 100,000 paid employees. The highest incidence rates were noted for: chronic disorders of the voice organ (7.3 per 100,000), pneumoconioses (7.2), infectious and parasitic diseases (6.6) and permanent bilateral hearing loss (3.6). As much as 73.0% of patients affected by occupational diseases had been exposed to harmful agents for more than 20 years. In the industrial sectors of the national economy, the highest incidence was noted among workers employed in the mining industry (281.7 cases per 100,000 paid employees), particularly in coal mining (325.2). The highest incidence rates were recorded in the Podlaskie (87.3), Lubelskie (82.1), and Silesian (66.3) voivodships. CONCLUSION The incidence of occupational diseases in Poland continues to abate. The downward trend is primarily due to a lower incidence of chronic diseases of the voice organ and hearing loss. However, an increased number of cases of infectious and parasitic diseases, mainly borreliosis, was revealed.

[The prognostic factors in perthes disease]

The purpose of this study was to evaluate the role of selected factors which may play role in the estimation of late result during Perthes disease and which one can be eliminated during treatment period. The study population consisted of 311 patients (50 patients with bilateral disease, 361 hips joint) who had reached skeletal maturity at last follow up. All hips were treated by containment methods (bed rest and traction in abduction, Petri cast, brace, varus osteotomy, Salter osteotomy and shelf acetabuloplasty). Both clinical and radiological parameters (taken during fragmentation stage) were included in our study: gender, age at the onset, hip joint abduction, type of treatment, extend of the femoral head necrosis according to the Herring and Catterall classification, LLD, premature growth plate arrest, ATD and ATD index, lateral acetabulum shape - type I - normal, concave lateral acetabulum margin, type II--flat, horizontal and type III--convex, sloping, femoral head subluxation, femoral head sphericity disturbance according to the Mose, risk factors according to the Catterall, Wiberg angle, Eyre-Brook index. Long-term results were evaluated according to the Stulberg classification and were divided into two groups: good result--Stulberg group 1 or 2 and poor and bad result--Stulberg group 3, 4 or 5. The unilateral and bilateral Perthes disease was estimated separately. The statistical analysis revealed in unilateral Perthes disease that next risk factors may lead to poor or bad late result: age at the onset 9 and more years, group 3 or 4 according to Catterall and group C according to Herring classification, type III lateral acetabulum shape, hip joint abduction less than 10 degrees, premature growth plate arrest, ATD index less than 0.8, femoral head subluxation more than 20%, femoral head sphericity disturbance more than 5mm, Gage sign, calcification laterally to the femoral head (sensitivity 85.0%, specificity 98.7%). Bilateral Perthes disease: age at the onset over 6 years, group 3 or 4 according to Catterall and group C according to Herring classification, hip joint abduction less than 10 degrees and calcification laterally to the femoral head (sensitivity 81.8%, specificity 92.3%). The statistical analysis showed which clinical and radiological factors may play an important role in estimation of late results during Perthes disease. Additionally during fragmentation stage of Perthes disease we have possibility to correct or eliminate some of the risk factors - femoral head subluxation, lateral acetabulum shape and hip joint abduction and improve the late result.

[Perthes disease with onset after nine years of age]

The aim of this study is to evaluate and compare selected clinical and radiological hip joint parameters in Perthes disease with onset before and after 9 years of age. Analysis was based on 261 patients with unilateral Perthes disease. Patient with bilateral changes ware excluded because of earlier onset before 9 years old. The average age of patients at the time of initial symptoms was 7,1 years ( 2,5 - 13 years). The follow-up ranged from 16 to 50 years (average 20, 2 years). The clinical analysis was based on evaluation of age, gender and range of passive abduction. The radiological assessment was based on Catterall and Herring classifications, lateral subluxation, premature physeal closure by Bowen classification, limb length discrepancy, shape of the lateral acetabulum rim, ATD distance and index, center-edge angle, the Mose Classification, epiphyseal index and quotient. Assessments of final results were based on The Mose Classification and the Stulberg Classification. We affirmed that, in children with the onset of disease after 9 years of age, asymmetrical premature physeal closure, major lateralization, grater contour of the head deviation (Mose) and trochanteric overgrowth were more frequent occurred than in children with Perthes disease before 9 years of age. Patients who were over the age of 9 years at the time of onset and have a hip in Catterall 3 group and 4 group together with the lateral pillar B group or C group get a poor outcome. There were not any differences in the outcomes in Catterall 1 and 2 group together with Hering A group depending on age at the time of onset. Both age at the time of onset after 9 and quantity of femoral head necrosis have the most significant impact on the outcome, leading to poor final results. In accordance with our observation we do advise caution in older children's treatment with femoral varus osteotomy.

Leg length discrepancy in Legg-Calve-Perthes disease

The purpose of this study was to determine the incidence of the leg length discrepancy (LLD) in Legg-Calve-Perthes disease and whether there is any correlation between LLD and age at onset, gender, type of treatment, and severity of disease. The study population consisted of 261 patients with unilateral involvement who had reached skeletal maturity at last follow-up. All hips were treated by containment methods (bed rest and traction in abduction, Petri cast, brace, varus osteotomy, Salter osteotomy, and shelf acetabuloplasty). The late results were classified according to the Stulberg classification. LLD was found in 33 patients and ranged from 1 to 5.2 cm (average 2.51 cm). The limb shortening was observed in Herring group B (average 2.18 cm) and C (average 2.82 cm) and was statistically significant more common in group C. The statistical analysis revealed no statistical difference between the age at onset, sex, and type of treatment with regard to LLD; nevertheless, patients in Herring group C with LLD were younger than patients in group B, and LLD was seen more often after varus osteotomy. The amount of residual shortening of the affected limb in Legg-Calve-Perthes disease at the end of skeletal growth seems to depend on the extent of involvement and the presence of a growth arrest. A varus osteotomy produces more significant shortening than other methods of treatments. The age at the onset of symptoms and sex do not influence the amount of LLD, but early onset of the disease can result in more severe limb shortening.

[Subjective symptoms related to mobile phone use--a pilot study]

Research findings indicate that the use of mobile phones may lead to a number of symptoms such as headache, impaired concentration and memory, fatigue. In Poland this problem has not as yet been addressed by scientific studies.

THE AIM

The present project was undertaken to investigate whether the symptoms of ill health reported by young people may be associated with the use of mobile phone.

MATERIAL AND METHODS

A survey using a self-reported questionnaire was conducted among randomly selected university students in Lodz, Central Poland. The questionnaire was designed specifically for this study and contained items on health condition and complaints as well as on frequency of mobile phone use. The number of questionnaires necessary for the study was assessed using the simple random sample method. Out of the 160 copies distributed among the students, 140 (87.5%) were completed. Eventually, 117 questionnaires were subject to analysis; the data from respondents who reported health problems (neck trauma in a car accident, chronic sinusitis and arterial hypertension) were excluded. The following statistical methods were used to analyse questionnaire data: t-Student test for equal and unequal variances or F-Snedecor test for comparing parameters in two study groups, Fisher exact test for comparing frequency, and single and multiple logistic regression models for quantitative risk assessment of negative health outcomes in relation to exposure level and with control for confounders. The subjects were 61 (52.1%) males and 56 females (47.9%).

RESULTS

Most of the subjects (62%) assessed their health condition as good, 31% as very good and 7% as fair. 70% complained of headache and 20% of dizziness. Impaired concentration occurred in 56% of respondents. Facial dermatitis was reported by 11%. The most prevalent symptom related to mobile phone use was the thermal sensation within the auricle and behind/around the ear. This was reported by 33 subjects (28.2%). Out of 82 subjects who complained of headache, only 8 (6.8%) related this symptom to mobile phone use. Only 10 subjects of 65 reporting impaired concentration thought it could be associated with their using a mobile phone. The symptoms and health complaints reported by the respondents in no case were the reason for a medical check-up or taking any medication.

CONCLUSIONS

The large number of young people complaining of headache and impaired concentration calls for further research to investigate the underlying reasons. It cannot be excluded that one of them may be exposure to EMF emitted by mobile phone. The explanation should be sought through further experimental and epidemiologic studies.