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Biomedical subjects

L K Jensen

Publications and source records attributed to L K Jensen.

At least 19 recordsLinked to original sources
PubMed2000

Validity of self-reporting and video-recording for measuring knee-straining work postures.

The aim of this study was to compare the validity of self-reporting and video-recording as methods of measuring the duration of knee-straining work postures, and to evaluate the reproducibility of timings of the video-recordings. Thirty-nine carpenters and 33 floorlayers were video-filmed while working, and were asked immediately afterwards to quantify the amount of time spent in knee-straining positions. The investigators recorded the periods of knee-straining work with a stopwatch during playback of the video-film, and the agreement between the two investigators' measurements was studied in 13 pairs of measurements. The video-observation method was very effective for timing knee-strain work. Furthermore, Spearman's correlation coefficient (0.88) indicated a good association between observed and self-reported knee-straining work. Estimation of self-reported knee-straining work collected by interview showed good correlation with measurements of video-recordings. When judging the repeatability of timings of knee-straining work from the video-recordings, a high level of agreement was seen between the two observers in the 13 dual measurements of time spent in knee-straining work positions.

Humans↗
PubMed2000

Work-related knee disorders in floor layers and carpenters.

Previous studies indicate an increased prevalence of knee disorders in some occupations possibly related to kneeling working positions. The purpose of the present study was to examine the relationship among knee-straining work, self-reported knee-complaints, and physical signs of knee disorders. The duration of knee-straining work was estimated from videotapes of representative work tasks. Floor layers (n = 133), carpenters (n = 506), and compositors (n = 327) aged 26 to 72 years without previous acute knee traumas were examined in a cross-sectional study by questionnaire. A stratified random sample of the questionnaire responders; 67 floor layers, 127 carpenters, and 101 compositors had independent double examinations for physical signs of knee disorders. The videotapes showed that knee-straining work constituted 56% of working time for floor layers, 26% for carpenters, and none for compositors. The prevalences of self-reported knee-complaints were positively associated with the amount of knee-straining work and were significantly different for the three trades. Floor layers and carpenters who were presently working in their trade had a higher prevalence of knee complaints than floor layers and carpenters who had left their trade. Age, seniority, weight, body mass index, smoking, and knee-straining sports activity had no significant effects. The clinical study showed a positive association for knee-straining work, hyperkeratosis, and bursitis. A similar pattern was found for signs of intraarticular knee disorders by one physician but not by another. The reproducibility of these signs was low. More studies are needed to define clinically important knee disorders for epidemiological studies.

Adult↗
PubMed2000

Radiographic knee osteoarthritis in floorlayers and carpenters.

OBJECTIVES: The aim of the present study was to examine the relationship between knee-straining work and radiological findings of knee osteoarthritis and to study the relation between radiological findings and self-reported knee complaints and clinical signs of knee osteoarthritis. METHODS: The material consisted of 133 floorlayers, 506 carpenters, and 327 compositors, 26-72 years of age, who had completed a questionnaire and reported no previous knee trauma. A stratified sample of these questionnaire respondents, 50 floorlayers, 51 carpenters, and 49 compositors, were radiologically examined for knee osteoarthritis by 2 radiologists. The X-ray films were independently assessed by 2 radiologists and blinded with respect to knee complaints, trade, and age. RESULTS: The radiological investigation showed estimated prevalences of knee-osteoarthritis (grades 2-4) for 14% of the floorlayers, 8% of the carpenters, and 6% of the compositors (not significantly different). For the subjects > or =50 years of age the estimated prevalences of the combination of radiological grades 2-4 for knee osteoarthritis and knee complaints during the last 12 months were 29% [95% confidence interval (95% CI) 17-44%], 9% (95% CI 1-26%), and 1% (95% CI 1-10%) for the floorlayers, carpenters, and compositors, respectively. Radiological grades 2-4 were mainly found for subjects above the age of 50 years, subjects with knee complaints, and floorlayers. Radiological knee osteoarthritis was positively associated with self-reported knee complaints and with clinical signs of intraarticular and retropatellar crepitation. CONCLUSIONS: The data suggest that work in which a considerable amount of time is spent in knee-straining positions may be a risk factor for the development of knee osteoarthritis above the age of 50 years.

Adult↗
PubMed1999

[Relationship between occupation and elbow pain, epicondylitis].

Twelve controlled epidemiological studies describing the relationship between epicondylitis and work were found. The studies showed evidence for an association between forceful work and a combination of repetition and forceful work and development of elbow pain, epicondylitis. No controlled studies showing an association between work with visual display units or use of computer mouse and epicondylitis were found. No relationship was found between unaccustomed work and development of epicondylitis. Age and time spent in the employment seem to be disposing factors. Generally the studies did not distinguish between medial and lateral epicondylitis. The studies were characterized by small study populations. Further research including quantitative evaluation of exposure factors and patophysiology is needed.

Computers↗
PubMed1996

Bis-intercalation of a homodimeric thiazole orange dye in DNA in symmetrical pyrimidine-pyrimidine-purine-purine oligonucleotides.

One- and two-dimensional 1H NMR spectroscopy were used to characterize the binding of a homodimeric thiazole orange dye, 1,1'-(4,4,8,8-tetramethyl-4,8-diazaundecamethylene)-bis-4-(3 -methyl-2,3-dihydro-(benzo- 1,3-thiazole)-2-methylidene)-quinolinium tetraiodide (TOTO), to various double-stranded DNA oligonucleotides containing symmetric (5'-pyr-pyr-pu-pu-3')2 or (5'-pu-pu-pyr-pyr-3')2 sequences. It was found that TOTO binds preferentially to oligonucleotides containing a (5'-CTAG-3')2 or a (5'-CCGG-3')2 sequence. Binding to the (5'-CCGG-3')2 sequence is less favored than to the (5'-CTAG-3')2 sequence. The complexes of TOTO with d(CGCTAGCGCTAGCG)2 (10) and d(CGCTAGCCGGCG):d(CGCCGGCTAGCG) (11) oligonucleotides, each containing two preferential binding sites, was also examined. In both cases TOTO forms mixtures of 1:1 and 1:2 dsDNA-TOTO complexes in ratios dependent on the relative amount of TOTO and the oligonucleotides in the sample. Binding of TOTO to the two oligonucleotides is sequence selective at the (5'-CTAG-3')2 and (5'-CCGG-3')2 sites. The 1H NMR spectra of both the 1:2 complexes and the three different 1:1 complexes have been assigned. A slight negative cooperativity is observed in formation of the 1:2 complexes. The ratio between the two different 1:1 complexes formed with oligonucleotide 11 is 2.4 in favor of binding to the (5'-CTAG-3')2 site. This is very similar to results obtained when the two sites are in different oligonucleotides. Thus the distribution of TOTO among the (5'-CTAG-3')2 and (5'-CCGG-3')2 sites is independent of whether the two sites are in the same or two different oligonucleotides.

Base Sequence↗
PubMed1996

Occupation as a risk factor for knee disorders.

The objective of the present study was to review the literature on the risk of knee disorders in connection with kneeling or squatting work and heavy physical work. A systematic review of the literature revealed 19 controlled studies on this correlation: 16 on osteoarthrosis, 5 on bursitis, 3 on meniscal lesions, and 0 on chondromalacia. All the studies demonstrated a significantly increased prevalence of knee osteoarthrosis (all degrees) for subjects with kneeling or squatting work. The prevalence ratio in most of these studies was between 1.4 and 4. Four of eight studies demonstrated a significantly increased prevalence of knee osteoarthrosis in subjects with heavy physical work. The prevalence ratio in most of these studies was between 1.4 and 4.1. All the studies on bursitis showed an increased prevalence of bursitis in subjects with kneeling work. Occupational exposure could not be sufficiently documented as the cause of meniscal lesions and chondromalacia.

Adolescent↗
PubMed1994

[Side-effects and doping control of anabolic steroids].

We present a case of a 26 year-old male body-builder who had used the anabolic steroids (AS) trenbolone and stanozolol for 10 weeks. After four weeks creatine-kinase (CK) including CK-B (cardiac specific isoenzymes) levels were elevated five to ten times. He was without cardiac symptoms and electrocardiography was normal. Three weeks after he stopped using AS, CK and CK-B levels had normalized. One of the drugs, stanozolol could not be detected by the doping-control, maybe because of a fast excretion time. Sale, use and delivery of AS is prohibited in Denmark, but is used in spite of the prohibition. It is important to spread knowledge about the risks of AS among the users.

Adult↗
PubMed1991

Modifications of health behaviour in response to air pollution notifications in Copenhagen.

Ambient air quality is a major issue today in large cities all over the world. On the theoretical background of the health belief model and the health locus of control model, we studied the knowledge and beliefs about air pollution and the modifications of health behaviour brought about by information to the public about projected levels of air pollution, with special emphasis on reduction of outdoor activity and avoidance of car driving. Data were collected with a questionnaire among a sample of residents in the Copenhagen area. The respondents were almost universally knowledgeable about the prime emission source and concerned about the possible health effects of the air pollution in the area. Avoidance of outdoor activity was associated with personal experiences of symptoms ascribed to the air pollution, employment status, and with female sex, but not with knowledge or beliefs about the degree or health implications of the air pollution. The willingness to avoid car driving was positively associated with the belief that one can oneself influence one's health and with female sex. Lung diseased respondents were generally more prone to protect themselves than the healthy, both by avoiding outdoor activity and by being less willing to avoid car driving. The present study was conducted in an only moderately polluted city, and it is not clear whether the findings and conclusions can be generalized to more polluted cities. The study partly supported the underlying theories of the determinants of health behaviour, but also indicated a need for a broader theoretical framework, incorporating aspects of the respondents' life situation and personal experience which would be relevant to the specific type of health behaviour under study.

Adult↗
PubMed1990

A randomized trial comparing two methods of cold knife conization with laser conization.

In a randomized study, 62 women were submitted to cold knife conization with application of Sturmdorf sutures, 60 to cold knife conization without sutures, and 61 to laser conization. Early hemorrhage occurred in 1.6, 13.3, and 6.6% of women, respectively (P less than .05), and late hemorrhage in 15.3, 3.6, and 11.7%, respectively. Considering early and late hemorrhage together, there was no significant difference among the three treatment groups. Dysmenorrhea tended to be more common after application of Sturmdorf sutures, as it was reported by 27.8, 13.2, and 14.3% of patients, respectively, but the difference was not statistically significant. Dysmenorrhea occurred in 13% of the cases with a cone height of 20 mm or less and in 26% of the cases with a cone height greater than 20 mm (P less than .05). Endocervical cells were present significantly more often after sampling with a cytobrush than with a cotton swab (P less than .0001), whereas the method of conization had no influence. In smears obtained with a cytobrush, endocervical cells were present in 88.0, 84.9, and 82.5% of the cases; in smears obtained with a cotton swab, endocervical cells were present in 46.6, 57.7, and 54.5%, respectively. We conclude that cold knife conization without Sturmdorf sutures is about equal to laser conization in overall complications, but the laser is preferable for outpatient treatment because of a lower frequency of early hemorrhage. Sturmdorf sutures should be avoided. Smears at follow-up should be taken with a cytobrush and a wooden spatula.

Adult↗
PubMed1989

[Organic brain damage in garage workers after long-term exposure to diesel exhaust fumes].

Diesel motors are employed to an increasing extent for occupational transport and fumes from diesel driven vehicles constitute an increasing problem as regards atmospheric pollution but, in particular, they constitute a considerable risk to health for the workers exposed to diesel exhaust fumes in their daily work. In the clinic for occupational medicine, The University Hospital, Copenhagen, 14 garage workers were examined. Eleven of these had been exposed to great quantities of diesel exhaust fumes for 2 to 29 years. All 11 presented acute symptoms due to diesel exhaust fumes in the form of headache, vertigo, fatigue, irritation of mucous membranes, nausea, abdominal discomfort or diarrhoea. Seven persons had been employed for more than five years as garage workers. Six complained of failure of memory, difficulty in concentration, irritability, increased sleep requirement, psychological changes or reduced libido. Neuropsychological examination was undertaken in these six persons and in five of them organic brain damage, mainly of slight extent, was demonstrated. Diesel exhaust fumes contain many toxic substances: carbon monoxide, nitrous gases, sulphur oxides, aldehydes and hydrocarbons. It is not possible to indicate a single compound which is responsible for possible brain damage and a combination effect may well be concerned. This is a casuistic material. Only few investigations have previously been available which illustrated a possible connection between the neurotoxic effects and, in particular, brain damage. It is now considered important to emphasize that this may constitute a problem on exposure to diesel exhaust fumes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The efficiency of the cytobrush and cotton swab in obtaining endocervical cells in smears taken after conization of the cervix.

In a randomised study of cervical smears after conization, the efficacy of the combined wooden spatula and cytobrush was compared with that of the combined wooden spatula and cotton swab. The conization technique involved a could knife and two Sturmdorf sutures. A total of 75 women participated, 57 had smears taken with both methods. Eighteen with only one of the methods. Out of 66 taken with a wooden spatula and a cytobrush. 48 (72.7%) contained endocervical cells and 53 (80.3%) contained either endocervical or metaplastic cells. Out of 66 smears taken with a wooden spatula and a cotton swab, only 25 (37.9%) contained endocervical cells and 40 (60.6%) contained endocervical or metaplastic cells. Both differences were significant (P less than 0.001 and P less than 0.05, respectively). The combined use of a wooden spatula and cytobrush is recommended for cytological smears after conization.

Cervix Uteri↗
PubMed1989

Atrial natriuretic peptide during the menstrual cycle.

Plasma atrial natriuretic peptide levels were found to decrease from 82.5 pg/ml in the follicular phase to 55.8 pg/ml in the luteal phase in 10 normal menstruating women. The reduced level of plasma atrial natriuretic peptide could be a compensatory response to the natriuretic effect of the increased plasma progesterone in the luteal phase.

Adult↗
PubMed1987

Epilepsy in the elderly: life expectancy and causes of death.

All patients over the age of 60 who experienced seizures between 1979-83, were registered. The number of deaths was registered until July 2, 1985. Included were 162 patients who received no anti-epileptic drugs prior to the study period; 87 patients had established epilepsy at the time of admission. The number of deaths among previously untreated patients significantly exceeded expectation. Mortality was not significantly correlated to severity of epilepsy. In patients with brain tumor all but one died within the first year. Mortality among patients with postapoplectic seizures was significantly higher than expected being especially during the first year. Numbers of deaths among patients with seizures of unknown cause did not differ from the expected, neither did causes of death. Numbers of deaths in patients with established epilepsy at the time of admission was significantly higher than expected although none had malignant tumours and only 4 had postapoplectic seizures thus illustrating the influence of selecting patients with chronic active epilepsy. Eleven patients died suddenly and unexpectedly of unknown cause, which was more than expected. These patients were found dead under circumstances compatible with death occurring during seizure. Epilepsy was mentioned on the death certificate in only one case, indicating that the frequency of sudden, unexpected death among epileptics could easily be underestimated.

Aged↗
PubMed1986

The value of EEG in the investigation of postapoplectic epilepsy.

During the 5 years 1979-1983 61 patients within the county of Frederiksberg developed postapoplectic seizures after the age of 60. Of these patients EEG was performed on 48. These EEG's were compared to the EEG's from 25 patients of the same age with epilepsy due to cerebral tumors 33 patients with acute stroke and 24 patients with stroke sequelae who had not experienced seizures. Slow wave activity and foci were seen more often among patients with acute stroke than among patients with postapoplectic seizures whereas paroxysmal activity occurred less often in patients with acute stroke than among patients with postapoplectic seizures patients with stroke sequelae and patients with seizures due to cerebral tumours. Patients with stroke sequelae with proven hemispheric localization had focal abnormalities more often than patients with postapoplectic seizures but apart from this EEG difference between patients with postapoplectic seizures and patients with stroke sequelae or seizures due to brain tumours were not found. In 12 of the patients with postapoplectic seizures and in 20 of the patients with stroke sequelae without seizures EEG at the time of the acute stroke was available. Differences between patients with and patients without seizures were not found neither at the time of the acute stroke nor at the time of readmission due to stroke sequelae or due to onset of seizures. It is concluded that a routine EEG is without value in the diagnosis of postapoplectic seizures in the elderly.

Acute Disease↗