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Biomedical subjects

T Kuusela

Publications and source records attributed to T Kuusela.

At least 37 records · Page 2Linked to original sources

Degeneration of cervical intervertebral disks in fighter pilots frequently exposed to high +Gz forces.

This study investigated the occurrence and the degree of cervical disk degeneration among senior fighter pilots frequently exposed to high +Gz forces, compared with nonexposed controls matched for age and sex. A resistive magnetic resonance (MR) scanner operating at 0.1 T was used to image the cervical intervertebral disks. Sagittal MR images were obtained and disk degeneration was graded 0-6. Both the occurrence and the median degree of disk degeneration were greater among the pilots than among the controls. The greatest difference in the occurrence of disk degeneration (grades 1-6), which also reached statistical significance, was detected for the C3-4 disk: 88% among the fighter pilots and 64% among the controls, respectively. With respect to the moderate degenerative changes (grades 3 and 4) in the C3-4 disk, the difference in the occurrence (88% vs. 36%) was again statistically significant. There was no difference between the other disks. The median disk degeneration between the groups differed (2.0 vs. 1.0), the difference being the most remarkable (3.0 vs. 1.0) for the C3-4 disk. The differences in the median disk degeneration were also statistically significant. These findings suggest that frequent exposure to high +Gz forces may cause premature disk degeneration.

Adult↗

Magnetic resonance study of disc degeneration in young low-back pain patients.

The correlation of roentgenographic findings, clinical history, and incipient disc degeneration (DD), diagnosed with magnetic resonance imaging, was analyzed in young patients with low-back pain (LBP). One or more lumbar discs were abnormal in 57% of the 20-year-old LBP patients (n = 75) and in 35% of the asymptomatic controls (n = 34) in MRI. Narrowed disc spaces and alterations attributed to lumbar Scheuermann's disease, shown on the radiographs, were always associated with DD in MRI. Such a strong relationship was not observed with transitional vertebrae, spondylolisthesis, spina bifida, or postural abnormalities. However, an increased weight, a positive straight leg raising test, and a reduced lumbar mobility was consistent with an increase in frequency of DD. Magnetic resonance imaging is a safe and sensitive method for studying the presence and etiologic factors of DD.

Adult↗

Disc degeneration and lumbar instability. Magnetic resonance examination of 16 patients.

Flexion and extension radiographs of 75 young males with low back pain disclosed abnormal segmental motion of the lumbar spine in 16 patients with translational movements in 20 intervertebral segments. These 16 patients were further investigated by magnetic resonance imaging to assess disc degeneration in the unstable segments. On T2-weighted images of the 20 segments, the disc was normal in 13 and degenerated in only 7 patients. Thus, the initial factor in lumbar instability in young patients with low back pain is not always degeneration of the disc.

Adult↗

Early detection of developing osteoarthritis by scintigraphy: an experimental study on rabbits.

Bone scintigraphy (99mTc-MDP) was used to study the development of experimental osteoarthritis produced by extension immobilization in rabbit knees. The purpose of the study was to determine a repeatable and noninvasive method for following the joint reaction leading to osteoarthritis. In comparison with the contralateral joints activity uptake in immobilized joints was already detectable in bone scintigraphy at 24 h, at the same time as the earliest changes in the biochemical reactions of joint tissues can be detected.

Animals↗

Extrinsic allergic alveolitis in the tobacco industry.

A total of 57 subjects who had been exposed to mould dust in the tobacco industry were studied. Their working environment showed exposure to spores of different moulds, and 29 subjects (51%) showed antibodies against one or more of the microbes. Fifteen (26%) had work related respiratory symptoms. Eight (14%) showed slight radiographic pulmonary fibrosis. Spirometry showed a tendency toward restriction and obstruction, especially in small airways. Diffusion capacity was decreased in 18% of the workers. Three clinical cases of typical allergic alveolitis were also found. All this suggests that exposure of spores of different moulds (especially Aspergillus fumigatus) in the manufacture of tobacco products may induce symptoms and signs relating to extrinsic allergic alveolitis.

Adult↗

Rarity of mineral fibre pleurisy among persons exposed to Finnish anthophyllite and with low risk of mesothelioma.

Endemic pleural plaques are reported from many parts of the world. In Central Europe and in Finland no connection with malignant mesotheliomas has been found, whereas this tumour is often encountered in areas in Turkey where endemic plaques also occur. There seem, however, to be differences in the radiological appearances found in these areas. In the present study chest radiographs of 317 persons with pleural plaques from the endemic area of Finland were scrutinized. It was found that 4.7% showed a blunted costophrenic angle unilaterally and 0.9% bilaterally. The prevalence of sequelae of pleurisy is statistically very highly significantly lower than in people with pleural plaques in Turkey. As the risk of mesothelioma appears to be low in Finland, the results are in accordance with the hypothesis that the risk of mesothelioma in a given population is higher if in that population there is a high incidence of benign asbestos pleurisy.

Adolescent↗

Stress response of the tibial cortex: a longitudinal radiographic study.

The influence of physical exercise on bone tissue was studied in a sample of 30 conscripts, who served in the coast commando battalion . A repeated roentgen examination of the lower legs was performed after 10, 20 and 40 weeks' service. In the anterior cortex of mid-diaphysis of the tibia a structural change in bone could be regularly observed. In the first examination (after 10 weeks) the cortical bone was longitudinally striated. In the next control (after 20 weeks) the finding was less pronounced. After 40 weeks the bone structure was quite homogenous and solid. The cortical thickness did not change significantly during the 40 weeks follow-up. Most of the diagnosed stress lesions (73%) in bone were developed during the first 10 weeks.

Adaptation, Physiological↗

Semiquantitative analysis of rabbit knee articular surfaces based on stereomicroscopic examination of the cartilage.

A semiquantitative stereomicroscopic method was devised in order to examine rabbit knee articular surfaces. With the aid of a drawing tube mounted on a stereomicroscope, enlarged pictures (magnification of X 14-19) of ink-stained or SEM specimens of joint surfaces were drawn and the structural details classified. The point-counting method or a computer-coupled analyzer was used to analyze the pictures. The data thus obtained underwent statistical evaluation. The method proved to be very useful for the quantitation of experimentally induced changes on cartilage surfaces.

Anatomy↗

Effects of immobilization for 6 weeks on rabbit knee articular surfaces as assessed by the semiquantitative stereomicroscopic method.

The effects of a 6-week immobilization period on rabbit knee articular cartilage surfaces were investigated by a new semiquantitative stereomicroscopic method following ink staining and processing for scanning electron microscopy. All surfaces of the immobilized knee joint were affected and displayed significant degenerative alterations. The knee joint contralateral to the immobilized one exhibited slight changes which could be interpreted as a sign of altered loading after immobilization. Articular surfaces of the patella and lateral condyle of the femur proved to be best suited for surface analysis on account of the small size, distinct borders and inherent evenness of the cartilage in non-treated animals.

Anatomy↗

Investigation of articular cartilage surface morphology with a semiquantitative scanning electron microscopic method.

A semiquantitative scanning electron microscopic method for analysis of the articular cartilage surface morphology was developed. The method was based on a survey of large picture montages (ca. 70 X 100 cm) and classification of the cartilage surface changes at three levels. Computer technique was utilized in the analysis. The method ensured numerical expression and statistical treatment of the results. With this method we investigated the effects of physical exercise and immobilization on the articular cartilage of rabbit patella.

Animals↗

The rate of calcium extraction during EDTA decalcification from thin bone slices as assessed with atomic absorption spectrophotometry.

The rate of calcium extraction with EDTA (ethylenediamine tetraacetic acid) from thin bone slices (300 micrometer-3 mm thick) was determined by aid of an atomic absorption spectrophotometer. A 0.5 mm thick bone slice was completely decalcified with 15% (0.40 M), 8% (0.22 M), and 4% (0.11 M) EDTA in 24 h, 3 days, and 5 days, respectively (vol. 15 ml, temp. 4 degrees C, pH 7.4). At 37 and 60 degrees C the speed of demineralization was slightly increased as compared with that at 20 degrees C, while no difference was observed between 4 and 20 degrees C. Bone slices with a thickness of 0.3, 0.5, 1 and 2 mm were decalcified -- in the same order -- in 24 h, 2, 3, and 5 days (8% EDTA, 4 degrees C, pH 7.4). At pH 7.4, the decalcification rate was a little slower than at pH 5.0 and 8.5. Agitation did not affect the decalcifying velocity, nor did the volume of the agent, except when the volume was very small. The demineralization of ordinary bone, containing both compact and spongy bone, was found to be more rapid than that of homogeneous bone reported earlier. The acidic buffers and New Decalc, which served as reference substances, exerted a more vigorous decalcifying effect thatn EDTA. K formate/formic acid buffer, pH 3.15, demineralized a 1 mm thick bone slice in 24 h and 2 days was needed with Na lactate/lactic acid buffer, pH 3.70. With New Decalc, pH 0.9, the corresponding demineralization was accomplished in 1.5 h. Atomic absorption spectrophotometer proved to be a useful tool in the evaluation of calcium extraction velocity from bone slices.

Animals↗