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Biomedical subjects

H Roos

Publications and source records attributed to H Roos.

At least 55 records · Page 3Linked to original sources
PubMed1998

Isokinetic knee extensor strength and functional performance in healthy female soccer players.

The aims of this study were to determine the relationship between isokinetic knee extensor muscle strength at 60 degrees/s and 180 degrees/s and five functional performance tests (one-leg-hop, triple-jump, vertical-jump, one-leg-rising and square-hop), to determine the relationship between the five different functional performance tests and to present normative data and limb symmetry index concerning healthy female soccer players. In total 101 female soccer players (X = 20.3 years) were tested. A limb symmetry index, using weak/strong leg, varied from 83.9 to 96.3 in the tests. Between the functional performance tests there were in general correlations of r = 0.4-0.8 (P < 0.001). A correlation of r = 0.77 (P < 0.001) was obtained between one-leg-hop and triple-jump. No differences were found between the right and the left leg or the dominant and the non-dominant leg. Using linear regression models corrected for body weight, height and age, there were low correlations between the isokinetic strength measurements and the functional tests. It is not recommended using functional performance testing and isokinetic testing interchangeably.

Adult↗
PubMed1997

Chromosome aberration frequencies in human lymphocytes irradiated in a multi-layer array by protons with different LET.

PURPOSE: To provide data on the dose-and linear energy transfer (LET)-dependence of the production of dicentrics in human lymphocytes. MATERIALS AND METHODS: Track segment irradiation with 16.5 MeV protons was performed in a multi-layer array allowing the simultaneous exposure of human peripheral lymphocytes in three successive samples. Within these samples the dose-averaged linear energy transfer (LD) of protons increased with increasing depth, i.e. LD = 3.5, 5.3 and 19.0 keV/microm. Dicentrics were scored in first division solid-stained metaphases. RESULTS: Dicentric yields measured in the first and second samples fit the linear-quadratic model, those of the third sample fit a linear model of the dose response relationship. Relative to 137Cs gamma-rays, limiting RBE values of 2.9, 4.3 and 21.5 were determined from the ratios of the respective linear coefficients of the dose effect curves. The linear dose effect coefficient increases approximately proportionally with increasing LET. The quadratic coefficient is approximately constant for protons with LD of 3.5 and 5.3 keV/microm, and is not significantly different from zero at LD= 19.0 keV/microm. CONCLUSION: This result is well in line with theoretical predictions on the variations of dose-effect coefficients with radiation quality. However, such an evaluation can only be obtained from clearly defined track segment experiments.

Chromosome Aberrations↗
PubMed1997

Synovial fluid concentrations of the C-propeptide of type II collagen correlate with body mass index in primary knee osteoarthritis.

OBJECTIVE: To explore in a cross sectional study in patients with primary knee osteoarthritis (OA) the relations between body mass index (BMI), disease stage, and the concentrations of a putative joint fluid marker of type II collagen synthesis, procollagen II C-propeptide. PATIENTS AND METHODS: The study included 142 patients with knee OA (median age 68, median BMI 24.1). OA was staged radiologically. The concentrations in synovial fluid of procollagen II C-propeptide were measured by a sandwich enzyme immunoassay. RESULTS: Joint fluid concentrations of procollagen II C-propeptide were increased in knees with OA (median 3.7 ng/ml), compared with published reference values for knees in healthy adult volunteers (median 1.3 ng/ml). The concentrations of procollagen II C-propeptide were independently related to both OA stage and BMI (r = 0.343, p < 0.0001 and r, = 0.253, p = 0.002, respectively). CONCLUSIONS: Joint fluid concentrations of this putative marker of collagen II synthesis are high in early and mid-stage OA, but decrease in end stage disease. In addition and for the first time it was shown that the concentrations in synovial fluid of procollagen II C-propeptide increase with increasing BMI in primary knee OA. The increased joint fluid values of this marker in patients with primary knee OA and a high BMI, may reflect increased rates of collagen synthesis in their joint cartilage and could relate to the previously shown increased risk for disease progression in such patients.

Adult↗
PubMed1996

Analysis of chromosome aberrations in human peripheral lymphocytes induced by in vitro alpha-particle irradiation.

Irradiation of human lymphocytes by alpha-particles under different conditions has been seen to be substantially more effective in the induction of dicentric chromosomes than irradiation by gamma-rays. However, the relative biological effectiveness (RBE) determined in these studies differed by a factor of more than 10. These variations in RBE are likely to be due in part to differing exposure conditions. Therefore, a technique designed to insure uniformity of irradiation was developed in the present study, and complications due to the cell cycle kinetics were controlled. After stimulation with phytohaemagglutinin (PHA), separated lymphocytes were allowed to attach for 3 h to the thin foil bottom of an irradiation chamber. Cell monolayers were exposed with alpha-particles from Am. Strong over-dispersion was noted for the cell-to-cell variance of the number of dicentrics. The dose response of dicentrics was linear, with a yield of 0.27 dicentrics per cell and per Gy. This corresponds to a low dose RBE of 15 relative to Cs gamma-ray exposure under the same experimental conditions.

Alpha Particles↗
PubMed1996

Dose dependent of sister chromatid exchanges in humans lymphocytes induced by in vitro alpha-particle irradiation.

Exposure of human G0 lymphocytes to high-LET particles under different conditions has been seen, unlike low-LET radiations, to be substantially effective in the induction of sister chromatid exchanges (SCE). However, whereas for fast neutrons a linear dose response of SCE has been determined, there is no sign of a dose-response relationship for alpha-particles. A likely reason for this lack of dose dependence may be the irradiation procedure. Therefore, a technique developed in our laboratory to ensure uniformity of irradiation with alpha-particles was used in the present study. Monolayers of 3 h-stimulated lymphocytes were exposed with alpha-particles from 241Am. Underdispersion was found for the cell-to-cell variance of the number of SCE. The dose response of SCE was linear, with a yield of 3.4 SCE per cell and per Gray.

Alpha Particles↗
PubMed1996

[The transverse movement of the temporo-mandibular joint (translation movement) of the dog, also with reference to dysplasia of this joint in the dachshund].

Contrary to the accepted opinion, transverse movement is possible in the temporo-mandibular joint of the dog. This movement is arched and is important for mastication. Analysis of transverse movement of the temporo-mandibular joint was done in 20 dog breeds. Accidentally dysplasia of the temporo-mandibular joint was found in the dachshund, a phenomenon which has not been described before.

Animals↗
PubMed1996

Scheimpflug attachment for ophthalmological slitlamps.

Scheimpflug imaging is a technique suited for the quantification of minor opacities of the human eye lens. In the past, several Scheimpflug systems have been developed but being fairly complex and expensive, they have not been widely used. At present, only one instrument is on the market. For these reasons, a new Scheimpflug attachment-to be operated in connection with a slitlamp-was developed. The system is of compact, light-weight and modular design and consists of commercially available components. The Scheimpflug image, recorded by a CCD camera, is digitized in real time by a PC. It is displayed on a video monitor for on-line alignment. The data obtained are permanently stored on optical disk and are available for further analysis. The design of a prototype instrument is described. The practical applicability of the instrument and the high quality of the images is demonstrated.

Adult↗
PubMed1996

[Biological role of movement in the temporomandibular joint in sheepdogs and house cats].

The temporomandibular joints of the dog and the cat differ in morphology and movement. Characteristic differences in the teeth and the movement of the mandibula result in species-specific mastication: The dog grinds and crunches food. Moving the molars vertically, the cat cuts food to pieces. It has been postulated that the cat masticates more thoroughly than the dog. This is not true. The unilateral mincing of the cat is due to the extremely secodont teeth without possibility to grind.

Animals↗
PubMed1996

Procollagen II C-propeptide in joint fluid: changes in concentration with age, time after knee injury, and osteoarthritis.

OBJECTIVE: To determine in a cross sectional study the concentrations in joint fluid of the C-propeptide of collagen II (pCol II-C) in patients with knee injury and developing osteoarthritis (OA). METHODS: Synovial fluid (SF) samples were collected from knees of healthy volunteers, from patients with injury to the knee causing lesions of the anterior cruciate ligament and/or menisci, and from patients with posttraumatic or primary OA. Concentrations of pCol II-C were determined by enzyme immunoassay with a polyclonal antiserum against the bovine propeptide. RESULTS: The median concentration of pCol II-C in joint fluid in the reference group was 1.3 ng/ml (range 0.1-5.7 ng/ml). Median concentrations of pCol II-C in joint fluid were increased 2-4-fold in all 3 study groups over that in the reference group. Very high concentrations of propeptide were noted in samples from patients younger than about 18 years. Propeptide concentrations were increased after knee injury, with a suggested peak at about 1-4 years evident for patients with cruciate ligament injury. pCol II-C levels were increased at all stages of OA development, except in the most advanced phases. CONCLUSION: The increased levels of pCol II-C in SF may reflect an increased rate of synthesis of collagen II in the joint cartilage of patients with knee injury and developing OA. The increase reaches a maximum well before radiographic changes indicative of OA are apparent, and occurs during a disease phase characterized by signs of increased degradation of collagen II, aggrecan, and other matrix components. Further studies of markers of matrix metabolism of cartilage, bone, and other joint tissues in human and animal models of OA may aid in the identification of process markers, individuals at risk, and new therapeutic targets.

Adolescent↗
PubMed1995

Correlation of interstitial pneumonia with human cytomegalovirus-induced lung infection and graft-versus-host disease after bone marrow transplantation.

In a retrospective analysis lung biopsy specimens obtained postmortem from 30 consecutive allogeneic bone marrow transplant recipients who had died of either either interstitial pneumonitis (IP; 18/30 patients) or various other causes (12/30 patients) were studied for the local presence of human cytomegalovirus (HCMV) by culture, in situ hybridization, polymerase chain reaction (PCR) and immunohistochemistry for HCMV proteins. All patients suffering from IP were found to be HCMV positive in the lung biopsy. PCR revealed the highest sensitivity for HCMV detection in lung biopsies, but in 15/18 PCR-positive samples local HCMV infection could be confirmed by at least one additional technique. All the lung biopsies obtained from the 12 patients without IP were negative for HCMV by all techniques applied, except one with a weak HCMV-DNA signal in the PCR assay. The severity of the clinical, as well as histological and immunohistological alterations in the lung did not correlate with the amount of HCMV-DNA or the number of HCMV-positive cells detected in the biopsy. An increase of HLA-class II antigen and of ICAM-1 expression on the alveolar epithelium, as well as presence of activated CD8+ or CD4+ lymphocytes infiltrating only HCMV-positive lung biopsies revealed T cell-mediated immune reactions to be involved in the pathogenesis of IP. Since all analyzed patients presented with severe acute or extensive chronic graft-versus-host disease (GvHD), but only those with pulmonary HCMV infection developed IP, dissemination of HCMV appears to be the primary requirement for the initiation of IP. GvHD, however, may interfere with normal control of subsequent antiviral immune response and, thus, provoke the immunopathology of IP.

Adolescent↗
PubMed1995

Effect of wire eccentricity on the performance of cylindrical proportional counters.

A theoretical and experimental investigation of the influence of eccentricity of the multiplication wire on the performance of cylindrical proportional counters is presented. The electric field in the counter is calculated by the method of images, and the Townsend formalism is used to derive the gas gain. The experimental determination of detector performance is carried out with 37Ar. The dependence of the gas gain and of the counter resolution on eccentricity is discussed, and it is shown that eccentricities up to 0.2 are of no concern in microdosimetric measurements with cylindrical proportional counters.

Radiometry↗
PubMed1995

Osteoarthritis of the knee after injury to the anterior cruciate ligament or meniscus: the influence of time and age.

The degree of cartilage changes by arthroscopic and radiologic examination was evaluated in a retrospective, cross-sectional study of 1012 patients with knee complaints at different times after knee injury. Patients were classified by age, sex, trauma date and type of injury. The condition of the cartilage was graded on a 1-10 scale based on findings at arthroscopy and on weight-bearing radiographs. Patients with injury to the anterior cruciate ligament (isolated or combined with injury to meniscus or collateral ligaments) showed the first radiologic signs (joint space narrowing) of osteoarthritis (OA) at an average age of about 40 years, while patients with isolated meniscus injury had the same stage of disease at an average age of about 50 years. Both study groups displayed the first radiologic signs of OA on average about 10 years after the injury and showed increasingly serious arthroscopic and radiologic signs of joint damage with increased time between injury and examination. For patients who sustained an isolated meniscus injury between the ages of 17 and 30, the average time until development of radiologic signs of OA was about 15 years, while for those who had the same injury over the age of 30, the corresponding time interval was only about 5 years. We conclude from this that knee OA becomes increasingly severe with increased time between joint injury and examination. OA changes appear sooner in older patients with knee injury than in the young.

Adolescent↗
PubMed1995

Markers of cartilage matrix metabolism in human joint fluid and serum: the effect of exercise.

The concentrations of cartilage proteoglycan (aggrecan), stromelysin-1, tissue inhibitor of metalloproteinases-1 (TIMP-1) and procollagen II C-propeptide in knee joint fluid and the levels of aggrecan, hyaluronan and keratan sulfate in serum were measured before and after exercise in 33 healthy athletes. The samples before exercise were obtained after 24 h rest from running or soccer and the samples after exercise were obtained 30-60 min after the exercise. Nine athletes ran on a treadmill for 60 min, 16 ran on road for 80 min and 8 played one soccer game (90 min). A reference group of 28 patients with knee pain but not evidence of joint pathology or injury was used for comparison. In joint fluid no single marker from the degradative processes in cartilage matrix changed significantly with exercise but all showed a rising trend. All markers except stromelysin showed lower concentrations in athletes at rest compared to the reference group. In serum from runners before exercise the concentration of keratan sulfate was significantly higher than in both the soccer and reference groups and further increased after exercise. The increase in markers after exercise may reflect an effect of mechanical loading in combination with a possible high turnover rate of body cartilage matrix in these individuals.

Adult↗
PubMed1995

Soccer after anterior cruciate ligament injury--an incompatible combination? A national survey of incidence and risk factors and a 7-year follow-up of 310 players.

All players in Swedish soccer teams are required to have insurance in the same company. From the archives of the insurance company, all 3,735 injuries reported in 1986 in 188,152 Swedish soccer players were reviewed. Of these, 937 were knee injuries. All players were asked by mail to fill in a questionnaire and 83 percent replied. The patient records from the different hospitals were requested. The anterior cruciate injuries represented one third of the reported knee injuries. The relative risk of sustaining an anterior cruciate ligament injury was increased in female players, in elite players, and in players in the forward position. The odds ratios were 1.6 (1.3-2.1), 3.3 (1.7-6.1) and 1.8 (1.4-2.5), respectively. The injuries occurred at a younger age in females than in males. 50 percent of the injured players were treated with anterior cruciate ligament surgery, predominantly as a reconstructive procedure, with use of a patellar tendon transplant. 30 (20) percent of the players with anterior cruciate ligament injury were active in soccer after 3 (7) years, compared to 80 (50) percent of an injured control population of soccer players. None of the elite players was active at the same level after 7 years. A comparison of anterior cruciate ligament-injured players, whether treated by surgical reconstruction or not, revealed no difference with regard to the proportion of players still playing soccer after 7 years.

Adult↗
PubMed1994

Temporal patterns of stromelysin-1, tissue inhibitor, and proteoglycan fragments in human knee joint fluid after injury to the cruciate ligament or meniscus.

Stromelysin-1, tissue inhibitor of metalloproteinases-1 (TIMP-1), and proteoglycan fragments were quantified in knee synovial fluid samples in a cross-sectional study of patients who had injury to the anterior cruciate ligament or the meniscus. The average concentrations of stromelysin-1 and TIMP-1 increased 25-fold and 10-fold within the first day after the trauma, respectively, and the concentration of proteoglycan fragments increased 4-fold. From approximately 1-6 months after injury, the levels of these markers were higher after injury to the cruciate ligament than after injury to the meniscus. From 6 months to 18 years after trauma, however, the levels of stromelysin-1 and TIMP-1 in patients who had an injury to the ligament were the same as the levels in patients who had a meniscal lesion, but the levels were increased compared with those for a reference group of healthy volunteers. The molar balance of stromelysin-1 to TIMP-1 in synovial fluid in both groups of injured joints changed from a balance representing an excess of free inhibitor in the normal joint to one representing an excess of free enzyme in the injured joint. The increased release of these markers to joint fluid both early and late after trauma may be caused by a change in the loading patterns in the knee with an injured ligament or meniscus or by synovitis induced by bleeding. The increased release may be associated with the frequent development of posttraumatic osteoarthritis in patients with these injuries.

Adult↗