Improvement 2-9 years after ankle fracture.
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Ankle Injuries↗
Biomedical subjects
M Lehto
Publications and source records attributed to M Lehto.
Fibronectin, laminin, and collagen types I, III, IV and V in the healing rat colon anastomosis.
The purpose of this work was to study normal anastomotic healing in the rat colon. The unprepared sigmoid colon was divided and a colo-colostomy performed using a one-layer inverting technique. Frozen sections were taken and studied immunohistologically with specific antibodies to fibronectin, laminin and collagen types I, III, IV and V. From day one onwards a strong fibronectin reaction was observed in the anastomosis, reaching maximum staining intensity on postoperative day five. Type III collagen and pericellular type V collagen were at first detected in the anastomosis on day two. From day three onwards all collagens studied and laminin were present in the repair tissue (laminin and type IV and V collagen in the regenerating capillary walls). Maximum immunofluorescence was observed on day seven and it remained on a high level throughout the study, except for fibronectin, which weakened gradually after the fifth postoperative day. The results indicate that healing of the colon anastomosis occurs by rapid accumulation of connective tissue components between the inverted leaves of the colonic wall, as also new capillaries consisting of the basement membrane components, type IV and V collagen as well as laminin, are formed.
Anastomosis, Surgical↗
Fibronectin in the ruptured human Achilles tendon and its paratenon. An immunoperoxidase study.
The purpose of the present study was to examine the role and distribution of fibronectin--a major connective tissue protein--in normal and ruptured Achilles tendon and its paratenon using peroxidase antiperoxidase (PAP) method and conventional histology. Samples were taken intraoperatively 6 to 48 hours after rupture from 30 patients, and 4 male cadavers served as controls. In controls fibronectin could not be detected in the tendinous connective tissue or in the areolar tissue of the paratenon. In the ruptured tendons fibronectin was detected around the tenocytes and in the collagen fibres in the necrotic and mucinous degenerated areas, but also in the macroscopically healthy areas of the tendon. In the oedematous paratenon vascular walls were rich in fibronectin and fat cells were outlined by fibronectin. Areas of homogenous deposition of fibronectin were also frequently seen in the paratenon. A vast amount of fibronectin was observed also at the site of rupture. The present results indicate that there are striking changes in the composition of connective tissue in degenerated tendon and paratenon. These changes seem to have increased susceptibility of the tendon to rupture.
Achilles Tendon↗
Motor ability and personality with reference to soccer injuries.
Thirty-seven male soccer players performed a series of motor ability tests and answered the Sixteen Personality Factor Questionnaire (the 16PF). A past-injury examination and interview was performed by a physician and occurrence of injuries was followed up prospectively for one year. Stepwise regression analyses revealed significant associations between past injuries and long reaction time as well as personality factors N (astute) and H (shy). We conclude that both weakness of motor abilities, especially long reaction time, and a specific personality type may predispose a player to soccer injuries.
Adolescent↗
Collagen types I and III and fibronectin in healing anterior cruciate ligament after reconstruction with carbon fibre.
The presence of the connective tissue components fibronectin and collagen types I and III have been demonstrated by immunohistological methods after reconstruction of the anterior cruciate ligament of pigs with carbon fibre. The carbon fibre ligament prosthesis was covered with pediculated fascia lata. During the initial 16-week period, fibronectin was seen both in the surrounding fascial layer and between the carbon fibres of the substitute. Type III collagen was also found, especially in the fascial layer, but collagen was absent from the carbon fibre prosthesis and was seen only in the fascial layer. Results indicate that the tissue in the 'neoligament' after carbon fibre reconstruction consists mostly of granulation tissue with a high amount of fibronectin, and type III collagen from mesenchymal cells without sufficient amount of type I collagen with tensile strength to withstand subsequent mobilization and rehabilitation.
Animals↗
Suppression of autologous mixed leukocyte reaction in type 1 diabetes mellitus by in vivo-activated T lymphocytes.
In vivo-activated interleukin 2 receptor-positive T lymphocytes (Tac cells) are demonstrable and the autologous mixed leukocyte reaction (AMLR) is impaired in several autoimmune diseases, including type 1 insulin-dependent diabetes mellitus (IDDM). We investigated AMLR in greater detail, together with possible relationships between AMLR and Tac lymphocytes in IDDM. Coculture experiments with HLA identical patient-healthy sibling pairs revealed that both responder and stimulator cells of diabetic patients function abnormally in AMLR. Suppressive Tac lymphocytes among responder T cells seemed to impair their proliferation. The removal of Tac cells by immunomagnetic beads led to a striking enhancement of proliferation, while the restoration of AMLR cultures with enriched Tac cells was accompanied by a diminished response. The reasons for the poor stimulatory capacity of patient cells are at present unknown but may be due to altered function and/or structure of HLA-DR molecules.
Cells, Cultured↗
Alterations in dry mass content of collagen fibers in degenerative tendinopathy and tendon-rupture.
The dry mass concentration and collagen fiber morphology of intact, as well as of degenerated and ruptured human Achilles, biceps brachii, extensor pollicis longus and quadriceps tendons, were determined by using the interference microscopical technique. The variation in the collagen fiber thickness was demonstrated in different intact tendons, the fibers being largest in the Achilles and smallest in the extensor pollicis longus tendons. However, the intact tendons exhibited only thick collagen fibers. In the degenerative tendinopathies an increase of the dry mass content was observed, being especially marked in calcifying tendinopathy. In the degenerated tendons the average collagen fiber diameter had decreased, and two clearly distinct populations of thick and thin fibers were observed. The dry mass content of the thick fibers was significantly greater than that of the thin fibers. The present results demonstrate striking changes in the collagen and its dry mass content in degenerative tendinopathy, thus also increasing the susceptibility to ruptures.
Collagen↗
Sports injuries in elderly athletes: a three-year prospective, controlled study.
A 3-year prospective, controlled study of sports injuries in elderly athletes (over 60 years of age) treated at an outpatient sports clinic was carried out in order to determine the number, profile, and specific features of these injuries compared with those of young athletes (between 21 and 25 years). During the study period, 57 elderly and 457 young adult athletes visited the clinic. The majority of the patients in both groups were male (83% of the veterans and 85% of the young). Forty-eight veterans (84%) were endurance sportsmen, while only 115 of the young patients (25%) went in for endurance sports. In both groups the knee joint was most frequently affected, in the young athletes (36%) more frequently than in the elderly (21%). In the elderly athletes shoulder (18%) as well as Achilles tendon and calf (20%) complaints were significantly more common than among young athletes (7% and 5%, respectively). Most (70%) of the injuries in the elderly were overuse injuries, but these comprised only 41% in the young.
Adult↗
Connective tissue changes of the multifidus muscle in patients with lumbar disc herniation. An immunohistologic study of collagen types I and III and fibronectin.
The connective tissue components, Types I and III collagen fibronectin, were immunohistologically analyzed using their specific antibodies for localization and semiquantitative estimation in 24 patients (11 women and 13 men, all under 55 years of age) operated on for herniated lumbar intervertebral disc. Nine cadavers without known back problems (2 women, 7 men) served as controls. In controls, Type I collagen was present in the endo- and perimysial structures of the muscle, more conspiciously in the former. Type III collagen, together with fibronectin, were more abundant in the perimysium than in the endomysium. Thickening of these structures was not evident in the controls. In most patients Types I and III collagen and fibronectin distribution was similar to that of the controls. However, fibrotic changes of both and endo- and perimysial structures involved all Types I and III collagen and fibronectin in ten cases. In two patients an increase in Type I collagen staining intensity in the endomysium was recorded and thickening of the endomysial structures was observed in six patients. There were correlations with the severity of the connective tissue structural changes to atrophy of the muscle and furthermore to disability of the patient in the 1-year postoperative check-up. These findings suggest that if marked fibrosis of the muscle occurs, it can be a factor impairing recovery from the disease during the long-term postoperative course.
Adult↗
Immediate decrease in antigen-presenting function and delayed enhancement of interleukin-1 production in human epidermal cells after in vivo UVB irradiation.
Human skin was irradiated in vivo with a single UVB dose (100 mJ/cm2 or 200 mJ/cm2) to examine simultaneously the antigen-presenting function and interleukin-1 (IL-1) production capacity of irradiated epidermal cells (EC). Suction blisters were produced on irradiated areas on days 0, 3 and 7 after UVB. Irradiated EC were harvested and co-cultured with autologous T lymphocytes in the presence of antigens (PPD, HSV) or mitogen (ConA). Culture supernatants were tested for IL-1 activity using the thymocyte comitogenity assay. We found that a single 200 mJ/cm2 dose of UVB caused an immediate suppression of the antigen-presenting function of EC, but no alteration in their IL-1 production capacity or surface marker expression (ATPase, CDI). PPD- and HSV-induced lymphocyte proliferation was decreased 70-80% and ConA-driven proliferation 30% when compared to non-irradiated EC. However, this suppression was restored on days 3 and 7 after UVB irradiation, this being coexistent with an increased capacity of EC to produce IL-1. It remains to be elucidated whether the immediate UVB-induced photoimmunosuppression observed in the present study is due to inhibitory mediators or impaired membrane function of EC or both.
Adult↗
Basophil histamine release and lymphocyte proliferation tests in latex contact urticaria. In vitro tests in latex contact urticaria.
Basophil histamine release and lymphocyte proliferation tests were examined with latex allergen prepared from surgical gloves in 15 patients with latex contact urticaria. The basophil histamine release test (BHRT) yielded positive results in 13/14 (93%) patients, whereas commercial latex RAST was positive in only 9/15 (60%) patients. Lymphocyte proliferation test (LPT) was positive in 3/15 (20%) patients, suggesting that cell-mediated immune reactions may also occur in latex allergy. However, patch tests to latex were negative and neither were epidermal Langerhans cells able to present latex antigen to T lymphocytes in vitro.
Adult↗
Collaboration between human blood dendritic cells and monocytes in antigen presentation.
We compared human blood dendritic cells and monocytes for their capacity to produce secreted and membrane interleukin 1 (IL-1), stimulate mixed leukocyte reaction (MLR) and augment microbial antigen-induced T lymphocyte proliferation. Our enriched dendritic cell and monocyte fractions contained greater than 80% and greater than 93% dendritic cells and monocytes, respectively. Monocytes produced about ten times higher amounts of membrane and secreted IL-1 than dendritic cells, which in turn were more potent in presenting HLA-DR antigens in MLR. Both accessory cell types presented purified protein derivative of tuberculin (PPD) equally well, whereas monocytes were better with fixed Bacillus Calmette Guérin (BCG) bacteria. Processing of BCG was chloroquine-sensitive. Coculture experiments suggested that there was collaboration or synergy between dendritic cells and monocytes in antigen processing and presentation.
Antigen-Presenting Cells↗
Fibronectin and laminin in Achilles tendon.
Ten intact and 22 ruptured Achilles tendons were studied by immunohistochemical techniques. In intact tendons, both fibronectin and laminin were found in vascular walls, myotendineal junction, and endomysium, but not in the connective tissue of the tendons. In ruptured tendons the distribution of laminin was not changed. Fibronectin deposits, on the contrary, could be detected on the tear surface and in the collagen fibers of the ruptured tendons.
Achilles Tendon↗
Concentrations of tumor-associated trypsin inhibitor and C-reactive protein in serum in acute pelvic inflammatory disease.
We measured tumor-associated trypsin inhibitor (TATI) and C-reactive protein (CRP) in serum of 29 patients with proven pelvic inflammatory disease (PID). TATI values were increased in seven (24%), paralleling increases in CRP. TATI was increased by about 3.5-fold in seven of eight patients with CRP concentrations greater than 90 mg/L, but in none of 21 patients with CRP concentrations less than 90 mg/L. TATI concentration and severity of PID as determined by laparoscopy or endometrial biopsy were not correlated. These results suggest that, in severe infections, regulation of TATI synthesis resembles that of acute-phase proteins.
Acute-Phase Proteins↗
Glycogen-enzymes containing bodies in type 2 fibres of tenotomized muscles in the rat.
Inclusion bodies containing glycogen-enzymes were found in 30 to 60% of type 2 fibres of tenotomized calf muscles (m. gastrocnemius, m. soleus, m. plantaris) in rats, using histochemical reactions. The bodies appeared within 1 week after the tenotomy and were localized both in the central and the subsarcolemmal regions and rarely extruded into the extracellular space. These aggregates are 3 to 15 microns in length and 2 to 11 microns in diameter. In addition to glycogen, these bodies also contained various enzymes of the glycogen metabolism such as phosphorylase, a branching enzyme, and glucose-6-phosphatase, but showed no NADH-reductase, lactate dehydrogenase, or myofibrillar ATP-ase activity. The results indicate that glycogen-enzymes containing bodies are a degenerative phenomenon, which occurs only in type 2 fibres of the tenotomized muscles.
1,4-alpha-Glucan Branching Enzyme↗
Changes in the connective tissue composition of the submucosal layer of colonic anastomosis. An immunohistologic study in rats.
Submucosal healing of colonic anastomosis was studied in rats. The unprepared sigmoid colon was divided and colo-colostomy performed, using a one-layer inverting technique. Frozen sections were studied immunohistologically with specific antibodies to fibronectin, laminin and collagen types I, III, IV and V. From the first to the fifth postoperative day the submucosa was highly oedematous. A clear fibronectin reaction was observed in the submucosa, reaching maximum on postoperative day 5. From day 3 onwards the fluorescence intensities of types I and III collagen in the young granulation tissue and of types IV and V collagen and laminin in the regenerating capillaries rapidly increased, with maximum on day 7. The striking changes in the submucosa indicate that the healing process involves not only the actual area of the anastomosis, but also widely the submucosal layer of the adjacent intestine.
Anastomosis, Surgical↗
Enrichment of dendritic cells from human peripheral blood.
A simplified method is described for purification of dendritic cells from human peripheral blood. The method is based on depletion of phagocytes with carbonyl iron and magnet, followed by centrifugation of nonphagocytic cells on Percoll and elimination of contaminating T lymphocytes, B lymphocytes, natural killer cells, and monocytes from the low-density cell fraction by treatment with monoclonal antibodies and complement. The purity of enriched dendritic cells was about 80% and these cells represented 0.2% of the starting mononuclear cell population. Dendritic cells were potent autologous and allogeneic stimulators in mixed leukocyte cultures.
Antibodies, Monoclonal↗
Cortical and trabecular osteopenia after immobilization. A quantitative histological study of the rat knee.
The aim of this investigation was to examine the effect of short-term immobilization on subchondral cortical and trabecular bone tissue in the rat tibia and to determine whether there was any difference when the knee was immobilized in extension or flexion. Thirty-six male rats were used in this study, and in 18 the knee was fixed in extension and in 18 in flexion. The time of immobilization was for 1, 2 and 3 weeks, with 12 animals in each group and 6 knees in extension and 6 in flexion. The following parameters were measured: (1) the mean thickness of subchondral and both periosteal cortices; (2) cortical porosity; (3) trabecular bone volume; (4) relative osteoid volume, and (5) relative osteoid surface. The mean cortical thickness decreased during the period of immobilization and the cortical porosity significantly increased. The trabecular bone volume was unaltered in the first week, but after 3 weeks it had decreased. The relative osteoid volume decreased significantly during the three weeks, and the relative osteoid surface moderately increased. No relationship was found between the quantitative osteopenic alteration of subchondral bone and the position of immobilization.
Animals↗