Biomedical subjects

Johannes Zeichen

Publications and source records attributed to Johannes Zeichen.

13 recordsLinked to original sources

PubMed2006

Changes of Achilles midportion tendon microcirculation after repetitive simultaneous cryotherapy and compression using a Cryo/Cuff.

BACKGROUND: Cryotherapy and compression have been shown to decrease pain and improve function. The dosage and timing of these options remain unclear. PURPOSE: To examine the effects of a standardized compression and cryotherapy device (Cryo/Cuff) on midportion Achilles tendon microcirculation during intermittent administration. STUDY DESIGN: Descriptive laboratory study. METHODS: Twenty-six subjects were included (13 men and 13 women; age, 32.3 +/- 12 years; body mass index, 25.4 +/- 5 kg/m(2)). Each underwent three 10-minute applications of the device, followed by a 10-minute recovery period. A continuous real-time assessment of parameters of Achilles tendon midportion microcirculation was performed with a laser Doppler spectrophotometry system. RESULTS: Superficial tendon oxygen saturation dropped significantly from 35.9 +/- 21 arbitrary units (AU) to 13.5 +/- 15, 15.9 +/- 16, and 11.1 +/- 11 AU (P = .0001) during each period of cryo-compression, respectively. There was significant increase during the recovery period (55.4 +/- 29, 65.2 +/- 26, and 65.7 +/- 27 AU; P = .003), up to +83% of the baseline level. At 8-mm tendon depth, cryo-compression preserved local oxygen with -4% (P = .001) of the baseline level and small but significant increased oxygen saturation of up to +13% (P = .0001). Relative postcapillary venous tendon filling pressures were favorably reduced both superficially (57% +/- 34%, 67% +/- 27%, and 64% +/- 38%, respectively; P = .0004) and deep (76% +/- 13%, 79% +/- 11%, and 78% +/- 18%, respectively; P = .0002). Superficial capillary blood flow was reduced from 48.4 +/- 48 to 5 +/- 7, 4 +/- 5, and 3 +/- 4 AU at each period, respectively (-94%, P = .0003), with increased flow during recovery periods of up to 58 +/- 64, 58 +/- 79, and 47 +/- 71 AU, respectively (+20%, P = .265). Deep flow was reduced from 197 +/- 147 to 66.7 +/- 64, 55 +/- 46, and 43 +/- 39 AU, respectively (-78%, P = .0002) without increase during recovery periods. CONCLUSION: Cryo/Cuff exerts beneficial effects on the microcirculatory level of the midportion Achilles tendon with decreased capillary blood flow, preserved deep tendon oxygen saturation, and facilitated venous capillary outflow.

Achilles Tendon↗

PubMed2006

Rapid rehabilitation programme following sacral stress fracture in a long-distance running female athlete.

Stress fractures occur in normal bone due to mechanical overload by cyclic stress increasing the osteoclastic activity, thus facilitating weakening leading to fracture of bones. Long-distance running may lead to stress fractures of the mid- and distal tibia and of the metatarsal bones. Stress fractures to the sacrum are rare. Certain factors for stress fractures in runners have been identified, such as leg-length inequality, a high longitudinal arch of the foot, forefoot varus, and menstrual irregularities in case of female athlete triad. We report on a 22-year-old female runner (usually training 140 km/week) suffering a sacral fatigue-type fracture. The female athlete triad with eating disorders, dysmenorrhea, and osteopenia was ruled out. Sexual hormone blood samples proofed normal values. The diagnosis was performed using magnetic resonance imaging 2 weeks after the onset of buttock pain. A conservative treatment regimen was initiated with strict physical rest for the first 2 weeks, and then gradual increase of physical activity with 60-90 min of daily cycling and moderate 2 x 60 min cross-training. After another 2 weeks time, daily 60-90 min of walking, Nordic pole walking, and moderate strength training two times a week was performed. At 7 weeks running was started, gradually increased to 90 km/week without any pain. A rapid rehabilitation programme after sacral stress fractures involving low impact physical activity, such as Walking and Nordic pole walking, is applicable to female athletes after ruling out the female athlete triad.

Adult↗

PubMed2006

Recurrent shoulder instability among athletes: changes in quality of life, sports activity, and muscle function following open repair.

BACKGROUND: Recurrent anterior shoulder instability is a disabling condition in young athletes with possibly underestimated impact on quality of life and sports activity. Commonly used clinical scoring systems do not reflect the impairment of quality of life and sports activity. It was our aim to assess the return to preinjury levels of quality of life and sports activity as well as the changes in muscle function among competitive and recreational athletes. HYPOTHESIS: Patients suffering from post-traumatic recurrent shoulder instability have to adopt their participation in sports and therefore discover a reduction in quality of life. Open stabilization procedures are able to improve shoulder function and to reduce recurrence rates. However, return to preinjury shoulder function is not guaranteed. STUDY DESIGN: Retrospective longitudinal cohort study on 19 consecutive athletes with recurrent, post-traumatic shoulder instability. All patients were treated with an open, capsulo-labral repair. The minimum follow-up was 24 months. METHODS: Life quality (SF12) and sports activity data (Athletic Shoulder Outcome Scoring System) were retrospectively collected for the time before injury (time 1) and for the time with recurrent instability (time 2). Two years after surgical stabilization (time 3), we followed our patients with different clinical outcome scores, rotator surface EMG measurement, isokinetic muscle strength testing, and a radiological evaluation. This design of a three-step follow-up allowed for calculating the impact on quality of life and sports activity following the injury. RESULTS: Two years after surgery, the clinical scoring systems revealed good-to-excellent results in all patients. Quality of life physical component summary remained diminished by 9.2% despite the surgical procedure and was therefore significantly lower as compared to preinjury levels (p < 0.05). Sports activity was also significantly lower at the time of follow-up (p < 0.05). In this specific procedure, external rotation was not impaired postoperatively. EMG testing showed an overall reduction of muscle activity, however not significant. Isokinetic muscle strength was significantly diminished for external rotation and shoulder abduction. CONCLUSIONS: Open reconstruction procedures for recurrent shoulder instability can restore shoulder function and stability to near-normal values. Despite good-to-excellent clinical results, there is a significant impairment of quality of life and sports activity 2 years after surgery. Muscle activity and muscle strength are diminished. Recurrent shoulder instability remains a disabling condition to the young athlete. Future strategies have to emphasize restoration of quality of life, sports activity, and muscle function.

Adolescent↗

PubMed2006

Hinged external fixation and closed reduction for distal humerus fracture.

Elbow fractures are relatively rare in extremity injuries. Functional deficits often comprise the outcome. We report of a 77-year-old diabetic lady with a distal humerus fracture. She was treated with external fixation and closed reduction. Special emphasis was directed to early motion exercises. Follow-up after 1 year demonstrated a range of motion of 0-30-130 degrees for extension and flexion of the elbow joint. No neurovascular deficits were seen. The use of a hinged device was successful in re-establishing a good function. Although there are no earlier reports using this technique in acute treatment, we consider this strategy as an alternative option in carefully selected cases.

Accidental Falls↗

PubMed2006

[Arthroscopic partial meniscectomy].

OBJECTIVE: Excision of damaged meniscal tissue whereby the mechanical obstacles to joint movement are eliminated. As much functional, intact meniscal tissue should be retained as possible. Resection of only the bare minimum. INDICATIONS: Symptomatic, irreparable lesions of the meniscus due to trauma or degeneration. CONTRAINDICATIONS: Reparable lesions of the meniscus. Local skin affections. SURGICAL TECHNIQUE: Introduction of the arthroscope through an anterolateral or central portal. The instrument portal is positioned in accordance with the situation of the meniscal lesion to be treated. The tissue to be excised is either broken into fragments with different punches or resected en bloc. POSTOPERATIVE MANAGEMENT: Functional postoperative management without immobilization. Full loading on the leg. RESULTS: Very good and good clinical results can be achieved in the short and long term after arthroscopic partial meniscectomy. In a study by Burks et al., 88% of 146 patients with stable knee joints had a very good or good result 14.7 years after partial meniscectomy. 95% of 57 patients were satisfied or very satisfied with the result 12 years after partial medial meniscectomy. A degenerative meniscal tear, axial deformity, higher age, and anterior cruciate ligament insufficiency are factors associated with an increased rate of arthrosis in the long term.

Ambulatory Surgical Procedures↗

PubMed2005

Achilles tendon and paratendon microcirculation in midportion and insertional tendinopathy in athletes.

BACKGROUND: Neovascularisation can be detected qualitatively by Power Doppler in Achilles tendinopathy. Quantitative data regarding tendon microcirculation have not been established and may be substantial. PURPOSE: To assess the microcirculation of the Achilles tendon and the paratendon in healthy volunteers as well as in athletes with either midportion or insertional tendinopathy. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: In 66 physically active volunteers, parameters of Achilles tendon and paratendon microcirculation, such as tissue oxygen saturation, relative postcapillary venous filling pressures, and microcirculatory blood flow, were determined at rest at 2-mm and 8-mm tissue depths. Forty-one patients never had Achilles pain (25 men, 27 +/- 8 years), 14 patients had insertional pain (7 men, 29 +/- 8 years), and 11 patients had midportion tendinopathy (7 men, 38 +/- 13 years, not significant). RESULTS: Achilles tendon diameter 2 cm and 6 cm proximal to the insertion was increased in symptomatic tendons. Compared with the uninvolved opposite tendon, deep microcirculatory blood flow was significantly elevated at insertional (160 +/- 79 vs 132 +/- 42, P < .05) as well as in midportion tendinopathy (150 +/- 74 vs 119 +/- 34, P < .05). The microcirculation in the uninvolved opposite tendon and the normal athlete controls were not significantly different from each other (132 +/- 42 insertional asymptomatic vs 119 +/- 34 mid-portion vs 120 +/- 48 healthy tendon). Insertional paratendon deep microcirculatory flow was elevated in all groups, whereas tissue oxygen saturation and relative postcapillary venous filling pressures were not significantly different. CONCLUSION: Microcirculatory blood flow is significantly elevated at the point of pain in insertional and midportion tendinopathy. Postcapillary venous filling pressures are increased at both the midportion Achilles tendon and the midportion paratendon, whereas tissue oxygen saturation is not different among the studied groups. We found no evidence of an abnormal microcirculation of the asymptomatic limb in Achilles tendinopathy.

Achilles Tendon↗

PubMed2004

Alpha-smooth muscle actin containing contractile fibroblastic cells in human knee arthrofibrosis tissue. Winner of the AGA-DonJoy Award 2003.

INTRODUCTION: Primary arthrofibrosis is of major concern after joint trauma or knee ligament surgery. The underlying mechanism in detail remains unclear. Highly differentiated fibroblastic cells, so-called myofibroblasts, express the actin isoform alpha-smooth muscle actin (ASMA) and have been found to play a major role in tissue contraction during wound healing and organ fibrosis. We therefore studied the expression of myofibroblasts in human primary knee arthrofibrosis tissue. MATERIALS AND METHODS: Tissue samples were taken from the infrapatellar fat pad and intercondylar region of nine patients who underwent revision surgery due to arthrofibrosis after anterior cruciate ligament (ACL) reconstruction (study group). Control tissue was taken from five patients who underwent primary ACL reconstruction (control group I) and from eight patients, who underwent second-look arthroscopy after primary ACL reconstruction (control group II). ASMA containing fibroblasts were immunostained with a monoclonal antibody. Histomorphometry was performed for total cell amount, ASMA containing fibroblasts, and vessel cross-sections. RESULTS: The arthrofibrosis group showed a tenfold higher amount of ASMA containing myofibroblasts (23.4% vs. 2.3%) than in control group I. There was a significantly higher total cell count and lower vessel density than in control group I. Control group II showed an upregulation of myofibroblasts almost five times that in control group I; nevertheless there was no evidence of scar formation or tissue fibrosis. CONCLUSIONS: Myofibroblasts are responsible for scar tissue contraction during wound healing. In arthrofibrosis tissue fibroblast contraction may be involved in tissue fibrosis and contraction with consecutive loss of motion. We found that myofibroblasts are upregulated in arthrofibrosis tissue. ACL reconstruction itself caused an up regulation of myofibroblast content. Nevertheless these patients did not show any clinical or histological signs of arthrofibrosis. Thus it is reasonable to assume that the ratio of myofibroblasts and total cell amount in connective tissue are responsible for the onset of arthrofibrosis. Address the expression of this highly differentiated cell type may therefore present a target for future therapeutic interventions.

Actins↗

PubMed2003

Cyclic mechanical strain induces NO production in human patellar tendon fibroblasts--a possible role for remodelling and pathological transformation.

The mechanism by which tendon fibroblasts can detect strain forces and respond to them is fairly unknown. Nitric oxide (NO) is a messenger molecule that among others can respond to shear stress in endothelial cells. Therefore, it was investigated whether cyclic mechanical strain induces NO in vitro in human patellar tendon fibroblasts. Human patellar tendon fibroblasts were cultured from remnants of patellar tendon transplants after reconstructive surgery. Fibroblasts were cultured on elastic silicone dishes. The cells were longitudinally strained (5%, 1 Hz) for 15' or 60'. As a control, no strain was applied. The experiments were finished after 0', 5', 15', and 30'. NO was determined using the Griess reaction. 15' strain showed at 0' and 5' 200% activation, which thereafter at 15' and 30' returned to normal levels. 60' strain showed a biphasic pattern. At 5' and 30', NO levels were increased to 175%. At 15', NO measurement displayed 120% increased levels. Mechanical strain induces NO production by tendon fibroblasts. Therefore, NO produced by tendon fibroblasts, as a response to alteration in their mechanical microenvironment, could modulate fibroblast function. The results of our study suggests that strain-related adaptive changes may, at least in part, be controlled by a process in which strain-related NO production from the fibroblast network may play a pivotal role. Moreover, these are basic findings that are important for further unravelling pathophysiology of tendon diseases.

Adaptation, Biological↗

PubMed2003

Modulation of cell functions of human tendon fibroblasts by different repetitive cyclic mechanical stress patterns.

Mechanical stress is a factor that is thought to play an essential role in tissue generation and reparation processes. The aim of the present study was to investigate the influence of different repetitive cyclic longitudinal stress patterns on proliferation, apoptosis and expression of heat shock protein (HSP) 72. To perform this study, human tendon fibroblasts were seeded on flexible silicone dishes. After adherence to the dish, cells were longitudinally stressed with three different repetitive stress patterns having a frequency of 1 Hz and an amplitude of 5%. The proliferation and apoptosis rates were investigated 0, 6, 12 and 24 hours after application of cyclic mechanical longitudinal strain. Expression of HSP 72 was tested after 0, 2, 4 and 8 hours. Control cells were also grown on silicone dishes, but did not receive any stress. Stress patterns applied during one day resulted in a significant increase in proliferation and a slight increase in apoptosis. HSP 72 expression was rather unchanged. A stress pattern applied during two days resulted in a reduced proliferation and apoptosis rate whereas the expression of HSP 72 showed a significant increase. This study shows that different stress patterns result in different cellular reactions dependent on the strength of applied stress. Repetitive stress applied during one day stimulated proliferation and apoptosis in contrast to an extended stress duration. The latter induced an inhibition of proliferation and apoptosis probably through an increased HSP 72 activity. This may be related to an excess of applied stress. Our results may implicate future modulation techniques for tissue reparation and tissue engineering.

Annexin A5↗

PubMed2002

Cyclic mechanical stretching of human patellar tendon fibroblasts: activation of JNK and modulation of apoptosis.

Accelerated rehabilitation after tendon, ligament and bone injuries is widely accepted to avoid adverse effects of immobilization. However, progressive rehabilitation may also lead to an excessive inflammatory soft tissue response and often leads to structural and functional problems such as excessive scarring. The equivalent at the molecular/cellular level is in part the regulation of the sensitive homeostasis between proliferation and apoptosis. However, little attention has been paid to this aspect of tendon pathogenesis. This study investigated the response profile of human tendon fibroblasts in terms of apoptosis and anticipated alteration of Jun N-terminal kinase (JNK) activation to cyclic mechanical stretching. Human tendon fibroblasts of six patients were stretched for 15 or 60 min with 1 Hz and an elongation of 5%. Activation of stress-activated protein kinase (SAPK)/JNK was measured by western blot analysis. Apoptotic cells were determined in the stretched cells and in controls by annexin-V staining and detection by flow cytometry. Additionally DNA laddering was determined by ligation-mediated (LM) polymerase chain reaction (PCR). Application of 15 and 60 min stretch increased activation of SAPK/JNK at a maximum after 60 min. However, JNK activation after the longer stretch period 50% less than after the shorter stretch period (15 min). The apoptosis rate was correspondingly increased after short stretch application but not after longer stretch. This might be caused by an inactivation of the activated JNKs by cell protection mechanisms. The findings suggest that mechanical stretching directly activates intracellular signaling pathways, which in turn induce apoptosis. The longer stretch period resulted in a decreased apoptotic rate due to development of stress tolerance. This might be caused by heat-shock protein mediated suppression of JNK activation. This novel observation is an important issue, as defined mechanical stretching, depending on its duration, modulates apoptosis and thus affects tendon remodeling.

Adaptor Proteins, Signal Transducing↗

PubMed2002

A modified method to culture human osteoblasts from bone tissue specimens using fibrin glue.

INTRODUCTION: To establish primary osteoblast cultures is a challenge. The methods for isolation mostly comprise digestion with extracellular matrix degrading enzymes after mincing the bone samples. These methods are labour intensive and lead to an inefficient recovery of cells. Therefore, the aim of this study was to develop a more reliable method for culturing human osteoblasts. MATERIALS AND METHODS: Bone tissue specimens were obtained from 20 patients undergoing reconstructive operations. Bone specimens were dissected and put into petri dishes with the bottom covered with fibrin glue. To identify the nature of the outgrowing cells, cytological staining was performed, i.e. Von Kossa, Azan, Dahl's, alkaline phosphatase, and collagen type I. RESULTS: Mean time interval of cellular outgrowth was 12 days after preparing the bone tissue specimens. Confluence of the cell cultures was reached after four to five weeks on average. All cells were positively stained using Von Kossa, alkaline Phosphatase and collagen type I. The matrix consisted of lime, calcium and collagens. CONCLUSION: A simplified method to culture osteoblasts from all kinds of bone tissue specimens is presented. The fibrin glue allows firm adhesion of the specimens to the petri dish. This allows the cells to grow out without disturbance. Normally, due to movements during medium exchange the adhesive bonds are disrupted. The fibrin glue retains the adhesive bonds. This method allows studying human osteoblasts in different clinical settings.

Aged↗

PubMed2002

Upper sympathetic trunk lesion after video-assisted fracture stabilization of the thoracic spine: a case report.

This case report draws attention to the upper sympathetic trunk lesion as a complication of video-assisted thoracic spine surgery. A 39-year-old man developed an upper sympathetic trunk lesion after right-sided thoracoscopic fracture stabilization of T5 and T6. Dizziness and reduced perspiration persisted at the most recent follow-up 8 months after surgery. This rare complication can be overlooked and remain undiagnosed. Diagnosis is based on clinical symptoms and neurologic examination. There are no treatment options. Symptoms can be bothersome for the patient and may persist. In the upper thoracic spine, the course of the sympathetic trunk lies in close proximity of the vertebral bodies; thus, care must be taken to avoid it when resecting the posterior parts of the vertebral body.

Adult↗

PubMedDate not supplied

Modulation of proliferation and differentiation of human bone marrow stromal cells by fibroblast growth factor 2: potential implications for tissue engineering of tendons and ligaments.

Bone marrow stromal cells (BMSCs) play a central role in the repair and regeneration of mesenchymal tissues. For tissue engineering of ligaments and tendons, both stimulation of cell proliferation and differentiation with increased expression of essential extracellular matrix proteins and cytoskeletal elements are desirable. This study analyzes the effect of low-dose (3 ng/mL) fibroblast growth factor 2 (FGF-2) and high-dose FGF-2 (30 ng/mL) on proliferation (bromodeoxyuridine content, spectrophotometry), differentiation (transcription of collagen I, collagen III, fibronectin, elastin, alpha-smooth muscle actin, and vimentin, reverse transcription-polymerase chain reaction, and cell density and apoptosis (annexin V, fluorescence-activated cell sorting) of human BMSCs, and compares the results with those of a control group without FGF-2. Low-dose FGF-2 triggered a biphasic BMSC response: on day 7, cell proliferation reached its maximum and was significantly higher compared with the other groups. On days 14 or 28, collagen I, collagen III, fibronectin, and alpha- smooth muscle actin mRNA expression was significantly enhanced in the presence of low-dose FGF-2. In contrast, high-dose FGF-2 did not stimulate differentiation or proliferation. Vimentin mRNA was expressed only in cultures with low-dose and high-dose FGF-2 after 14 and 28 days. Cell density was significantly higher in cultures with low-dose FGF-2 compared with the group with high-dose FGF-2 on days 7, 14, and 28. The apoptosis rate remained stable, at a rather high level, in all groups. Microscopic investigation of the cell cultures with low-dose FGF-2 showed more homogeneous, dense, fibroblast-like, spindle-shaped cells with long cell processes compared with cultures with high-dose, or no FGF-2. Low-dose FGF-2 may be useful for tissue engineering of ligaments and tendons by increasing BMSC proliferation and stimulating mRNA expression of specific extracellular matrix proteins and cytoskeletal elements.

Bone Marrow Cells↗