Regulation of smooth muscle actin expression and contraction in adult human mesenchymal stem cells

Prior studies have demonstrated the expression of a contractile actin isoform, alpha-smooth muscle actin, in bone marrow stromal cells. One objective of the current study was to correlate contractility with alpha-smooth muscle actin expression in human bone marrow stroma-derived mesenchymal stem cells. A second objective was to determine the effects of transforming growth factor-beta1, platelet derived growth factor-BB, and a microfilament-modifying agent on alpha-smooth muscle actin expression and alpha-smooth muscle actin-enabled contraction. Adult human bone marrow stromal cells were passaged in monolayer and their inducibility to chondrocytic, osteoblastic, and adipogenic phenotypes was demonstrated. Western blot analysis was employed along with densitometry to quantify the alpha-smooth muscle actin content of the cells and their contractility was evaluated by their contraction of a type I collagen-glycosaminoglycan sponge-like matrix into which they were seeded. Transforming growth factor-beta1 (1 ng/ml) significantly increased and platelet-derived growth factor-BB (10 ng/ml) decreased alpha-smooth muscle actin expression and the contractility of the cells. Cytochalasin D also blocked cell contraction. There was a notably high correlation of cell-mediated contraction normalized to the DNA content of the matrices with alpha-smooth muscle actin content of the cells by linear regression analysis (R(2) = 0.88). These findings lay the groundwork for considering the role of alpha-smooth muscle actin-enabled contraction in mesenchymal stem cells and in their connective tissue cell progeny.

Die Versorgung dislozierter 3- und 4-Fragmentfrakturen des proximalen Humerus mit einem winkelstabilen Plattenfixateur

In the presented prospective study 35 consecutive patients with displaced 3- and 4-part fractures of the proximal humerus, including fracture dislocations, were treated with a fixator plate comprising angular stability between May 2001 and December 2002. After 18.5 (8-29) months 31 (89%) fractures were available for follow-up. Good and very good results were obtained in 64%. A poor result was documented in 23%. 64% of the patients had no or mild pain, 71% were able to abduct the arm over 90 degrees . Fracture classification according to Neer and AO had no influence on the outcome, with a mean Constant Score of 76 points. Partial avascular necrosis (AVN) of the humeral head was seen in 16% of all cases representing 4% of the fractures without dislocation and 80% of the fracture dislocations. Fracture dislocation (p=0.02) and AVN (p=0.005) had a negative effect on the Constant Score, with AVN being a predictor for a high level of pain (p=0.04). Secondary dislocation of the greater tuberosity was seen in two patients, loosening of screws in one patient and a fracture below the plate in another one. Secondary dislocation or loss of reduction of the head was not recorded. Angle stable plate fixation with tension band wiring of the tuberosities is an effective and safe option to treat this difficult fractures, also in elderly patients with osteoporotic bone. Because 40% of the 4-part fractures with fracture dislocation yielded a satisfactory or better result, the plate fixator with angular stability may be an alternative to prosthetic replacement in selected cases.

Growth factor regulation of smooth muscle actin expression and contraction of human articular chondrocytes and meniscal cells in a collagen-GAG matrix

Recent work has demonstrated that human articular chondrocytes and meniscus cells can express the gene for a contractile actin isoform, alpha-smooth muscle actin (SMA), in vivo. The objective of the present study was to evaluate the effects of two growth factors, transforming growth factor (TGF)-beta1 and platelet-derived growth factor (PDGF)-BB, on the SMA content of these cells and their contraction of a collagen-glycosaminoglycan (GAG) analog of extracellular matrix in vitro. TGF-beta1 was found to markedly increase SMA content of the cells and PDGF-BB decreased SMA expression, with both findings achieving statistical significance. A notable finding was the increased contraction of the collagen-GAG matrix induced by TGF-beta1 and the decrease in contraction resulting from PDGF-BB treatment, indicating a causal relationship between expression of SMA and the contractility of the cells. A novel cell force monitor, employed to estimate the force exerted per cell, demonstrated a higher force exerted by the TGF-beta1-treated cells. The findings demonstrate that the expression of SMA by articular chondrocytes and meniscal cells and their associated contractile behavior can be regulated by selected growth factors. This work provides a foundation for the rational investigation of the mechanisms underlying SMA-enabled contraction of these cell types and the control of this behavior in tissue engineering.

Smooth muscle actin expression by human articular chondrocytes and their contraction of a collagen-glycosaminoglycan matrix in vitro

Recent studies have demonstrated that human articular chondrocytes can express the gene for a contractile muscle actin, alpha-smooth muscle actin (SMA), in situ. One objective of this work was to evaluate the SMA-content of isolated human articular chondrocytes using Western blot analysis and to correlate the amount of SMA in the cells with passage number and the number of days in culture. A second objective was to determine if articular cartilage-derived cells expressing the gene for SMA in vitro also continue to express type II collagen. A final aim of the current study was to determine if SMA-containing cartilage-derived cells were capable of contracting a collagen glycosaminoglycan analog of extracellular matrix in vitro. Articular chondrocytes were isolated from 13 patients undergoing total joint arthroplasty. Cells were serially passaged through passage 7. Samples were allocated for Western blot analysis of SMA. Cells in monolayer culture were also stained immunohistochemically for SMA and type II collagen. Cells from passage 3 and 7 were seeded into a porous type I collagen-glycosaminoglycan matrix and the diameter of the scaffolds measured every other day for 21 days. Immunohistochemistry of the articular cartilage samples revealed SMA in the articular chondrocytes in situ with a greater percentage of cells staining positive in the superficial half (60 +/- 1.2%; mean +/- SEM) of the cartilage than in the basal half (28 +/- 1.3%). There was an increasing amount of SMA in the cells in monolayer culture with passage number and a meaningful correlation of the SMA content with the days in culture (linear regression analysis; R2 = 0.72). Double staining for SMA and type II collagen showed that type II collagen-expressing cells in monolayer could also express SMA. SMA-containing cells were found to contract the collagen glycosaminoglycan matrix, with the cells containing more SMA (passage 7 cells) displaying more matrix contraction than those with a lesser amount of SMA (passage 3 cells). The results indicate that control of the expression of SMA may be important when employing articular chondrocytes, expanded in monolayer culture, for implantation alone or in a cell-seeded matrix for cartilage repair procedures.

Expression of smooth muscle actin in osteoblasts in human bone

It is well known that certain connective tissue cells (viz., dermal fibroblasts) can express the gene for a muscle actin--alpha-smooth muscle actin--and can contract. This process contributes to skin wound closure and is responsible for Dupuytren's contracture. The objective of this study was to determine if human osteoblasts can also express the gene for alpha-smooth muscle actin. Immunohistochemistry using a monoclonal antibody for alpha-smooth muscle actin was performed on human cancellous bone samples obtained from 20 individuals at the time of total joint arthroplasty. The percentages of resting and active osteoblasts on the bone surfaces containing this muscle actin isoform were evaluated. Explants of human bone were also studied for the expression of alpha-smooth muscle actin in the tissue and in the outgrowing cells with time in culture. Western blot analysis was performed to quantify the alpha-smooth muscle actin content of the outgrowing cells relative to smooth muscle cell controls. Nine +/- 2% (mean +/- SEM; n = 20) of the cells classified as inactive osteoblasts and 69 +/- 3% (n = 19) of the cells identified as active osteoblasts on the bone surface contained alpha-smooth muscle actin. This difference was highly statistically significant (Student's t test, p < 0.0001). Similar profiles of alpha-smooth muscle actin-expressing cells were found in explants cultured for up to 12 weeks. Cells forming a layer on the surface of the explants and growing out from them in monolayer also contained alpha-smooth muscle actin by immunohistochemistry and Western blot analysis. Human osteoblasts can express the gene for alpha-smooth muscle actin. This expression should be considered a phenotypic characteristic of this cell type, conferred by its progenitor cells: bone marrow stromal-derived stem cells, and perhaps pericytes and smooth muscle cells.

Expression of smooth muscle actin in connective tissue cells participating in fracture healing in a murine model

The role of alpha-smooth muscle actin (SMA)-expressing fibroblasts in the contraction of skin wounds has been known for three decades. Recent studies have demonstrated that osteoblasts can also express the gene for this contractile muscle actin isoform and can contract a collagen-glycosaminoglycan analog of extracellular matrix in vitro. These findings provided rationale for the hypothesis that SMA-expressing cells contribute to fracture healing by drawing the bone ends together. To begin to test this hypothesis, immunohistochemistry was employed to evaluate the distribution of connective tissue cells expressing SMA in a mouse model of successful fracture healing. The results demonstrated that the majority of the cells comprising the mesenchymal tissue interposed between the fracture ends contained SMA after 7 and 21 days, supporting the working hypothesis. Most of the osteoblasts lining the surfaces of newly forming bone and the chondrocytes comprising the cartilaginous callus also expressed this contractile actin isoform. The maximal SMA expression extended from 7 to 21 days postfracture. The finding of high levels of SMA expression in connective tissue cells participating in fracture healing suggests that SMA-enabled contraction may be playing a role in the healing process. These results warrant further study of the specific SMA-dependent cell behavior.

Osteo-fasciocutaneous parascapular flap transfer for reconstruction of the first ray of the foot

BACKGROUND

Severe bone and soft tissue defects of the first metatarsal bone after trauma, tumor resection or osteomyelitis are challenging to treat. Partial amputation of the foot may be the consequence. However, due to its significance for gait, salvage of the first ray should be considered, whenever possible. One option for bone and soft tissue reconstruction, therefore, might be an osteo-fasciocutaneous parascapular flap transfer.

METHODS

Five patients with bone and soft tissue defects of the first ray of the foot but intact MTP joint were treated with osteo- fasciocutaneous parascapular flap transfer, two after tumor resection, and three after severe bone and soft tissue trauma. Patients were followed for 12-36 months clinically and radiologically.

RESULTS

All flaps survived. One revision was necessary because of venous thrombosis, which was treated successfully by thrombectomy and patch plastic. All osteosyntheses united and the scapular bone transplant adapted nicely to the new loading conditions. All patients were content with the result and would agree to have the operation again. Two patients were able to stand tiptoe and go jogging, one patient still had limitations of ADLs due to the concomitant injuries.

CONCLUSION

The osteo- fasciocutaneous flap proved to be very versatile and safe for foot reconstruction due to its favorable vascular anatomy. In all patients (partial), amputation of the foot could be avoided.

Regeneration of articular cartilage

Loss of articular cartilage from the ends of bones forming diarthrodial joints can be the source of profound pain and disability, and eventually lead to complete degeneration of the joint, necessitating total joint replacement. Until a few years ago, there seemed little hope of treating such defects. Novel surgical procedures and cell therapies have recently been found, however, to stimulate the formation of reparative tissue resulting in the relief of pain and restoration of function, at least for a limited time period. Moreover, studies of the healing of chondral defects in animal models have revealed that there is some potential for regeneration of this connective tissue. The introduction of certain biomaterial scaffolds along with selected surgical procedures and cell therapies has been demonstrated in animal studies to facilitate the cartilage reparative process and now offers the promise of extending the longevity of clinical treatments of cartilage defects. Collectively these findings provide the basis for the rational development of approaches for the more complete regeneration of articular cartilage, and demonstrate that meaningful clinical outcomes can be achieved even if complete regeneration is not achieved.

Expression of smooth muscle actin in cells involved in distraction osteogenesis in a rat model

Distraction osteogenesis has proven to be of great value for the treatment of a variety of musculoskeletal problems. Little is still known, however, about the phenotypic changes in the cells participating in the bone formation process, induced by the procedure. Recent findings of the expression of a contractile muscle actin isoform, alpha-smooth muscle actin (SMA), in musculoskeletal connective tissue cells prompted this immunohistochemical study of the expression of SMA in cells participating in distraction osteogenesis in a rat model. The tissues within and adjacent to the distraction site could be distinguished histologically on the basis of cell morphology, density, and extracellular matrix make-up. The percentage of SMA-containing cells within each tissue zone was graded from 0 to 4. The majority of the cells in each of the zones stained positive for SMA within five days of the distraction period. The SMA-containing cells included those with elongated morphology in the center of the distraction site and the active osteoblasts on the surfaces of the newly forming bone. These finding warrant further investigation of the role of this contractile actin isoform in distraction osteogenesis and investigation of the effects of modulation of this actin isoform on the procedure.

[Modified Pirogoff's amputation]

OBJECTIVE

The goal of Pirogoff's amputation of the hindfoot is a weight-bearing stump with minimal loss of limb length and stable soft tissue coverage with preservation of the sensation of the sole of the heel.

INDICATIONS

Non-reconstructable forefoot and midfoot after complex trauma, deep bony and soft tissue infection, infected Charcot foot, necrosis or gangrene due to vasculopathy, malignant tumors and deformities.

CONTRAINDICATIONS

Possibility for reconstruction of the forefoot and midfoot, minor amputation, loss or irreversible destruction of the sole of the heel.

SURGICAL TECHNIQUE

The incision runs from dorsal, 1-2 cm distal of the Chopart joint, to plantar, 5-6 cm distal of the Chopart joint for creation of an adequate plantar skin flap. Exarticulation of the foot from dorsal to plantar through the Chopart joint with preservation of the posteromedial neurovascular bundle. Enucleation of the talus. Minimal resection of the cuboidal and posterior facets of the calcaneus as well as the malleoli inclusive of the distal tibial joint surface. The calcaneus is brought under the tibia and a tibiocalcaneal arthrodesis is performed with two compression screws.

POSTOPERATIVE MANAGEMENT

No weight bearing until stable scar formation, early mobilization in a walker. Interim prosthesis after 2-4 weeks and definitive prosthesis after 2-3 months.

RESULTS

From January 2010 to December 2014 six patients were treated with a modified Pirogoff's amputation. Primary wound healing was achieved in four patients and in two patients wound healing was impaired. In one patient the wound was conservatively healed and the other patient needed below knee amputation. Early primary prosthetic treatment was possible in four patients. The tibiocalcaneal arthrodesis healed in all five remaining cases. All patients with a healed Pirogoff stump were able to walk for short distances in bare feet without the prosthesis.

[Experiences with a hydroxyapatite-coated, macroporous surface hip endoprosthesis]

INTRODUCTION

Cementless hip arthroplasty is not completely satisfactory--even with macroporous structured surface. Medium term results are sometimes disappointing because of insufficient secondary stability. Thus our aim was to improve fixation by additional coating with hydroxyapatite.

METHODS

200 consecutive patients who had hydroxyapatite-coated cementless hip replacement with a macroporous hip prosthesis (09/92-03/96) were studied prospectively. All patients were included in a prospective follow up schedule according to the criteria of Johnston et al. As measure of clinical outcome we calculated Harris Hip Score as well as Enghs Score to assess radiologic fixation and stability.

RESULTS

91% could be followed up regularly. No revision because of aseptic loosening had to be done. Analysis of clinical results showed almost painless patients from early after the operation--especially no thigh pain. Average HHS after 2 years was 97. Radiological evaluation showed early and complete osteointegration of all components. According to Engh-Score they are stable and well fixed.

CONCLUSION

HA coated macroporous implants provide some striking advantages, which encouraged us to continue with this system. By early and secure bony ingrowth a fibrous interface is avoided and thereby also long-lasting thigh pain.

Plantare Lisfranc-Luxationsfraktur

We report a 30-year-old patient suffering a plantar dislocation fracture after he dropped a heavy weight on his foot. The patient was treated immediately after diagnosis was secured by CT scan. Median approach and dermatofasciotomy of the foot were followed by anatomic reduction of the fractures and the Lisfranc dislocation and fixed by internal osteosynthesis. After 3 months the patient was able to ambulate pain free without walking aids. Plantar dislocation is a very rare direction of comminuted Lisfranc dislocation fractures. The outcome may be favorable with early reduction and stable internal fixation of the fractures. One always has to be aware of the major soft tissue trauma associated with complex Lisfranc dislocation fractures.

[Amputation and exarticulation of the lesser toes]

OBJECTIVE

Amputations and exarticulations of the toes may be necessary due to several reasons. The goal is to remove necrosis or infection prior to its spread to the midfoot region. From a functional or cosmetic point of view, amputation/exarticulation of a single toe plays no major role. However, this can be different with exarticulation of several toes.

INDICATIONS

Necrosis, trauma, infection, tumor, deformity.

CONTRAINDICATIONS

Conditions where amputation/exarticulation of a toe is insufficient, e. g., in progressing peripheral arterial disease.

SURGICAL TECHNIQUE

The toe can either be amputated through the distal phalanx or exarticulated in the metatarsophalangeal joint.

POSTOPERATIVE MANAGEMENT

Orthopedic shoes or orthotic devices are rarely necessary when a single toe is amputated/exarticulated. However, concomitant deformities of the foot have to be thoroughly addressed. If more than one toe is amputated, silicone spacers may be necessary to prevent the remaining toes from deviating.

RESULTS

Amputations and exarticulations of the toes are frequent and the procedure is technically simple. However, the complication rate is high due to typical indications making amputation necessary.

[ How to gauge the importance of sports medicine for the medical training of medical students?]

AIM

Education in sports medicine is offered heterogeneously in German medical schools. The self-image of sports has changed from a traditional, competition-oriented way to adventure, entertainment, wellness and health. Therefore, changes of our curricula to a practical-oriented way of teaching are required. In a first step the motivations and expectations of the students have to be evaluated.

METHODS

90 students enrolled in a sports medicine class were evaluated using a questionnaire and compared to 60 students not participating in the sports medicine class.

RESULTS

The main motivation for the students to sign in was the future possibility to subspecialize in sports medicine, followed by interest in the subject. The main reasons not to participate were the time factor followed by lack of interest. 80 % of the students were regularly practising sports. 66 % commented on having been involved in sports trauma. 90 % of the students believe that practical-oriented education is absolutely necessary.

CONCLUSION

Evaluation of the students motivation, knowledge as well as a discussion of the current practice to teach sports medicine at medical school confirm the need for modification of our curricula to a more practical-oriented education.

[Training in sports medicine for medical students--Evaluation of a practice-oriented teaching concept]

INTRODUCTION

Education in Sports Medicine is offered heterogeneously in German medical schools. Efficacy and acceptance among medical students are unknown. The self-image of sports has changed from a traditional, competition-oriented way to adventure, entertainment, wellness and health. Therefore changes of our curricula to a practical oriented way of teaching are required. In this regard a new curriculum was developed. The main focus, besides an interdisciplinary class in sports medicine was to offer practical education in sports to the students.

METHODS

Efficacy and acceptance of the class were evaluated using a questionnaire. 90 medical students (58 male, 32 female) were included into the study .

RESULTS

The interdisciplinary topics of the class were graded positively. Most of the presentations were regarded as very useful for the future practice. Empathy and commitment of the professor were keystones to good scores. The "fun-factor" was the key for the success of the practical assignment. Practical training was regarded as fundamental for a sports medicine class.

DISCUSSION

Evaluation of the new concept as well as a discussion of the current practice to teach sports medicine at medical school confirm the need of a more practical oriented education, in order to meet the requirements of sports medicine in a time with changing self image of sports.

[The influence of the body weight on the 133 xenon clearance of the brachial muscles (author's transl)]

Muscles blood flow (MBF) was determined by 133-Xenon-Clearance at rest in 78 persons free of vascular symptoms. Significant differences were found between males and females with normal body weight. Depending on the special composition of both groups (normal subjects and obese under 60 years) there was no significant decrease of MBF with increasing age.

[Systolic time interval as a means of evaluating the cardiac functional capacity in patients with and without heart insufficiency]

Determining the systolic time intervals in a non-invasive method which is easy to apply and inexpensive, and it can be repeated as many times as necessary. The patient is subjected to low psychic stress so that even elderly and sick patients may undergo it. The STI method may be applied to case control and the observation of the development of a disease following pharmacological treatment. The method makes it possible to differentiate between healthy persons and patients suffering from cardiac insufficiency, and concealed insufficiencies of the cardiac circulation may be detected. The STI interpretation must take into account those factors which have an effect on the STI length. The results can be considerably upgraded through the use of certain indices, PI being the main one. The PI index is of particular value if the effect of the treatment by glycoside medication is to be observed.

[Orthotic Supply after Complex Trauma of the Foot]

BACKGROUND

After complex trauma of the foot, patients frequently need orthotic care. There have been no systematic studies on the quality of care or patient satisfaction. Therefore the goal of this study was to evaluate patient satisfaction and the quality of orthotic care.

PATIENT AND METHODS

In a prospective non-randomized, cross-sectional intervention study, the quality of care and patient satisfaction with orthotic devices were evaluated clinically and pedographically. This was followed by a lengthy discussion and recommendation to improve the insoles or shoes. These improvements were followed up by a written/telephone survey. 39 of the 50 recruited patients with complex trauma of the foot (78 %) were supplied with orthotic devices (insoles, modifications of the sole and orthopaedic shoes).

RESULTS AND CONCLUSION

Most patients (76 %) were content with their orthotic care. However, shortcomings were noted in 20 patients. These were: insufficient arch support/stabilization, inadequate support of roll-off and unsatisfactory unloading of the forefoot. 23 % of the patients did not use their orthotic devices. Compliance increased after counseling. However, half of the patients had problems in obtaining reimbursement for the modifications recommended. In conclusion, orthotic treatment of patients after complex trauma of the foot is demanding. Modifications of the devices are frequently needed. Interprofessional collaboration plays an important role.

[Metabolic risk factors in the very old]

55 patients well advanced in years of the vitality group I after Franke were examined according to clinical and laboratory-chemical criteria as well as by means of ECG in rest. The particular relations between metabolic risk factors and the occurrence of diseases of heart and circulation in persons well advanced in years were explained. Here could be established that persons who advanced in years, on the one hand, from the epidemiologic point of view show favourable laboratory parameters for the metabolic risk factors, on the other hand, however, slightly increased serum values of the risk factors may also be connected with old age. In a similar way the finding from the ECG in rest could be interpreted.

[Ambulation training with bilateral limited weight bearing after foot injuries]

AIM

Bilateral foot injuries are not uncommon. Operative treatment usually requires partial weight bearing over several weeks. This is a challenge for physiotherapy especially for ambulation training. We describe a new rehabilitation aid allowing for bilateral limited weight bearing during ambulation.

METHODS

Ambulation training was initiated in the early postoperative period using the Regensburg ambulation aid. A lift system allows for exact limitation of weight bearing on both sides controlled by balances integrated into the floor. Using a rail system a 15 m free walking distance is available. This study included 10 patients with bilateral foot fractures. The functional outcome was assessed using the AOFAS score and quality of life with the SF-36 score. Plain X-rays were used to evaluate loss of correction. The control group consisted of 20 patients where ambulation training was discontinued for at least 6 weeks postoperatively.

RESULTS

The system is very safe, during the entire period no complication was recorded. Acceptance among the patients was extremely high. Worries about unwanted weight bearing could be reduced. Patients mobilized with early ambulation training showed a better compensation of gait if compared to the control group. Secondary problems in the knee, hip or spine, as well as muscular deficiencies had a significantly lower incidence. No loss of correction could be seen in either of the two groups.

CONCLUSION

The presented ambulation aid is a significant contribution to the physiotherapy of bilateral foot injuries.

[Cardiovascular radiography, changes in the thoracic aorta, ECG and clinical parameters in hypertension. 2. Changes in the thoracic aorta in hypertension]

In 142 hypertensives and a control group of 230 normotensives the measure of the aorta after Kreuzfuchs was estimated. In the two groups a significant increase of the width of the aorta was found with growing age. Whilst the width of the aorta concerning the degree of severity I of hypertension on an average were slightly below those of normotensives, they were increased in the degrees of severity II and III, but a further increase could not be ascertained at the transition from degree of severity II to III. On the other hand, the duration of hypertension is of particular importance when a dilation of the aorta is present. Also between deformation of the heart and measure of the aorta close relations which may conclude to a homogenous development are to be seen particularly in the younger patients. The influence of the sclerosis of the aorta in the sense of an additional dilation of the aorta could not be clearly confirmed on the basis of our material. On the other hand, the frequency of calcium depositions significantly increased with growing age in the region of the aortic arce and in the group of younger patients with the duration of hypertension, whereas the different degrees of severity II and III had a smaller influence. It is interesting that several patients showed normal widths of the aorta despite a duration of the hypertension of more than 5 years and a degree of severity III.

[The relation of anthropometric parameters and echocardiography findings in the evaluation of left ventricular form and function in extreme obesity]

For the characterization of the left-ventricular thickness of the wall, of the diameter and of the functional parameters in obesity in a short-term investigation on 18 extremely adipose female normotonics and 17 normotonics with normal weight the echocardiographic investigation in the M-mode in the short parasternal axis was performed. The women with overweight had a by 28% (p less than 0.001) greater fractional shortening, a by 8% (p less than 0.01) greater ejection fraction, a by 23% (p less than 0.05) greater stroke volume and a by 34% (p less than 0.001) greater cardiac output as well as a by 13% smaller left-ventricular end-systolic volume than normotonic women with normal weight. Index of stroke volume and cardiac output did not differ. The women with overweight had a significantly larger left-ventricular end-diastolic diameter and a thicker interventricular septum as well as a larger thickness of the left-ventricular posterior wall in the systole. The results allowed the conclusion that changed left-ventricular parameters both with regard to the form and to the function in obesity per se might be the expression of the physiological adaptation to an increased requirement and the borderlines to the transition into a disturbed left-ventricular function and development of a left-ventricular hypertrophy were not fixed. Long-term studies should bring further explanation concerning these problems.

[Effect of obesity and food restriction on health and aging]

Based on experiences in animal studies, an attempt is made to illustrate all those mechanisms influencing the ageing process of human beings. The experimental part especially investigates the influence of food restriction in obese on the cardiovascular system and biological age. In middle-aged obese patients a normalization of initially altered noninvasive cardiodynamic parameters was achieved by isocaloric reduction diet. The biological age was influenced by food restriction too. If there is a correlation of overweight, food restriction and expectation live with human beings should be subject of further investigations.

[Nutrition and aging]

Proceeding from experiences with animal-experimental studies is tried to show all those mechanisms which have influence on the ageing process of man. In these cases in the experimental part of the study is particularly investigated the influence of the restriction of food in obese patients on the cardiovascular system, the lipid metabolism and the biological age. In obese patients of middle age by isocaloric reduction diet a normalisation of the at present changed non-invasive cardiodynamic parameters could be achieved. Apart from a normalisation of cholesterol and LDL-cholesterol, however, a decrease of the HDL-cholesterol of the same intensity was found. The biological age could be influenced under restriction of food. To what extent overweight and food restriction in man closely correlate with the life expectancy remains the subject of further investigations.

[Unrecognised dissociation of the bipolar hip prosthesis Avantage® (Biomet®) after closed reduction of a dislocation: a rare complication]

An 84-year-old female patient was admitted to our emergency department with a periprosthetic fracture of the left femur with an implanted Avantage prosthesis (Biomet®). Conventional X-ray images revealed besides the fracture a lateralisation of the prosthesis stem. An additional CT scan showed a dissociation of the polyethylene inlay from the head of the prosthesis which took place 3 years ago in the course of a closed reposition of a postoperative luxation. This event shows the relevance of a precise analysis of X-ray images after reposition regarding the exact articulation of the different prosthesis components.