Posture results from numerous alternating factors and reflects the attitude of an individual towards a definite situation. If the different conditions, namely the capacity and the willingness of posture, do not correspond to the requirements of the situation the "normal" erect posture will change. The development from abnormal posture into irreversible abnormalities and damages in posture is easy. In order to eliminate these risks one can try to reduce the potential of the situation on the one hand and to improve the capacity of the individual through adequate physical exercise on the other. The practice of daily physical activity at school or during leisure time is the best way to compensate for lack of exercise, to modify prolonged unfavourable situations, and to develop the physical capacity in such a way that dangerous loads can be supported without damage. The versatility of training, in combination with adequate gymnastical exercises and sports help to educate the sense of posture and movement with the effect that erect posture can be adopted and maintained. But only children who feel that erect posture is reflecting their personal image will finally keep the erect posture. Special attention is given to elite training in childhood and adolescence, when the vertebral column is particularly exposed to danger by the intensity of the training and must be protected against deformations by carefully chosen preventive measures.

Humans↗

PubMedDate not supplied

Endothelin A and B receptors change their expression levels during development of human placental villi.

Endothelin receptors have recently been found in non-vascular tissues including the human placenta. The present study investigated developmental changes in location and expression levels of endothelin A and B receptors (ETA-R, ETB-R) in human placentae and isolated trophoblast by comparing first and third trimester tissues. In the first trimester all cells and tissues were immunolabelled for ETA-R and ETB-R, whereas in third trimester placentae the syncytiotrophoblast (ETA-R, ETB-R) and macrophages (ETA-R) were unstained. Immunoblotting for both receptors revealed up to three bands at 33-35, 50 and 75 kDa, respectively, which were differentially present in the first and third trimester. Pre-adsorption of antibodies with oligopeptides used for antigen-generation weakened the immunoreactions. ETA-R protein levels decreased (P< 0.05) in total villous tissue and isolated trophoblast, whereas ETB-R was unchanged. ETB-R transcripts (RT-PCR) prevailed in both stages and tissues, but in contrast to the protein levels its preponderance decreased from first trimester to term in villous tissue (P< 0.01), because of a four to five-fold increase in ETA-R and only a two-fold (P< 0.05) increase in ETB-R mRNA levels (P< 0.01). We conclude that ET receptor location, intracellular processing and expression levels in human villous tissue change between the first and third trimester. This may reflect changing functions of ET-1 during placental development.

Abortion, Legal↗

PubMedDate not supplied

[Accuracy of determination of the hip centre in navigated total knee arthroplasty].

AIM: In navigated knee arthroplasty the hip centre is determined by rotary motion of the femur (pivoting). The accuracy of this functional hip centre determination in vivo is unclear. In the following paper the accuracy of pivoting in the determination of the hip centre was examined. METHODS: Navigated (TC-PLUS, Solution, PLUS Orthopedics) total knee arthroplasty (PI Galileo, PLUS Orthopedics) was performed on 25 patients with primary arthritis of the knee joint. The position of the femoral component and the hip centre were postoperatively determined by computer tomography. Through comparison with the intraoperatively documented data, the deviation of the pivoted from the true hip centre in the frontal and sagittal planes was calculated. The degree of arthritis of the hip was determined on plain radiographs according to Kellgren. RESULTS: The mean deviation was determined to 1.0 +/- 0.7 degrees in the frontal plane and 2.5 +/- 1.6 degrees in the sagittal plane (p = 0.002). This corresponds to a mean overall deviation of 20 +/- 10 mm. The data were continuously, non-parametrically distributed without any outliers. A great range of motion (ROM) in the frontal as well as sagittal planes during pivoting resulted in a less accurate determination of the hip centre. There was no correlation to the degree of arthritis of the hip. CONCLUSION: The results indicate a recommendable ROM during pivoting for maximal accuracy of hip centre determination of 20 to 30 degrees in the sagittal plane and 30 to 40 degrees in the frontal plane. Arthritis of the hip is not a contraindication for functional determination of the hip centre.

Arthroplasty, Replacement, Knee↗