Quercetin treatment mollified ischaemia-reperfusion injury to skeletal muscle by scavenging destructive superoxide and enhancing the cytoprotective nitric oxide concentration.

Background: Endothelial cells cultured in vitro are commonly used as a model for testing the effects of therapeutic or detrimental agents on endothelium. Cells originating from different vascular beds display, however, a heterogeneity of function and phenotype. Here we compared the production of angiogenic growth factors and the sensitivity to exogenous growth factor stimulation of two popular endothelial cell types. Methods: Experiments were performed on human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1) incubated in optimal conditions for 24-48 h. Results: The profile of the spontaneously produced growth factors differed significantly between the two different cell lines tested. HUVEC did not produce detectable amounts of VEGF, whereas HMEC-1 released 24.9 pg/ml and this amount was significantly increased in response to IL-1β. Instead, HUVEC produced high concentrations of soluble form of VEGF receptor-1 (VEGF-R1), whereas the release of VEGF-R1 from HMEC-1 was 10-fold lower. Small amounts of bFGF were found in media from both cell types, but higher levels were detected in HMEC-1 cultures. In contrast, the secretion of interleukin-8 (IL-8) and matrix metalloproteinase-1 (MMP-1) were 30-40 folds higher in HUVEC than in HMEC-1. The cell types differed also in their sensitivity to exogenous growth factors. The basal proliferation of HUVEC was very low but could be effectively stimulated by supplementation with VEGF or bFGF. HMEC-1 proliferated spontaneously and their proliferation rate was not further augmented by growth factors. Similarly, the spontaneous outgrowth of capillaries was negligible in HUVEC but well-pronounced in HMEC-1. Conclusions: Production of angiogenic agents and sensitivity to exogenous growth factors is cell-type dependent.HUVEC, which do not release VEGF, can be easily stimulated with exogenous factors, whereas HMEC-1, which are able to produce VEGF, do not respond well to the additional stimulation. Our study demonstrates that conclusions resulting from in vitro experiments performed on only one type of endothelial cells can be misleading. (Eur. Surg. 2003; 35:214-218) Vergleich des angiogenetischen Potentials von Endothelzellen aus humanen Nabelschnurvenen und aus humanen Mikrogefäßen Zusammenfassung: Grundlagen: Endothelzellen aus verschiedenen Blutgefäßen unterscheiden sich in Funktion und Phenotyp. Wir verglichen zwei häufig verwendete Endothelzelllinien in Hinblick auf die Produktion von AngiogeneseWachstumsfaktoren, als auch die Sensitivität auf Stimulation durch exogene Wachstumsfaktoren. Methodik: Die Durchführung der Experimente erfolgte mit Endothelzellen aus humanen Nabelschnurvenen (HUVEC) und aus humanen Mikrogefäßen (HMEC-1), welche zuvor in optimalen Bedingungen für 24 bis 48 Stunden inkubiert wurden. In einigen Experimenten wurden die Zellen mit IL-1β (5 ng/ml) stimuliert. Die Proliferation von Zellen wurde durch Behandlung mit VEGF165 oder bFGF (10-30 ng/ml) induziert. Ergebnisse: Die Profile der spontan produzierten Wachstu...

Clinical experience shows that the results after the use of long nerve grafts for reconstruction are sometimes poor. Nevertheless several authors have stressed that the concomitant big defect in the soft tissues necessitating the use of long grafts is the reason for some of the failures. In 22 rabbits the saphenous nerve was used as a nerve graft. Animals were separated into 3 groups with different lengths of the grafts, namely 3 cm (group 1), 5 cm (group 2) and 7 cm (group 3). In the left hindlimb the proximal end of the graft was coapted to the cut motor nerve branch of vastus medialis. In a second stage the distal end of the graft was coapted to the nerve branch of rectus femoris. After a total period of 15 months the maximum tetanic tension in the reinnervated rectus femoris and in the contralateral unoperated muscle was determined. Biopsies of the graft and the motor branch distal to the graft were taken in order to count the number of regenerated myelinated nerve fibers. The average maximum tetanic tension in the rectus femoris muscle reinnervated by the 3 cm long graft was 27.2 N, in group 2 the force was 20.5 N. In group 3 the maximum force was 17.6 N, which meant an average loss of 29% compared to the contralateral unoperated muscle. The mean number of regenerated myelinated fibres distal to the graft in the rectus femoris motor branch was 1683 in group 1 and decreased to 1137 in group 3. The results show that the length of the graft influences the results after nerve grafting to a certain extent, but a combination of other factors like concomitant soft tissue injury and destroyed target organs may also be responsible for some of the poor results after the clinical use of long nerve grafts.

Myogelosis is a common diagnosis in the case of chronic pain conditions, especially in the region of the pectoral girdle musculature, the glutei muscles, and the erector spinae muscle. Although such indurative areas continue to be palpable even on the cadaver, few studies concerning the morphological substrate of these areas have been undertaken. Selected biopsies as well as larger tissue samples were taken from 11 corpses and prepared for histological study. Following staining, the frozen sections were examined morphometrically. A histologically constant, significant morphological alteration was found in the areas of concern. The spaces between the individual muscle fibers of healthy muscle tissue appear relatively wide, the endomysium of the myogelotic area are clearly narrowed. Split fibers, ragged red fibers, Type II fiber atrophy, and fibers with a moth‐eaten appearance have been detected. The morphometry shows considerable increase in thickness of the affected muscle fibers, suggestive of a pathological, local hypertrophy. The changes described may well represent a fixed condition, so that it should not be surprising that myogelosis therapy is difficult and protracted. Clin. Anat. 12:266–271, 1999. © 1999 Wiley‐Liss, Inc.

Transcutaneous electrical stimulation of the quadriceps femoris muscle was applied in 14 paraplegic patients (10 spastic patients with spinal cord lesions and 4 patients with conus-cauda lesions with denervation atrophy). In both the spastic and the denervated group, the vastus lateralis muscle was biopsied and computed tomography (CT) images of the entire upper leg were made both at the onset and termination of the 8-month training period. The stimulation was carried out twice a day for 20 min. The increase in muscle tissue was significant in the CT images. The biopsies showed that the fiber diameter of both fiber types increased during the training period in the spastic group from 47 to 67 microns and in the denervated group from 22 to 38 microns. In both groups, the differences were significant between the first and second biopsies. Both groups showed a marked Type 2 fiber predominance. The histological and CT findings correlated with the clinical improvement of muscle function.