In a randomized, prospective double blind trial evaluating antibiotic prophylaxis for internal fixation of proximal femur fractures, the prognostic value of preoperative risk parameters, namely triceps skinfold, upper arm circumference, dynamometry, serum albumin, transferrin, prealbumin, lymphocyte count and serum zinc was analyzed. A population at risk of postoperative infection could be defined with serum albumin value and lymphocyte count: a serum albumin of less than 40 g/l correlated with increased local complications and a lymphocyte count under 1400 microliters coincided with increase in systemic infections. No correlation between perioperative transfusion and postoperative infections was found.
In this study we investigated whether expanded goat chondrocytes have the capacity to generate cartilaginous tissues with biochemical and biomechanical properties improving with time in culture. Goat chondrocytes were expanded in monolayer with or without combinations of FGF-2, TGF-beta1, and PDGFbb, and the postexpansion chondrogenic capacity assessed in pellet cultures. Expanded chondrocytes were also cultured for up to 6 weeks in HYAFF-M nonwoven meshes or Polyactive foams, and the resulting cartilaginous tissues were assessed histologically, biochemically, and biomechanically. Supplementation of the expansion medium with FGF-2 increased the proliferation rate of goat chondrocytes and enhanced their postexpansion chondrogenic capacity. FGF-2-expanded chondrocytes seeded in HYAFF-M or Polyactive scaffolds formed cartilaginous tissues with wet weight, glycosaminoglycan, and collagen content, increasing from 2 days to 6 weeks culture (up to respectively 2-, 8-, and 41-fold). Equilibrium and dynamic stiffness measured in HYAFF M-based constructs also increased with time, up to, respectively, 1.3- and 16-fold. This study demonstrates the feasibility to engineer goat cartilaginous tissues at different stages of development by varying culture time, and thus opens the possibility to test the effect of maturation stage of engineered cartilage on the outcome of cartilage repair in orthotopic goat models.
Allopurinol (AP) protects skeletal muscle function against ischaemia-induced injury, but the mechanism is not yet clear. As AP acts as a competitive xanthine oxidase inhibitor, both a reduction of oxygen-derived free radicals and an enhancement of purine resynthesis (salvage pathway) might be involved. We investigated the in vivo kinetics of high-energy phosphates in skeletal muscle after AP pretreatment using 31P-magnetic resonance spectroscopy during 2 h of ischaemia and 3 h of reperfusion in rat hindlimbs. Three animals (group A) were pretreated with a total of 160 mg/kg AP i.p., 3 control animals (group B) received the same amount of 0.9% saline solution. ATP decreased to 18.6 +/- 1.3% of the pre-ischaemic value in group A and to 17.3 +/- 2.8% in group B after 2 h of ischaemia, and rose to only 47.7 +/- 1.5 and 50.5 +/- 1.8%, respectively, after 3 h of reperfusion. Phosphocreatine fell to 7.2 +/- 2.9 and 7.6 +/- 2.2% of pre-ischaemic values after 2 h of ischaemia and rose again to 36.5 +/- 12.9 and 45.4 +/- 20.4% after 3 h of reperfusion. Inorganic phosphate (Pi) increased 5-fold after 2 h of ischaemia, irrespective of the treatment. After 3 h of reperfusion, Pi was still 4 times the pre-ischaemic value. The kinetics of ATP, PCr, and Pi levels were not statistically different between the two groups. These results indicate that the ATP salvage pathway does not play an important role in AP-induced attenuation of ischaemia/reperfusion-induced muscle damage.