Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects.

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non-union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty-four New-Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed.

The effect of bone marrow concentrate and hyperbaric oxygen therapy on bone repair.

Neoangiogenesis represents an essential part of bone regeneration. Therefore the improvement of neovascularization is the subject of various research approaches. In addition autologous mesenchymal stem cells concentrate in combination with bone substitute materials have been shown to support bone regeneration. In a rabbit model we examined the proposed synergistic effect of hyperbaric oxygen therapy (HBOT) and bone marrow concentrate (BMC) with porous calcium phosphate granules (CPG) on neoangiogenesis and osseous consolidation of a critical- size defect. The animal groups treated with HBOT showed a significantly higher microvessel density (MVD) by immunhistochemistry. Furthermore HBOT groups presented a significantly larger amount of new bone formation histomorphometrically as well as radiologically. We conclude that the increase in perfusion as a result of increased angiogenesis may play a key role in the effects of HBOT and consequently promotes bone healing.

Iodine deficiency in pregnant women in Austria.

BACKGROUND/OBJECTIVES: In Austria, iodine deficiency has been considered to be eliminated owing to table salt fortification with iodine, but whether this also applies to pregnant women is unclear. Even mild iodine deficiency during gestation may lead to neurocognitive sequelae in the offspring. SUBJECTS/METHODS: This is a cross-sectional investigation of urinary iodine excretion in 246 pregnant women (first trimester n=2, second trimester n=53, third trimester n=191, gestational diabetes mellitus n=115, no gestational diabetes mellitus n=131). The iodine content of morning spot urine samples was determined using inductively coupled plasma mass spectrometry. RESULTS: Pregnant women in the Vienna area had a median urinary iodine concentration (UIC) of 87 µg/l. Only 13.8% of the cohort were in the recommended range of 150-249 µg/l, whereas 21.5% had a UIC of 0-49 µg/l, 40.2% had a UIC of 50-99 µg/l and 19.5% had a UIC of 100-149 µg/l. In all, 4.9% had a UIC over 250 µg/l. A total of 137 women of foreign origin had a significantly higher iodine excretion compared with Austrian-born women. Maternal or gestational age had no influence on UIC. Although 79 women on iodine supplementation had a significantly higher iodine concentration compared with women without iodine supplementation (97.3 vs 80.1 µg/l, P=0,006), their UIC was below the recommended range, indicating that doses of 100-150 µg per day are not sufficient to normalize iodine excretion. Sodium and iodine concentrations in the urine were tightly correlated (R=0.539, n=61), suggesting that low intake of iodized salt might contribute to insufficient iodine supply. CONCLUSIONS: This study shows that pregnant women in the Vienna area have a potentially clinically significant iodine deficiency and that currently recommended doses of iodine supplementation may not be sufficient.

Hyperthermic isolated limb perfusion with cis-diamminedichloro-platinum. II. An experimental study in dogs with a balloon-occlusion technique for repeated high-dose treatment.

Isolated organ perfusion is attractive for regional high-dose chemotherapy because of its advantage to reduce whole body toxicity. Intraoperative hyperthermic isolated perfusion procedures involving a heart-lung machine have been developed, but repeated treatments carry a high risk of vessel and tissue damage. Therefore, a study of isolated hyperthermic limb perfusion in four dogs was conducted using a balloon-occlusion technique including a hyperthermia unit, two low-flow rotary pumps, a bubble oxygenator, and two polyurethane balloon catheters. After 15 min infusion of cisplatinum the concentrations of serum platinum (Pt) in the isolated limb and in the whole body were measured by atomic absorption spectroscopy. Regional exposure to Pt was more than 10-fold higher than systemic exposure. After 60 min isolated limb perfusion, the area under the curve (AUC) of Pt concentrations in the isolated limb showed values between 767.4 and 1055.6 micrograms/l x 60 min, whereas in the whole body values between 59.8 and 75.9 micrograms/l x 60 min were obtained. Repeated isolated limb perfusions with the balloon-occlusion technique were performed in three dogs without systemic side effects. This model of regional chemotherapy may be useful for preoperative chemotherapy in malignant tumors of the limbs.