Periodontal disease: modulation of the inflammatory cascade by dietary n-3 polyunsaturated fatty acids

Periodontal disease, including gingivitis and periodontitis, is caused by the interaction between pathogenic bacteria and the host immune system. The ensuing oxidative stress and inflammatory cascade result in the destruction of gingival tissue, alveolar bone and periodontal ligament. This article reviews the underlying mechanisms and host-bacteria interactions responsible for periodontal disease and evidence that nutritional supplementation with fish oil may provide a protective effect. Historical investigations of diet and disease have highlighted an inverse relationship between ingestion of fish oil, which is high in n-3 polyunsaturated fatty acids, and the incidence of typical inflammatory diseases such as arthritis and coronary heart disease. Ingestion of n-3 polyunsaturated fatty acids, such as docosahexaenoic acid and eicosapentaenoic acid, results in their incorporation into membrane phospholipids, which can alter eicosanoid production after stimulation during the immune response. These eicosanoids promote a reduction in chronic inflammation, which has led to the proposal that fish oil is a possible modulator of inflammation and may reduce the severity of periodontal diseases. Tentative animal and human studies have provided an indication of this effect. Further human investigation is needed to establish the protective effects of fish oil in relation to periodontal disease

Proteinuria in aging rats due to low-protein diet during mid-gestation

Nephrogenesis in the rat starts mid-gestation and continues into lactation. Maternal low protein (LP) intake leads to renal injury in rats and associates with mild renal injury in humans. We hypothesized that LP during early nephrogenesis or throughout gestation would induce more renal injury in rat offspring than when LP was only present before nephrogenesis. Pregnant rats were fed LP diet (9% casein) at early gestation (LPE, day 0-7), mid (LPM, day 8-14), late (LPL, day 15-22) or throughout gestation (LPA, day 0-22) and compared to controls on 18% casein diet. Offspring were studied at 18 months. Renal injury was assessed by 24 h proteinuria, plasma urea, antioxidant enzyme activities, and apoptosis (Bax/Bcl2). Proteinuria was higher in LPM males and LPE and LPM females. In LPM males glutathione peroxidase activity was lower, while in LPE males catalase activity was higher. Antioxidants were not much affected in females. Bax expression was higher in LPM males and females, while Bcl2 expression was higher in LPA females. Thus even before nephrogenesis (day 0-7), LP impacted on renal integrity in adult life, while LP during a later phase (day 15-22) or throughout gestation had less effect. In summary, for aging rat kidney LP poses the greatest threat when restricted to early nephrogenesis

The reliability of running performance in a 5 km time trial on a non-motorized treadmill

The purpose of the study was to establish the reliability of performance and physiological responses during a self-paced 5 km running time trial on a non-motorized treadmill. 17 male runners (age: 32±13 years, height: 177±7 cm, body mass: 71±9 kg, sum of 7 skinfolds: 55±21 mm) performed familiarization then 2 separate maximal 5 km running time trials on a non-motorized treadmill. Physiological responses measured included heart rate, oxygen uptake, expired air volume, blood lactate concentration, tissue saturation index and integrated electromyography. Running time (1 522±163 s vs. 1 519±162 s for trials 1 and 2, respectively) demonstrated a low CV of 1.2% and high ICC of 0.99. All physiological variables had CVs of less than 4% and ICCs of \u3e0.92, with the exception of blood lactate concentration (7.0±2 mmol·L−1 vs. 6.5±1.5 mmol·L−1 for trials 1 and 2, respectively; CV: 12%, ICC: 0.83) and the electromyography measures (CV: 8–27%, ICC: 0.71–0.91). The data demonstrate that performance time in a 5 km running time trial on a non-motorized treadmill is a highly reliable test. Most physiological responses measured across the 5 km run also demonstrated good reliability