Do gender, disability, and morbidity affect aging rate in the LLFS? Application of indices of cumulative deficits

We used an approach of cumulative deficits to evaluate the rate of aging in 4954 participants of the Long-Life Family Study (LLFS) recruited in the U.S. (Boston, New York, and Pittsburg) and Denmark. We used an array of 85 health-related deficits covering major health dimensions including depression, cognition, morbidity, physical performance, and disability to construct several deficit indices (DIs) with overlapping and complementary sets of deficits to test robustness of the estimates. Our study shows that the DIs robustly characterize accelerated rates of aging irrespective of specific of deficits. When a wider spectrum of health dimensions is considered these rates are better approximated by quadratic law. Exponential rates are more characteristic for more severe health dimensions. The aging rates are the same for males and females. Individuals who contracted major diseases and those who were free of them exhibited the same aging rates as characterized by the DI constructed using mild deficits. Unlike health, disability can qualitatively alter the aging patterns of the LLFS participants. We report on systemic differences in health among the LLFS centenarians residing in New York and Boston. This study highlights importance of aggregated approaches to better understand systemic mechanisms of health deterioration in long-living individuals.     

Biocompatilibity-related surface characteristics of oxidized NiTi

In the present study, we examined the effect of NiTi oxidation on material surface characteristics related to biocompatibility. Correspondence between electron work function (EWF) and adhesive force predicted by electron theory of adsorption as well as the effect of surface mechanical stress on the adhesive force were studied on the nonoxidized and oxidized at 350, 450, and 600 degrees C NiTi alloy for medical application. The adhesive force generated by the material surface towards the drops of alpha-minimal essential medium (alpha-MEM) was used as a characteristic of NiTi adsorption properties. The study showed that variations in EWF and mechanical stress caused by surface treatment were accompanied by variations in adhesive force. NiTi oxidation at all temperatures used gave rise to decrease in adhesive force and surface stress values in comparison to the nonoxidized state. In contrary, the EWF value revealed increase under the same condition. Variations in surface oxide layer thickness and its phase composition were also followed. The important role of oxide crystallite size in EWF values within the range of crystallite dimensions typical for NiTi surface oxide as an instrument for the fine regulation of NiTi adsorption properties was demonstrated. The comparative oxidation of pure titanium and NiTi showed that the effect of Ni on the EWF value of NiTi surface oxide is negligible.     

Inhibiting and disaggregating effect of gel-filtered Galega officinalis L. herbal extract on platelet aggregation

The in vitro inhibiting and disaggregating effect on platelet aggregation of a gel-fractionated herbal extract from Galega officinalis L. is examined. The obtained Sephadex G-25 filtered fraction was 35-36 times more active than the crude extract. The threshold concentration at which this fraction inhibits platelet aggregation (5-10% inhibition) by 50 microM adenosine 5'-diphosphate (ADP) is 4.5-5 microg per 1 ml platelet-rich plasma (PRP). At a concentration of 35 microg/ml PRP the fraction inhibits 50% of aggregation by ADP and at a concentration of 125 microg/ml PRP fully inhibits the aggregation of PRP by ADP. At a concentration of 40 microg/ml PRP the fraction inhibits initiation of platelet aggregation by 0.18 mg/ml collagen and at 50 microg/ml PRP inhibits the initiation of aggregation by 0.7 units/ml thrombin. The G-25 filtered fraction shows a strong disaggregating effect on aggregated PRP. At a concentration of 65-75 microg/ml PRP, the fraction is able to disaggregate the 50-53% of aggregated platelet-rich plasma by 50 microM ADP, and 25% of aggregated PRP by 0.18 mg/ml collagen.     

Ascorbate as a "redox sensor" and protector against irradiation-induced oxidative stress in 32D CL 3 hematopoietic cells and subclones overexpressing human manganese superoxide dismutase

PURPOSE: To determine whether increased expression of manganese superoxide dismutase (MnSOD) protects cells from irradiation by preventing the production of reactive oxygen species (ROS), a new approach to detecting free radical intermediates using ascorbate as an endogenous spin trap was used. MATERIALS AND METHODS: Cells from the 32D cl 3 hematopoietic cell line or a subclone overexpressing MnSOD (2C6) were incubated with dehydroascorbate for 30 min and irradiated to doses from 0 to 50 Gy. Radical intermediates reacting with spin traps or ascorbate were measured by electron spin resonance spectroscopy. Results were compared to irradiation-induced changes in thiol levels, irradiation survival curves, and accumulation of 8-OHdG as a measurement of DNA oxidative damage. RESULTS: Manganese superoxide dismutase-overexpressing 2C6 cells maintained higher levels of ascorbate (5.4 +/- 0.5 and 2.6 +/- 0.5 nmol/10(6) cells, respectively) and thiols (14.0 +/- 0.1 and 11.1 +/- 0.2 nmol/10(6) cells) compared to 32D cl 3 parent cells. Cells overexpressing MnSOD produced lower levels of ROS than did the parental 32D cl 3 cells, as evidenced by lower expenditure of ascorbate and GSH after irradiation. Increased ascorbate levels protected both 32D cl 3 and 2C6 cells from irradiation killing, as demonstrated by an increased shoulder on survival curves and decreased DNA 8-OHdG accumulation. CONCLUSIONS: Manganese superoxide dismutase overexpression protects 2C6 cells from irradiation damage by scavenging ROS that readily interact with major endogenous antioxidants--ascorbate and GSH--in nontransfected hematopoietic 32D cl 3 cells.     

Effect of exercise performed immediately before a meal of moderate fat content on postprandial lipaemia

The majority of the studies that have found a lowering effect of exercise on postprandial lipaemia have employed exercise 12-18 h before a test meal of exaggerated fat content (over 60 % total energy). The aim of the present study was to investigate whether this effect is manifest when exercise is performed immediately before a test meal of moderate fat content. Eleven healthy young men cycled for 45 min at 62 % maximal heart rate or rested, and, immediately afterwards, consumed a meal of moderate fat content (35 % total energy, 0.65 g/kg body mass) in a random counterbalanced design. Blood samples were drawn before exercise, before the meal, and for 8 h postprandially. No significant differences were observed in plasma triacylglycerol concentrations and areas under the triacylglycerol concentration v. time curves between exercise and rest, although exercise reduced the postprandial lipaemic response by 17 %. Non-esterified fatty acids, glucose, and insulin did not differ significantly between the trials. In conclusion, moderate exercise performed immediately before a meal of a fat content typical to the Western diet had only a modest effect on postprandial lipaemia.     

Heat shock changes the heterogeneity distribution in populations of Caenorhabditis elegans: does it tell us anything about the biological mechanism of stress response?

In this paper we analyze survival data of populations of sterilized nematodes, Caenorhabditis elegans, exposed to heat shocks of different duration at the beginning of their adult lives. There are clear hormesis effects after short exposure to heat and clear debilitation effects after long exposure. Intermediate durations result in a mixture of these two effects. In this latter case, the survival curves for the control and experimental populations intersect. We show that observed effects may be explained by using a model of discrete heterogeneity. According to this model, each population of worms in the experiment is a mixture of subcohorts of frail, normal, and robust individuals; exposure to heat changes the initial proportion of worms in the subcohorts (heterogeneity distribution); and these changes depend on the duration of exposure. In other words, exposure to heat does not influence mortality rates (survival functions) in the subcohorts but does cause individuals to move from one subcohort to another. In a biological interpretation of this finding we hypothesize that, when coping with stress, the organisms of worms use several lines of defense. Switching these lines on and off in response to stress in individual organisms generates the spectrum of observed survival effects at the population level. We discuss possible molecular biological mechanisms of stress response and directions for further research.     

Dose-dependent effect of melatonin on life span and spontaneous tumor incidence in female SHR mice

From the age of 3 months until their natural death, female Swiss-derived SHR mice were given melatonin with their drinking water (2 or 20mg/l) for 5 consecutive days every month. Intact mice served as controls. There were 54 mice in each group. The results of this study show that the treatment of melatonin did not significantly influence food consumption, but its administration at lower doses did decrease the body weight of mice; it slowed down the age-related switching-off of estrous function; it did not influence the frequency of chromosome aberrations in bone marrow cells; it did not influence mean life span; and it increased life span of the last 10% of the survivors in comparison to controls. We also found that treatment with low dose melatonin (2mg/l) significantly decreased spontaneous tumor incidence (by 1,9-fold), mainly mammary carcinomas, in mice whereas higher doses (20mg/l) failed to influence tumor incidence as compared to controls. For this reason, we conclude that the effect of melatonin as a geroprotector is dose-dependent.     

Ultrasound follow-up study of arthroscoped patients with gonitis.

The purpose of the present study was to evaluate by ultrasound methods and carry out a one-year follow-up study of synovial proliferation in the knee joint of patients with rheumatoid arthritis prior to and after arthroscopy and arthroscopic (AS) synovectomy. MATERIAL AND METHODS: 24 patients with a proven rheumatoid arthritis and affected knee joints were recruited for the study. Arthroscopic synovectomy of one of the affected joints was performed in all of them. The synovitis was evaluated clinically and ultrasonographically in 24 knee joints prior to the AS synovectomy and 7 days, and 3, 6 and 12 months after it. RESULTS: Either synovial thickening or villonodular proliferation in the knee joints were the findings in the examined patients using arthrosonography. All patient showed improvement of the disease activity index after the arthroscopic synovectomy and weakening of the baseline ultrasound evidence for synovial thickening and villonodular proliferation (p < 0.001). During the 12-month follow up study two patients were found at ultrasonography to have (without any clinical evidence for that) recurrence of the synovial thickening three months after arthroscopy. Ten patients had synovial thickening or villonodular proliferation recurrence during the 12 months of follow up with clinical evidence of gonitis; one case showed ultrasonographic evidence of hydrops. There was a complete consistency between the ultrasound and arthroscopic protocols with respect to the presence of synovial proliferation and intra-articular effusion. CONCLUSION: Arthosonography is an easy, safe, low-cost, non-invasive modality for diagnosis and follow-up of patients with rheumatoid arthritis prior to and after arthroscopic synovectomy and for assessment of the clinical prognosis in such patients.     

Mandibular fractures in children. A retrospective study

This study reviews the treatment of mandibular fractures in children for the period 1986-1995. The sample included 107 children under 15 years of age, which were studied by age, sex, cause and type of fracture, method of treatment and complications. The children were divided into four groups according to the development of the dentition: 0-5 years, 6-9 years, 10-12 years and 13-15 years. Boys to girls ratio was 3.46:1 and the highest incidence was observed in boys over 13 years of age. Associated injuries were more common in younger children (56%). Most of the fractures were the results of traffic accidents (28.97%), games and sports (25.23%), beating (19.63%) or falls (15.88%). Unilateral fractures were more common (69.16%) than bilateral (30.84%). Intermaxillar fixation for 3 weeks was the method of treatment used in 84.12% of the patients. Complications appeared to be rare.