Objective: To evaluate the nutritional status of vitamin D in urban populations of healthy elderly people living at home, in different regions of Argentina. Design: Cross-sectional study. Subjects: In total, 386 ambulatory subjects over 65 y of age from seven cities (between latitude 261S and 551S) were asked to participate between the end of winter and the beginning of spring. Of these, 369 accepted, 30 were excluded because of medical history or abnormal biochemical determinations. Finally, 339 subjects (226 women and 113 men) (X7s.d.) (71.37 5.2 y) were included. Results: Serum 25OHD levels were lowest in the South (latitude range: 411S-551S): 14.275.6 ng/ml (Po0.0001vs North and Mid regions); highest in the North (261S-271S): 20.777.4 ng/ml (Po0.03 vs Mid, Po0.0001vs South); and intermediate in the Mid region (331S-341S) 17.978.2 ng/ml. Serum mid-molecule PTH (mmPTH) and 25OHD were inversely related: (r ¼ À0.24, Po0.001). A cutoff level of 25OHD at which serum mmPTH levels began to increase was established at 27 ng/ml. A high prevalence (87-52%) of subjects with 25OHD levels in the deficiency-insufficiency range (25OHD levels o20 ng/ml) was detected. Conclusion: This study shows that vitamin D deficiency/insufficiency in the elderly is a worldwide problem. Correction of this deficit would have a positive impact on bone health of elderly people. Sponsorship: Asociació n Argentina de Osteología y Metabolismo Mineral (AAOMM).

No studies had investigated circadian and circannual rhythms of bone biomarkers in whole saliva. We evaluated the salivary daily and seasonal rhythm of carboxy-terminal telopeptide of type I collagen (CTX) and bone alkaline phosphatase (b-ALP). Forty clinical and oral healthy ambulatory pre- and postmenopausal women from two southern Argentine cities: Comodoro Rivadavia (latitude 45º S) and Ushuaia (latitude 54º S) were included in the study. CTX levels were evaluated in serum, urine, and saliva, and b-ALP levels were measured in serum and saliva. In both groups of women, salivary CTX showed a maximum percentage of change early in the morning (80%) and a minimum in the late afternoon (45%), similarly to the pattern observed in urinary samples. No daily rhythm was observed in serum or salivary b-ALP. 25-Hydroxyvitamin D levels decreased in winter vs. summer (p < 0.01) without differences between the two studied groups. Conversely, parathormone reached higher levels in winter (p < 0.05) which induced a slight non-significant increment in salivary CTX and b-ALP levels. The results showed that, as in serum and urinary samples, salivary CTX exhibits daily and a slight seasonal rhythmicity. Whole non-stimulated saliva is a useful tool to detect several oral and systemic diseases because it has important advantages compared to serum and urinary samples. Then, it may also be a promising sample to test changes in bone metabolism contributing to diagnose and to monitor the therapy of several metabolic bone diseases.

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Nifurtimox disposition was investigated using the rat isolated perfused-liver method after administration of 25 micrograms mL-1 nifurtimox, and its disappearance was monitored by analysing the perfusate sample at various times. Biliary excretion was also measured. The drug concentration profile underwent a biexponential decline over the 2-h study period, with a terminal half-life of 62.76 +/- 17.56 min. Nifurtimox is a high clearance compound (15.23 +/- 5.53 mL min-1). The extraction ratio was 0.621 +/- 0.159. Biliary excretion accounted for 0.05% of the dose, the remainder consisting of highly polar metabolites. By 2 h, a minimal fraction of unchanged nifurtimox was recovered from the perfusate. Nifurtimox activity against Trypanosoma cruzi (clone CA-1) during the perfusion was also determined. Epimastigotes isolated from continuous culture were exposed to the samples of perfusate at different perfusion times in a microtitre plate. After an incubation time of 72 h at 27 degrees C, the parasite number in each well was counted under a microscope. From 0 to 75 min after the perfusion, the anti-trypanosomal activity decreased, but an increase in activity was observed at the later times. These findings show that active metabolites are formed during the perfusion.

High‐fat diets can produce deleterious effects on bone metabolism in growing animals. Objective: To investigate in healthy growing rats the effect of high saturated‐fat diets on bone mass and endochondral ossification. Weaning male Wistar rats (n=20) were fed ad libitum one of the 2 diets, for 4 wks: control (C; fat=7% w/w) (AIN‐93G) or a high‐fat diet containing 20% w/w of beef‐tallow (BT). Then rats were sacrificed. Total skeleton bone mineral density (BMD) and bone mineral content (BMC) were evaluated by DXA (Lunar DPX‐L).The following histomorphometric parameters were evaluated: Bone volume (BV/TV)(%) and cartilage growth plate thickness (CGP.Th).Statistics: Student's t test & Pearson's correlations coefficients were calculated. Results (as mean±SD): BMD(mg/cm2), C=245±13 vs BT=244±13 (p>0.05); BMC(mg), C=1085±319 vs BT=689± 224; (BV/TV)(%), C=45±5 vs BT=38±3 (p<0.03); total GPC.Th(mm), C=0.44±0.04 vs BT=0.43±0.03 (p>0.05); proliferative zone GPC.Th(mm), C=0.21±0.01 vs BT=0.18± 0.01 (p>0.001).The correlation between BMC vs proliferative zone CGP.Th was ‐0.881 (p<0.05).ConclusionHigh saturated‐fat diets lead to a decreased in BMC associated with a significant increased in CGP.Th as well as a reduction in BV/TV. Based on these findings, we suggest that high saturated‐fat diets acts as a dependent risk factor for bone modeling interfering the acquired of bone mass. Awarded by UBACyT O 008 ‐ O015.