Aging bone in men and women: beyond changes in bone mineral density

Using peripheral quantitative computed tomography (pQCT) we assessed trabecular and cortical bone density, mass and geometric distribution at the tibia level in 512 men and 693 women, age range 20–102 years, randomly selected from the population living in the Chianti area, Tuscany, Italy. Total, trabecular and cortical bone density decreased linearly with age (p<0.0001 in both sexes), and the slope of age-associated decline was steeper in women than in men. In men, the cortical bone area was similar in different age groups, while in women older than 60 years it was significantly smaller by approximately 1% per year. The total cross-sectional area of the bone became progressively wider with age, but the magnitude of the age-associated increment was significantly higher in men than in women (p<0.001). The minimum moment of inertia, an index of mechanical resistance to bending, remained stable with age in men, while it was significantly lower in older compared with younger women (0.5% per year). The increase in bone cross-sectional area in aging men may contribute to the maintenance of adequate bone mechanical competence in the face of declining bone density. In women this compensatory mechanism appears to be less efficient and, accordingly, the bone mechanical competence declines with age. The geometric adaptation of increasing cross-sectional bone size is an important component in the assessment of bone mechanical resistance which is completely overlooked, and potentially misinterpreted, by traditional planar densitometry.     

Theory of mind deficits in children with fragile X syndrome

Background Given the consistent findings of theory of mind deficits in children with autism, it would be extremely beneficial to examine the profile of theory of mind abilities in other clinical groups such as fragile X syndrome (FXS) and Down syndrome (DS). Aim The aim of the present study was to assess whether boys with FXS are impaired in simple social situations that require them to understand their own and others’ mental states – in essence: do they have a ‘theory of mind’? Method Well-standardized tasks of theory of mind, the location change false belief task and the appearance–reality tasks were employed to examine whether any impairment might be specific to the FXS or part of a more generalized developmental deficit. Results The results suggest that children with FXS do have impairment in theory of mind that is comparable to the deficit reported in other groups with learning disabilities such as DS. However, closer inspection of the impairment between these groups revealed qualitative differences in error types (realist vs. phenomenist), suggestive of atypical development that goes beyond general cognitive delay. Conclusion The findings are discussed in terms of the teasing apart of different components of social cognition in order to identify syndrome-specific deficiencies and proficiencies.     

Identification of kinetochore-containing (CREST+) micronuclei in mouse bone marrow erythrocytes.

A methodology for the characterization of kinetochore-containing (CREST+) micronuclei (MN), based on the use of antikinetochore antibodies (derived from CREST patients) and indirect immunofluorescence, was applied to mouse bone marrow erythrocytes. The proposed protocol allows us to obtain fluorescent signals of good quality and highly reproducible data. The clastogenic agent mitomycin C (MMC; 1 mg/kg body wt) and the two aneugenic compounds chloral hydrate (CH; 200 mg/kg body wt) and colchicine (COL; 1 mg/kg body wt) were used to verify the sensitivity of this approach to chemicals with different mechanisms of action. These compounds were tested at a 20 h time interval from treatment and all of them were able to significantly increase (P less than 0.001) the frequency of MN in polychromatic erythrocytes. Of the MN observed in preparations from control animals, 45% were CREST+ and this percentage increased significantly (P less than 0.001) after treatment with CH or COL. On the contrary, only 22% CREST+ MN were found after treatment with MMC (statistical comparison with the control value: P less than 0.001). The CREST characterization of MN induced in vivo in mouse bone marrow allows us to infer the origin of MN formation, thus contributing to the identification of aneugenic agents.     

Retinoic acid is enriched in Hensen''s node and is developmentally regulated in the early chicken embryo.

Retinoic acid (RA) has been considered as a potential morphogen in the chicken limb and has also been suggested to be involved in early embryonic development. On the basis of biological activity, previous reports suggest that Hensen's node, the anatomical equivalent in the chicken of the Spemann's organizer, may contain RA. Here, by using a molecular assay system, we demonstrate that Hensen's node contains retinoids in a concentration approximately 20 times more than that in the neighboring tissues. Furthermore, stage 6 Hensen's node contains approximately 3 times more retinoid than that of stage 4 embryos. These endogenous retinoids may establish a concentration gradient from Hensen's node to adjacent tissues and play a role in establishing the primary embryonic axis in the vertebrate. The results also suggest that the retinoid concentration in Hensen's node is developmentally regulated.     

Quality of data reported to a smaller-hospital pilot surveillance program.

This data quality study assessed the accuracy of data collected as part of a pilot smaller-hospital surveillance program for methicillin-resistant Staphylococcus aureus (MRSA) infection and bloodstream infection (BSI). For reported MRSA infection, estimated values were as follows: sensitivity, 40%; specificity, 99.9%; and positive predictive value, 33.3%. For reported BSI, estimated values were as follows: sensitivity, 42.9%; specificity, 99.8%; and positive predictive value, 37.5%.     

Fludarabine in patients with advanced and/or resistant B-chronic lymphocytic leukemia

Abstract: In this study, we evaluated the efficacy of fludarabine (FLU), an adenine nucleoside analogue, in 35 previously treated patients with advanced and progressed B-cell chronic lymphocytic leukemia (B-CLL) and in 6 at diagnosis. All patients were treated at a dose of 25 mg/m² per day for 5 consecutive days (mean number of courses was 5, with a range from 4 to 6). The majority of patients experienced a beneficial effect on hematological parameters. In particular, a remarkable reduction of lymphocyte count together with an increase of neutrophils and platelets was observed. The overall response rate was 42% with 1 complete response and 16 partial responses. Ten patients achieved minor responses and the remaining 14 showed no benefit from treatment. An increased response rate was achieved in 6 untreated patients who showed an overall response rate of 67% (4/6). The major complications observed were neutropenia (66%) and febrile episodes (44%) that were generally infection-related and were fatal in 3 cases. Because we were dealing with patients whose disease was advanced and/or resistant to treatment, the overall results may be considered encouraging with acceptable toxic reactions not superior to those frequently observed with polychemotherapy.