No evidence for sex-specific effects of the maternal social environment on offspring development in Japanese quail (Coturnix japonica)

The social environment of reproducing females can cause physiological changes, with consequences for reproductive investment and offspring development. These prenatal maternal effects are often found to be sexspecific and may have evolved as adaptations, maximizing fitness of male and female offspring for their future environment. Female hormone levels during reproduction are considered a potential mechanism regulating sex allocation in vertebrates: high maternal androgens have repeatedly been linked to increased investment in sons, whereas high glucocorticoid levels are usually related to increased investment in daughters. However, results are not consistent across studies and therefore still inconclusive. In Japanese quail (Coturnix japonica), we previously found that pair-housed females had higher plasma androgen levels and tended to have higher plasma corticosterone levels than group-housed females. In the current study we investigate whether these differences in maternal social environment and physiology affect offspring sex allocation and physiology. Counter to our expectations, we find no effects of the maternal social environment on offspring sex ratio, sex-specific mortality, growth, circulating androgen or corticosterone levels. Also, maternal corticosterone or androgen levels do not correlate with offspring sex ratio or mortality. The social environment during reproduction therefore does not necessarily modify sex allocation and offspring physiology, even if it causes differences in maternal physiology. We propose that maternal effects of the social environment strongly depend upon the type of social stimuli and the timing of changes in the social environment and hormones with respect to the reproductive cycle and meiosi

How reliable is MRI in diagnosing cartilaginous lesions in patients with first and recurrent lateral patellar dislocations?

<p>Abstract</p> <p>Background</p> <p>Lateral dislocation of the patella (LPD) leads to cartilaginous injuries, which have been reported to be associated with retropatellar complaints and the development of patellofemoral osteoarthritis. Therefore, the purpose of this study was to determine the reliability of MRI for cartilage diagnostics after a first and recurrent LPD.</p> <p>Methods</p> <p>After an average of 4.7 days following an acute LPD, 40 patients (21 with first LPDs and 19 with recurrent LPDs) underwent standardized 1.5 Tesla MRI (sagittal T1-TSE, coronal STIR-TSE, transversal fat-suppressed PD-TSE, sagittal fat-suppressed PD-TSE). MRI grading was compared to arthroscopic assessment of the cartilage.</p> <p>Results</p> <p>Sensitivities and positive predictive values for grade 3 and 4 lesions were markedly higher in the patient group with first LPDs compared to the group with recurrent LPDs. Similarly, intra- and inter-observer agreement yielded higher kappa values in patients with first LPDs compared to those with recurrent LPDs. All grade 4 lesions affecting the subchondral bone (osteochondral defects), such as a fissuring or erosion, were correctly assessed on MRI.</p> <p>Conclusions</p> <p>This study demonstrated a comparatively good diagnostic performance for MRI in the evaluation of first and recurrent LPDs, and we therefore recommend MRI for the cartilage assessment after a LPD.</p

Does osteoporosis reduce the primary tilting stability of cementless acetabular cups?

Background: Cementless hip cups need sufficient primary tilting stability to achieve osseointegration. The aim of the study was to assess differences of the primary implant stability in osteoporotic bone and in bone with normal bone density. To assess the influence of different cup designs, two types of threaded and two types of press-fit cups were tested. Methods: The maximum tilting moment for two different cementless threaded cups and two different cementless press-fit cups was determined in macerated human hip acetabuli with reduced (n=20) and normal bone density (n=20),determined using Q-CT. The tilting moments for each cup were determined five times in the group with reduced bone density and five times in the group with normal bone density, and the respective average values were calculated. Results: The mean maximum extrusion force of the threaded cup Zintra was 5670.5 N (max. tilting moment 141.8 Nm) in bone with normal density and. 5748.3 N (max. tilting moment 143.7 Nm) in osteoporotic bone. For the Hofer Imhof (HI) threaded cup it was 7681.5 N (192.0 Nm) in bone with normal density and 6828.9 N (max. tilting moment 170.7 Nm) in the group with osteoporotic bone. The mean maximum extrusion force of the macro-textured press-fit cup Metallsockel CL was 3824.6 N (max. tilting moment 95.6 Nm) in bone with normal and 2246.2 N (max. tilting moment 56.2 Nm) in osteoporotic bone. For the Monoblock it was 1303.8 N (max. tilting moment 32.6 Nm) in normal and 1317 N (max. tilting moment 32.9 Nm) in osteoporotic bone. There was no significance. A reduction of the maximum tilting moment in osteoporotic bone of the ESKA press-fit cup Metallsockel CL was noticed. Conclusion: Results on macerated bone specimens showed no statistically significant reduction of the maximum tilting moment in specimens with osteoporotic bone density compared to normal bone, neither for threaded nor for the press-fit cups. With the limitation that the results were obtained using macerated bone, we could not detect any restrictions for the clinical indication of the examined cementless cups in osteoporotic bone

Edge and bulk effects in the Terahertz-photoconductivity of an antidot superlattice

We investigate the Terahertz(THz)-response of a square antidot superlattice by means of photoconductivity measurements using a Fourier-transform-spectrometer. We detect, spectrally resolved, the cyclotron resonance and the fundamental magnetoplasmon mode of the periodic superlattice. In the dissipative transport regime both resonances are observed in the photoresponse. In the adiabatic transport regime, at integer filling factor $\nu =2$, only the cyclotron resonance is observed. From this we infer that different mechanisms contribute to converting the absorption of THz-radiation into photoconductivity in the cyclotron and in the magnetoplasmon resonances, respectively.Comment: 15 pages, 4 figures, submitted to Phys. Rev.

Long-term cultivation of colorectal carcinoma cells with anti-cancer drugs induces drug resistance and telomere elongation: an in vitro study

BACKGROUND: The role of telomerase activation in the expression and/or maintenance of drug resistance is not clearly understood. Therefore, we investigated the relationships, among the telomerase activity, telomere length and the expression of multidrug resistance genes in colorectal cancer cell lines cultivated with anti-cancer drugs. METHODS: LoVo and DLD-1 cells were continuously grown in the presence of both CDDP and 5-FU for up to 100 days. Cell proliferation, telomerase activity, telomere length and the expression of multidrug resistance genes were serially monitored as the PDL increased. RESULTS: The expression of multidrug resistance genes tended to increase as the PDL increased. However, an abnormal aneuploid clone was not detected as far as the cells were monitored by a DNA histogram analysis. Tumor cells showing resistance to anti-cancer drugs revealed a higher cell proliferation rate. The telomere length gradually increased with a progressive PDL. The telomerase activity reached a maximum level at 15 PDL in LoVo cells and at 27 PDL in DLD-1 cells. An increase in the mRNA expression of the telomerase components, especially in hTERT and in hTR, was observed at the same PDLs. CONCLUSIONS: These results suggest that a high telomerase activity and an elongation of telomeres both appear to help maintain and/or increase drug resistance in colorectal cancer cells. Cancer cells with long telomeres and a high proliferative activity may thus be able to better survive exposure to anti-cancer drugs. This is presumably due to an increased chromosome stability and a strong expression of both mdr-1 and MRP genes

A Precision Measurement of pp Elastic Scattering Cross Sections at Intermediate Energies

We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range $30 \leq \theta_{c.m.} \leq 90$ deg. Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Comment: 23 pages 29 figure