Postnatal ossification sequences in Acrocephalus scirpaceus and Chroicocephalus ridibundus (Aves: Neognathae): The precocial–altricial spectrum and evolution of compound bones in birds

Although the development of the avian skeleton has attracted considerable attention, most of the studies have been concentrated on the embryonic period, while studies on the postnatal period are rare. We studied the postnatal development of the skeleton in two phylogenetically distant birds, an altricial passerine Acrocephalus scirpaceus and a semiprecocial charadriiform Chroicocephalus ridibundus. The neonates of the former, despite being altricial, have well-ossified skeleton—the degree of development approaches that of the semiprecocial gull. However, after hatching the limb bones (particularly those of the hind limb) ossify earlier in the gull which is probably related to faster acquisition of locomotor abilities. We have observed that, in contrast to previous reports from neognathous birds, in the ankle of the gull, the ascending process fuses with the astragalus rather than with the calcaneum. This type of development is present in palaeognaths and nonavian dinosaurs but has not yet been reported in neognaths. This indicates a greater diversity within Neognathae and suggests a more complex scenario for the evolution of the avian ankle. However, data from a greater number of species are needed to establish the developmental sequence ancestral for neognathous birds. Furthermore, the sequence of bone fusions in the wrist of Acrocephalus is similar to the fossil-documented evolutionary sequence observed in the phylogeny of early birds, with the semilunate carpal and major metacarpal fusing first, followed by the alular metacarpal fusing with the major metacarpal and then the major and minor metacarpal fusing proximally. These data underscore the importance of developmental studies for reconstructing the evolutionary history.     

Predictors of Coronary and Carotid Atherosclerosis in Patients with Severe Degenerative Aortic Stenosis

Background. Patients with degenerative aortic stenosis (AS) exhibit elevated prevalence of coronary artery disease (CAD) and internal carotid artery stenosis (ICAS). Our aim was to investigate prevalence of significant CAD and ICAS in relation to demographic and cardiovascular risk profile among patients with severe degenerative AS.Methods. We studied 145 consecutive patients (77 men and 68 women) aged 49-91 years (median, 76) with severe degenerative AS who underwent coronary angiography and carotid ultrasonography in our tertiary care center. The patients were divided into two groups according to the presence of either significant CAD (n=86) or ICAS (n=22).Results. The prevalence of significant CAD or ICAS was higher with increasing number of traditional risk factors (hypertension, hypercholesterolemia, diabetes, smoking habit) and decreasing renal function. We found interactions between age and gender in terms of CAD (p=0.01) and ICAS (p=0.06), which was confirmed by multivariate approach. With the reference to men with a below-median age, the prevalence of CAD or ICAS increased in men aged >76 years (89% vs. 55% and 28% vs. 14%, respectively), whereas the respective percentages were lower in older vs. younger women (48% vs. 54% and 7% vs. 17%).Conclusions. In severe degenerative AS gender modulates the association of age with coronary and carotid atherosclerosis with its lower prevalence in women aged >76 years compared to their younger counterparts. This may result from a hypothetical “survival bias”, i.e., an excessive risk of death in very elderly women with severe AS and coexisting relevant coronary or carotid atherosclerosis.     

Cambridge Neuropsychological Test Automated Battery in assessment of cognitive parameters in patients with systemic lupus erythematosus in relation to autoantibody profile

Objectives

To relate the cognitive parameters of systemic lupus erythematosus (SLE) patients in remission to their profile of autoantibodies.

Material and methods

The study included 32 patients with SLE in remission, with mild disease activity as indicated by SELENA-SLEDAI < 6. For neuropsychological assessment, the Cambridge Neuropsychological Test Automated Battery (CANTAB) was applied, using motor screening (MOT), big little circle (BLC), paired associated learning (PAL), stockings of Cambridge (SOC), and graded naming tests (GNT). Detection of autoantibodies against dsDNA, nucleosome (aNuc), Sm, and anticardiolipin (aCL: IgG and IgM) was performed with immunoassays.

Results

The SLE patients demonstrated standard scores below norms, matched according to age and gender, in the following tests: GNT (–0.87 ±0.85), SOC PSMM (–0.47 ±0.97), PAL (–1.88 ±3.58), and BLC (–0.31 ±1.90). GNT scores under –0.5 were found significantly more frequently in SLE patients, seen in roughly 66% of test subjects. Values for PAL and mean subsequent thinking time of stockings of Cambridge (SOC MSTT) were found to be lower than –0.5 in approximately half of the patients. Mean error of motor screening (MOT ME) was found to negatively correlate with mean latency of motor screening (MOT ML) (r = –0.55). PAL significantly correlated with SOC MSTT (r = 0.38) and with GNT (r = 0.36). Anti-dsDNA antibody level correlated negatively with MOT ME (r = –0.46). Anti-Nuc antibodies correlated with MOT ML (r = 0.41) but negatively correlated with MOT ME (r = –0.58). The levels of anti-Sm, anti-CL IgM and IgG did not correlate significantly with the outcomes of CANTAB. The age of the patients correlated negatively with MOT ME (r = –0.36), positively with BLC (r = 0.53) and negatively with SOC MSTT (r = –0.43). The level of anti-Nuc antibodies correlated with anti-dsDNA level (r = 0.62) and of anti-CL IgM with anti-Sm (r = 0.39) and anti-CL IgG (r = 0.87).

Conclusions

CANTAB reveals a decrease in selected cognitive functions in patients with SLE. ACL IgG and anti-dsDNA antibodies indicated SLE patients prone to develop a decrease in cognitive functions.     

Torsion dynamics in the evolution from acute to chronic mitral regurgitation

BACKGROUND AND AIM OF STUDY: Left ventricular (LV) torsion reduces transmural fiber strain gradients during systole, and torsional recoil in early diastole is thought to assist LV filling. To test the hypothesis that deterioration of torsional dynamics accompanied LV dysfunction during the evolution of mitral regurgitation (MR), torsion was measured during the progression from acute to chronic MR in a canine model. METHODS: Seven dogs underwent cardiopulmonary bypass for LV marker placement and creation of MR by disrupting the posterior leaflet. After 7-10 days, three-dimensional marker coordinates were measured with biplane videofluoroscopy to study LV geometry, size and function, plus maximal torsional deformation, time of maximal torsion relative to end-ejection, and early diastolic torsional recoil during the first 5% of filling. After three months, the animals were re-studied. RESULTS: Progression from acute to chronic MR was associated with a significant decrease in maximum LV dP/dt (1,574+/-213 to 1,300+/-252 mmHg/s, p <0.01) and an increase in LVEDP from 11+/-5 to 15+/-5 mmHg (p <0.01). After three months of MR, maximum torsional deformation decreased from 6.3+/-1.9 to 4.7+/-2.0 degrees (p = 0.04), as did early diastolic recoil (-3.8+/-1.0 to -1.5+/-1.7 degrees, p = 0.03). CONCLUSION: Progression from acute to chronic MR is accompanied by decreased and delayed systolic LV torsional deformation and a decline in early diastolic recoil, which may contribute to LV dysfunction by increasing transmural strain gradients during systole and impairing diastolic filling. As torsional deformation and recoil can be measured non-invasively with MRI in humans, such measurements might prove useful in patients with progressive MR as an adjunct to determine the timing of surgical repair.