Coxsackie A 13 virus in the foci of rheumatism.

Faeces and nasopharyngeal washing were examined in 12 patients and 27 contacts of these patients in family foci (primary foci) of rheumatism and in 37 patients and 32 contacts of these patients in secondary foci of rheumatism (in hospitals). Results of stimultaneous examinations of 127 children of the control groups served as the control. An analysis of the results of the investigation showed the Coxsackie A 13 virus was found considerably more frequently in both the patients (83.3%) and their contacts (148.1%) in the primary foci of rheumatism than outside these foci (11.9--15.3%). The difference is statistically significant. Wide distribution of Coxsackie A 13 virus was also observed in clinical departments in which children were hospitalized at the acute stage of rheumatism. We failed to establish marked differences in the rate of detection of other viruses in the foci of rheumatism in comparison with the control groups.     

Ultrastructure and antigens in differentiation of thymus lymphocytes in human embryogenesis]

Thymus lymphocytes of 7--8-week human embryos have nuclei of irregular form with 1--3 distinct nucleoli characterized by absence of compact chromatin or heterchromatin. The electron-dense cytoplasm of these cells contains polysomes and an insignificant number of mitochondria. No receptors to sheep red blood cells and T antigen are revealed on their surface. In 11--12-week human embryos one can observe a decrease in the size of thymus lymphocytes, appearance of heterochromatin in their nuclei and receptors to sheep red blood cells (79%), and T antigen (60%) on the cell surface. Subsequently the quantity of compact chromatin in thymus lymphoid cells increases, and the cells acquire definitive properties and structure.     

Proportions and function of the limbs of glyptodonts

Vizcaíno, S.F., Blanco, R.E., Bender, J.B. & Milne, N. 2010: Proportions and function of the limbs of glyptodonts. Lethaia, Vol. 44, pp. 93–101. This study examines the limb bone proportions and strength of glyptodonts (Xenarthra, Cingulata). Two methods are used to estimate the body mass and location of the centre of gravity of the articulated specimens. These estimates, together with measurements of the femur and humerus, are used to calculate strength indicators (SI). The other long bones of the limbs are used to calculate limb proportion indices that give an indication of digging ability, speed, and limb dominance in armadillos, the glyptodonts’ living closest relatives. The results show that regardless of how the body mass and centre of gravity are calculated, the majority of the glyptodont’s weight is borne by the hindlimbs. The SI calculations show that femora are sturdy enough to bear these loads. The fact that the femora have higher SI than the humerii indicates that sometimes the hindlimbs are required to bear an even greater proportion of the body weight, possibly when rising to a bipedal posture or pivoting on their hindlimbs to deliver a blow with their armoured tail. The analysis of limb proportions indicates that both the hindlimb and the forelimb have proportions that correlate strongly with body mass. This outcome supports the other results, but also shows that forelimbs must be also involved in manoeuvring the glyptodont body. □Glyptodonts, Mammalia, Xenarthra, limbs, strength indicators.     

Quenched coumarin derivatives as fluorescence lifetime phantoms for NADH and FAD

Two-photon fluorescence lifetime imaging is a versatile laboratory technique in the field of biophotonics and its importance is also growing in the field of in vivo diagnostics for medical purposes. After years of experience in dermatology, endoscopic implementations of the technique are now posing new technical challenges. To develop, test, and compare instrumental solutions for this purpose suitable reference samples have been devised and tested. These reference samples can serve as reliable NADH- and FAD-mimicking optical phantoms for 2-photon fluorescence lifetime imaging, as they can be prepared relatively easily with reproducible and stable characteristics for this quite relevant diagnostic technique. The reference samples (mixtures of coumarin 1 and coumarin 6 in ethanol with suitable amounts of 4-hydroxy-TEMPO) have been tuned to exhibit spectral and temporal fluorescence characteristics very similar to those of NADH and FAD, the two molecules most frequently utilized to characterize cell metabolism.