Diagnosis and differentiation of von Willebrand's disease type II

Out of 113 patients with vWD 15 were of type II. The basic test programme included F VIII:C, vWF-Ag, RCF and BT (Ivy). All type II patients had relatively high vWF-Ag and low RCF values. CIEP proved increased anodal migration velocity. IRMA testing of vWF:Ag was showing narrow correlation with RCF. Thrombocyte count was unchanged after DDAVP infusion and RIPA was always diminished. Finally multimeric sizing was done in 6 patients. From the completely diagnosed patients 5 are of type IIA and one seems to have type IIC. Nobody of the 15 had the characteristics of type IIB.     

Amino acid transport in the unfertilized and fertilized mouse egg.

The transport of methionine into unfertilized and fertilized mouse eggs appears to involve active transport mechanisms with similar Vmax, Km, substrate specificity and independence from Na+. An exchange diffusion system with a similar amino acid specificity to the uptake system has also been found in both types of egg. An estimate of 6.5 fmol has been made for the size of the total internal pool of exchangeable amino acids.     

Chromosome-type exchange aberrations are induced by inhibiting repair of UVC-induced DNA lesions in quiescent human lymphocytes

Human lymphocytes in the quiescent stage were UVC-irradiated and then incubated for 90 min in the presence of the DNA-repair inhibitor ara-C. The cells were then cultured and analyzed for chromosome aberrations. A single treatment with UVC or ara-C gives rise to a very low yield of dicentrics, whereas the combined treatment can induce a high frequency of these chromosome-type aberrations. The yield in the combined treatment is approximately proportional to the square of the UVC fluence in the range 1-3 J/m2. In addition, the experiments demonstrate that synergistic effects arise when cells are treated with UVC + ara-C and then exposed to X-rays. The results can be explained on the assumption that the UVC + ara-C treatment induces DNA double-strand breaks which, to the first approximation, are randomly distributed over the chromosomes. These breaks are able to interact with each other as well as with X-ray-induced DNA double-strand breaks to form a chromosome-type exchange aberration.