Polymorphous low-grade adenocarcinoma of the parotid salivary gland

Polymorphous low-grade adenocarcinoma is an unusual tumor that has been described as occurring in the minor salivary glands, particularly of the palate. To our knowledge, there is only one previous report that has documented the occurrence of this type of lesion in the major salivary glands. We describe an elderly patient with polymorphous low-grade adenocarcinoma arising in the parotid gland that was originally diagnosed as carcinoma ex pleomorphic adenoma.     

CTLA4 mediates antigen-specific apoptosis of human T cells

The regulation of T cell-mediated immune responses requires a balance between amplification and generation of effector function and subsequent selective termination by clonal deletion. Although apoptosis of previously activated T cells can be induced by signaling of the tumor necrosis factor receptor family, these molecules do not appear to regulate T-cell clonal deletion in an antigen-specific fashion. We demonstrate that cross-linking of the inducible T-cell surface molecule CTLA4 can mediate apoptosis of previously activated human T lymphocytes. This function appears to be antigen-restricted, since a concomitant signal T-cell receptor signal is required. Regulation of this pathway may provide a novel therapeutic strategy to delete antigen-specific activated T cells.     

The morphological mechanism of the development of myosatellitocytes from the structural elements of the muscle fiber during increased functional activity of the skeletal muscles

Under increased muscular activity in some muscular fibers disintegration areas of myofibrillar apparatus has been revealed. Migration of myonuclei into these microregions starts the mechanism of their segregation due to plasmolemma produced from the reticulum sarcoplasmaticum and triad systems surface. After plasmolemma production in "sarcocytes" intensive development and differentiation of organellae occur. As a result of differentiation "sarcocytes" transform in to myosatellitocytes of type-2 and migrate under lamina externa muscular fibers. So, a hypothesis about formation of myogenic tissue's cellular phase from the myosymplastic one has been confirmed.     

Stability of the polyribosomes of Blakeslea trispora Thaxter during normal translation, its stimulation and inhibition

beta-Ionone is found to stimulate considerably carotinoids synthesis in Blakeslea trispora. The stabilization of carotene-synthesizing ability of B. trispora in the presence of beta-ionine under prolonged incubation time is observed. Stabilization of polyribosomes in the presence of beta-ionine is observed when studying polyribosome content in B. trispora. A hypothesis is expressed on the existence of biochemical "receptors" as a linkage between synthesized protein and destroying mRNA.     

Determination of fibrin and fibrinogen split products by their anticoagulant activity

A new diagnostic method to determine fibrinogen and fibrin splitting products is based on the fact that high-molecular fragments acting as specific inhibitors of fibrin self-assembly compose these products. Fibrinogen and fibrin splitting products are detected and determined quantitatively by prolongation of coagulation time in the test with the standard monomeric fibrin. The number of units of anticoagulating activity in the studied urine are the results of the determinations. Sensitivity of the method if necessary may be increased by adding of a certain amount of the fibrinogen and fibrin splitting products to the test that makes a favourable background for the action of the products. The method is rather sensitive, reliable and simple. It may be used in ordinary clinical laboratories. The method proved to be quite satisfactory when testing renal diseases at the clinic. It is of great significance for early detection of the transplanted kidney rejection. The new method is compared with the known immunological method which consist in determination of the inhibitory effect of the fibrinogen and fibrin splitting products on agglutination of erythrocytes of specific antibodies; the erythrocytes being subjected to "tanning" and "loading" with fibrinogen. A satisfactory correlation is found between the results of two methods.     

The Bi2O3-SrO phase diagram

The phase relations in the Bi₂O₃-SrO system have been examined in air at temperatures above 740 °C. Intermediate phases were found to agree with previous work, but the homogeneity ranges and high-temperature phase relationships were in some cases at variance. A modified phase diagram is proposed.