George I. Malinin

Cytotoxic effect of dimethylsulfoxide on the ultrastructure of cultured Rhesus kidney cells

Abstract Cultured Rhesus kidney cells were incubated in the 7.5 and 15% solutions at 4 and 25 ° C and for periods ranging from 10 to 60 min. The ultrastructural alterations, while varying from cell to cell, were evident even following the 10-min incubation interval. The most frequent and least severe structural changes included lipid accumulation, increased number of lysosomes, dilation and degranulation of rough surfaced endoplasmic reticulum, as well as the swelling of mitochondria and damage to mitochondrial membranes. The more severe instances of cellular lesions were represented by the extensive damage to cell membranes, karyorrhexis, total obliteration of the internal structure of mitochondria, and areas of complete loss of hyaloplasm. The extent and frequency of cellular lesions appeared to be determined primarily by the concentration of DMSO with the temperature and duration of incubation being important ancillary determinants.

Induction of erythroid differentiation in friend murine erythroleukemic cells by inorganic selenium compounds

Abstract Inorganic selenium compounds are shown to be inducers of hemoglobin synthesis in malignant murine erythroleukemia (MEL) cells. SeO2 can induce hemoglobin synthesis at 1 20 the concentration of butyric acid and 1 5000 the concentration of dimethylsulfoxide (DMSO), two potent inducers of erythroid differentiation in MEL cells. SeO2 and H2SeO3 showed an equivalent capacity to stimulate hemoglobin synthesis in three different MEL cell lines. The incorporation of 3H-glycine into hemoglobin was demonstrated in lysates of SeO2-induced MEL cells.

A Review of DNA Flow Cytometric Preparatory and Analytical Methods

The detection of cell surface antigens is the most familiar application of flow cytometry in clinical immunology. Rapid advances in immunocytochemical applications of monoclonal antibodies, which may now be regarded as “true” reagents in the clinical laboratory, have made possible the immunological characterization of various tumors (1–3) and the classification of cells of the immune system (4–6). This extensive immunological characterization was virtually unattainable a few years earlier.

Microscopic and Histochemical Manifestationsof Hyaline Cartilage Dynamics

Structure and function of hyaline cartilages has been the focus of many correlative studies for over a hundred years. Much of what is known regarding dynamics and function of cartilage constituents has been derived or inferred from biochemical and electron microscopic investigations. Here we show that in conjunction with ultrastructural, and high-magnification transmission light and polarization microscopy, the well-developed histochemical methods are indispensable for the analysis of cartilage dynamics. Microscopically demonstrable aspects of cartilage dynamics include, but are not limited to, formation of the intracellular liquid crystals, phase transitions of the extracellular matrix and tubular connections between chondrocytes. The role of the interchondrocytic liquid crystals is considered in terms of the tensegrity hypothesis and non-apoptotic cell death. Phase transitions of the extracellular matrix are discussed in terms of self-alignment of chondrons, matrix guidance pathways and cartilage growth in the absence of mitosis. The possible role of nonenzymatic glycation reactions in cartilage dynamics is also reviewed.

Turnover of phospholipids in HUT 102 lymphoblasts and chromatographic characterization of purified lecithins after their exposure to long-wave UV light, psoralen, and UV light and psoralen

The turnover of 32P-labeled phospholipids in HUT 102 lymphoblasts was determined after a 2 h interaction of lymphoblasts with 8-methoxypsoralen (8-MOP) (15 micrograms ml-1), longwave UV light (UVA) irradiation and PUVA (8-MOP and UVA). In parallel experiments, micellar suspensions of lyso-phosphatidylcholine (PtdC), dipalmitoyl-PtdC and dilinoleoyl-PtdC, treated in a similar manner, served for the correlative assessments of cellular lipid changes. The dark reaction, UVA irradiation and PUVA all depressed total phospholipid levels in HUT 102 cells, although only PUVA induced a statistically significant decline. Thin layer chromatography (TLC) analysis revealed that neither UVA nor 8-MOP alone triggered any significant changes in the cellular content of phosphatidylinositol (PtdI), phosphatidylinositol 4-monophosphate (PtdIP) and phosphatidylinositol 4,5-bisphosphate (PtdIP2), whereas the lyso-PtdC and PtdI content of lymphoblasts showed a two-fold increase after PUVA. The TLC analysis of lyso-PtdC and micelles of dipalmitoyl-PtdC did not reveal any detectable changes after the dark reaction with 8-MOP, UVA irradiation and PUVA. In contrast, the derivatives of dark and UVA mediated reactions of 8-MOP with dilinoleoyl-PtdC were detected by TLC. These results suggest that the formation of 8-MOP derivatives of cellular phospholipids effected by PUVA, modulates the turnover of phosphoinositides and the rate of cellular proliferation.

Periodic acid-induced blastogenesis of lymphocytes is independent of phosphoinositide turnover.

The blastogenic transformation of lymphocytes by periodic acid was investigated to determine if blastogenesis induced by this mitogen was preceded by phosphoinositide turnover as previously shown for the lectins. Although periodate oxidation stimulated nucleic acid synthesis and interleukin-2 production, no changes in phosphoinositide turnover could be detected when compared to control lymphocyte cultures. These data indicate that increased phosphoinositide turnover is not an absolute prerequisite for lymphocyte proliferation.

The interaction of bisulfite and its free radical analog-nitroxyldisulfonate with periodic acid-oxidized lymphocytes and their effect on blastogenesis

Nitroxyldisulfonate [Fremys salt; (KSO3)2NO.] and bisulfite (NaHSO3) have abolished periodic acid (H5IO6)-induced blastogenesis of human peripheral blood lymphocytes (HPBL), but only inhibited the blastogenic response of H5IO6-oxidized rat and mouse lymphocytes, as determined by the rates of nucleic acids synthesis, BrdUrd incorporation and by cell numbers in S + G2 + M phases of the cell cycle. The viability of the intact human, rat and mouse lymphocytes remained essentially unimpaired by 30 min pulses of 1 mM Fremys salt or bisulfite. The marked inhibition of periodic acid-induced blastogenesis, exerted by Fremys salt and by bisulfite, was attributed to the effect of the corresponding carbonyl addition derivatives formed in situ of the oxidized cell membranes. Consequently, it is concluded that Fremys salt like bisulfite possibly forms addition derivatives with membrane carbonyls of viable target cells.

Production and partial characterization of interleukin 2 induced by periodic acid oxidation of lymphocyte membranes

Murine splenocytes, when stimulated to undergo blastogenesis by H5IO6 oxidation, produced a lymphokine with a spectrum of properties identical to that generally ascribed to IL-2 released by lectin-stimulated cells. These included the sustained propagation of IL-2-dependent CT6 cells, as well as identical thermal and enzymatic stabilities. Cell membrane carbonyls generated in situ by the oxidation of cell membranes served as triggers for subsequent IL-2 production by the activated cells. Reduction of membrane carbonyls by NaBH4, and their addition reaction with NaHSO3 and NH2OH abrogated cell activation and inhibited, but did not abolish, IL-2 production. None of the specific carbonyl reagents, e.g., NaBH4, NaHSO3, and NH2OH, have by themselves induced blastogenic transformation, although they did elicit IL-2 production. It is therefore concluded that cell membrane carbonyls serve as triggers for IL-2 production by H5IO6-transformed cells, although an increased rate of DNA synthesis per se is not an indispensable precondition for IL-2 synthesis.

Effect of mitogens on the cell cycle progression and the quantification of T-lymphocyte surface markers in acquired immune deficiency syndrome.

The cell cycle progression and viability of stimulated and intact lymphocytes from 20 subjects with acquired immune deficiency syndrome (AIDS) was determined by flow cytometry. As compared to controls, 62% less AIDS lymphocytes, cultured for 72 hr in the presence of lectins (Con‐A, PHA, PWM), had entered the proliferative phases of the cell cycle, while the respective value for periodic‐acid (H5lO6)‐stimulated cells was 34%. The helper‐suppressor ratios and natural kill cell percentages of the unstimulated and PHA‐activated AIDS lymphocytes increased approximately 3‐fold after 72 hr in culture. The natural killer (NK) cell fraction of the PHA‐stimulated and unstimulated AIDS cultures comprised approximately 20% as compared to 10% in controls. However, no changes in the percentages of T‐lymphocytes were detected in the AIDS cell cultures. Throughout the culture period, viability of the unstimulated AIDS lymphocytes exceeded 90%, whereas in stimulated cultures it fluctuated within the 65‐90% range. It is concluded that the liability of AIDS lymphocytes to mitogens is probably a direct consequence of the human immunodeficiency virus (HIV) infection.

Induction of erythroid differentiation in murine erythroleukemic cells by short chain aliphatic carbonyl compounds and their corresponding precursors: Evidence for a common inducing signal

Proerythroblastoid murine erythroleukemic (MEL) cells may be induced to differentiate along the erythroid pathway by avariety of chemical agents [l-5]. The state of erythroid differentiation is recognized unequivocally by increased hemoglobin synthesis and concomitant morphological changes [ 5,6]. While the precise nature or the cellular receptor sites of the erythroid differentiation induction signal remain undetermined [ 1,3], it has been suggested that the cell membrane may be the initiation site [ 1,3] as evidenced by changes of certain cell membrane-related functions [7,8]. We have shown recently that SeOz and H