Induction of interdigitating reticulum cell-like differentiation in human monocytic leukemia cells by conditioned medium from IL-2-stimulated helper T-cells

Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features. Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned medium significantly down-regulated the expression of CD14 antigen. Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is necessary for the differentiation and maturation of IDC.     

Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae)

We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation.     

Kinetic and molecular orbital studies on the rate of oxidation of monosubstituted phenols and anilines by lactoperoxidase compound II in comparison with the case of horseradish peroxidase

The second-order rate constant (k4) for the oxidation of monosubstituted phenols and anilines by lactoperoxidase compound II was examined by Chance's method [B. Chance, Arch. Biochem. Biophys. 71 (1957), 130–136]. When the electronic states of these substrates were calculated by an ab initio molecular orbital method, it was found that the log k4 value correlates well with the highest occupied molecular orbital (HOMO) energy level but not with the net charge or frontier electron density. These results are essentially similar to those reported previously in the case of horseradish peroxidase [J. Sakurada, R. Sekiguchi, K. Sato, and T. Hosoya, Biochemistry 29 (1990), 4093–4098], showing some dissimilar features which are considered to reflect the structural difference between the two enzymes.Abbreviations HOMO highest occupied molecular orbital - HRP horseradish peroxidase - LPO lactoperoxidase (EC 1.11.1.7) - LUMO lowest unoccupied molecular orbital     

Destruction and reorganization of the receptor membrane in labellar chemosensory cells of the blowfly. Recovery of responses to sugar after destruction

Recovery from destruction by sodium deoxycholate (DOC) was studied with the receptor membrane of the blowfly, Phormia regina. The recovery can be divided into two processes, colchicine dependent and colchicine independent. The colchicine-dependent process was completely depressed by pretreatment with colchicine at 5 mM for 2 min (partially at 0.1 mM for 10 min), but the colchicine-independent one persisted. Vinblastine also caused depression but lumicolchicine did not. Records of responses obtained from the DOC-treated sugar receptor showed long response latencies that gradually became indistinct with recovery. Colchicine also affected this change in response latency after the DOC treatment. These results suggest that the colchicine-dependent recovery process is related to microtubules in the distal process of the receptor cell. The recovery time course and the change in response latency could be quantitatively explained by the simple assumptions that DOC underwent desorption from the receptor membrane (colchicine-independent recovery process) and that regeneration of the disrupted distal process of the receptor cell accompanied recovery in the number of available receptor sites (colchicine-dependent recovery process).     

Interaction of palytoxin and cardiac glycosides on erythrocyte membrane and (Na+ + K+) ATPase

Palytoxin (PTX), at extremely low concentrations (0.01-1 nM), caused K+ release from rabbit erythrocytes. Among the various chemical compounds tested, cardiac glycosides potently inhibited the PTX-induced K+ release. The order of inhibitory potency (IC50) was cymarin (0.42 microM) greater than convallatoxin (0.9 microM) greater than ouabain (2.3 microM) greater than digitoxin (88 microM) greater than digoxin (90 microM). Their corresponding aglycones, even at 10 microM, did not inhibit the K+ release, but competitively antagonized the inhibitory effect of the glycosides. All these cardiotonic steroids inhibited the activity of (Na+ + K+)-ATPase prepared from hog cerebral cortex in narrow concentration ranges (IC50 = 0.15-2.4 microM), suggesting that the inhibition of K+ release is not related to their inhibitory potency on the (Na+ + K+)-ATPase activity, and the sugar moiety of cardiac glycosides is involved in the inhibition. On the other hand PTX, at higher concentrations (greater than 0.1 microM), inhibited the (Na+ + K+)-ATPase activity. However, this inhibitory effect of PTX was not antagonized by ouabain. It is suggested that, compared with ouabain, PTX has additional binding site(s) on the (Na+ + K+)-ATPase.     

The standardization of the candidate national standard anti-D blood-typing serum with the Groupamatic MG50 system

The utility of the Groupamatic MG50 system for quantitative expression of agglutination in terms of continuous response was studied. By use of the characteristics of the design of this system, in which the change in voltage reflects the degree of agglutination, a linear regression relationship between the log ratio of light flux obtained by transformation of the voltage and the log dilution factor of the serum was demonstrated. The availability of the parallel line assay method to the standardization of the blood grouping antisera was also described.     

Mammalian signal peptidase: partial purification and general characterization of the signal peptidase from microsomal membranes of porcine pancreas

Signal peptidase has been enriched extensively from microsomal membranes of porcine pancreas. Microsomal membranes were washed with 1 M KCl and Brij 35, and then solubilized with 1% Nonidet P-40. The solubilized signal peptidase was purified by DEAE-cellulose chromatography and Sepharose CL-6B filtration. Cleavage of pre-human placental lactogen with the partially purified enzyme gave the mature form, whose NH2-terminus was identified as valine. The signal peptidase is heat-labile and approximately 90% of the enzymatic activity was lost at 60 degrees C within 1 min. The pH optimum of the activity was 7 to 8. Chymostatin and o-phenanthroline at concentrations of 2.5 mM inhibited the signal peptidase activity by 62% and 30%, respectively.     

Behavior of Japanese monkey (Macaca fuscata) mothers and neonates at parturition

Parturitional behavior in 12 caged Macaca fuscatawas analyzed. Wild-caught mothers showed adequate maternal behaviors immediately following the neonate’s expulsion. Parity differences existed in the behaviors; primiparae were more idiosyncratic than were multiparae. Among multiparae, those with two or more offspring were uniformly adequate, but those with a single birth experience varied in the adequacy of the maternal care they provided at parturition. Mothers embraced and licked their neonates and had ventroventral contact with them frequently immediately after parturition but decreased these behaviors after expulsion of the placenta. In contrast, mothers showed allogrooming after consuming the placenta. Placentophagy was correlated with the level of orality represented by maternal licking behaviors. An isolation-reared primipara reacted to her newborn in a basically negative manner, although she showed little actual aggression. She showed a rapid shift in her negative behavior during the immediate postpartum period. This mother’s newborn sought contact with her, indicating the neonate’s active role in establishing a stable mother-neonate bond.