Are the Indonesian and Western Indian Ocean Coelacanths Conspecific: A Prediction

It is hypothesized that the ancestor of the extant western Indian Ocean and Indonesian populations of Latimeria was continuously distributed along the deeper coasts of massed Africa–Madagascar–Eurasia in early geologic time. The collision of India with Eurasia, roughly 50 MY ago, caused the formation of the Himalayan Mountains and subsequent developement of numerous rivers. The rivers, which flow down both coasts of India, and areas even further east, deposited, and continue to deposit, great amounts of silt along both coasts of India. The siltation destroyed possible coelacanth habitats, thus isolating coelacanth populations to the west of India from those to the east and allowing them to diverge.     

Pleiotropic aspartate taxis and serine taxis mutants of Escherichia coli.

Mutants that at one time were thought to be specifically defective in taxis toward aspartate and related amino acids (tar mutants) or specifically defective in taxis toward serine and related amino acids (tar mutants) are now shown to be pleiotropic in their defects. The tar mutants also lack taxis toward maltose and away from Co2+ and Ni2+. The tsr mutants are altered in their response to a variety of repellents. Double mutants (tar tsr) fail in nearly all chemotactic responses. The tar and tsr mutants provide evidence for two complementary, converging pathways of information flow: certain chemoreceptors feed information into the tar pathway and others into the tsr pathway. The tar and tsr products have been shown to be two different sets of methylated proteins.     

The LFA-1, Mac-1 glycoprotein family and its deficiency in an inherited disease

A family of functionally important, high-molecular-weight glycoproteins with identical beta subunits has recently been defined on leukocyte cell surfaces. Soon after these molecules and at least some of their functions had been defined with monoclonal antibodies, an inherited disease, LFA-1, Mac-1 deficiency, was discovered in humans. This deficiency has confirmed that this glycoprotein family is of central importance in leukocyte cell surface adhesion reactions.     

Reduction mammaplasty with discovery of occult breast carcinoma in twins: case reports.

A pair of twins is presented in whom breast carcinomas were found. A reduction mammaplasty in the first twin uncovered an occult intraductal carcinoma. Subcutaneous mastectomies were then done in both twins for identical, mirror-image lesions, The first twin subsequently required a radical mastectomy on the involved side.     

Motility and ultrastructure of large granular lymphocytes on lipid bilayers reconstituted with adhesion receptors LFA-1, ICAM-1, and two isoforms of LFA-3

Large granular lymphocytes, mediators of NK activity, bind to other cells using both the LFA (lymphocyte function-associated)-1-ICAM and the CD2-LFA-3 adhesion pathways. Here we have studied the motility and ultrastructure of large granule lymphocyte (LGL) on lipid bilayers containing purified LFA-1, ICAM-1, and the transmembrane and glycophosphatidylinositol isoforms of LFA-3. LGLs moved at 8 microns/min on ICAM-1 but poorly (less than 1 microns/min) on its receptor pair LFA-1. TM-LFA-3 promoted locomotion at a rate close to ICAM-1, whereas the cells were less motile on GPI-LFA-3. The difference in the rates of locomotion on the two isoforms of LFA-3 is presumably attributable to their difference in anchoring and lateral mobility in the bilayer. In spite of the variation in motility the ultrastructure of the adhering cells was similar on all four ligands. LGLs contacted the membrane variably, i.e., cells adhering only in a few small areas or in larger areas were detected on each ligand. The relative percentage of the plasma membrane facing the lipid bilayer was greatest on ICAM-1 and least on the transmembrane isoform of LFA-3, demonstrating no correlation with motility. The ratio of adjacent plasma membrane to lipid bilayer was virtually constant for all four ligands. Activation of the LGLs with a combination of CD2 mAb T11(2) and T11(3) (T11(2/3) mAb) reduced the movement on ICAM-1 and virtually immobilized the cells on the other bilayers. In the presence of T11(2/3) mAb, the area of cell membrane attaching to bilayers containing ICAM-1 and GPI-LFA-3 was decreased and the percentage of plasma membrane facing other cells was increased. No preferential orientation of the Golgi apparatus or degranulation was detected in the absence or presence of T11(2/3) mAb, but a significantly lower percentage of LGLs on ICAM-1 contained a profile of the Golgi apparatus after exposure to T11(2/3) mAb. The results demonstrate that the motility of LGLs depends on the type of receptor in the opposing bilayer, the receptor mobility in the bilayer, and the activation of the cells. The ultrastructure of LGLs binding to any of the adhesion molecules does not have the characteristics of LGLs in cytolytic contact with target cells, suggesting that the mediation of an attack on a target requires more complex stimulus than any one of the single adhesion proteins tested here.     

Synthetic leukotriene B4 is a potent chemotaxin but a weak secretagogue from human PMN

We have examined the effects of very pure (> 99.8%) chemically synthesized leukotriene B₄ of verifeid structuer on the chemotactc and secretry behavior of human polymphonuclear leukocytes (PMN). The synthetic material is highly chemotactic and shows the same concentration dependence of this activity as does natural LTB₄. Synthetic LTB₄ is also a weak degranulating agnet in cytochalasin B treated PMN. Maximally it released 11%, 17% and 26% as much N-acetyl-β-D-dlucosaminidise, myeloperoxidase and lysozyme as did N-formyl-methionine-leucine-phneylalanine (fMLP). Thus LTB₄ differs significantly from other chemotaxisn, as such as C5a and fMLP, in that it is a poor secretagogue for enzymes of the specific adn azurophilic granules of human PMN.     

Aryl hydrocarbon hydroxylase activity in pulmonary alveolar macrophages and lymphocytes from lung cancer and noncancer patients: A correlation with family histories of cancer

Aryl hydrocarbon hydroxylase (AHH) activity was measured in pulmonary alveolar macrophages (PAMs) and peripheral blood lymphocytes from cigarette smokers with and without primary lung cancer. Frequency distribution analysis of AHH induction ratios for the two groups revealed an increased number of individuals in the lung cancer patient group with high lymphocyte induction values (P less than 0.05). A similar increase was not shown for high-PAM AHH values in lung cancer patients (P greater than 0.2). When individual PAM and lymphocyte AHH values were compared between noncancer and lung cancer patients, a positive correlation was observed for noncancer patients (r=0.195, P less than 0.001), but no correlation of these values was noted for lung cancer patients. The lung cancer patients were divided into three subgroups of patients showing (I) high PAM and low lymphocyte AHH levels, (II) low PAM and low lymphocyte AHH levels, and (III) low PAM and high lymphocyte AHH levels. When the incidence of family history of cancer was compared for these subgroups, no family cancer history was recorded for persons in subgroup II; however, individuals in subgroups I and III presented family cancer history incidence of 9.5% and 39.3%, respectively. Patients in group III averaged 6 years younger than those in group I. These data suggest that familial factors may be identified among lung cancer patients and that these factors appear to associate as either a cause of an effect with the capacity of pulmonary alveolar macrophages and lymphocytes to be induced for AHH. The data support the hypothesis that high AHH values may be characteristic of lung cancer patients but show that enzyme values determined from a single tissue, either PAMs or lymphocytes, may not be appropriate for showing whether high AHH inducibility is correlated with lung cancer.     

Introduction of a lipophilic thioether tether in the minor groove of nucleic acids for antisense applications

A 2′-O-hexylthiotrityl adenosine phosphoramidite has been synthesized and incorporated into oligonucleotide phosphodiesters and phosphorothioates. This tether has potential antisense applications, offers a convenient nucleophile for conjugation of various moieties that would reside in the minor groove, and may form novel tertiary structures.