Sigmoid shape of the oxygen equilibrium curve and the P50 of human hemoglobin

The fractional saturation of hemoglobin with oxygen was plotted against P/P₅₀ and the slope of the abscissa at 1 was calculated for 38 OEC data sets of human Hb A. There was a linear correlation between the slope and the Hill coefficient (n_max), and the slope was about one-forth that of n_max. This implies that the slope of the abscissa at 1 of Y vs P/P₅₀ plot can provide information about the magnitude of cooperativity in hemoglobin oxygen binding.     

A new antisickling agent: in vitro studies of its effect on S/S erythrocytes and on hemoglobin S

2-(benzoylamino) pyridinium benzoate (BAPB) has exhibited an antisickling effect with homozygous S/S erythrocytes in vitro. This study suggests that BAPB prevents sickling by inhibiting the gelation of hemoglobin S.     

A new antisickling agent: In vitro studies of its effect on S/S erthrocytes and on hemoglobin S

Summary 2-{benzoylamino} pyridinium benzoate (BAPB) has exhibited an antisickling effect with homozygous S/S erythrocytes in vitro. This study suggests that BAPB prevents sicklin by inhibiting the gelation of hemoglobin S.Acknowledgments. This research has been partly funded by a Sickle Cell Research grant from the State of Tennessee to Meharry Medical College. We gratefully appreciate the technical assistance of Mr Rudolf Harlan and Mrs Marjorie Deveau of the School of Graduate Studies. We offer our thanks to Dr J. W. Davis, J. D., Coordinator, Sickle Cell Project, Meharry Medical College for constant encouragement.     

Determination of apparent mean mass of proteins associated with heme in the hemoglobin molecule of Arenicola marina (L.), Annelida, Polychaeta]

Protein and iron concentrations and maximum combined oxygen concentration were measured in the blood of the lugworm Arenicola marina. The calculated mean molecular mass of the heme-associated proteins was higher than that reported for known invertebrate and vertebrate intracellular hemoglobins. The difference is probably due to the presence of polypeptide chains not linked to heme groups in the extracellular annelid hemoglobins.     

Electrophoretic analysis of lactate NAD oxidoreductase in interspecific hybrids between three species of the genus Sphaeroma: S. monodi, S. Rugicauda and S. hookeri]

The electrophoretic analysis of lactate NAD oxydoreductase in interspecific hybrids between three species of genus Sphaeroma (S. monodi, S. rugicauda and S. hookeri hookeri) leads, for each category of hybrids, to a distribution between the two parental enzymatic patterns and, consequently, shows the absence of an isozyme appropriate to these hybrids.     

Photosynthesis and respiration II. Effect of 3-(3,4-dichlorophenyl)-1,1-dimethylurea and of partial pressure of oxygen on the rates of carbon dioxide exchange in light and in darkness of detached wheat leaves

Zusammenfassung Es werden der Einfluss des Photosynthesehemmstoffs DCMU und des O₂-Partialdrucks auf die Photosynthese und die Licht- und Dunkelatmung untersucht. Die Ergebnisse zeigen erneut, dass Licht- und Dunkelatmung 2 verschiedene Prozesse sind.     

High poly A content of the native genome of murine oncornaviruses : presence of 65-70 S RNA lacking polyadenylic sequences]

High molecular weight Poly (A) minus RNA was isolated from native genome of murine oncornaviruses. The Poly (A) content of viral genomes seems to depend more on cellular multiplication than viral maturation.     

Organization in "barrels" of layer-IV cells of the S1 cortex in the mouse: effects of lesions or deprivation of the mystacial vibrissa]

In newborn mice the mystacial pads of the upper lips were submitted to different destructive or functionally reducing procedures. The effects on the barrels of the somato-sensory cortex were judged in mature animals and classified into 3 categories: 1. the barrels were present and normal; 2. the cortex was devoid of barrel structures; 3. the barrels were disorganized. Only procedures which involved peripheral lesions, and not those which reduced only the functional level, produced effects as deep as absence or disorganization of the barrels.     

Role of the Raphe Magnus nucleus in morphine analgesia : studies with intracerebral microinjections in the rat]

Microinjections of low concentration of morphine (5 micrograms) into the nucleus Raphé Magnus of the Rat produce a strong analgesia that can be reversed by systemic naloxone, an opiate antagonist. The administration of naloxone (5 micrograms) into the Raphé Magnus considerably reduces the effects of intravenous morphine. The effects of microinjections of morphine are strongly reduced by Cinanserin, suggesting a role for serotoninergic mechanisms in morphine analgesia.     

Adenyl cyclase activity of the cell membrane throughout the cell cycle: ultrastructural study of the cell line BHK 21/C 13]

Adenylate cyclase activity in the surface membrane of baby Hamster kidney (BHK 21/C13) cells is ultrastructurally studied as a function of the cell cycle. Cells are synchronized by a physical method suited to structural and functional investigations. The activity is highest through G1, decreases in S, markedly drops as cells traverse G2 and is very low or often seems not present at all in M.     

A glycoprotein: galactosyltransferase activity in the ascitic fluid and serum of mice with the YC8 tumor]

Tranfer of (14C)-gal from exogenous UDP(14C)-gal has been demonstrated with ovomucoid as glycoprotein acceptor in ascitic fluid sera from Balb/c mice bearing isogenic YC8 tumor. Transfer exists without ovomucoid, in great ratio in ascitic fluid and in sera from ascitic mice too, showing occurrence of endogenous acceptors, the origin of which has to be proved.     

Inhibitory effect of the tissue antagonism of interferon on the development of 180/TG Crocker tumor: recognition of a new murine lectin]

Crude and purified murine lectin preparations are extracted from costal cartilage (TAI). They inhibit the antiviral state induced by interferon. They also agglutinate the Crocker 180/TG tumor cells. After IP inoculation in mice, the purified lectin preparation significantly decreases tumor incidence and increases the animal's life span.     

Labelling the adults of the tobacco caterpillarSpodoptera littoralis (Boisd.) (Prodenia littura F.; noctuidae: Lepidoptera) with P32

Zusammenfassung Radioaktive Markierung der Larven vonSpodoptera littoralis mittels³²P ist nicht nur in den daraus resultierenden Imagines, sondern auch in den Eiern und den daraus schlüpfenden F1-Räupchen gut nachweisbar.     

Interaction of epidermal growth factor with human fibroblasts in culture: an autoradiographic study at the ultrastructural level]

The potent mitogen epidermal growth factor (EGF) binds to specific receptors on human fibroblasts. In the present study we have used a quantitative EM autoradiographic approach to visualize the events involved in the binding process. When 125I-EGF is incubated at 4 degrees C for 120 min, labeled EGF primarily localizes to the plasma membrane of the fibroblast but when incubated at 37 degrees C for 120 min., over 2/3 of the labeled material is internalized by the cell. The internalized radioacitivity is primarily localized to lysomes. These studies demonstrate a temperature-dependent internalization of EGF following initial binding to specific plasma membrane receptors.     

Mutants of Bacillus thuringiensis with altered sporulation: morphologic responses to several treatments applied in the exponential phase]

During log-phase of growth, wild strain and and oxytetracycline-resistant mutants with altered sporulation exhibit distinct responses to some treatments, autolysis, osmotic pressure, ultraviolet irradiation and bacteriophage infection.