The offspring of marriage between two first cousins with the same reciprocal translocation t(2;7)(p11;q31)

Summary A marriage between two first cousins who have the same 2/7 balanced translocation is reported. The chromosome rearrangement was primarily detected in amniotic fluid cells cultured for prenatal chromosome analysis because of advanced maternal age. The translocation was also found in the couple's two normal children and in three other members of the family. The possible zygotic chromosome constitutions following 2:2 meiotic segregation in consanguineous parents with the same translocation are discussed.     

Survival of Airborne Pasteurella tularensis at Different Atmospheric Temperatures

The aerosol survival, recovery, and death rate of Pasteurella tularensis SCHU S5 disseminated in particle sizes of 1 to 5 mum were significantly affected by air temperature. The highest aerosol recovery of viable P. tularensis was observed within -7 and 3 C; the recovery decreased significantly below and above this temperature range. The death rate of airborne P. tularensis was not significantly influenced by an increase in temperature from -40 to 24 C. However, a progressive increase in atmospheric temperature from 24 to 35 C resulted in increased death rates; thus, a linear relationship appeared to be present between the temperature and death rates. At 49 C, the recoveries of viable airborne P. tularensis were significantly lower and the death rates were higher than at the other temperatures.     

Studies on Transformations of Hemophilus influenzae : II. The molecular weight of transforming DNA by sedimentation and diffusion measurements

The sedimentation and diffusion coefficients have been determined for Hemophilus influenzae transforming activity and DNA using P³²-labeled DNA. The methods employed the Spinco fixed boundary separation cell for measurements of the sedimentation coefficient and the Northrop-Anson diffusion cell to determine the diffusion coefficient. There was a very close correlation between the amount of DNA and transforming activity sedimented or diffused. The sedimentation coefficient (s_20°), for both biological activity and DNA was 27 and the diffusion coefficient (D_20°) 1 x 10^-8 cm²/sec. The molecular weight calculated from these coefficients gave a value of 16 million. There was no difference in the sedimentation coefficients for the two unlinked markers, streptomycin and erythromycin resistance, and the diffusion coefficients for single markers or the linked markers, streptomycin and cathomycin, were the same.     

The GTP-Insensitive Component of High-Affinity [3H]8-Hydroxy-2-(Di-n-Propylamino)tetralin Binding in the Rat Hippocampus Corresponds to an Oxidized State of the 5-Hydroxytryptamine1A Receptor

Previous studies on central 5-hydroxytryptamine1A (5-HT1A) receptors have consistently shown the existence of a GTP-insensitive component of agonist binding, i.e., binding of [3H]8-hydroxy-2-(di-n-propylamino)tetralin ([3H]8-OH-DPAT) that persists in the presence of 0.1 mM GTP or guanylylimidodiphosphate (GppNHp). The molecular basis for this apparent heterogeneity was investigated pharmacologically and biochemically in the present study. The GppNHp-insensitive component of [3H]8-OH-DPAT binding increased spontaneously by exposure of rat hippocampal membranes or their 3-[3-(cholamidopropyl)dimethylammonio]-1-propane sulfonate-soluble extracts to air; it was reduced by preincubation of solubilized 5-HT1A binding sites in the presence of dithiothreitol and, in contrast, reversibly increased by preincubation in the presence of various oxidizing reagents like sodium tetrathionate or hydrogen peroxide. In addition, exposure of hippocampal soluble extracts to short-cross-linking reagents specific for thiols produced an irreversible increase in the proportion of GppNHp-insensitive over total [3H]8-OH-DPAT binding. The pharmacological properties of this GppNHp-insensitive component of [3H]8-OH-DPAT binding were similar to those of 5-HT1A sites in the absence of nucleotide. Sucrose gradient sedimentation of solubilized 5-HT1A binding sites treated by dithiothreitol or sodium tetrathionate showed that oxidation prevented the dissociation by GTP of the complex formed by the 5-HT1A receptor binding subunit (R[5-HT1A]) and a guanine nucleotide-binding protein (G protein). Moreover, the oxidation of -SH groups by sodium tetrathionate did not prevent the inactivation of [3H]8-OH-DPAT specific binding by N-ethylmaleimide, in contrast to that expected from an interaction of both reagents with the same -SH groups on the R[5-HT1A]-G protein complex. These data suggest that the appearance of GTP-insensitive [3H]8-OH-DPAT specific binding occurs as a result of the (spontaneous) oxidation of essential -SH groups (different from those preferentially inactivated by N-ethylmaleimide) on the R[5-HT1A]-G protein complex.