Crosses and genome relationship in the Hordeum patagonicum group

Five taxa in the Hordeum patagonicum group have been described, viz, H. patagonicum (Haum.) Covas, H. santacrucense Parodi et Nicora, H. setifolium Parodi et Nicora, H. mustersii Nicora, and H. chilense Roem. et Schult. var. magellanicum Parodi et Nicora. In the present investigation a crossing programme including all major types was performed. The combinations showed high crossability, high pollen fertility and seed set in the F₁ hybrids and some segregation of pollen fertility was observed in F₂. The meiotic pairing of the hybrids was high, indicating that the same basic genome is present in all the major types. The data indicate close relationships among the parents and that the different forms should be treated as subspecies of the same species despite their large morphological differences. Some populations differed in having one or even two reciprocal translocations.     

The intravenous distribution of a radiolabeled, potentially useful cluster ion of copper and penicillamine

The 64Cu-radiolabeled mixed valence cluster ion of copper and penicillamine (Cu(I)8Cu(II)6Pen12Cl5-) is easily prepared and purified in a 30 minute procedure. Mice were dosed intravenously with this substance at 0.1 mg/kg, and the distribution of the isotope among organs and tissues was quantified by gamma scintillometry of the isotope's positron annihilation radiation. The largest concentration was found in urine (a 96-fold increase over whole body specific activity at 20 minutes), and this finding is consistent with the compound's inulin-like renal clearance. Isotope levels were also elevated in kidney and liver tissues (2.36-and 3.62-fold, respectively), while all other organs and tissues examined were found to be depleted of the label. A pre-injection of unlabeled cluster at 60 mg/kg effectively blocked radiolabel interaction with liver tissue. This intensely red-violet compound did not stain viable liver cells, and it was not significantly decomposed by liver homogenates over a three hour period. These results suggest cluster interaction at saturable binding sites on liver cell surfaces. The unlabeled cluster shows no indication of toxicity, and the labeled version might have biomedical applications.     

Maternal vitamin D intake and mineral metabolism in mothers and their newborn infants.

Pregnant women receiving daily supplements of 400 IU (10 microgram) of vitamin D2 from the 12th week of pregnancy had plasma calcium concentrations higher at 24 weeks but similar at delivery to those in control pregnant women who did not receive the supplements. Infants of the women receiving the supplements had higher calcium, lower phosphorus, and similar magnesium concentrations on the sixth day of life and a lower incidence of hypocalcaemia than infants of the control women. Plasma concentrations of 25-hydroxycholecalciferol, which showed a seasonal variation, were higher in mothers and infants in the treated group. Cord-blood calcium, magnesium, phosphorus, and 25-hydroxycholecalciferol concentrations correlated with maternal values at delivery. Breast-fed infants had higher calcium and magnesium and lower phosphorus and 25-hydroxycholecalciferol concentrations than artificially fed infants. A defect of dental enamel was found in a high proportion of infants (many of whom had suffered from hypocalcaemia) born to the control women. These results suggest that vitamin D supplementation during pregnancy would be beneficial for mothers, whose intake from diet and skin synthesis is appreciably less than 500 IU of vitamin D daily.