Inter-character relationships and heterosis observed in opaque-2 maize crosses and in their normal analogues

Hybrids obtained from two series of diallel crosses made between six o 2 converted inbred lines on the one hand and their normal analogues on the other were compared for twenty-five characters including yield and several of the yield components, including the parents. Observations on simple inter-character correlation coefficients presented here have shown that the majority of the correlations at the o 2 level are of the same order as at the normal level. A number of correlations of the o 2 type are inferior to those of their normal analogues, whereas a few are favoured by the o 2 gene including the correlation of grain yield with kernels per row. A measure of heterosis for each hybrid over its mid-parent also demonstrated that the o 2 types show poorer heterosis in more cases than do their normal counterparts. Still, in nearly 40 percent of the cases the o 2 hybrids were found to be more heterotic than their normal analogues, particularly for the various maturity characters and several of the yield components. Thus, the possibility of improvement exists in breeding maize with the opaque-2 gene.

Protein quality traits and their relationships with yield and yield components of opaque-2 and analogous normal maize hybrids and inbred lines

Diallel cross hybrids obtained by crossing six opaque-2 (o 2) converted inbred lines were compared with a similar series of crosses made between the analogous normal inbred lines together with the parents, for a number of protein quality and oil traits. The results obtained show that there is only a minor decrease in percent protein or yield of protein per hectare caused by the presence of the o 2 gene in recessive homozygous condition, compared with its normal counterpart. On the other hand, percent lysine in the whole kernel, lysine yield per hectare and percent lysine in protein are increased by 53, 45 and 55 percent, respectively, in the o 2 inbred lines and hybrids compared with their normal analogues. Percent oil and oil yield remain almost unaltered by the presence or absence of the o 2 gene. As well as lysine, the content of other amino acids, such as aspartic acid, arginine, glycine, threonine, valine and histidine are also, in general, increased by the presence of the o 2 gene in recessive homozygous condition.The results obtained have shown that a number of correlation coefficients between the protein quality traits and yield components related to kernel characteristics are negative and significant, especially in the presence of the o 2 gene in recessive homozygous condition. Only two correlation coefficients have been found that could be used with advantage by opaque-2 maize breeders. They are a stronger positive correlation of percent protein with percent lysine, and lysine yield per hectare with 1000 grain weight, in o 2 maize than in normal maize.The results presented here also show that there is more heterotic dilution in the o 2 hybrids than in the normal analogues for traits like percent protein, percent lysine (whole kernel basis) and percent lysine in protein. It has been observed that the inbred lines with the o 2 gene in recessive homozygous condition and a superior protein quality tend to produce hybrids of superior quality.

The treatment of precocious puberty with cyproterone acetate

Nine patients (8 girls and 1 boy) suffering from precocious puberty received daily 100 mg/m2 cyproterone acetate orally. This treatment inhibited the vaginal bleeding; breast-size and the axillary hair and pubic hair did not further increase. The height increment per year and the bone maturation slowed down. The urinary excretion of androgens was temporarily diminished. It is probable that the growth prognosis could be improved by the administration of cyproterone acetate.

A longitudinal study of the urinary excretion of individual steroids in children from 3 to 7-years-old

A longitudinal study was made of the daily urinary excretion, on or near each birthday, of a number of C19 and C21 steroids in 9 healthy girls and 5 healthy boys aged 3 to 7 years. The amount of androsterone excreted by each individual increased slowly during the period of study but the absolute amounts varied greatly between individuals. The excretion of aetiocholanolone was greater than that of androsterone, contrary to reported findings in older children. Small amounts of DHA were found. Testosterone was found in only about 40% of samples; epitestosterone in 70 % and 11β-OH-androsterone in only 62 %. Cortisol metabolites were excreted in amounts which increased with age and all three metabolites of corticosterone were present in most specimens. 11-Deoxycortisol was found in about 50 % of the samples and THS in 63 %. The mean trend in the ratio of glucuronides to sulphates of the 11-deoxy-17-oxosteroids decreased with increasing age, but the 11-deoxy-11-oxy ratio of 17-oxosteroids increased as did the 5α/5β ratio of the C19 and C21 steroids.

No sex differences were observed. The excretion of cortisol metabolites showed a positive correlation with height and weight. 11-Deoxy-17-oxosteroids were positively correlated with the weight. No significant relationships between steroid excretion and skeletal maturity were found.

A longitudinal study of the urinary excretion of individual steroids in children from 8 to 12 years old

A longitudinal study was made of the urinary excretion of a number of C19 and C21 steroids in 11 healthy boys and 9 healthy girls aged 8–12 yr. Urine collections were made every 6 months, over periods ranging from 1 to 2½ yr. in different children. The excretions of most substances showed surprisingly regular increments in individual children. Differences between individual children were marked and often consistent; some children excreted high amounts of one substance and low amounts of another, and other childen the reverse. The variation between individuals in the excretion of substances such as androsterone and aetiocholanolone was reduced when the results were plotted against skeletal rather than chronological age. DHA was excreted by all subjects, but at a very low level before the skeletal age of 10 yr. The glucuronide: sulphate ratio of the 11-deoxy-17-oxosteroids fell consistently from 8 to 12 yr. whereas the ratio of 5α-: 5β-11-deoxy-17-oxosteroids increased. Boys excreted more C19 steroids than girls with the same skeletal maturity score. This comparison is physiologically more meaningful than comparing boys and girls of the same chronological age.

Urinary levels of C19 and C21 steroids in healthy young men and their relation to muscle and limb bone widths

The urinary excretion of a number of individually estimated C19 and C21 steroids was measured in 26 healthy young men. The relation between the levels of excretion of certain steroids and the widths of bone, muscle and fat in the upper arm, calf and thigh measured in radiographs was studied. There was a positive relation between the excretion of androsterone and aetiocholanolone and muscle width, and also between total cortisol metabolites and bone width. There was a highly significant negative regression of total corticosterone metabolites on muscle width.