Radioimmunoassay of serum digoxin in relation to digoxin intoxication

Serum digoxin estimations were done in 98 patients receiving digoxin for heart failure of varied aetiology. Digoxin toxicity or the lack of it was determined on the basin of established electrocardiographic criteria. Fifty-two patients were classified as 'toxic' and 46 as 'non-toxic'. The difference is the mean digoxin levels between the two groups was highly significant (P less than 0.001). The mean serum digoxin level in 'non-toxic' patients was slightly higher than that found by other investigators. Fairly good correlations have been noted between different dosage schedules and various rhythm disturbances. Death was attributed to digoxin toxicity in only 2 patients who showed electrocardiographic evidence of intoxication at the time of death.

Genetic analysis of the duplicate loci, cluster and short branch in Gossypium hirsutum L

Six generations, namely P1, P2, F1, F2, B1 and B2, of five different crosses involving diverse parents, H14 (Local standard), Res H141 (Reselection of H141), 419/49 (Punjab), 5143C (Ceylon) and Banda-I (Africa) on one hand and PRS-72 a cluster type strain on the other, were studied to gain understanding of the genetics of short fruiting branch and cluster boll bearing in upland cotton, Gossypium hirsutum L. Observations were recorded on cluster vs. noncluster normal plants in the first and second filial and B1 and B2 generations. The segregation ratios of cluster: normal boll bearing in the F2 and B2 (test cross) progenies confirmed that the character is monogenic recessive (cl1cl1) in inheritance. Though the penetrance of the gene which controlled cluster boll bearing was complete, its expression varied. As many as 15 different types of 'cluster' have been described. Length of cluster bearing sympods varied. On average the sympod lengths in PRS-72 and the cluster type F2 and B2 were 2.13 and 4.54 cm, respectively, suggesting influence of specific modifiers evolved in the cluster donor parent and the different genetic backgrounds. It was suggested that there is a dosage effect of modifiers and interaction of homeologous duplicate allele (Cl2 Cl2) in governing the length of the cluster bearing sympods.

The mechanism of sex determination in Rumex acetosella

Cytogenetic studies were made with particular emphasis on the sex-determining mechanism in Rumex acetosella (6 x = 42) and its hybrids (F 1, F 2, BC 1 and BC 2) with R. hastatulus (synthetic 4 x = 16 = 4 A +4 X = ♀ and 4 x = 18 = 4 A + 2 (X Y 1 Y 2) = ♂). Rumex acetosella was almost strictly dioecious with 50∶50 male and female. Breeding tests revealed that the males were heterogametic. The longest chromosomes (S), usually two, are the sex chromosomes of this hexaploid species. The S chromosomes are homomorphic in both male and female. The sex chromosome: autosome ratios, and the strong epistatic male effect of the S (M) chromosome in the polyploid dioecious species and in the hybrids, are evidence of an X/Y Melandrium type sex-determining mechanism controlled by a single pair of homomorphic sex chromosomes. Thus, the sex chromosome formula of the males was S (F) S (M) and that of females was S (F) S (F). The present approach is a new method for resolving the sex-determining mechanism in a dioecious species.