Nutritional copper deficiency and penicillamine administration: some effects on bone collagen and arterial elastin crosslinking

Nutritional copper deficiency effects marked changes in the crosslinking of collagen and elastin, presumably in relationship to copper's role as a cofactor for lysyl oxidase. Lysyl oxidase controls one of the initial steps in the crosslinking of elastin and collagen, i.e., the conversion of peptidyl lysine or hydroxylysine residues to peptidyl alpha-aminoadipic-delta-semialdehyde derivatives. Once lysine-derived aldehydic functions in collagen and elastin are formed, crosslinks occur via aldol and Schiff-base type condensations. A decrease in the degree of crosslinking results in changes in the biomechanical properties of both collagen- and elastin-rich tissues. Some of these changes are described with respect to chick bone and aorta. Likewise, penicillamine blocks crosslinking reactions. In this case, however, it is probably because of the formation of thiazolidine complexes between penicillamine aldehydic functions. The administration of penicillamine at different levels to young growing chicks allows the isolation of fibrous insoluble elastin varying in aldehyde content.

Supergenes in polymorphic land snails. II. Partula suturalis

The colour and banding of the shell of Partula suturalis are controlled by a single locus (M) with a series of at least six alleles. MX, giving apex as a homozygote, is dominant to MF1, giving frenata, which is dominant to the other alleles. MF2 is similar to MF1 except in its relation with MA. MF2MA produces bisecta and provides a striking example of a heterozygote that is qualitatively different from both homozygotes for the alleles producing it. MA gives atra as a homozygote and is dominant to MC and MS. MC, giving cestata as a homozygote, is recessive to all except MS. MS, giving strigata, is the universal recessive. It is suggested that the locus may be complex. The direction of coiling of the shell is determined by the H locus with HS (sinistrality) dominant to HD (dextrality). The expression of coiling is delayed by one generation, the maternal genotype determining the phenotype of the offspring. M and H are not linked. Self-fertilisation occurs infrequently and non-randomly.

Supergenes in polymorphic land snails. I. Partula taeniata

The general colour of the shell in Partula taeniata is controlled by at least two loci. One of these (C) has a series of six alleles which determine the yellow (Y) and neutral brown (N) series of colours. Alleles for darker colours are dominant to those for lighter colours, but dominance is not always complete. The pink (P) colours are determined by a second locus (P) which modified the expression of the lighter alleles of the C locus. Orangeshell colour segregates with yellow but its allelic relationship is unknown. Colour of the lip is controlled by a locus (L) with pink lip dominant to white lip. The colour of the spire is determined by a locus (S) with dark (N4) spire dominant to light spire. An intermediate spire colour shows the same pattern of inheritance and may represent the effect of another allele. Banding of the shell is dominant to absence of bands, with two loci (B1 and B2) determining the type of banding. An allele at B1 produces the frenata pattern; an allele at B2 produces zonata; together they produce lyra. All the loci for which linkage data are available are linked so strongly that the whole array may be considered a supergene. Self-fertilisation takes place primarily during early reproductive life. About 20 per cent of the young of the first mating of an individual are produced by selfing, but over the whole reproductive span the frequency is only about 2-5 per cent. There is inconclusive evidence for heterozygote advantage of banded individuals.

The relation of phenotype to habitat in an introduced colony of Cepaea nemoralis

The introduced colony of Cepaea nemoralis at Lynchburg, Virginia, contains only yellow shells. The population respond to the characteristics of the environment by adjusting the frequencies of the banding morphs and by regulating the amount of fusion of adjacent bands. In this respect they fulfill a prediction based on the observations of Clarke (1960) on British colonies of Cepaea hortensis.

Intrauterine tranfusion: 101 consecutive cases treated at Queen Charlotte's Maternity Hospital

Intrauterine transfusion was performed or attempted in 101 cases during a period of four and a half years. After exclusion of six cases, for reasons detailed in the text, 95 cases are considered in detail. Intrauterine transfusion was successfully performed in 93 of these, with a mean of 2.8 transfusions each. Forty-four babies (46.3%) survived and all but one are so far developing normally.