SURROGATE MOTHERING:EXPLOITATION OR EMPOWERMENT?

The morality of surrogate mothering is analyzed from a "consequentialist" framework which attempts to separate those consequences that invariably accompany a given act from those that accompany it only in particular circumstances. Critics of surrogacy argue that it transfers the burden and risk of pregnancy onto another woman, separates sex and reproduction, and separates reproduction and childrearing; none of these acts is necessarily wrong, either morally or for women's or society's basic interests. While surrogate mothering can be rendered immoral if women are coerced into the practice or become victims of subordinating or penalizing contracts, it has the potential to empower women and increase their status in society by providing a job that is less risky and more enjoyable than other jobs women are forced to take and by achieving greater social recognition for reproductive labor.     

ARE PREGNANT WOMEN FETAL CONTAINERS?

Purdy explores the argument that women's rights to control their bodies should be subordinated to the welfare of their fetuses. She gives examples ofinstances where women's decisions about pregnancy and childbirth have been overridden by physicians and judges. She examines the nature of the mother fetus relationship, the social context of the current conflict between maternal and fetal rights, and the extent of a woman's legally enforceable duty to her fetus. Purdy acknowledges that women may owe a reasonable duty to their fetuses to try to prevent disease or handicap. However, given the uncertainties of modern medicine, the value-laden nature of many physicians' decisions, and the lack of adequate adequate prenatal care, women should not be held responsible for situations that are due largely to society's shortcomings. Purdy concludes that it is unjust to use the law to coerce women into accepting medical advice.     

Estrogen hydroxylase activity in the human placenta at term

Placental estrogen hydroxylase (EH) enzyme activity was measured at term using the catechol-O-methyl transferase coupled method in normal and high risk conditions. The identity and ratio of products formed during incubation of microsomes as analysed by high performance liquid chromatography in chronic hypertension, toxemia and diabetes mellitus was not different from controls. The mean enzymatic activity was also not different among the conditions studied as expressed mean +/- SE pmol/min/mg, protein: chronic hypertension (7.8 +/- 1), toxemia (8 +/- 1.6), diabetes mellitus (6.1 +/- 0.9) and controls (8.3 +/- 1.5). The cofactor dependence of EH was studied showing that NADPH is a better substrate for the enzyme than NADH.     

Rapid Extraction of DNA and rRNA from Sediments by a Novel Hydroxyapatite Spin-Column Method

We describe a novel hydroxyapatite spin-column method of nucleic acid extraction from natural sediments by which DNA and rRNA can be extracted separately. This very rapid method produces pure nucleic acid that can be utilized in some of the most common molecular biological procedures used in the analysis of natural microbial communities.     

Excess amino acid polymorphism in mitochondrial DNA: contrasts among genes from Drosophila, mice, and humans

Recent studies of mitochondrial DNA (mtDNA) variation in mammals and Drosophila have shown an excess of amino acid variation within species (replacement polymorphism) relative to the number of silent and replacement differences fixed between species. To examine further this pattern of nonneutral mtDNA evolution, we present sequence data for the ND3 and ND5 genes from 59 lines of Drosophila melanogaster and 29 lines of D. simulans. Of interest are the frequency spectra of silent and replacement polymorphisms, and potential variation among genes and taxa in the departures from neutral expectations. The Drosophila ND3 and ND5 data show no significant excess of replacement polymorphism using the McDonald-Kreitman test. These data are in contrast to significant departures from neutrality for the ND3 gene in mammals and other genes in Drosophila mtDNA (cytochrome b and ATPase 6). Pooled across genes, however, both Drosophila and human mtDNA show very significant excesses of amino acid polymorphism. Silent polymorphisms at ND5 show a significantly higher variance in frequency than replacement polymorphisms, and the latter show a significant skew toward low frequencies (Tajima's D = -1.954). These patterns are interpreted in light of the nearly neutral theory where mildly deleterious amino acid haplotypes are observed as ephemeral variants within species but do not contribute to divergence. The patterns of polymorphism and divergence at charge-altering amino acid sites are presented for the Drosophila ND5 gene to examine the evolution of functionally distinct mutations. Excess charge-altering polymorphism is observed at the carboxyl terminal and excess charge-altering divergence is detected at the amino terminal. While the mildly deleterious model fits as a net effect in the evolution of nonrecombining mitochondrial genomes, these data suggest that opposing evolutionary pressures may act on different regions of mitochondrial genes and genomes.      

Chromatographic techniques for the isolation and purification of lipoproteins

Various modes of chromatography are available for lipoprotein separation. Gel permeation and affinity chromatography are used for preparative purposes and to separate lipoproteins according to size and apolipoprotein content, respectively. Development of rigid supports for gel permeation has led to large improvements in speed and resolution. Reversed-phase high-performance liquid chromatography (HPLC) of apolipoproteins offers the best performance in terms of speed and resolution of structural variants. Due to its high speed and superior resolving power, the recently developed technique of capillary electrophoresis should emerge as an important method for lipoprotein analysis.     

Genetic variation,breeding system evolution,and conservation of the narrow sand dune endemic Stellaria arenicola and the widespread S. longipes (Caryophyllaceae)

Genetic variation was examined by electrophoresis in 14 populations of Stellaria arenicola, an endemic of the Athabasca sand dunes in northern Saskatchewan, Canada, and seven populations of S. longipes, its progenitor. Three of the 5. longipes populations were sympatric with the endemic. Populations of the endemic were found to have fewer alleles per polymorphic locus (2.21 vs. 2.37), fewer polymorphic loci (29.9 vs. 33.8), and lower genetic diversity (0.087 vs. 0.107) than populations of the progenitor. Genetic identities for all pairs of populations were high (0.932 to 1.000). The endemic had one novel allele and shared ten alleles with progenitor populations from the sand dunes that were not found in other populations of S. longipes. Populations of both species were found to partition most of their genetic variation within populations. An investigation of the multilocus outcrossing rates revealed that S. arenicola had higher rates of selling and biparental inbreeding than S. longipes. This study suggests that partial genetic isolation through a shift in the breeding system, in addition to previously reported strong directional selection, has been important in the sympatric evolution of the endemic S. arenicola. The close genetic relationship between populations of S. arenicola and S. longipes found on the Athabasca sand dunes supports the suggestion that the endemic evolved while sympatric to the gene pool of the progenitor species that is found presently in the region.