Sequence of a novel mRNA coding for a C-terminal-truncated form of human NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase

We amplified, using the polymerase chain reaction (PCR) and NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (type-I 15-PGDH)-specific primers, RNA extracted from the HL-60 cell line. Two bands, differing in size by approx. 160 bp, were detected with ethidium bromide staining after electrophoresis of amplification products and hybridization with a 15-PGDH-specific probe. Sequencing these DNA bands revealed that the largest corresponded to the 15-PGDH cloned from human placenta [Ensor et al., J. Biol. Chem. 265 (1990) 14888-14891]. The smaller sequence coded for a predicted C-terminal-truncated form of 15-PGDH. This subtype of the type-I 15-PGDH mRNA was also found using RT-PCR in human liver, placenta and a cell line derived from a human medullary thyroid carcinoma (TT cells). Hybridization studies using specific probes indicated that this new mRNA form probably corresponded to the 3.4-kb mRNA, one of the two 15-PGDH mRNAs previously detected in Northern blot analysis.     

Presence of a gene encoding choline sulfatase in Sinorhizobium meliloti bet operon: choline-O-sulfate is metabolized into glycine betaine

Glycine betaine is a potent osmoprotectant accumulated by Sinorhizobium meliloti to cope with osmotic stress. The biosynthesis of glycine betaine from choline is encoded by an operon of four genes, betICBA, as determined by sequence and mutant analysis. The betI and betC genes are separated by an intergenic region containing a 130-bp mosaic element that also is present between the betB and betA genes. In addition to the genes encoding a presumed regulatory protein (betI), the betaine aldehyde dehydrogenase (betB), and the choline dehydrogenase (betA) enzymes also found in Escherichia coli, a new gene (betC) was identified as encoding a choline sulfatase catalyzing the conversion of choline-O-sulfate and, at a lower rate, phosphorylcholine, into choline. Choline sulfatase activity was absent from betC but not from betB mutants and was shown to be induced indifferently by choline or choline-O-sulfate as were the other enzymes of the pathway. Unlike what has been shown in other bacteria and plants, choline-O-sulfate is not used as an osmoprotectant per se in S. meliloti, but is metabolized into glycine betaine. S. meliloti also can use this compound as the sole carbon, nitrogen, and sulfur source for growth and that depends on a functional bet locus. In conclusion, choline-O-sulfate and phosphorylcholine, which are found in higher plants and fungi, appear to be substrates for glycine betaine biosynthesis in S. meliloti.     

General practitioner funding policy: from where to whither?

Six public policy objectives relating to general practitioner (GP) funding since 1938 have been identified. They concern national health insurance, rural GP shortages, care for the poor, health promotion, cost effectiveness and community control. Each of these objectives is examined in turn, focusing on the extent to which each has been met. In all cases past policies have been, at best, only partially successful in meeting their objectives and have required little in the way of dismantling prior to the introduction of new GP funding initiatives subsequent to 1993. Theoretical principles relating to the development of efficient and coherent public policy are discussed. New Zealand policy relating to funding of GP services has rarely conformed to such principles. There is an emerging consensus between social democrats and libertarians that targeted programmes for the poor is the equitable and efficient way to proceed. A key policy decision concerns the balance between planned primary care services for low income groups and more traditional market style arrangements for others.     

The mouse Id2 and Id4 genes: structural organization and chromosomal localization

The development of an antigen presentation system based on the plum pox potyvirus (PPV) is here described. The amino-terminal part of PPV capsid protein was chosen as the site for expression of foreign antigenic peptides. Modifications in this site were engineered to avoid the capability of natural transmission by aphids of this PPV vector. As a first practical attempt, different forms of an antigenic peptide (single and tandem repetition) from the VP2 capsid protein of canine parvovirus (CPV) were expressed. Both chimeras are able to infect Nicotiana clevelandii plants with similar characteristics to wild-type virus and remain genetically stable after several plant passages. The antigenicity of purified chimeric virions was demonstrated, proving the suitability of this system for diagnostic purposes. Moreover, mice and rabbits immunized with chimeric virions developed CPV-specific antibodies, which showed neutralizing activity.     

Developmental mechanics determine long bone allometry

Evolutionary and developmental factors responsible for the scaling relationships observed in animal skeletons are poorly understood. We have created a mathematical model for long bone cross-sectional development which incorporates both intrinsic growth and extrinsic, adaptive bone modeling in response to changes in bone mechanical strains during ontogeny. The model successfully simulates the developing morphology in individual animals and the bone geometric allometric relationships among adults across many species (range from mouse to elephant in size). Our results suggest that long bone scaling characteristics are not a result of intrinsic genetic factors but are the results of highly conserved, extrinsic biophysical processes whereby bone tissue strains modulate skeletal morphogenesis.