Allelic variation at the linked AP1 and PhyC loci in hexaploid wheat is associated but not perfectly correlated with vernalization response.

Vernalization requirement is an important trait in temperate crop plants such as wheat and must be considered when selecting varieties for cultivation under different climatic conditions. To determine the growth habit of wheat varieties, plants need to be grown under different vernalization regimes, a lengthy but necessary process for breeders involved in crossing winter with spring germplasm. If haplotypes can be associated with growth habit, then molecular marker assays that are reliable, cheap, and quick can be developed to assist in the selection of plants with the desired phenotype. We have analyzed 81 accessions that have different vernalization requirements and putative different origins of spring habit for sequence variation at the Apetala1 (AP1) locus, which underlies Vrn-1, and at the linked Phytochrome C (PhyC) locus. Good correspondence was found between the AP1 genotype and the PhyC haplotype for 77 of the 81 accessions. Two varieties displayed a recombination event between the AP1 and PhyC loci, and one variety carried a recombinant PhyC gene. In addition, one variety carried an apparent AP1 winter allele, but displayed the Vrn-A1 spring habit. The PhyC haplotype for this variety also indicated the presence of a Vrn-A1 spring allele. Our data suggest that both the AP1 promoter region and PhyC SNPs can be used as diagnostic markers for vernalization response at the vrn-A1 locus, but that neither are perfect tags.

Arabidopsis-rice: will colinearity allow gene prediction across the eudicot-monocot divide?

With the genomic sequencing of Arabidopsis nearing completion and rice sequencing very much in its infancy, a key question is whether we can exploit the Arabidopsis sequence to identify candidate genes for traits in cereal crops using a map-based approach. This requires the existence of colinearity between the Arabidopsis and cereal genomes, represented by rice, which is readily detectable using currently available resources, that is, Arabidopsis genomic sequence, rice ESTs, and genetic and physical maps. A detailed study of the colinearity remaining between two small regions of Arabidopsis chromosome 1 and rice suggests that at least in these regions of the Arabidopsis genome, conservation of gene orders with rice has been eroded to the point that it is no longer identifiable using comparative mapping. Although our analysis does not preclude that tracts of colinear gene orders may be identified using sequence comparisons or may exist in other regions of the rice and Arabidopsis genomes, it is unlikely that the extent of colinearity will be sufficient to allow map-based cross-species gene prediction and isolation. Our research also highlights the difficulties encountered in identifying orthologs using BLAST searches in incomplete sequence databases. This complicates the interpretation of comparative data among highly divergent species and limits the exploitation of Arabidopsis sequence in monocot studies.

'Green revolution' genes encode mutant gibberellin response modulators.

World wheat grain yields increased substantially in the 1960s and 1970s because farmers rapidly adopted the new varieties and cultivation methods of the so-called 'green revolution'. The new varieties are shorter, increase grain yield at the expense of straw biomass, and are more resistant to damage by wind and rain. These wheats are short because they respond abnormally to the plant growth hormone gibberellin. This reduced response to gibberellin is conferred by mutant dwarfing alleles at one of two Reduced height-1 (Rht-B1 and Rht-D1) loci. Here we show that Rht-B1/Rht-D1 and maize dwarf-8 (d8) are orthologues of the Arabidopsis Gibberellin Insensitive (GAI) gene. These genes encode proteins that resemble nuclear transcription factors and contain an SH2-like domain, indicating that phosphotyrosine may participate in gibberellin signalling. Six different orthologous dwarfing mutant alleles encode proteins that are altered in a conserved amino-terminal gibberellin signalling domain. Transgenic rice plants containing a mutant GAI allele give reduced responses to gibberellin and are dwarfed, indicating that mutant GAI orthologues could be used to increase yield in a wide range of crop species.

Important role of carotid afferents in control of breathing.

The purpose of the present study was to determine the effect on breathing in the awake state of carotid body denervation (CBD) over 1-2 wk after denervation. Studies were completed on adult goats repeatedly before and 1) for 15 days after bilateral CBD (n = 8), 2) for 7 days after unilateral CBD (n = 5), and 3) for 15 days after sham CBD (n = 3). Absence of ventilatory stimulation when NaCN was injected directly into a common carotid artery confirmed CBD. There was a significant (P < 0.01) hypoventilation during the breathing of room air after unilateral and bilateral CBD. The maximum PaCO2 increase (8 Torr for unilateral and 11 Torr for bilateral) occurred approximately 4 days after CBD. This maximum was transient because by 7 (unilateral) to 15 (bilateral) days after CBD, PaCO2 was only 3-4 Torr above control. CO2 sensitivity was attenuated from control by 60% on day 4 after bilateral CBD and by 35% on day 4 after unilateral CBD. This attenuation was transient, because CO2 sensitivity returned to control temporally similar to the return of PaCO2 during the breathing of room air. During mild and moderate treadmill exercise 1-8 days after bilateral CBD, PaCO2 was unchanged from its elevated level at rest, but, 10-15 days after CBD, PaCO2 decreased slightly from rest during exercise. These data indicate that 1) carotid afferents are an important determinant of rest and exercise breathing and ventilatory CO2 sensitivity, and 2) apparent plasticity within the ventilatory control system eventually provides compensation for chronic loss of these afferents.

Accident and emergency. A godsend for the East End.

A primary care unit established in an A&E department is well attended and has cut waiting times. Nurse practitioners running the unit have powers to prescribe and refer to specialists. The unit reflects growing recognition that A&E departments must serve patients previously considered the responsibility of GPs.

Innovation in accident and emergency management: establishing a nurse practitioner-run minor injuries/primary care unit.

The establishment of a nurse practitioner-run Minor Injuries and Primary Care Unit in the Accident and Emergency department of an east London district general hospital is outlined. The establishment of clinical protocols, operational policies, staff recruitment and training, budgeting and publicity are discussed. The effective utilization of emergency nurses' skills is illustrated by a reduction in waiting times, standardized optimum clinical practice, improved patient satisfaction, increased health promotion opportunities and improved communication and referrals to, and from, Primary Care facilities. The potential for other such units and the changing role of A & E departments is highlighted.

Minor Injuries Unit: expanding the scope of accident and emergency provision.

The Minor Injuries Unit at St Charles Hospital, London, opened in early 1993. Its establishment is placed in the context of radical changes occurring in Accident and Emergency provision within the UK. The unit's success has exceeded initial expectations and mirrors the potential for such units detailed in recent studies. The use of treatment and prescription protocols are discussed. The effective utilisation of existing and potential nursing skills is demonstrated.

Variations in the perceived need for orthodontic treatment in a sample of 14-year-old children in North Derbyshire.

The investigation explored the possibility that failure to present for orthodontic treatment might result from failure by the child or parent to recognise the existence of an irregular dentition, or to perceive an irregular dentition as a cause for concern. Although a previous investigation by the present authors revealed that a substantial number of the 14-year-old children who had not received and were not scheduled for treatment were in need of orthodontic intervention, use of the SCAN index showed that the great majority did not perceive themselves as having a markedly unattractive dental appearance. Furthermore, almost 86 per cent of the children who had not received and were not scheduled for orthodontic treatment declared themselves happy with their dental aesthetics, as did a similar proportion of their parents. On the other hand, a large majority of children scheduled for orthodontic treatment, together with their parents, reported themselves unhappy with the dental aesthetics.

The orthodontic condition and treatment status of a sample of 14-year-old children in North Derbyshire.

In conjunction with a survey of the general dental health of 14-year-old children in North Derbyshire, an investigation was undertaken into their orthodontic condition and treatment status. It was found that approximately 60 per cent of children had not already received and were not scheduled for orthodontic treatment, but that many of these had abnormalities warranting orthodontic intervention. Girls were more likely than boys to receive orthodontic treatment, but children of socio-economic classes 1, 2 and 3N were not significantly more likely to receive treatment than were children of socio-economic classes 3M, 4 and 5.

Children with juvenile chronic arthritis: their beliefs about their illness and therapy.

Seventy-five patients aged 7 to 17 with juvenile chronic arthritis were interviewed to identify their beliefs about the physical nature of their illness and the relevance and modes of action of their clinical treatment. Children in the 7-11 age group were found to perceive their arthritis largely in terms of its immediately manifestations, to have little conception of internal pathology, and to be less aware of the value of their medical therapy. Children in the 12-17 age group showed a greater tendency to recognize arthritis as a condition of internal pathology, to experience distressing fantasies about the internal appearance of their affected joints, and to appreciate the purpose of their therapy.

The child's perception of the disease and the experience of pain in juvenile chronic arthritis.

Interviews conducted among 39 children with juvenile chronic arthritis supported the hypothesis that the meaning which the child attributes to sensations originating in his joints influences the extent to which those sensations constitute pain. Children in both 6-11 and 12-17 age groups reported similar qualities of sensation from their affected joints, but the older children attributed a more unpleasant meaning to their sensations because of their greater understanding of the significance of internal pathology. By association, the 12-17s consequently reported joint sensations specifically, as more unpleasant and stronger than did the 6-11s.

Factors influencing the expectation of pain among patients in a children's burns unit.

The study was undertaken to identify factors increasing anxiety, fear and anticipation of pain among patients in a children's Burns Unit and to establish means of modifying such factors in order to reduce the children's experience of pain during nursing and treatment sessions. Sixty patients were observed and, where possible, interviewed at periods throughout their stay in the unit. The results indicated that expectation of pain might be reduced by correcting the child's erroneous beliefs about the nature of the healing process and the role of clinical therapy, and by undertaking certain changes in the manner in which treatment and nursing procedures upon the conscious patient were normally conducted.