Patients' narratives of orthognathic treatment for facial asymmetry: a qualitative study.

To explore patients' experiences of orthognathic treatment for facial asymmetry and their adaptation to facial changes after surgery, we did a qualitative, cross-sectional study of patients after treatment for non-cleft asymmetry at two UK sites. A total of 15 patients aged 19-40 years were approached after being identified using patient databases and clinical notes. Individual and photo-elicitation interviews were conducted covering experiences prior to treatment, during treatment, and after surgery. Interviews were transcribed and thematic narrative analysis undertaken. Participants were largely positive about their orthognathic treatment. The following themes were identified: preoperative (becoming aware, negative impacts of asymmetry, committing to treatment, establishing expectations), pre-surgery orthodontics and inpatient experiences (challenges and coping strategies, preparedness, support, and shared experiences); and postoperative (surgery as 'worth it', positive impacts of treatment, adapting to facial change). Undergoing orthognathic surgery was portrayed as a journey involving recognisable narratives (treatment unfinished, threat of liminality, treatment as resolution, and treatment as transformation). Patients' experiences of facial asymmetry are associated with feeling 'abnormal', and negative impacts, and orthognathic treatment for facial asymmetry is worthwhile. Having the feeling that something is 'wrong' legitimised by clinicians allows patients access to a recognisable treatment narrative (resolution). Orthognathic treatment is also described as transformation from 'normal abnormality' to being 'normal'. Nevertheless, the associated challenges can be frustrating, particularly if resolution is hard to envisage. Further psychological input could help patients cope with these challenges and the complex process of adapting to facial change.

Fainting (vasovagal syncope): case reports.

The paper presents four examples of patients fainting. Although we all undergo yearly CPD updates, until you experience a medical emergency, you can never truly be ready for one.

The emerging pharmacotherapeutic significance of the breast cancer resistance protein (ABCG2).

The breast cancer resistance protein (also termed ABCG2) is an ATP-binding cassette transporter, which mediates the extrusion of toxic compounds from the cell, and which was originally identified in relation to the development of multidrug resistance of cancer cells. ABCG2 interacts with a range of substrates including clinical drugs but also substances such as sterols, porphyrins and a variety of dietary compounds. Physiological functions of ABCG2 at both cellular and systemic levels are reviewed. For example, ABCG2 expression in erythrocytes may function in porphyrin homeostasis. In addition, ABCG2 expression at apical membranes of cells such as hepatocytes, enterocytes, endothelial and syncytiotrophoblast cells may correlate to protective barrier or secretory functions against environmental or clinically administered substances. ABCG2 also appears influential in the inter-patient variation and generally poor oral bioavailability of certain chemotherapeutic drugs such as topotecan. As this often precludes an oral drug administration strategy, genotypic and environmental factors altering ABCG2 expression and activity are considered. Finally, clinical modulation of ABCG2 activity is discussed. Some of the more recent strategies include co-administered modulating agents, hammerhead ribozymes or antisense oligonucleotides, and with specificity in cell targeting, these may be used to reduce drug resistance and increase drug bioavailability to improve the profile of chemotherapeutic efficacy versus toxicity. While many such strategies remain in relative infancy at present, increased knowledge of modulators of ABCG2 could hold the key to novel approaches in medical treatment.

In vitro monitoring of in vivo development of human anti-thymoglobulin antibodies by ELISA.

Thymoglobulin (rATG), polyclonal immunoglobulin, is prepared from rabbits immunized with human thymocytes. It is effective in prevention and treatment of renal allograft rejection. Human antibodies against antilymphocyte preparations can reduce efficacy by accelerating drug clearance or by inducing serum sickness. We developed an enzyme-linked immunosorbent assay (ELISA) to study posttreatment development of anti-rATG. In an Institutional Review Board-approved trial, we tested 101 allograft recipients for anti-rATG antibodies. Patients received rATG intravenously at 1.25 to 2.0 mg/kg/d for 2 to 14 days. Serum samples were obtained pretreatment and at weeks 1, 2, 4, 6, and months 3 and 6 post-rATG. ELISA plates were coated with rATG (10 microg/mL). Samples were diluted 1:100 and tested in quadruplicate. Positive samples were titrated. Horseradish peroxidase-conjugated (HRPO) affinity-purified goat anti-human immunoglobulin G (H&L) antibody reacted with bound human antibody. A chromagenic substrate for HRPO was added and optical density (OD, 490 nm) was read. An OD of twice the negative control was considered positive. Mean ODs of negative and positive controls were 0.113 +/- 0.030 and 1.042 +/- 0.196, respectively. Ten patients had detectable anti-rATG before rATG administration (1:100). Thirty-five of 101 patients (35%) developed anti-rATG antibody. Patients showed an initial positive anti-rATG antibody from days 8 to 59 after infusion and titers from 1:100 to 1:4000. In spite of rATG's postulated anti-B-cell activity, this study confirms that rATG induces sensitization at a frequency and titer seen with other xenogeneic antilymphocyte antibodies. Formation of such antixenoantibodies can have a negative impact on treatment response and hence warrant monitoring.

Breast cancer research: affecting the future.

Research plays a pivotal role in the oncology treatment continuum. As research moves from the academic arena into the community, the nurse practitioner is more likely to be faced with the challenge of enrolling and managing trial participants. This article addresses various issues related to breast cancer research and the management of trial participants.

Association of rheumatoid arthritis with an amino acid allelic variation of the T cell receptor.

OBJECTIVE: To investigate allelic variations of T cell receptor residues for a contribution to rheumatoid arthritis (RA) susceptibility. METHODS: We conducted an RA case-control study involving 1,579 northwest Europeans: 766 patients with erosive and rheumatoid factor-positive disease and 813 control subjects. Productive changes of segments TCRAV6S1, TCRAV7S1, TCRAV8S1, TCRAV10S2, and TCRBV6S1, TCRBV6S7 were investigated by single-strand conformation polymorphisms. The TCRAV8S1 association was confirmed by restriction fragment length polymorphism. RESULTS: In the systematic study (77 patients and 119 controls), an increase in 1 TCRAV8S1 genotype was found in the RA patients (P = 0.0004). This finding was replicated in 2 further populations, one from France (212 patients and 254 controls) and the other from Britain (477 patients and 440 controls), with a similar odds ratio (OR), which allowed pooling of the data and confirmation of the association (OR 1.3 [95% confidence interval 1.1-1.7], P = 0.008). CONCLUSION: These findings show evidence that TCRA is an RA susceptibility locus.

Genetic mapping of susceptibility loci in the genes involved in rheumatoid arthritis.

Eighty-nine multicase rheumatoid arthritis families, each containing at least one affected sib pair, have been studied for evidence of genetic linkage to a panel of 315 microsatellite DNA markers. The families were located through the UK national data repository of the Arthritis and Rheumatism Council. Microsatellites were genotyped by semiautomated technology using Applied Biosystems sequencers (ABI 373). Using the SIBPAIR statistical package, linkage to HLA was confirmed (p < 0.0003). Several possible linkages outside HLA were noted, including at least one (p < 0.004) that merits further investigation.

Analysis of three deletion breakpoints in Xp21.1 and the further localization of RP3.

The gene responsible for X-linked retinitis pigmentosa (xlRP) in Xp21.1 (RP3) was initially localized by deletion analysis to within a 150- to 170-kb region between the CYBB locus and the proximal deletion junction (BBJPROX) from a patient, BB, who suffered from Duchenne muscular dystrophy (DMD), McLeod syndrome, chronic granulomatous disease (CGD), and xlRP. This gene has recently been isolated and was found to be located outside and 400 kb proximal to the BB deletion. Further analysis of BBJPROX has identified the breakpoint junction sequence, showing that it occurs within an Alu repetitive element on the proximal side but with no significant homology to the distal sequence in dystrophin intron 30. Analysis of an overlapping deletion in patient NF, who suffered from DMD, CGD, and McLeod syndrome, shows that this deletion is within 4 kb but extends centromeric to BBJPROX, consistent with the location of RP3 outside the BB deletion region. A sequence with strong homology to a THE-1 transposon-like element was identified 7-13 kb from the proximal BB and NF breakpoints. These elements have been implicated in several highly unstable genomic regions. A third overlapping deletion, in a patient, SB, who suffered from CGD, McLeod syndrome, and xlRP, has here been shown to extend 380 kb proximal to the NF breakpoint, consistent with the finding that RP3 lies outside the BB deletion. This deletion has now been shown to disrupt the RP3 (RPGR) gene. The reason for the retinitis pigmentosa phenotype in patient BB remains unclear, but the most likely explanations include a long-range chromosomal position effect, a small secondary rearrangement, and the presence of a coincident autosomal form of retinitis pigmentosa.

Identification of a novel gene, ETX1 from Xp21.1, a candidate gene for X-linked retintis pigmentosa (RP3).

A novel gene encoding a 2.2 kilobase transcript has been isolated from the Xp21.1 region of the human X chromosome by exon amplification. The gene, called EXT1, spans 80 kilobases and contains 12 exons, at least two of which are alternatively spliced and have predicted products of 464 and 471 amino acids respectively. Conceptual translation of the open reading frames shows one product with a 30 amino acid signal peptide, which is absent from the alternative transcript, followed by three complement control protein domains, a hydrophobic region with a possible role in membrane anchorage and short 17 amino acid putative cytoplasmic carboxyl terminus. An alternative first exon contains a 39 amino acid open reading frame which is rich in serine and threonine residues and contains a potential chondroitin/dermatan sulphate attachment site. Northern analysis showed ETX1 expression within the retina and heart with lower levels in several other tissues. Since ETX1 lies within the region thought to contain the x-linked retinitis pigmentosa (xIRP) gene, RP3, it was screened for mutation within a set of 45 xIRP patients using single strand conformation analysis and/or chemical cleavage of mismatch using reverse transcription/polymerase chain reaction amplification of polyA+RNA from blood cells. Three low frequently variants (17-23Ldel, P225S, S413F) were found in both patients and controls; one of which (P225S) was found in four of 45 unrelated patient chromosomes and one of 178 control chromosomes (p <0.001). The allelic association between P225S and xIRP alleles suggests a common ancestral chromosome bearing the P225S variant and an RP3 mutation at a neighbouring locus.

Linkage of the gene that encodes the alpha 1 chain of type V collagen (COL5A1) to type II Ehlers-Danlos syndrome (EDS II).

Ehlers-Danlos syndrome (EDS) is a group of heritable disorders of connective tissue with skin, ligaments and blood vessels being the main sites affected. The commonest variant (EDS II) exhibits an autosomal dominant mode of inheritance and is characterized by joint hypermobility, cigarette paper scars, lax skin and excessive bruising. As yet no gene has been linked to EDS II, nor has linkage been established to a specific region of the genome. However, several candidate genes encoding proteins of the extracellular matrix have been excluded. Using an intragenic simple sequence repeat polymorphism, we report linkage of the COL5A1 gene, which encodes the alpha 1(V) chain of type V collagen, to EDS II. A maximum LOD score (Zmax) for linkage of 8.3 at theta = 0.00 was generated for a single large pedigree.

A simple method for rapid isolation of microsatellites from yeast artificial chromosomes.

Microsatellites are widely recognised as providing a rich source of polymorphic markers for genetic mapping. Consequently, highly polymorphic CA repeats tightly linked to a disease locus are invaluable tools in linkage studies. We have developed an efficient technique for cloning microsatellite repeats from a region of interest contained within a yeast artificial chromosome (YAC). The YAC material is digested with a frequent cutting restriction endonuclease and ligated to polymerase chain reaction (PCR) amplifiable catch-linkers. A 5' biotinylated (CA)11 oligonucleotide is then used to select fragments containing a complementary repeat by binding to streptavidin-coated magnetic beads. The catch-linkers enable these fragments to be PCR amplified, cloned and sequenced. Primers are then designed to amplify the repeat locus and to confirm its genomic localization and heterozygosity. We have successfully used this technique to clone a new (CA)18 microsatellite from a 360-kb YAC. The YAC contains the CYBB locus in Xp21.1 and is thought to contain at least part of the RP3 gene responsible for X-linked retinitis pigmentosa. This new CA repeat is highly polymorphic with nine alleles identified so far and a heterozygosity of 0.75.

Genetic analysis of a kindred with X-linked mental handicap and retinitis pigmentosa.

A kindred is described in which X-linked nonspecific mental handicap segregates together with retinitis pigmentosa. Carrier females are mentally normal but may show signs of the X-linked retinitis pigmentosa carrier state and become symptomatic in their later years. Analysis of polymorphic DNA markers at nine loci on the short arm of the X chromosome shows that no crossing-over occurs between the disease and Xp11 markers DXS255, TIMP, DXS426, MAOA, and DXS228. The 90% confidence limits show that the locus is in the Xp21-q21 region. Haplotype analysis is consistent with the causal gene being located proximal to the Xp21 loci DXS538 and 5'-dystrophin on the short arm of the X chromosome. The posterior probability of linkage to the RP2 region of the X chromosome short arm (Xp11.4-p11.23) is .727, suggesting the possibility of a contiguous-gene-deletion syndrome. No cytogenetic abnormality has been identified.

Heterogeneity analysis in 40 X-linked retinitis pigmentosa families.

Analysis of genetic heterogeneity in 40 kindreds with X-linked retinitis pigmentosa (XLRP), with 20 polymorphic markers, showed that significant heterogeneity is present (P = .001) and that 56% of kindreds are of RP3 type and that 26% are of RP2 type. The location of the RP3 locus was found to be 0.4 cM distal to OTC in the Xp21.1 region, and that of the RP2 locus was 6.5 cM proximal to DXS7 in Xp11.2-p11.3. Bayesian probabilities of linkage to RP2, RP3, or to neither locus were calculated. This showed that 20 of 40 kindreds could be assigned to one or the other locus, with a probability > .70 (14 kindreds with RP3 and 6 kindreds with RP2 disease). A further three kindreds were found to be unlinked to either locus, with a probability > .8. The remaining 17 kindreds could not be classified unambiguously. This highlights the difficulty of classifying families in the presence of genetic heterogeneity, where the two loci are separated by an estimated 16 cM.

Linkage analysis in a family with complete type congenital stationary night blindness with and without myopia.

A family is described with X-linked congenital stationary night blindness of the complete type (CSNB1) in which clinical variation between affected males resulted in diagnostic difficulties. In two affected male cousins, one had congenital nystagmus and myopia, while the other was initially thought to have retinitis pigmentosa with optic atrophy and was hyperopic. The diagnosis of X-linked congenital stationary night blindness was established by clinical, psychophysical and electrophysiological criteria, and DNA markers flanking the CSNB1 locus were analysed in the family. The results show that both affected males have inherited the same haplotype from their carrier mothers, excluding the possibility that a myopia gene in linkage disequilibrium with CSNB1 has recombined with this locus.

Linkage analysis in X-linked congenital stationary night blindness.

X-linked congenital stationary night blindness (XL-CSNB) is a nonprogressive disorder of the retina, characterized by night blindness, reduced visual acuity, and myopia. Previous studies have localized the CSNB1 locus to the region between OTC and TIMP on the short arm of the X chromosome. We have carried out linkage studies in three XL-CSNB families that could not be classified as either complete or incomplete CSNB on the criteria suggested by Miyake et al. (1986. Arch. Ophthalmol. 104: 1013-1020). We used markers for the DXS538, DMD, OTC, MAOA, DXS426, and TIMP loci. Two-point analyses show that there is close linkage between CSNB and MAOA (theta max = 0.05, Zmax = 3.39), DXS426 (theta max = 0.06, Zmax = 2.42), and TIMP (theta max = 0.07, Zmax = 2.04). Two multiply informative crossovers are consistent with CSNB lying proximal to MAOA and distal to DXS426, respectively. Multipoint analysis supports this localization, giving the most likely order as DMD-17 cM-MAOA-7.5 cM-CSNB-7.5 cM-DXS426/TIMP-cen, and thus refines the localization of CSNB.

Magnesium absorption: mechanisms and the influence of vitamin D, calcium and phosphate.

Magnesium absorption has been studied in both humans and animals under diverse experimental conditions. As a result, the data often appear confusing and conflicting. In this review we attempt to summarize information concerning Mg absorption and, where possible, to reconcile apparently conflicting observations. Most studies suggest that Mg is absorbed predominantly in the distal intestine. At usual Mg intakes, Mg absorption occurs primarily by intercellular diffusional and solvent drag mechanisms. There is evidence for a saturable component of Mg absorption in the small intestine and the descending colon that is important at low dietary Mg intakes. Pharmacological doses of vitamin D increase Mg absorption in both vitamin D-deficient and vitamin D-replete animals. A substantial amount of Mg absorption, however, occurs independent of vitamin D. In addition, vitamin D may reduce Mg retention through increases in urinary Mg excretion. Intestinal interactions between Mg and calcium or phosphate have been demonstrated in both humans and animals. The nature of these interactions cannot be readily explained by data currently available.

Comparison of calcium and magnesium absorption: in vivo and in vitro studies.

Transport characteristics of Ca and Mg were compared at three different levels of the absorptive process in male (120-170 g) Wistar rats. Balance studies in intact rats revealed that fractional Ca absorption decreased with increased Ca intake so that net Ca absorption remained constant. Fractional Mg absorption decreased modestly with increased Mg intake so that net Mg absorption increased proportionately with increased dietary Mg. Everted duodenal sacs demonstrated the presence of active Ca absorption with serosal-to-mucosal (S/M) ratio of 2.65 +/- 0.20 (n = 6), which was greater than unity (P less than 0.001). In contrast, the S/M for Mg did not exceed unity. Mucosal duodenal Ca uptake exhibited a large saturable (Michaelis constant of 4.80 +/- 0.34 mM, maximal velocity of 4.71 +/- 0.13 nmol.min-1.mg-1) and a small nonsaturable component (0.12 +/- 0.01 nmol.min-1.mg-1) in 5-wk-old rats (120 g). In 72-wk-old rats (600 g) the diffusional component of Ca uptake became predominant, and the slope increased significantly to 0.32 +/- 0.01 (P less than 0.05). Duodenal Mg uptake was completely concentration dependent and exhibited no age-related changes.

Vitamin D-independent regulation of calcium and phosphate absorption.

Convincing evidence for the stimulatory action of 1,25-dihydroxyvitamin D (1,25(OH2)D) on transcellular absorption of calcium (Ca) and inorganic phosphate (P) has led to the consensus that this hormone is the major regulator of Ca and P absorption. Careful review of the literature, however, suggests important regulation of Ca and P absorption by factors and agents other than those mediated by vitamin D. Thus, in rapidly growing neonatal rats, the intestine is insensitive to vitamin D and Ca absorption is entirely mediated through passive mechanisms. Patterns of change in Ca absorption associated with pregnancy and lactation are identical in vitamin D-replete and vitamin D-deplete rats. The presence of active Ca and P absorption in young, growing rats rigidly deprived of vitamin D and of active Ca and P secretion in mature rats optimally replete with vitamin D, also suggests the participation of non-vitamin D factors in the regulation of intestinal Ca and P absorption. The possibility that Ca and P in the peri-enterocyte environment may regulate their own absorption is discussed. Kinetic analysis of 1,25(OH2)D-induced transport mechanisms indicates that saturation would occur at low substrate concentrations, thus raising the question whether these mechanisms would have major regulatory roles under normal dietary conditions. There is also suggestive evidence indicating that even under conditions of low dietary Ca or P intake, the adaptive changes in intestinal absorption may not be mediated by vitamin D alone. Bile salts, lactose and prolactin are discussed as examples of agents which can stimulate Ca and/or P absorption through vitamin D-independent mechanisms.