The CD11b promoter directs high-level expression of reporter genes in macrophages in transgenic mice [published erratum appears in Blood 1995 Apr 1;85(7):1983]

CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.     

Functional role of CLC-2 chloride inward rectifier channels in cardiac sinoatrial nodal pacemaker cells

A novel Cl⁻ inward rectifier channel (Cl,ir) encoded by ClC-2, a member of the ClC voltage-gated Cl⁻ channel gene superfamily, has been recently discovered in cardiac myocytes of several species. However, the physiological role of Cl,ir channels in the heart remains unknown. In this study we tested the hypothesis that Cl,ir channels may play an important role in cardiac pacemaker activity. In isolated guinea-pig sinoatrial node (SAN) cells, Cl,ir current was activated by hyperpolarization and hypotonic cell swelling. RT-PCR and immunohistological analyses confirmed the molecular expression of ClC-2 in guinea-pig SAN cells. Hypotonic stress increased the diastolic depolarization slope and decreased the maximum diastolic potential, action potential amplitude, APD₅₀, APD₉₀, and the cycle-length of the SAN cells. These effects were largely reversed by intracellular dialysis of anti-ClC-2 antibody, which significantly inhibited Cl,ir current but not other pacemaker currents, including the hyperpolarization-activated non-selective cationic “funny” current (I_f), the L-type Ca²⁺ currents (I_Ca,L), the slowly-activating delayed rectifier I_Ks and the volume-regulated outwardly-rectifying Cl⁻ current (I_Cl,vol). Telemetry electrocardiograph studies in conscious ClC-2 knockout (Clcn2^−/−) mice revealed a decreased chronotropic response to acute exercise stress when compared to their age-matched Clcn2^+/+ and Clcn2^+/− littermates. Targeted inactivation of ClC-2 does not alter intrinsic heart rate but prevented the positive chronotropic effect of acute exercise stress through a sympathetic regulation of ClC-2 channels. These results provide compelling evidence that ClC-2-encoded endogenous Cl,ir channels may play an important role in the regulation of cardiac pacemaker activity, which may become more prominent under stressed or pathological conditions.     

Cardiac risks and management of complications in pregnant women with congenital heart disease

There are a growing number of women with congenital heart disease reaching adulthood and contemplating and/or undergoing pregnancy. However, pregnancy imposes hemodynamic stress on the heart and this can result in maternal, fetal and neonatal complications. Most women with congenital heart disease do well during pregnancy, but some women with high-risk cardiac lesions will not tolerate the hemodynamic changes of pregnancy. Physicians must be aware of the potential risks for the mother both during and after pregnancy, the risks to the fetus and neonate, and the risks and benefits of medications and procedures used during pregnancy. For women with complex cardiac conditions, management during pregnancy benefits from multidisciplinary care involving cardiologists with expertise in pregnancy, obstetricians with expertise in maternal fetal medicine, neonatologists and obstetric anesthetists, among others. This review will focus on the cardiac risks faced by women with congenital heart disease; particularly those at high risk, and on management strategies to mitigate risk and address cardiac complications.     

Characterization of the p67phox gene: genomic organization and restriction fragment length polymorphism analysis for prenatal diagnosis in chronic granulomatous disease

The genetic defect in the p67phox-deficient form of chronic granulomatous disease (CGD) follows an autosomal recessive pattern of inheritance. When genomic DNA from normal individuals is digested with HindIII and probed with p67phox cDNA an allelic restriction fragment length polymorphism (RFLP) of 4.0 kb or 2.3 kb is detected. We cloned and characterized the p67phox gene using the cDNA and sequenced the exon/intron boundaries, mapping 16 exons on the 40-kb gene. The polymorphic region was then sequenced to identify the inheritance pattern of amniocentesis-derived fetal cells by genomic amplification. The proband, a 9-year-old female patient with p67phox-deficient CGD, and her phenotypically normal mother are homozygous for the RFLP marker, whereas the father and two brothers are heterozygous. The fetus was shown to be heterozygous as well, showing it had inherited at least one normal p67phox gene from the father and that it was predicted to have a normal phenotype. Cord blood samples at birth showed normal oxidative function. Amplification allows rapid detection of the inheritance pattern for fetal diagnosis in informative families. We report the genomic structure of p67phox and an amplification-based method for detection of the marker on chromosome 1q25, used here for prenatal diagnosis of CGD.     

Poverty, socio-economic position, social capital and the health of children and adolescents with intellectual disabilities in Britain: a replication

Background When compared with their nonintellectually disabled peers, people with intellectual disabilities (IDs) have poorer health and are more likely to be exposed to poverty during childhood. Given that exposure to child poverty has been linked to poorer health outcomes, we attempted to estimate the extent to which the health inequalities faced by children and adolescents with IDs may be accounted for by their more disadvantaged socio‐economic position. Methods Secondary analysis of data on a nationally representative sample of 12 160 British children aged under 17 years extracted from the Department of Work and Pensions' Families and Children Study. Results After controlling for age and sex, children with IDs were significantly more likely (corrected odds ratio = 2.49) to be reported to have less than good health than their nonintellectually disabled peers. However, 31% of the elevated risk for poorer health was accounted for by between‐group differences in socio‐economic position and social capital. Conclusions A socially and statistically significant proportion of the increased risk of poorer health among children and adolescents with IDs may be attributed to their increased risk of socio‐economic disadvantage.     

The Resident Choice Scale: a measure to assess opportunities for self-determination in residential settings

Background A 26‐item Resident Choice Scale was designed to assess service practices for promoting resident choice. Method The staff working with 560 UK/Irish adults with intellectual disability were interviewed. Specific examples of practices promoting resident choice were requested and independently rated by the interviewer. Results The interrater reliability of Resident Choice items was found to be acceptable (subsample n = 50). The psychometric properties of the Resident Choice Scale total score and scores on eight subscales were also acceptable. Consistently strong associations were found between greater resident choice and greater resident ability and, to a lesser extent, fewer resident challenging behaviours. Few associations were found between resident choice and autism or mental health problems. Even when controlling for resident ability and challenging behaviour, consistent associations were found between greater resident choice and the concurrent variables of greater community presence, fewer institutional practices, and greater user self‐reported satisfaction (subsample n = 50). Conclusions Taken together, this pattern of results indicates that the Resident Choice Scale shows promise as a measure of the environmental opportunities available for adults with intellectual disability to exercise self‐determination. Areas for future research testing the reliability and validity of the Resident Choice Scale are outlined.     

Escalation and Intensification of Radiotherapy for Stage III Non-small Cell Lung Cancer: Opportunities for Treatment Improvement

In this overview we review and model how radiotherapy tumour control and complication rates vary with dose, fractionation, schedule duration, irradiated volume and use of chemotherapy for stage III non-small cell lung cancer (NSCLC), and use the modelling to study the effectiveness of different NSCLC dose-escalation approaches being developed in the UK. Data have been collated for pneumonitis, lung fibrosis, early and late oesophagitis, cord and cardiac complications, and local progression-free survival at 30 months. Dependences of the various end points on treatment-related factors are catalogued and analysed using the linear-quadratic incomplete repair model to account for dose and fractionation effects, making linear corrections for differences in schedule duration, and loosely characterising volume effects using parallel- and series-type concepts. Tolerance limits are calculated for the different end points and distilled into ranges of prescribed dose likely to be tolerable when delivered in 2.5 and 4 week radiation and 6 week chemoirradiation schedules using conformal techniques. Worthwhile (～20%) gains in 30 month local progression-free survival should be achievable at safely deliverable levels of dose escalation. The analysis suggests that longer schedules may be more beneficial than shorter ones, but this finding is governed by the relative rates of tumour and oesophageal accelerated proliferation, which are quite imprecisely known. Consequently escalated 2.5, 4 and 6 week schedules are being developed; each should lead to useful improvements in local control but it is not yet known which schedule will be most effective.