Duration of benefit following completion of pulmonary rehabilitation in interstitial lung disease-an observational study

BACKGROUND

It remains unclear for how long the benefits of pulmonary rehabilitation (PR) last in interstitial lung disease (ILD). An increasing number of ILD patients complete PR and it is vital they be offered the most beneficial approaches.

METHODS

This is a retrospective, observational study of a cohort with ILD who had completed PR. Incremental shuttle walk (ISWT) and chronic respiratory disease questionnaire (CRDQ) were compared before PR, at course completion, and 6/12 months follow-up. Focus group discussions with ILD participants who had completed PR and their carers established qualitative views on existing and potential future PR provision.

RESULTS

79 participants with ILD were identified at course completion, with 39 followed to 12 months. 11 participants died during follow-up. Initial benefits from PR were not sustained at 6 months (ISWT change 0.0m (95% CI-23.2 to 23.2 m), CRDQ change 2.5 (95% CI-2.4 to 7.4)) and 12 months (ISWT change-0.7 m (95% CI-37.3 to 35.9 m), CRDQ change 4.0 (95% CI-2.2 to 10.2)). Continued home exercise gave longer lasting benefit in exercise capacity. Focus group discussions highlighted the value attached to PR and suggested areas for improvement.

CONCLUSIONS

Standard PR gives initial benefits in participants with ILD who complete the course, however these are not sustained. Tailored approaches to this group would be appreciated by this group and should be explored.

Ecological conditions of ponds situated on blast furnace slag deposits located in South Gare Site of Special Scientific Interest (SSSI), Teesside, UK

Slag, a by-product from the iron and steel industry, has a range of applications within construction and is used in wastewater treatment. Historically considered a waste material, little consideration was given to the environmental impacts of its disposal. South Gare (a Site of Special Scientific Interest) located at the mouth of the Tees estuary, UK, formed on slag deposits used to create a sea wall and make the land behind permanent. Over time, ponds formed in depressions with the water chemistry, being significantly impacted by the slag deposits. Calcium levels reached 504 mg/L, nitrate 49.0 mg/L and sulphate 1,698 mg/L. These levels were also reflected in the composition of the sediment. pH (5.10-9.90) and electrical conductivity (2,710-3,598 µS/cm) were variable but often notably high. Pb, Cu and Cd were not present within the water, whilst Zn ranged from 0.027 to 0.37 mg/L. Heavy metal levels were higher in surface sediments. Zinc was most dominant (174.3-1,310.2 mg/L) followed by Pb (9.9-431 mg/L), Cu (8.4-41.8 mg/L) and Cd (0.4-1.1 mg/L). A sediment core provided a historical overview of the ponds. The ponds were unfavourable for aquatic biodiversity and unsuitable for drinking water abstraction.

Ectopic fat and insulin resistance: pathophysiology and effect of diet and lifestyle interventions

The storage of triglyceride (TG) droplets in nonadipose tissues is called ectopic fat storage. Ectopic fat is associated with insulin resistance and type 2 diabetes mellitus (T2DM). Not the triglycerides per se but the accumulation of intermediates of lipid metabolism in organs, such as the liver, skeletal muscle, and heart seem to disrupt metabolic processes and impair organ function. We describe the mechanisms of ectopic fat depositions in the liver, skeletal muscle, and in and around the heart and the consequences for each organs function. In addition, we systematically reviewed the literature for the effects of diet-induced weight loss and exercise on ectopic fat depositions.

Mitochondrial mutation detection using enhanced multiplex denaturing high-performance liquid chromatography

In this study, we investigated the presence of mutations within the mitochondrial genome in 40 Caucasian subjects using an enhanced multiplex denaturing high-performance liquid chromatography (DHPLC) approach. The enhanced DHPLC approach has increased sensitivity and throughput, and reduced analysis time per individual sample compared to conventional methods. This technique involved amplifying the mitochondrial genome in 18 fragments ranging in size from 300 to 2000 bp using a novel proofreading polymerase (Optimase, Transgenomic Inc., Omaha, NE) with a low misincorporation rate. Fourteen of these fragments underwent subsequent restriction digestion using a combination of five restriction enzymes to enable multiplex DHPLC analysis; the remaining four underwent conventional DHPLC. Using this complete mitochondrial genome-screening approach, we confirmed a number of previously reported mutations and additionally identified a large number of novel mutations using an enhanced DHPLC technique.

Multi-View Active Appearance Models: application to X-ray LV angiography and cardiac MRI

This paper describes a Multi-View Active Appearance Model (AAM) for coherent segmentation of multiple cardiac views. Cootes' AAM framework was adapted by considering shapes and intensities from multiple views, while eliminating trivial difference in object pose in different views. This way, the coherence in organ shape and intensities between different views is modeled, and utilized during image search. The method is validated in two substantially different and novel applications: segmentation of combined end-diastolic and end-systolic left ventricular X-ray angiograms, and simultaneous segmentation of a combination of four chamber, two chamber and short-axis cardiac MR views.

Rapid denaturing high-performance liquid chromatography (DHPLC) for mutation scanning of the transforming growth factor β3gene using a novel proof-reading polymerase

We have utilized a novel variation on the conventional denaturing high-performance liquid chromatography (DHPLC) technology, which we term rapid DHPLC, combining changes in instrumentation, cartridge technology and analysis conditions to enable significant increases in throughput to be achieved. In addition, the use of a novel proof-reading polymerase for sample amplification with a low misincorporation rate enables simplification of the DHPLC patterns and hence enhanced mutation detection recognition. This scheme for increasing DHPLC throughput has been tested by scanning the transforming growth factor (TGF) beta3 gene for the presence of mutations for which there is limited published or on-line data available regarding the presence of gene polymorphisms. TGFbeta isoforms have multiple roles in cell division, growth, proliferation, transformation and differentiation. TGFbeta3 is a TGFbeta cytokine isoform, and has an important role in embryogenesis, cell differentiation and wound healing. The TGFbeta3 gene consists of seven exons and six introns spanning 43 000 bp of the human genome on chromosome 14q23-24. The rapid DHPLC approach enabled scanning of all seven exons and part of the promoter region (1000 bp upstream from exon 1 in the 5'-flanking regions) of the TGFbeta3 gene in 95 Caucasian individuals in only 8 days, in comparison to the 17 days it would have previously taken. Mutations were clearly identified in the promoter region of the TGFbeta3 gene but were absent from the exonic regions. Understanding the genetic variations affecting the TGFbeta3 gene is important as this molecule has multiple regulatory functions on a variety of cell types.

Expression, purification and crystallization of Aspergillus nidulans NmrA, a negative regulatory protein involved in nitrogen-metabolite repression

The NmrA repressor protein of Aspergillus nidulans was overproduced in Escherichia coli and purified to homogeneity. Gel-exclusion chromatography showed that NmrA was monomeric in solution under the buffer conditions used. The protein was crystallized in three forms, belonging to trigonal, monoclinic and hexagonal space groups. Two of these crystal forms (A and B) diffract to high resolution and thus appear suitable for structure determination. Crystal form A belongs to space group P3((1))21, with unit-cell parameters a = b = 76.8, c = 104.9 A. Crystal form B belongs to space group C2, with unit-cell parameters a = 148.8, b = 64.3, c = 110.2 A, beta = 121.8 degrees.

Current and future potential roles of the platinum drugs in the treatment of ovarian cancer

The discovery of cisplatin more than two decades ago was the most important therapeutic advance in the treatment of ovarian cancer. Today, cisplatin or carboplatin in combination with paclitaxel is the most commonly used first-line treatment for patients with advanced ovarian cancer. Although platinum drugs remain a critical component of chemotherapy in this type of cancer, cumulative toxicities can limit their use. These toxicities include nephrotoxicity, neurotoxicity and ototoxicity with cisplatin and myelosuppression with carboplatin. Although these adverse events can often be managed, the interventions themselves can complicate and add to the costs of treatment. Importantly, acquired resistance to traditional platinum drugs often develops in patients with ovarian cancer and can limit the usefulness of these drugs. Research into new platinum drugs has focused on identifying compounds with improved tolerability profiles and, importantly, those which can circumvent mechanisms of platinum resistance. New platinum drugs currently under development that are showing promise in ovarian cancer include oxaliplatin, nedaplatin, satraplatin, BBR3464 and ZD0473. If the encouraging in vitro activity shown by new compounds, such as ZD0473 and BBR3464, translates into efficacy in the clinic, they may offer an extended spectrum of activity which includes patients with ovarian cancer resistant to the classical platinum drugs.

Agonist-induced functional desensitization of recombinant human 5-HT2 receptors expressed in CHO-K1 cells

The desensitization characteristics of recombinant human 5-HT(2A), 5-HT(2B), and 5-HT(2C) receptors (VSV and INI isoforms) stably expressed in CHO-K1 (Chinese hamster ovary) cells was investigated by calcium fluorimetry. Comparative desensitization characteristics of the agonists 5-HT, m-chlorophenylpiperazine (mCPP), and 2,5-dimethoxy-4-iodoamphetamine hydrobromide (DOI) were performed. Human 5-HT(2C (INI)) receptors exhibited a greater degree of desensitization to all agonists tested than edited 5-HT(2C (VSV)) receptors. A 2-hr exposure to 5-HT resulted in a significantly larger reduction in response upon re-exposure to 5-HT at 5-HT(2C (INI)) receptors, as compared to 5-HT(2C (VSV)) receptors (72% and 47% respectively, P < 0.01). Both receptor isoforms were expressed at similar densities. Human 5-HT(2B) receptors exhibited the most dramatic degree of desensitization, with prior exposure to 5-HT reducing subsequent response to 5-HT by 80%, with an extremely rapid time-course (t(1/2) < 5 min). The response at 5-HT(2A) receptors was reduced by 54%. The partial agonists mCPP and DOI also elicited desensitization, generally in line with their relative efficacies at each receptor, but exhibited more rapid kinetic profiles than 5-HT. Heterologous desensitization of an endogenously expressed G(q/11)-coupled purinergic receptor was also examined following preincubation of the cell lines with 10 microM 5-HT. Only stimulation of 5-HT(2C (VSV)) receptors resulted in a profound attenuation of subsequent ATP mediated responses. These results demonstrate differing degrees of both homologous and heterologous desensitization of 5-HT(2) receptors. Additionally, the different desensitization profiles of 5-HT(2C (INI)) and 5-HT(2C (VSV)) receptor may be due to signal transduction differences caused by RNA editing.

Characterisation of agonist binding on human 5-HT2C receptor isoforms

The 5-HT2C receptor is expressed in different isoforms as a result of mRNA editing. Both INI (unedited) and VSV (a fully edited version) isoforms are abundant in rat brain. The VSV isoform lacks the high affinity recognition site for 5-HT, which may be caused by low efficiency coupling to G-proteins. In this study we have investigated the pharmacology of the agonist binding site of these two isoforms of the 5-HT2C receptor. The VSV isoform was expressed in Chinese hamster ovary cells (CHO) and the INI isoform in both Chinese hamster ovary cells and human embryonic kidney cells (HEK-293). Saturation analysis using [3H]5-HT revealed high and low affinity recognition sites on the INI isoform in both cell types whilst the VSV isoform did not have the high affinity binding site for [3H]5-HT. Displacement studies were undertaken using [3H]5-HT to label the receptors. In these studies the affinity of agonists (5-HT, Ro600175 ((S)-2-(6-Chloro-5-fluoroindol-1-yl)-1-methylethylamine), MK212 (6-Chloro-2-(piperazinyl) pyrazine), mCPP (1-(m-chlorophenyl)-piperazine), TfMPP (N-(m-trifluoromethylphenyl)piperazine), DOI (1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane), DOB (1-(4-bromo-2,5-dimethoxyphenyl)-2-aminopropane) and 8OH-DPAT (8-hydroxy-2-(di-N-propylamino)tetralin) was higher at the INI isoform, whilst antagonist affinity (ketanserin and mesulergine) did not change between the two receptor isoforms. There were no differences between the INI isoform expressed in the CHO and HEK-293. This suggests that the INI isoform of the 5-HT2C receptor is pharmacologically similar to the VSV form of the 5-HT2C receptor but that it couples more efficiently to G-proteins.

Identification of many crystal forms of Aspergillus nidulans dehydroquinate synthase

Extensive crystallization trials of Aspergillus nidulans dehydroquinate synthase, a potential novel target for antimicrobial drugs, in complexes with different ligands have resulted in the identification of nine crystal forms. Crystals of unliganded DHQS, binary complexes with either the substrate analogue, carbaphosphonate or the cofactor NADH, as well as the ternary DHQS-carbaphosphonate-cofactor complex, were obtained. The ternary complex crystallizes from ammonium sulfate and CoCl(2) in space group P2(1)2(1)2, with unit-cell parameters a = 133.8, b = 86.6, c = 74.9 A. The binary carbaphosphonate complex crystallizes from PEG 6000 in space group P2(1)2(1)2(1), with a = 70.0, b = 64.0, c = 197.6 A, and the binary cofactor complex crystallizes from PEG 3350 and sodium potassium tartrate in space group P2(1), with a = 83.7, b = 70.4, c = 144.3 A, beta = 89.2 degrees. DHQS in the absence of ligands crystallizes in space group P2(1), with a = 41.0, b = 68.9, c = 137.7 A, beta = 94.8 degrees. Each of these crystal forms are suitable for high-resolution structure determination. Structures of a range of DHQS-ligand complexes will be of value in the structure-based design of novel antimicrobial drugs.

Comparison of gated single-photon emission computed tomography with magnetic resonance imaging for evaluation of left ventricular function in ischemic cardiomyopathy

To perform a head-to-head comparison between magnetic resonance imaging (MRI) and gated single-photon emission computed tomography (SPECT) for the evaluation of left ventricular (LV) function (LV ejection fraction [LVEF], LV volumes, and regional wall motion) in patients with ischemic cardiomyopathy, we studied 22 patients with chronic coronary artery disease and LV dysfunction. Multislice, multiphase echoplanar MRI was performed with Philips Gyroscan ACS-NT15. Image analysis was performed using the MASS software package to determine LV end-systolic volume, LV end-diastolic volume, and LVEF. The same parameters were calculated using quantitative gated SPECT software (QGS, Cedars-Sinai Medical Center). The different parameters were compared using linear regression, and correlation coefficients were calculated. Regional wall motion was also determined from both techniques, according to a 13-segment model and a 3-point scoring system (from 1 = normokinesia to 3 = akinesia or dyskinesia). A summed wall motion score was also calculated for MRI and gated SPECT. Good correlations were found between MRI and gated SPECT for all parameters: (1) summed wall motion scoreMRI versus summed wall motion scoreSPECT: y = 0.74x + 8.0, r = 0.88, p <0.01; (2) LV end-systolic volumeMRI versus LV end-systolic volumeSPECT: y = 0.94x - 12.3, r = 0.87, p <0.01; (3) LV end-diastolic volumeMRI versus LV end-diastolic volumeSPECT: y = 0.93x - 18.4, r = 0.84, p <0.01; and (4) LVEFMRI versus LVEFSPECT: y = 0.97x + 0.68, r = 0.90, p <0.01. For regional wall motion, an exact agreement of 83% was found, with a kappa statistic of 0.77 (95% confidence intervals 0.71 to 0.83, SE 0.03), indicating essentially excellent agreement. Thus, close and significant correlations were observed for assessment of LVEF, LV volumes, and regional wall motion by MRI and gated SPECT in patients with ischemic cardiomyopathy.

Characterization of iodoacetate-mediated neurotoxicity in vitro using primary cultures of rat cerebellar granule cells

The neuroprotective efficacy of antioxidant molecules against iodoacetate (IAA) neurotoxicity in rat cerebellar granule cell (CGC) cultures was investigated. Transient exposure to IAA caused a concentration-dependent decrease in cell viability (ED50 = 9.8 microM). Dizocilpine maleate (MK-801), and 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzo[f]quinoxaline-7-sulfonamide (NBQX), failed to prevent IAA toxicity. Certain antioxidant molecules were shown to be neuroprotective against IAA when combined with MK-801 but were ineffective when administered alone. (S)-(-)-Trolox, butylated hydroxytoluene (BHT), and U-83836E exhibited EC50 values of 78, 5.9, and 0.25 microM, respectively, in the presence of 10 microM MK-801. IAA also induced an increase in intracellular oxidative stress, which was quenched by the antioxidants (in the presence of MK-801) in cultures loaded with the oxidant sensitive dye 2'7'-dichlorodihydrofluorescein diacetate (DCFH-DA).

Magnetic resonance imaging of ischemic heart disease: why cardiac magnetic resonance imaging will play a significant role in the management of patients with coronary artery disease

The role of magnetic resonance imaging in the diagnosis of ischemic heart disease has great potential impact on patient management, because a number of aspects of ischemic heart disease can be evaluated in one imaging session. High resolution coronary magnetic resonance angiography is currently available, although several technical improvements are awaited to make the technique routinely applicable. A major advance will probably include the availability of magnetic resonance blood pool contrast agents to improve vessel visualization. Contrast media, in combination with either first pass or delayed myocardial scanning, will also play an important role in myocardial perfusion imaging. Functional magnetic resonance assessment of regional and global ventricular function is currently a well-established technique and is considered a new gold standard, which may impact on routine cardiology practice. This review summarizes some of the recent magnetic resonance developments for evaluating various aspects of ischemic heart disease, including magnetic resonance coronary angiography, flow imaging, and imaging of myocardial perfusion and function.

Functional characterization of agonists at recombinant human 5-HT2A, 5-HT2B and 5-HT2C receptors in CHO-K1 cells

1. The goal of this study was to characterize the agonist pharmacology of human 5-HT2A, 5-HT2B and 5-HT2C (VSV) receptors expressed in CHO-K1 (Chinese hamster ovary) cells. 2. We used a fluorometric imaging plate reader (FLIPR) which allows rapid detection of rises in intracellular calcium levels upon the addition of agonists. 3. Stimulation of all three receptors by 5-HT caused a robust concentration dependent increase in intracellular calcium levels. No such effect was observed from non-transfected control CHO-K1 cells. 4. The rank order of potency of agonists at the different receptor subtypes varied. Tryptamines, BW-723C86, d-norfenfluramine, Ro 60-0175 and LSD exhibited the following rank order of potency; 5-HT2B>5-HT2C>5-HT2A. Piperazines such as m-Chlorophenylpiperazine (mCPP), ORG-12962, MK-212 and also ORG-37684 exhibited a rank order of potency of 5-HT2C>5-HT2B>5-HT2A. The phenylisopropylamines DOI and DOB had a rank order of 5-HT2A>5-HT2B>5-HT2C. 5. Many agonists tested had partial agonist actions when compared to 5-HT, and a wide range of relative efficacies were exhibited, which was cell line dependent. For example, mCPP had a relative efficacy of 65% at 5-HT2C receptors but <25% at either 5-HT2A or 5-HT2B receptors. 6. Interpretation of literature values of functional assays using different cell lines, different receptor expression levels and different receptor isoforms, is complex. Species differences and the previous use of antagonist radioligands to characterize agonist potency in binding assays emphasizes the importance of studying agonists in the same experiment using the same assay conditions and parental cell lines.

Dopamine and nicotinic receptor binding and the levels of dopamine and homovanillic acid in human brain related to tobacco use

Reports of a reduction in the risk of developing Parkinson's disease and Alzheimer's disease in tobacco smokers, together with the loss of high-affinity nicotine binding in these diseases, suggest that consequences of nicotinic cholinergic transmission may be neuroprotective. Changes in brain dopaminergic parameters and nicotinic receptors in response to tobacco smoking have been assessed in this study of autopsy samples from normal elderly individuals with known smoking histories and apolipoprotein E genotype. The ratio of homovanillic acid to dopamine, an index of dopamine turnover, was reduced in elderly smokers compared with age matched non-smokers (P<0.05) in both the caudate and putamen. Dopamine levels were significantly elevated in the caudate of smokers compared with non-smokers (P<0.05). However there was no significant change in the numbers of dopamine (D1, D2 and D3) receptors or the dopamine transporter in the striatum, or for dopamine D1 and D2 receptors in the hippocampus in smokers compared with non-smokers or ex-smokers. The density of high-affinity nicotine binding was higher in smokers than non-smokers in the hippocampus, entorhinal cortex and cerebellum (elevated by 51-221%) and to a lesser extent in the striatum (25-55%). The density of high-affinity nicotine binding in ex-smokers was similar to that of the non-smokers in all the areas investigated. The differences in high-affinity nicotine binding between smokers and the non- and ex-smokers could not be explained by variation in apolipoprotein E genotype. There were no differences in alpha-bungarotoxin binding, measured in hippocampus and cerebellum, between any of the groups. These findings suggest that chronic cigarette smoking is associated with a reduction of the firing of nigrostriatal dopaminergic neurons in the absence of changes in the numbers of dopamine receptors and the dopamine transporter. Reduced dopamine turnover associated with increased numbers of high-affinity nicotine receptors is consistent with attenuated efficacy of these receptors in smokers. A decrease in striatal dopamine turnover may be a mechanism of neuroprotection in tobacco smokers that could delay basal ganglia pathology. The current findings are also important in the interpretation of measurements of nicotinic receptors and dopaminergic parameters in psychiatric conditions such as schizophrenia, in which there is a high prevalence of cigarette smoking.

Apolipoprotein E and alpha-1 antichymotrypsin polymorphism genotyping in Alzheimer's disease and in dementia with Lewy bodies. Distinctions between diseases

The possibility of gene interactions in Alzheimer's disease (AD) has been suggested by the finding of an association of the AA genotype of the alpha-1 antichymotrypsin (AACT) gene and the apolipoprotein E (apoE) epsilon 4/4 genotype in AD. We tested this possibility by genotyping a large series of clinically and neuropathologically confirmed cases of AD and a series of cases with dementia with Lewy bodies (DLB) with a matched control group for the AACT locus and apoE. ApoE genotyping showed the established finding of an increased frequency of the apoE epsilon 4 allele in AD and in DLB. The AD and DLB groups differed between each other with a higher epsilon 2 allele frequency and a reduced incidence of the epsilon 4/4 genotype in DLB. Differences in the apoE frequencies may account for some of the differences between the two diseases. No association was found for the AACT A allele in AD or DLB in the groups as a whole or when stratified with respect to apoE, with the exception of a trend showing an increased incidence of the apoE epsilon 4/4 AACT AA genotype combination in AD patients (chi 2 = 3.18, p = 0.07), although in DLB this was not apparent (chi 2 = 0.0, p = 1.0). The AACT A allele is not a major risk factor for late-onset AD or DLB.

No association between a polymorphism in the presenilin 1 gene and dementia with Lewy bodies

The discovery of mis-sense mutations linking the presenilin-1 (PS-1) gene on chromosome 14 to Alzheimer's disease (AD) has lead to a thorough investigation of this locus. The PS-1 gene contains a polymorphism creating two alleles. The most common allele, allele 1, has been linked with late-onset AD. Given the clinical and pathological overlaps between AD and dementia with Lewy bodies we genotyped 46 pathologically confirmed cases of dementia with Lewy bodies for the PS-1 polymorphism and compared the allelic frequencies with 87 age-matched control cases and 103 age-matched AD cases. No association between dementia with Lewy bodies and PS-1 allele 1 was found either in the group as a whole, or in the group stratified according to dosage of the epsilon4 allele of the apolipoprotein E gene. We suggest that either the presenilin polymorphism has no effect on dementia with Lewy bodies or that any linkage is precluded by another, more influential, locus.

No association between an intronic polymorphism in the presenilin-1 gene and Alzheimer's disease

Mutations in the presenilin-1 (PS-1) gene are believed to be responsible for the majority of familial early-onset Alzheimer's disease (AD). The finding of an intronic polymorphism in the PS-1 gene prompted an investigation into its relevance in AD. An association between homozygosity for the most common allele (allele 1) in this intronic polymorphism and late-onset AD has been shown and has been confirmed by others though some studies do not support these findings. We genotyped a large series of sporadic AD cases (n = 120) and age-matched controls (n = 108) for this intronic polymorphism. We then compared both the frequency of allele 1 and allele 1 homozygosity between the AD group as a whole and in early-onset (n = 26) and late-onset (n = 94) groups with age-matched control groups (n = 29 and n = 79, respectively). No increase in the frequency or homozygosity of allele 1 in either the AD group as a whole, or when divided into late- and early-onset cases was found. Increases in the frequency of allele 1 homozygotes and in the number of non-apolipoprotein E epsilon4 carrying allele 1 homozygotes/heterozygotes was demonstrated in the early-onset AD cases although these values did not reach significance. We conclude that there is no relationship between this intronic polymorphism in the PS-1 gene and AD in the homogenous population genotyped in this study.

Dornase alfa. A review of pharmacoeconomic and quality-of-life aspects of its use in cystic fibrosis

Cystic fibrosis (CF) is a fatal hereditary disease; patients with CF have an average lifespan of 30 years. By cleaving neutrophil-derived DNA, dornase alfa (recombinant human deoxyribonuclease I) decreases the adhesiveness and visco-elasticity of sputum in the infected lungs of patients with CF. As a result, respiratory function is improved in patients with all degrees of disease severity, and the relative risk of pulmonary exacerbations is reduced in patients with mild to moderate disease. Resource utilisation (days spent in hospital or receiving parenteral antibiotics) in patients with mild to moderate disease is also reduced by dornase alfa, as evidenced by a placebo-controlled trial in > 900 patients. Cost savings generated by these reductions in resource use during 24 weeks of dornase alfa therapy offset about 17 to 37.5% of the acquisition cost of the drug, depending on local cost data for various countries. Reductions in resource utilisation with dornase alfa have not been observed in patients with severe disease. Available cost-effectiveness and cost-utility analyses are not fully published. One analysis estimated that the incremental cost of avoiding one hospitalisation was about $Can 15,000 relative to standard therapy after 1 year of treatment. Informal analysis in the UK suggests a cost per quality-adjusted life-year of 25,000 Pounds for dornase alfa. Some quality-of-life (QOL) domains (mainly cough frequency and chest congestion) have shown modest improvement in patients treated with dornase alfa, mainly those with mild CF. Persuasive evidence of QOL benefit is lacking in those with more severe disease. Identifying patients most likely to benefit from dornase alfa therapy is essential to maximise clinical and cost benefits. The lack of a demonstrated reduction in resource utilisation in patients with severe CF makes its use more difficult to justify economically in this group than in those with less severe disease. However, in the absence of other treatments for this group, economic considerations must be weighed against clinical benefits. In conclusion, the acquisition cost of dornase alfa is partially offset by savings gained by reducing resource utilisation in patients with mild to moderate CF, and the drug appears to improve quality of life in some patients, mostly those with less severe disease. However, in the absence of guidance from definitive cost-effectiveness analyses, individual healthcare providers must make their own decisions about how best to provide dornase alfa to patients with CF in a rational and cost-justifiable manner.

Molecular biology of APO E alleles in Alzheimer's and non-Alzheimer's dementias

Current research into the aetiology of the dementias is focused upon genetic factors which give rise to the disease process. Recently the Apolipoprotein E gene (APO E) and in particular the epsilon 4 allele has been shown to be a risk factor for late onset Alzheimer's disease (AD) where there is an increased frequency of the epsilon 4 allele. The epsilon 4 allele has also been shown to reduce the age at onset of dementia in AD in a dose dependent manner, with the epsilon 2 allele having an opposing effect. We have genotyped a large series of clinically and neuropathologically confirmed cases of AD and found the expected increase in the Apolipoprotein epsilon 4 allele frequency when compared to a control population. Similarly, in Lewy Body Dementia (LBD) an increased epsilon 4 frequency is also found though a normal epsilon 2 frequency exists, unlike in AD where the epsilon 2 frequency is reduced. No changes in APO E allele frequencies were found in presenile AD, Parkinson's disease with or without dementia, or in Down's syndrome. No association was found between any of the APO E alleles and the histopathological indices of AD, cortical senile plaques and neurofibrillary tangles, in any disease category. Neurochemical indicators of AD, loss of choline acetyltransferase activity was also unaffected by APO E genotype. Whilst their appears to be a strong association between the APO E allele and AD and also in LBD, other related neurodegenerative disorders associated with dementia do not show such a linkage. Changes in the epsilon 2 allele frequency may indicate a genetic difference between AD and LBD. The epsilon 4 allele does not appear to influence the burden of AD type pathology and this is particularly relevant given the relative lack of NFT in LBD indicating that factors other than SP or NFT may govern the onset of dementia.

Genetic regulation of the quinic acid utilization (QUT) gene cluster in Aspergillus nidulans

A large number of quinic acid non-utilizing qut mutants of Aspergillus nidulans deficient in the induction of all three quinic acid specific enzymes have been analysed. One class the qutD mutants, are all recessive and are non-inducible at pH 6.5 due to inferred deficiency in a quinate ion permease. Two regulatory genes have been identified. The QUTA gene encodes an activator protein since most qutA mutants are recessive and non-inducible although a few fully dominant mutants have been found. The QUTR gene encodes a repressor protein since recessive mutations are constitutive for all three enzyme activities. Rare dominant non-inducible mutants which revert readily to yield a high proportion of constitutive strains are inferred to be qutR mutants defective in binding the inducer. The gene cluster has been mapped in the right arm of chromosome VIII in the order: centromere - greater than 50 map units - ornB - 12 map units - qutC (dehydratase)-0.8 map units-qutD (permease), qutB (dehydrogenase), qutE (dehydroquinase), qutA (activator)-4.4 map units - qutR (repressor)-20 map units - galG. This organization differs from that of the qa gene cluster in Neurospora crassa, particularly in the displacement of qutC and qutR.

Identification and isolation of a putative permease gene in the quinic acid utilization (QUT) gene cluster of Aspergillus nidulans

Mutations in the qutD gene of Aspergillus nidulans cause the loss of ability to grow upon quinic acid as sole carbon source in media at normal pH 6.5 and failure to induce three enzyme activities specifically required for metabolism to protochatechuic acid. All 9 qutD mutants recovered are recessive and have been found to be pH sensitive, growing strongly on quinic acid media at pH 3.5 and producing significant induced enzyme activities. These properties are consistent with the hypothesis that the QUTD gene encodes an essential component of a permease required for transport of quinate ion into mycelium at pH 6.5. The QUTD gene has been located within the cloned QUT gene cluster of A. nidulans by transformation of qutD mutants with fragments of cloned sequences from phage lambda-Q1. The QUTD locus is in a region distinct from other QUT genes and which contains sequences homologous to the QA-Y gene in the corresponding QA gene cluster of Neurospora crassa.