ABSTRACT
BACKGROUND: Candidaemia is an important nosocomial infection, seen frequently in immunocompromised and critically ill patients and increasingly recognised in cystic fibrosis (CF) patients with totally implantable venous access devices (TIVADs). This study aims to investigate the incidence and risk factors for the development of TIVAD-associated candidaemia and to assess the rate of TIVAD-related complications in CF patients. METHODS: A 10-year retrospective study was carried out on adult CF patients attending a single centre. Complications were recorded including the incidence of candidaemia and correlated to clinical parameters. Complication rates were calculated based on incidence per 1000 catheter days. Statistical analysis was performed using Mann-Whitney U test and Fisher's exact test. RESULTS: Fourteen cases of candidaemia were observed in the CF cohort, primarily caused by Candida parapsilosis and Candida albicans. Candidaemia was associated with lower FEV1 (p = 0.0117) and higher frequency of pulmonary exacerbation (p < 0.0001). A TIVAD complication rate of 0.337/1000 catheter days was observed in the CF cohort. Complications included venous thrombosis, stenosis, and port extrusion; complications were independently associated with more frequent pulmonary exacerbations (p = 0.04). CONCLUSIONS: TIVAD complications are observed more commonly in those with lower FEV1 and frequent pulmonary exacerbations, suggesting that candidaemia may be related to antibiotic use and furthermore can occur following invasive procedures causing translocation of fungal species allowing transformation from colonisation to pathogenic infection.
Subject(s)
Candida/pathogenicity , Cystic Fibrosis/complications , Prostheses and Implants/adverse effects , Adult , Cystic Fibrosis/therapy , Female , Humans , Incidence , Male , Retrospective Studies , Risk FactorsABSTRACT
INTRODUCTION: Long-term daily azithromycin therapy reduces the frequency of exacerbations in chronic obstructive pulmonary disease (COPD) in a randomized controlled clinical trial setting. Concerns exist regarding arrhythmic and auditory toxicities from chronic use in the real-world setting. We hypothesized that risk factors for adverse drug reactions to azithromycin would be more frequent than previously reported, that certain specific subgroups would have different frequencies of these risk factors and that the whispered voice test would be a useful test with which to test for hearing deficits. METHODS: Following ethical approval, 47 consecutive hospital-based patients with a mean age 69 years ± 8.2, and with physician-diagnosed COPD (mean FEV1 45.1 ± 18 % predicted), were screened for subjective hearing impairment (screening questions and whispered voice test) and by electrocardiogram for prolonged QTc. Other potential risk factors and contraindications to long-term daily azithromycin were sought. RESULTS: In total, 38 patients (80.9 %) had at least one risk factor or contraindication to azithromycin treatment. 19 patients (40.4 % of total) had subjective hearing impairment. 17 (36.1 %) had prolonged QTc intervals. 4 patients (8.51 %) had contraindicating co-morbidities. Those on long-term oxygen therapy were significantly more likely to have at least one risk factors or contraindications to azithromycin (p = 0.0025). CONCLUSION: In a COPD population who would otherwise potentially be candidates for long-term daily azithromycin therapy, over 80 % had risk factors for complications from long-term daily azithromycin. Preventative treatment with long-term daily azithromycin may be appropriate for fewer COPD patients than previously thought, especially in those on long-term oxygen therapy.
Subject(s)
Anti-Bacterial Agents , Azithromycin , Hearing Disorders/chemically induced , Oxygen/therapeutic use , Pulmonary Disease, Chronic Obstructive/therapy , Aged , Anti-Bacterial Agents/therapeutic use , Contraindications , Female , Heart Failure/complications , Humans , Long QT Syndrome/complications , Male , Middle Aged , Risk Assessment , Risk Factors , Treatment OutcomeABSTRACT
We combined systematic cross-sectional scanning tunneling microscopy and spectroscopy investigations with Hall measurements on single Si delta-doped layers, as well as Si delta-doped superlattices in GaAs. We found that Si self-compensation involves nucleation and growth of electrically neutral Si precipitates at the expense of the conventional donor Si phase.
ABSTRACT
Resonant transport is demonstrated in a hybrid superconductor-semiconductor heterostructure junction grown by molecular beam epitaxy on GaAs. This heterostructure realizes the model system introduced by de Gennes and Saint-James in 1963 [P. G. de Gennes and D. Saint-James, Phys. Lett. 4, 151 (1963)]. At low temperatures a single marked resonance peak is shown superimposed to the characteristic Andreev-dominated subgap conductance. The observed magnetotransport properties are successfully analyzed within the random matrix theory of quantum transport, and ballistic effects are included by directly solving the Bogoliubov-de Gennes equations.
ABSTRACT
Structure characterisation of interfaces is a field of widespread application of high resolution transmission electron microscopy for its very high spatial resolution. Specimen thickness and electron optical condition have a deep influence on the high resolution electron transmission microscopy image contrast. Hence, in many cases, the real structure of the sample can be understood from experimental images only by comparison with the relevant simulation. Moreover, the understanding of the contrast variation of a few A at an interface is a task in which even the use of simulation could not produce an unequivocal solution of the experimental result. In this paper high resolution transmission electron microscopy image simulations show that two monolayers of crystalline material buried at an amorphous-crystalline interface can be successfully revealed and interpreted. The simulated images reproduce the experimental results as obtained from the Al/Si-As/n-GaAs (001) heterostructure.
ABSTRACT
Despite the strong evidence for a major role played by genetic factors in the aetiology of non-insulin-dependent diabetes mellitus (NIDDM), the genes involved are still unknown. Association studies of candidate genes for the inheritance of NIDDM have so far yielded inconclusive results. Some evidence exists for an association between NIDDM and the glucose transporter gene GLUT1, involved in basal glucose transport, although this has not been confirmed. In the present study we have tested the hypothesis of linkage between NIDDM and the GLUT1 gene, using affected sib-pairs. With this method the concordance observed for a given gene marker is compared with that expected under the assumption of no linkage between that marker and the disease. Fifty-four pedigrees (22 Italians and 32 British), for a total of 82 sib-pairs were studied by the affected sib-pair method proposed by Weeks and Lange, using two restriction fragment length polymorphisms (RFLPs) at the GLUT1 locus, the MspI RFLP, at an estimated 0.171 recombination frequency from the GLUT1 gene, and the XbaI RFLP, located within the GLUT1 gene and previously shown to be associated with the disease. Results showed that the MspI marker and NIDDM segregate independently; for the XbaI RFLP, linkage could be shown only if the results were weighted by the allele frequency [f(p) = 1/p], and only in the Italian and the combined (Italian and British) sib-pair groups. Multilocus analysis with both markers was also negative. We conclude that the GLUT1 gene is very unlikely to play a major role in the aetiology of NIDDM, although an accessory role cannot be excluded, and studies of the gene sequence should help to clarify this question.
