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1.
Transpl Infect Dis ; 22(2): e13264, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32053285

ABSTRACT

Cerebral abscess due to pigmented molds is a rare but usually fatal infection occasionally seen in transplant recipients. A 67-year-old man of Iraqi origin underwent a deceased donation renal transplant for renal failure and 2 months later was diagnosed with an abscess in the left posterior frontal lobe of his brain. Subsequent biopsy proved this to be due to the mold Rhinocladiella mackenziei. Further interventions included two operations to aspirate the lesion, voriconazole, then liposomal amphotericin B, then a combination of posaconazole and flucytosine which he continued for over 4 years. He also suffered from right ankle pain and was diagnosed with septic arthritis; R mackenziei was isolated from pus aspirated from the ankle joint. He responded well to the treatment and has had little loss of function, and on CT, the cerebral lesion has stabilized. Beta-D-glucan, initially at very high levels proved useful to monitor response over the 5 years and the latest sample was negative (38 pg/mL). This case is notable for the first disseminated case of this infection, its favorable outcome on a novel antifungal combination and a new approach to monitoring the course of disease.


Subject(s)
Antifungal Agents/therapeutic use , Brain Abscess/surgery , Central Nervous System Fungal Infections/therapy , Invasive Fungal Infections/therapy , Triazoles/therapeutic use , Aged , Amphotericin B/therapeutic use , Arthritis, Infectious/microbiology , Ascomycota/drug effects , Brain Abscess/microbiology , Central Nervous System Fungal Infections/diagnosis , Central Nervous System Fungal Infections/etiology , Humans , Immunocompromised Host , Invasive Fungal Infections/diagnosis , Invasive Fungal Infections/etiology , Kidney Transplantation/adverse effects , Male , Treatment Outcome
2.
Opt Express ; 27(26): 37099-37110, 2019 Dec 23.
Article in English | MEDLINE | ID: mdl-31878496

ABSTRACT

We demonstrate a new method of cavity-enhanced non-destructive detection of atoms for a strontium optical lattice clock. The detection scheme is shown to be linear in atom number up to at least 2×104 atoms, to reject technical noise sources, to achieve signal to noise ratio close to the photon shot noise limit, to provide spatially uniform atom-cavity coupling, and to minimize inhomogeneous ac Stark shifts. These features enable detection of atoms with minimal perturbation to the atomic state, a critical step towards realizing an ultra-high-stability, quantum-enhanced optical lattice clock.

3.
Sci Rep ; 9(1): 11704, 2019 Aug 12.
Article in English | MEDLINE | ID: mdl-31406188

ABSTRACT

We realize a two-stage, hexagonal pyramid magneto-optical trap (MOT) with strontium, and demonstrate loading of cold atoms into cavity-enhanced 1D and 2D optical lattice traps, all within a single compact assembly of in-vacuum optics. We show that the device is suitable for high-performance quantum technologies, focusing especially on its intended application as a strontium optical lattice clock. We prepare 2 × 104 spin-polarized atoms of 87Sr in the optical lattice within 500 ms; we observe a vacuum-limited lifetime of atoms in the lattice of 27 s; and we measure a background DC electric field of 12 V m-1 from stray charges, corresponding to a fractional frequency shift of (-1.2 ± 0.8) × 10-18 to the strontium clock transition. When used in combination with careful management of the blackbody radiation environment, the device shows potential as a platform for realizing a compact, robust, transportable optical lattice clock with systematic uncertainty at the 10-18 level.

4.
Rev Sci Instrum ; 90(4): 043101, 2019 Apr.
Article in English | MEDLINE | ID: mdl-31043041

ABSTRACT

We present a field-programmable gate array (FPGA) based control system that has been implemented to control a strontium optical lattice clock at the National Physical Laboratory, UK. Bespoke printed circuit boards have been designed and manufactured, including an 8-channel, 16-bit digital to analog converter board with a 2 µs update rate and a 4-channel direct-digital synthesis board clocked at 1 GHz. Each board includes its own FPGA with 28 digital output lines available alongside the specialized analog or radio frequency outputs. The system is scalable to a large number of control lines by stacking the individual boards in a master-slave arrangement. The timing of the digital and analog outputs is based on the FPGA clock and is thus very predictable and exhibits low jitter. A particular advantage of our hardware is its large data buffers that, when combined with a pseudoclock structure, allow complex waveforms to be created. A high reliability of the system has been demonstrated during extended atomic clock frequency comparisons.

7.
J Infect ; 70(2): 105-10, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25175926

ABSTRACT

OBJECTIVES: Recent literature has concluded antibiotic therapy results in fewer complications than appendicectomy for patients with uncomplicated appendicitis. This studies aim was to undertake a meta-analysis of major post-intervention outcomes in patients with suspected uncomplicated appendicitis treated with antibiotics or appendicectomy, and determine which treatment is associated with the lowest rate of major complications. METHODS: We analysed randomised trials of antibiotics vs. appendicectomy in adults with suspected uncomplicated appendicitis. The primary outcome measure was a composite of major complications, peritonitis and intra-abdominal abscess, occurring after appendicectomy or initiation of therapeutic antibiotics. RESULTS: The rate of major post-intervention complications was 0.8% (2/263) in the appendicectomy group and 10.1% (27/268) in the antibiotic group. This difference was statistically significant by the random effects model: Risk Ratio 7.71, 95% C.I. 2.33 to 25.53, Risk Difference 0.09: 95% C.I. 0.05 to 0.13. The Number Needed to Harm (NNH) from antibiotic therapy is 10.7. CONCLUSIONS: Suspected uncomplicated appendicitis has a lower rate of major post-intervention complications when managed with primary appendicectomy compared to antibiotic therapy.


Subject(s)
Appendectomy , Appendicitis , Postoperative Complications/epidemiology , Adolescent , Adult , Anti-Bacterial Agents/therapeutic use , Appendectomy/adverse effects , Appendectomy/statistics & numerical data , Appendicitis/drug therapy , Appendicitis/epidemiology , Appendicitis/surgery , Female , Humans , Male , Middle Aged , Young Adult
9.
Diagn Microbiol Infect Dis ; 62(3): 287-91, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18947811

ABSTRACT

Allergic bronchopulmonary aspergillosis (ABPA) is seen in approximately 10% of patients with cystic fibrosis (CF) and can be difficult to diagnose. Consensus criteria require the presence of multiple elevated immunologic markers such as total immunoglobulin E (IgE), Aspergillus IgE and Aspergillus IgG, or precipitins for a robust diagnosis. There is some degree of standardization of total IgE and Aspergillus IgE levels, but there is no standardization in the measurement of IgG antibodies or precipitins to Aspergillus. The interpretation of results may, therefore, be confusing. Eighty-seven patients with CF were categorized as having ABPA or as controls, using the consensus criteria and an in-house enzyme immunoassay to measure IgG levels to Aspergillus. All sera from patients were then analyzed by commercial fluorescent immunoassay (FEIA) for the quantitative detection of anti-Aspergillus IgG. FEIA results were analyzed against the consensus conference minimum diagnostic criteria to ascertain a cutoff point, which could predict a diagnosis of ABPA in CF. Eighty patients with CF and with no or incomplete evidence of ABPA had a mean FEIA score of 51.1 mg/L, whereas 7 CF patients with ABPA had a mean FEIA score of 132.5 mg/L. Using receiver operator characteristic curve analysis of the ImmunoCAP (Phadia) IgG score on ABPA versus all other patients gave an area under the curve of 0.933 (estimated SE, 0.027). This analysis provisionally suggested that a score of 90 mg/L may be used as a cutoff point, which would give a sensitivity of 91% and specificity of 88.0% for the diagnosis of ABPA, though this requires further validation. This quantitative approach to Aspergillus IgG measurement in patients with CF along with the results of other tests will hopefully provide a more accurate approach to the diagnosis of ABPA.


Subject(s)
Antibodies, Fungal/blood , Aspergillosis, Allergic Bronchopulmonary/diagnosis , Aspergillus fumigatus/immunology , Cystic Fibrosis/complications , Immunoglobulin G/blood , Adolescent , Adult , Aspergillosis, Allergic Bronchopulmonary/complications , Aspergillosis, Allergic Bronchopulmonary/immunology , Child , Child, Preschool , Humans , Immunoenzyme Techniques/methods , Middle Aged , ROC Curve , Sensitivity and Specificity , Young Adult
10.
J Med Microbiol ; 56(Pt 12): 1639-1643, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18033833

ABSTRACT

Candida species are the fourth most common cause of bloodstream infection (BSI) in the hospitalized patient. Candida glabrata is the most common non-Candida albicans Candida species in England and Wales with an attributed mortality of 48%. C. glabrata is known to demonstrate reduced susceptibility to fluconazole, resulting in treatment failures when employing this agent for empirical treatment of Candida BSI. The first part of this study demonstrated a technique utilizing a blood culture system commonly used by many laboratories (BACTEC 9240 automated detection system) that reduced the time to identification of this potentially resistant organism by up to 72 h. A presumptive identification was achieved by observing a difference in the duration of incubation required before growth was detected automatically between Lytic Anaerobic and Plus Aerobic culture bottles. Secondly, experiments exploring the growth characteristics of C. glabrata in BACTEC blood culture bottles containing various media were carried out to explore possible reasons underpinning this clinical observation. The detection of yeast in the anaerobic bottle of a blood culture pair consisting of Lytic Anaerobic and Plus Aerobic in a BACTEC 9240 system was found to be highly predictive of the isolation of C. glabrata (positive predictive value 93.3%, negative predictive value 98.3%). The reason for this appeared to be a component of the Lytic Anaerobic blood culture medium enhancing the growth of C. glabrata in that medium.


Subject(s)
Blood/microbiology , Candida glabrata/isolation & purification , Fungemia/microbiology , Microbiological Techniques , Anaerobiosis , Candida glabrata/classification , Candidiasis/blood , Candidiasis/microbiology , Culture Media , Humans , Retrospective Studies
11.
J Mol Diagn ; 8(3): 376-84, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16825512

ABSTRACT

The limitations of classical diagnostic methods for invasive fungal infections (IFIs) have led to the development of molecular techniques to aid in the detection of IFIs. Despite good published performance, interlaboratory reproduction of these assays is variable, and no consensus has been reached for an optimal method. This publication describes the first multicenter study of polymerase chain reaction methods, for the detection of Aspergillus and Candida species, currently used in the UK and Ireland by distribution and analysis of multiple specimen control panels. All three Candida methods were comparable, achieving a satisfactory level of detection (10 cfu), and the method of preference was dependent on the requirements of the particular laboratory. The results for the five Aspergillus assays were more variable, but two methods (2Asp and 4Asp) were superior (10(1) conidia). Formally, the overall performances of the two Aspergillus assays were comparable (kappa statistic = 0.77). However, on the Roche LightCycler, there was a clear sample-type effect that greatly reduced the detection limit of the 4Asp method when testing whole blood samples. Therefore, the preferred Aspergillus method relied on the amplification platform available to the user. This study represents the initial process to achieve a consensus method for the diagnosis of IFIs.


Subject(s)
DNA, Fungal/analysis , Molecular Diagnostic Techniques/methods , Mycoses/diagnosis , Polymerase Chain Reaction/methods , Aspergillosis/diagnosis , Base Sequence , Candidiasis/diagnosis , Consensus , Humans , Ireland , Molecular Diagnostic Techniques/instrumentation , Molecular Sequence Data , Polymerase Chain Reaction/instrumentation , Sensitivity and Specificity , Sequence Homology, Nucleic Acid , United Kingdom
12.
J Clin Invest ; 116(6): 1642-50, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16710478

ABSTRACT

The fungal pathogen Candida albicans has a multilayered cell wall composed of an outer layer of proteins glycosylated with N- or O-linked mannosyl residues and an inner skeletal layer of beta-glucans and chitin. We demonstrate that cytokine production by human mononuclear cells or murine macrophages was markedly reduced when stimulated by C. albicans mutants defective in mannosylation. Recognition of mannosyl residues was mediated by mannose receptor binding to N-linked mannosyl residues and by TLR4 binding to O-linked mannosyl residues. Residual cytokine production was mediated by recognition of beta-glucan by the dectin-1/TLR2 receptor complex. C. albicans mutants with a cell wall defective in mannosyl residues were less virulent in experimental disseminated candidiasis and elicited reduced cytokine production in vivo. We concluded that recognition of C. albicans by monocytes/macrophages is mediated by 3 recognition systems of differing importance, each of which senses specific layers of the C. albicans cell wall.


Subject(s)
Candida albicans/immunology , Glucans/immunology , Mannans/immunology , Receptors, Mitogen/immunology , Toll-Like Receptors/immunology , Animals , Candida albicans/genetics , Candidiasis/immunology , Carbohydrate Conformation , Carbohydrate Sequence , Cell Wall/chemistry , Cell Wall/metabolism , Cell Wall/ultrastructure , Cytokines/immunology , Glucans/chemistry , Humans , Leukocytes, Mononuclear/immunology , Mannans/chemistry , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Receptors, Mitogen/chemistry , Toll-Like Receptors/chemistry
13.
J Biol Chem ; 279(38): 39628-35, 2004 Sep 17.
Article in English | MEDLINE | ID: mdl-15271989

ABSTRACT

The outer layer of the cell wall of the human pathogenic fungus Candida albicans is enriched with heavily mannosylated glycoproteins that are the immediate point of contact between the fungus and cells of the host, including phagocytes. Previous work had identified components of the acid-labile fraction of N-linked mannan, comprising beta-1,2-linked mannose residues attached via a phosphodiester bond, as potential ligands for macrophage receptors and modulators of macrophage function. We therefore isolated and disrupted the CaMNN4 gene, which is required for mannosyl phosphate transfer and hence the attachment of beta-1,2 mannose oligosaccharides to the acid-labile N-mannan side chains. With the mannosylphosphate eliminated, the mnn4Delta null mutant was unable to bind the charged cationic dye Alcian Blue and was devoid of acid-labile beta-1,2-linked oligomannosaccharides. The mnn4Delta mutant was unaffected in cell growth and morphogenesis in vitro and in virulence in a murine model of systemic C. albicans infection. The null mutant was also not affected in its interaction with macrophages. Mannosylphosphate is therefore not required for macrophage interactions or for virulence of C. albicans.


Subject(s)
Candida albicans/pathogenicity , Candidiasis/immunology , Macrophages/immunology , Macrophages/microbiology , Mannosephosphates/metabolism , Alcian Blue , Animals , Candida albicans/genetics , Candida albicans/metabolism , Candidiasis/microbiology , Cell Line , Cell Wall/metabolism , Coloring Agents , Female , Macrophages/cytology , Male , Membrane Proteins/genetics , Membrane Proteins/immunology , Mice , Mice, Inbred BALB C , Mutagenesis , Mutation , Oligosaccharides/metabolism , Phosphorylation , Rats , Rats, Sprague-Dawley , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/immunology , Virulence
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