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Moonka DK, Kim D, Kapke A, Brown KA, Yoshida A. The influence of induction therapy on graft and patient survival in patients with and without hepatitis C after liver transplantation. Am J Transplant 2010; 10:590-601. [PMID: 19958339 DOI: 10.1111/j.1600-6143.2009.02880.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We used the United Network for Organ Sharing Database to determine the influence of antibody-based induction therapy on patient and graft survival in orthotopic liver transplant (OLT) recipients with and without hepatitis C (HCV). We identified all initial OLT patients with HCV serology. Patients were divided into four groups: HCV positive without induction (17 362), HCV positive with induction (3479), HCV negative without induction (20 417) and HCV negative with induction (4357). Both HCV positive and negative patients who received induction did better than those who did not. For HCV positive patients, 5-year patient survival was 70.8% versus 68.7% (p = 0.004) and graft survival was 65.2% versus 62.1% (p < 0.001). For HCV negative patients, 5-year patient survival was 78.8% versus 76.7% (p < 0.001) and graft survival was 74.0% versus 70.8% (p < 0.001). On multivariate analysis, induction was associated with improved patient (HR = 0.91: p = 0.024) and graft (HR = 0.88: p < 0.001) survival in HCV positive patients and improved patient (HR = 0.87: p = 0.003) and graft survival (HR = 0.87: p < 0.001) in HCV negative patients. The benefit of induction occurred early and largely dissipated when patients with death within a year were censored. The benefit of induction therapy appeared most pronounced in patients with renal insufficiency or on organ-perfusion support at transplant.
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Aoude AA, Motto AL, Galiana HL, Brown KA, Kearney RE. Power-based segmentation of respiratory signals using forward-backward bank filtering. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2008; 2006:4631-4. [PMID: 17945847 DOI: 10.1109/iembs.2006.259477] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present an automated method for the segmentation of ribcage and abdominal signals measured by noninvasive respiratory inductance plethysmography (RIP) into quiet breathing and artifact-corrupted segments. This procedure, which involves forward-backward filtering, is applicable to the automated off-line analysis of long records of respiratory signals. Examples of applications include home and sleep laboratory studies of cardiorespiratory data. The new procedure was successfully applied to the segmentation of cardiorespiratory signals acquired post-operatively from infants in the recovery room of the Montreal Children's Hospital (MCH).
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Goldstein JL, Johanson JF, Hawkey CJ, Suchower LJ, Brown KA. Clinical trial: healing of NSAID-associated gastric ulcers in patients continuing NSAID therapy - a randomized study comparing ranitidine with esomeprazole. Aliment Pharmacol Ther 2007; 26:1101-11. [PMID: 17894652 DOI: 10.1111/j.1365-2036.2007.03460.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The use of non-steroidal anti-inflammatory drugs (NSAID) is associated with an increased risk of gastric ulcer (GU) development. METHODS This multicentre, randomized, double-blind, parallel-group trial compared endoscopic healing rates at 4 and 8 weeks after treatment with oral esomeprazole 40 or 20 mg once daily, or ranitidine 150 mg twice daily, in patients with 1 baseline GU > or = 5 mm but no GUs or duodenal ulcers >25 mm in diameter who received continued cyclooxygenase-2-selective or non-selective NSAID therapies. The primary outcome was the percentage of patients in each treatment group who had no GUs at week 8. RESULTS Four hundred and forty patients were randomized to treatment. At week 8, GU healing rates (95% CI) with esomeprazole 40 mg, esomeprazole 20 mg and ranitidine were 85.7 (79.8-91.7)%, 84.8 (78.8-90.8)% and 76.3 (69.2-83.3)%, respectively; between-group differences were not statistically significant. Week-4 GU healing rates were 70.7 (62.9-78.4)% and 72.5 (65.0-79.9)% with esomeprazole 40 and 20 mg, respectively, and were significantly higher (P < 0.01 for both doses) than those with ranitidine [55.4 (47.1-63.7)%]. CONCLUSION In patients who require continued NSAID therapy, GU healing rates at 8 weeks numerically favoured esomeprazole but were not significantly different from ranitidine.
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Motto AL, Galiana HL, Brown KA, Kearney RE. Detection of movement artifacts in respiratory inductance plethysmography: performance analysis of a Neyman-Pearson energy-based detector. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:49-52. [PMID: 17271600 DOI: 10.1109/iembs.2004.1403087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In [3] we developed a method for the automated estimation of the phase relation between thoracic and abdominal signals measured by noninvasive respiratory inductance plethysmography (RIP). In the present paper, we improve on the phase estimator by including an automated procedure for the detection of periods of gross body movements. We assume that the number of sleep obstructive events during periods of gross body movements is zero in probability. We hope that combining the phase estimator with the gross body movement detector should yield improved diagnostic tools for the automated classification of obstructive hypopnea events.
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Ball HL, Ward-Platt MP, Heslop E, Leech SJ, Brown KA. Randomised trial of infant sleep location on the postnatal ward. Arch Dis Child 2006; 91:1005-10. [PMID: 16849364 PMCID: PMC2083001 DOI: 10.1136/adc.2006.099416] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To determine whether postnatal mother-infant sleep proximity affects breastfeeding initiation and infant safety. DESIGN Randomised non-blinded trial analysed by intention to treat. SETTING Postnatal wards of the Royal Victoria Hospital (RVI), Newcastle upon Tyne, UK. PARTICIPANTS 64 newly delivered mother-infant dyads with a prenatal intention to breastfeed (vaginal deliveries, no intramuscular or intravenous opiate analgesics taken in the preceding 24 h). INTERVENTION Infants were randomly allocated to one of three sleep conditions: baby in mother's bed with cot-side; baby in side-car crib attached to mother's bed; and baby in stand-alone cot adjacent to mother's bed. MAIN OUTCOME MEASURES Breastfeeding frequency and infant safety observed via night-time video recordings. RESULTS During standardised 4-h observation periods, bed and side-car crib infants breastfed more frequently than stand-alone cot infants (mean difference (95% confidence interval (CI)): bed v stand-alone cot = 2.56 (0.72 to 4.41); side-car crib v stand-alone cot = 2.52 (0.87 to 4.17); bed v side-car crib = 0.04 (-2.10 to 2.18)). No infant experienced adverse events; however, bed infants were more frequently considered to be in potentially adverse situations (mean difference (95% CI): bed v stand-alone cot = 0.13 (0.03 to 0.23); side-car crib v stand-alone cot = 0.04 (-0.03 to 0.12); bed v side-car crib = 0.09 (-0.03-0.21)). No differences were observed in duration of maternal or infant sleep, frequency or duration of assistance provided by staff, or maternal rating of postnatal satisfaction. CONCLUSION Suckling frequency in the early postpartum period is a well-known predictor of successful breastfeeding initiation. Newborn babies sleeping in close proximity to their mothers (bedding-in) facilitates frequent feeding in comparison with rooming-in. None of the three sleep conditions was associated with adverse events, although infrequent, potential risks may have occurred in the bed group. Side-car cribs are effective in enhancing breastfeeding initiation and preserving infant safety in the postnatal ward.
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Emlet DR, Schwartz R, Brown KA, Pollice AA, Smith CA, Shackney SE. HER2 expression as a potential marker for response to therapy targeted to the EGFR. Br J Cancer 2006; 94:1144-53. [PMID: 16622439 PMCID: PMC2361260 DOI: 10.1038/sj.bjc.6603078] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Since human epidermal growth factor receptor 2 (HER2) is known to participate with the epidermal growth factor receptor (EGFR) in mitogenic signalling, we hypothesised that HER2 overexpression might indicate responsiveness to EGFR targeted therapies. MCF7 breast cancer cells transfected with the HER2 gene were subcloned to establish a set of genetically related cell lines expressing graded levels of HER2 by immunoblot analysis. The subcloned cell lines and parental MCF7 cells were characterised by their growth characteristics, and cell by cell patterns of EGFR, HER2 and HER3 expression as well as levels of phosphorylated mitogen-activated protein kinase (MAPK) and AKT by laser scanning cytometry (LSC). Growth inhibition assays were used to characterise response to EGFR targeted therapy, and to determine the relationship between therapeutic response and levels of tyrosine kinase expression. The levels of growth inhibition of AG1478 and of the AG1478-trastuzumab combinations were correlated with levels of HER2 expression among the different cell lines. Among EGFR, HER2 and HER3, HER2 overexpression was the best single predictive marker, but combinations of two markers provided additional predictive information.
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MESH Headings
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal, Humanized
- Biomarkers, Tumor/genetics
- Breast Neoplasms/diagnosis
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Drug Screening Assays, Antitumor
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Laser Scanning Cytometry/methods
- Mitogen-Activated Protein Kinases/metabolism
- Phosphorylation
- Predictive Value of Tests
- Proto-Oncogene Proteins c-akt/metabolism
- Quinazolines
- Receptor, ErbB-2/analysis
- Receptor, ErbB-2/drug effects
- Receptor, ErbB-2/genetics
- Receptor, ErbB-3/analysis
- Receptor, ErbB-3/drug effects
- Receptor, ErbB-3/genetics
- Sensitivity and Specificity
- Structure-Activity Relationship
- Trastuzumab
- Tyrphostins/pharmacology
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Brown KA, Brain SD, Pearson JD, Edgeworth JD, Lewis SM, Treacher DF. Neutrophils in development of multiple organ failure in sepsis. Lancet 2006; 368:157-69. [PMID: 16829300 DOI: 10.1016/s0140-6736(06)69005-3] [Citation(s) in RCA: 475] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Multiple organ failure is a major threat to the survival of patients with sepsis and systemic inflammation. In the UK and in the USA, mortality rates are currently comparable with and projected to exceed those from myocardial infarction. The immune system combats microbial infections but, in severe sepsis, its untoward activity seems to contribute to organ dysfunction. In this Review we propose that an inappropriate activation and positioning of neutrophils within the microvasculature contributes to the pathological manifestations of multiple organ failure. We further suggest that targeting neutrophils and their interactions with blood vessel walls could be a worthwhile therapeutic strategy for sepsis.
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Brown KA, Boerboom D, Bouchard N, Doré M, Lussier JG, Sirois J. Human chorionic gonadotropin-dependent induction of an equine aldo-keto reductase (AKR1C23) with 20alpha-hydroxysteroid dehydrogenase activity during follicular luteinization in vivo. J Mol Endocrinol 2006; 36:449-61. [PMID: 16720716 DOI: 10.1677/jme.1.01987] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Aldo-keto reductases (AKRs) are multifunctional enzymes capable of acting on a wide variety of substrates, including sex steroids. AKRs having 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activity can reduce progesterone to 20alpha-hydroxy-4-pregnen-3-one (20alpha-DHP), a metabolite with lower affinity for the progesterone receptor. The objective of this study was to investigate the regulation of equine AKR1C23 during human chorionic gonadotropin (hCG)-induced ovulation/luteinization. The equine AKR1C23 cDNA was cloned and shown to encode a 322 amino acid protein that is conserved (71-81% identity) when compared with mammalian orthologs. RT-PCR/Southern blotting analyses were performed to study the regulation of AKR1C23 transcripts in equine preovulatory follicles isolated between 0 and 39 h after hCG treatment (ovulation occurring 39-42 h post-hCG). Results showed the presence of low AKR1C23 expression before hCG treatment, but a marked increase was observed in follicles obtained 12 h after hCG (P<0.05). Analyses of isolated preparations of granulosa and theca interna cells identified low mRNA expression in both cell types prior to hCG treatment, with granulosa cells clearly being the predominant site of follicular AKR1C23 mRNA induction. A specific polyclonal antibody was raised against a fragment of the equine protein and immunoblotting analyses showed an increase in AKR1C23 protein in granulosa cell extracts when comparing follicles isolated at 36 h post-hCG vs those collected prior to treatment, in keeping with mRNA results. Immunohistochemical data confirmed the induction of the enzyme in follicular cells after hCG treatment. The enzyme was tested for 20alpha-HSD activity and was shown to exhibit a K(M) of 3.12 microM, and a V(max) of 0.86 pmol/min per 10 microg protein towards progesterone. The levels of 20alpha-DHP measured in follicular fluid reflected this activity. Collectively, these results demonstrate for the first time that the gonadotropin-dependent induction of follicular luteinization is accompanied by an increase in AKR1C23 expression. Considering the 20alpha-HSD activity of AKR1C23, its regulated expression in luteinizing preovulatory follicles may provide a biochemical basis for the increase in ovarian 20alpha-DHP observed during gonadotropin-induced luteinization/ovulation. (The nucleotide sequence reported in this paper has been submitted to GenBank with accession number AY955082.).
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Nixon GM, Kermack AS, McGregor CD, Davis GM, Manoukian JJ, Brown KA, Brouillette RT. Sleep and breathing on the first night after adenotonsillectomy for obstructive sleep apnea. Pediatr Pulmonol 2005; 39:332-8. [PMID: 15704184 DOI: 10.1002/ppul.20195] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Adenotonsillectomy (T&A) has established effectiveness for the treatment of obstructive sleep apnea (OSA). However, more than 20% of children with OSA have respiratory compromise requiring medical intervention in the postoperative period. The reasons for this complication are not well-defined. We aimed to compare the nature and severity of sleep-disordered breathing in children with mild and severe OSA on the first night following adenotonsillectomy. Ten children were classified into groups of mild and severe OSA, based on preoperative testing. On the first night after T&A, they underwent polysomnography, including electroencephalograph, submental electromyography, bilateral electro-oculograms, monitoring of respiratory movements, heart rate, ECG, and oxygen saturation. Sleep-disordered breathing was assessed by the apnea-hypopnea index, the SaO(2) nadir, and the desaturation index, including dips in saturation below 90% (DI(90)). Sleep quality was assessed by sleep efficiency, time spent in each sleep state, and respiratory arousal index. Obstructive events occurred postoperatively in all children, but were more frequent in those with severe OSA preoperatively: the median (interquartile range) mixed/obstructive apnea/hypopnea indicies were 6.9 (2.2-9.8) events/hr and 21.5 (15.1-112.1) events/hr for the mild OSA group and the severe OSA group, respectively (P = 0.009). Obstructive events were the major cause of desaturation during sleep postoperatively. Sleep quality was severely disrupted in both groups, with reductions in both slow-wave sleep and rapid eye movement sleep. In conclusion, despite removal of obstructing lymphoid tissue, upper airway obstruction occurred on the first postoperative night in children with OSA. This study is the first to demonstrate the mechanism of respiratory compromise after adenotonsillectomy, a common postoperative complication in children with severe OSA.
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Brown TR, Su B, Brown KA, Schwartz MA, Tobia AM, Kappler F. Modulation of in vivo 3-deoxyglucosone levels. Biochem Soc Trans 2003; 31:1433-7. [PMID: 14641082 DOI: 10.1042/bst0311433] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fructoselysine 3-phosphate is synthesized in vivo by the recently discovered fructoseamine-3-kinase (F3K) from fructoselysine and ATP and decomposes to lysine, Pi and 3-deoxyglucosone (3DG). This pathway appears to dominate 3DG production in vivo, making it possible to modulate 3DG levels by stimulating or inhibiting the reaction. Present inhibitors are non-reacting substrate analogues with relatively high Ki values and can inhibit F3K sufficiently in vivo to reduce 3DG in diabetic rat plasma by approx. 50%. Stimulation of the F3K pathway by feeding glycated casein causes an increase of 10–20-fold in plasma levels of 3DG and 3-fold in kidney tubules. Consequences of this increase were studied in two systems: the Eker rat, a model of susceptible kidney tubules; and birth rates in two rat strains. In both cases substantial pathological effects were observed. In the Eker rats, an approx. 3-fold increase in kidney lesions was observed (P<0.00001). In both Fischer 344 and Sprague–Dawley rats, birth rates were reduced by 56% (P<0.0001) and 12% (P<0.015) respectively. These results suggest that inhibition of F3K is a promising new therapeutic target for diabetic complications, as well as other 3DG-dependent pathologies.
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Brown KA, Carpenter EP, Watson KA, Coggins JR, Hawkins AR, Koch MHJ, Svergun DI. Twists and turns: a tale of two shikimate-pathway enzymes. Biochem Soc Trans 2003; 31:543-7. [PMID: 12773153 DOI: 10.1042/bst0310543] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We are studying two enzymes from the shikimate pathway, dehydroquinate synthase (DHQS) and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Both enzymes have been the subject of numerous studies to elucidate their reaction mechanisms. Crystal structures of DHQS and EPSPS in the presence and absence of substrates, cofactors and/or inhibitors are now available. These structures reveal movements of domains, rearrangements of loops and changes in side-chain positions necessary for the formation of a catalytically competent active site. The potential for using complementary small-angle X-ray scattering (SAXS) studies to confirm the presence of these structural differences in solution has also been explored. Comparative analysis of crystal structures, in the presence and absence of ligands, has revealed structural features critical for substrate-binding and catalysis. We have also analysed these structures by generating GRID energy maps to detect favourable binding sites. The combination of X-ray crystallography, SAXS and computational techniques provides an enhanced analysis of structural features important for the function of these complex enzymes.
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Abstract
Yersinia pestis is the aetiological agent of plague, a disease of humans that has potentially devastating consequences. Evidence indicates that Y. pestis evolved from Yersinia pseudotuberculosis, an enteric pathogen that normally causes a relatively mild disease. Although Y. pestis is considered to be an obligate pathogen, the lifestyle of this organism is surprisingly complex. The bacteria are normally transmitted to humans from a flea vector, and Y. pestis has a number of mechanisms which allow survival in the flea. Initially, the bacteria have an intracellular lifestyle in the mammalian host, surviving in macrophages. Later, the bacteria adopt an extracellular lifestyle. These different interactions with different host cell types are regulated by a number of systems, which are not well characterized. The availability of the genome sequence for this pathogen should now allow a systematic dissection of these regulatory systems.
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Cavers M, Afzali B, Afzali Khoshkbijari B, Macey M, McCarthy DA, Irshad S, Brown KA. Differential expression of beta1 and beta2 integrins and L-selectin on CD4+ and CD8+ T lymphocytes in human blood: comparative analysis between isolated cells, whole blood samples and cryopreserved preparations. Clin Exp Immunol 2002; 127:60-5. [PMID: 11882033 PMCID: PMC1906277 DOI: 10.1046/j.1365-2249.2002.01711.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2001] [Indexed: 11/20/2022] Open
Abstract
Flow cytometric analysis was used to compare the expression of adhesion molecules on human CD4+ and CD8+ T lymphocytes in isolated blood mononuclear cells (MNCs) in whole blood samples and in cryopreserved MNC preparations. Examination of MNCs revealed that the CD11b and CD11c components of the beta2 integrins were preferentially expressed on CD8+ T cells, whereas CD62L was present on more CD4+ T cells. All CD4+ and CD8+ T lymphocytes were positive for CD11a but the CD8+ population had a higher intensity of expression of CD11a and also CD11b. Virtually identical results were obtained with T cells in whole blood samples. In relation to the beta1 integrins, the only difference between isolated CD4+ and CD8+ T cells was that the latter subset had a greater proportion of cells bearing CD49d. The naive cell marker CD45RA was present on the majority of CD8+ T cells whereas CD45RA and the memory marker CD45RO were evenly distributed within the CD4+ T cell subset. Although cryopreservation of lymphocytes did not modify the expression of beta1 and beta2 integrins it produced a marked reduction in the percentage of CD4+ and CD8+ T cells bearing CD62L. With regard to endothelial interactions, it appears that cryopreserved lymphocytes are suitable for inclusion in studies of integrin-mediated adhesion but not for those relating to tethering or recognition of addressins on high endothelial venules. Differences in adhesion molecule expression between CD4+ and CD8+ T lymphocytes could underlie the selective extravasation of these subsets into sites of infection and inflammation.
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Abstract
Identification of thoracoabdominal asynchrony (TAS) during breathing is currently detected by visual coding of records of ribcage (RC) and abdominal (AB) movements. There is thus a need to automate this process in order to save time and improve TAS detection accuracy. We studied 15 infants of 39-49 weeks postconceptional age. RC and AB signals were recorded continuously by inductance plethysmography for 4-24 hr immediately after herniorraphy. In our novel analysis approach, the records were divided into 10 sec epochs, and the equation RC = alphaAB + beta was fit to each epoch, using recursive linear regression with an exponential memory time constant of 1 and 2 sec. This yielded 10 sec signals for alpha corresponding to each epoch. The fraction of time that each alpha signal was positive was taken as a measure of synchrony between RC and AB for that epoch, while asynchrony was indicated by the fraction of time the signal was negative. We also assessed synchrony and asynchrony using a conventional measure known as thoracic delay (TD), which is based on the degree to which the peaks in RC and AB are coincident in time. Using TD as the basis of comparison, we found that our new recursive least squares method gave a positive predictive value of 99%. We conclude that our recursive least squares method is able to accurately identify portions of the RC and AB records that correspond to TAS, and we speculate that it may be useful in automating detection of TAS.
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Abstract
Characterising the factors that control the entry of leucocytes into tissue in response to inflammatory or microbial insult continues to generate considerable interest. Of all the tissues studied it is probably that of the CNS which is the most fascinating because of the specialised properties of its blood vessel walls, which constitute the blood-brain barrier (BBB). In health, very few leucocytes penetrate the BBB but in disorders such as MS the barrier becomes compromised with the result that there is an intense infiltration of the CNS by T lymphocytes whose subsequent activity appears to underlie the onset and progression of disease. The purpose of this article is to summarise and assess recent literature pertaining to how lymphocytes bind to cerebral endothelial cells, migrate across the blood vessel walls and enter the CNS parenchyma. Particular emphasis is devoted to the cellular and molecular aspects of these events and addressing the questions of whether certain subsets of circulating T lymphocytes are more favourably disposed than others to CNS infiltration and whether entry is dependent upon the initial expression of distinct groups of adhesion molecules and upon the generation of chemotactic factors. This article also focuses upon identifying the key stages of lymphocyte migration across the BBB and their susceptibility to antagonism by therapeutic agents. It is intended that the review will provide a useful source of information and offer additional insights into the mechanisms controlling lymphocyte passage across the BBB during pathological disturbance.
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MESH Headings
- Animals
- Antigen Presentation
- Astrocytes/pathology
- Autoimmune Diseases/blood
- Autoimmune Diseases/immunology
- Autoimmune Diseases/pathology
- Blood-Brain Barrier
- Brain/blood supply
- Brain/immunology
- Callithrix
- Cell Adhesion
- Cell Adhesion Molecules/physiology
- Chemokines/physiology
- Chemotaxis, Leukocyte/drug effects
- Chemotaxis, Leukocyte/physiology
- Cytokines/physiology
- Drug Design
- Drug Evaluation, Preclinical
- Encephalomyelitis, Autoimmune, Experimental/blood
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Extracellular Matrix Proteins/physiology
- Forecasting
- Humans
- Immunologic Memory
- Immunophenotyping
- Immunosuppressive Agents/pharmacology
- Immunosuppressive Agents/therapeutic use
- Interferon-gamma/metabolism
- Interleukin-2/metabolism
- Lymphocyte Activation
- Metalloendopeptidases/physiology
- Mice
- Microcirculation
- Multiple Sclerosis/blood
- Multiple Sclerosis/immunology
- Multiple Sclerosis/pathology
- Myelin Sheath/immunology
- Myelin Sheath/pathology
- Rats
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocyte Subsets/pathology
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Markowitz JE, Brown KA, Mamula P, Drott HR, Piccoli DA, Baldassano RN. Failure of single-toxin assays to detect clostridium difficile infection in pediatric inflammatory bowel disease. Am J Gastroenterol 2001; 96:2688-90. [PMID: 11569696 DOI: 10.1111/j.1572-0241.2001.04125.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The aims of this retrospective study were 1) to determine the ability of single-toxin assays for Clostridium difficile to detect infection among pediatric patients with inflammatory bowel disease (IBD) and 2) to determine the toxin assays routinely used by pediatric tertiary care hospitals in the United States. METHODS Stool specimens from patients with IBD (submitted from January, 1996, to August, 1999) were evaluated for the presence of C. difficile toxin A and toxin B. Toxin profile (toxin A alone, toxin B alone, toxin A and B together) was compared in positive specimens. A phone interview was conducted with representatives from laboratories in 22 pediatric hospitals to investigate which toxin assays were routinely used. RESULTS A total of 697 specimens were submitted from 284 IBD patients. In all, 81 IBD patients (28.5%) had at least one documented infection. Toxin A assay failed to identify 41.5% of C. difficile infections. Toxin B assay failed to detect 34.9% of C. difficile infections. Toxin profile changed in 55% of patients with multiple infections. Of the hospitals surveyed, 59% did not test for both toxins. CONCLUSIONS Single-toxin assays for C. difficile fail to detect a significant percentage of infections. The toxins identified during one infection are not predictive of the toxins identified in subsequent infections. Despite this, many pediatric hospitals do not routinely use both toxin assays to diagnose C. difficile infection. When infection is suspected, assays for C. difficile toxin A and toxin B should be requested.
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Qureshi SS, Lewis SM, Gant VA, Treacher D, Davis BH, Brown KA. Increased distribution and expression of CD64 on blood polymorphonuclear cells from patients with the systemic inflammatory response syndrome (SIRS). Clin Exp Immunol 2001; 125:258-65. [PMID: 11529918 PMCID: PMC1906134 DOI: 10.1046/j.1365-2249.2001.01596.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Evidence is growing to suggest that the multiple organ damage of the systemic inflammatory response syndrome (SIRS) arises from the untoward activity of blood polymorphonuclear cells (PMNs), which upon activation acquire the IgG high affinity receptor, CD64. In the current study, flow cytometry was used to assess the prevalence of CD64-bearing PMNs and the intensity of expression of CD64 in whole blood samples from 32 SIRS patients, 11 healthy normal subjects and from eight non-SIRS patients in the intensive care unit (ICU). The percentage of PMNs expressing CD64 was higher in SIRS patients (mean 65%) than in non-SIRS patients (mean 42%; P < 0.02) and in healthy controls (mean 19%; P < 0.001) and was particularly evident in patients with SIRS and sepsis (mean 71%; P < 0.02) as opposed to SIRS alone (mean 55%). There were more CD64 molecules expressed on PMNs from patients with SIRS (median 1331 molecules/cell) in comparison with PMNs from healthy subjects (median 678 molecules/cell; P < 0.01). The highest intensity of CD64 expression was associated with PMNs from patients with both SIRS and sepsis. Functional studies revealed that the supranormal binding of PMNs from patients with SIRS to endothelial monolayers treated with TNFalpha was impeded by anti-CD64 antibodies (mean 24% inhibition; P < 0.01). Monitoring the distribution of CD64+ PMNs and their level of CD64 expression could be of assistance in the rapid discrimination of patients with SIRS from other ICU patients and in the identification of PMNs which are likely to participate in the pathological manifestations of the disease.
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Abouljoud MS, Escobar F, Douzdjian V, Bajjoka I, Moonka D, Shick L, Brown KA. Recurrent disease after liver transplantation. Transplant Proc 2001; 33:2716-9. [PMID: 11498137 DOI: 10.1016/s0041-1345(01)02159-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abouljoud MS, Escobar F, Douzdjian V, Moonka D, Shick L, Brown KA. Successful strategy for reducing biliary complications after liver transplantation. Transplant Proc 2001; 33:2714-5. [PMID: 11498136 DOI: 10.1016/s0041-1345(01)02158-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Janocko LE, Brown KA, Smith CA, Gu LP, Pollice AA, Singh SG, Julian T, Wolmark N, Sweeney L, Silverman JF, Shackney SE. Distinctive patterns of Her-2/neu, c-myc, and cyclin D1 gene amplification by fluorescence in situ hybridization in primary human breast cancers. CYTOMETRY 2001; 46:136-49. [PMID: 11449404 DOI: 10.1002/cyto.1098] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Human solid tumors undergo clonal evolution as they progress, but evidence for specific sequences of genetic changes that occur in individual tumors and are recapitulated in other tumors is difficult to obtain. METHODS Patterns of amplification of Her-2/neu, c-myc, and cyclin D1 were determined by fluorescence in situ hybridization (FISH) in relation to the presence of p53 dysfunction and ploidy in 60 primary human breast cancers. RESULTS We show that there are clusters of genophenotypic abnormalities that distinguish lobular breast cancers from nonlobular tumors; that cyclin D1 amplification occurs prior to the divergence of lobular breast cancers from nonlobular cancers; that p53 dysfunction, Her-2/neu amplification, and c-myc amplification are characteristic features of nonlobular breast cancers, but not of lobular breast cancers; and that the frequencies of amplification of all three oncogenes examined increase progressively with increasing aneuploidy, but that each gene exhibits a different profile of increasing amplification in relation to tumor progression. Early amplification of c-myc appears to be an especially prominent feature of hypertetraploid/hypertetrasomic tumors. CONCLUSIONS The data suggest that in tumors containing multiple abnormalities, these abnormalities often accumulate in the same cells within each tumor. Furthermore, the same patterns of accumulation of multiple genophenotypic abnormalities are recapitulated in different tumors.
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Nambiar P, Carson G, Taylor JA, Brown KA. Identification from a bitemark in a wad of chewing gum. THE JOURNAL OF FORENSIC ODONTO-STOMATOLOGY 2001; 19:5-8. [PMID: 11494677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A wad of used chewing gum recovered from the scene of a burglary contained impressions of human teeth. Casts of these impressions displayed unique morphological characteristics which were found to show concordance with corresponding features present on casts of the posterior teeth of a suspect.
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Gottschlich MJ, Aardema KL, Burd EM, Nakhleh RE, Brown KA, Abouljoud MS, Hirst K, Moonka DK. The use of hepatitis C viral RNA levels in liver tissue to distinguish rejection from recurrent hepatitis C. Liver Transpl 2001; 7:436-41. [PMID: 11349265 DOI: 10.1053/jlts.2001.23909] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Persistence of hepatitis C virus (HCV) after orthotopic liver transplantation is almost universal in HCV-infected patients. Histological examination of liver biopsy specimens can be variable in distinguishing between recurrent hepatitis C and acute cellular rejection. The purpose of this study is to determine whether hepatic HCV RNA levels can be used to distinguish rejection from recurrent HCV by determining whether hepatic HCV RNA levels correlate with histological characteristics and clinical course. Seventy-two biopsy specimens were evaluated from 36 liver transplant recipients with HCV and elevated liver-related enzyme levels. Based on histological findings and clinical response to therapy, patients were defined as belonging to 1 of 5 groups: (1) definite rejection, (2) probable rejection, (3) indeterminate findings, (4) probable HCV, and (5) definite HCV. Hepatic HCV RNA was quantified using the Amplicor Monitor assay (Roche Diagnostic Systems Inc, Branchburg, NJ). There was a difference across groups in HCV RNA levels (P =.046). The median HCV RNA level was 10,695 copies/mg of tissue DNA in the definite-HCV group compared with 1,024 copies/mg of tissue DNA in the definite-rejection group. Using pairwise comparisons, significant differences were found between definite HCV and definite rejection, probable HCV and definite rejection, probable HCV and probable rejection, and probable HCV and indeterminate. Our findings support the following conclusions. (1) In liver transplant recipients, hepatic HCV RNA levels are statistically greater in patients with recurrent HCV than rejection, although there is considerable overlap between groups. (2) Patients with low HCV RNA levels were unlikely to have recurrent HCV. (3) Patients with minimal and indeterminate findings on biopsy (group 3) had low HCV RNA levels.
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Abstract
Continued discussion over organ allocation and distribution remained a focal point in the field of liver transplantation in the year 2000. Despite the ongoing debate, no significant changes were implemented in the current allocation system. By far, the most widely discussed topic in liver transplantation this year was live donor adult-to-adult liver transplantation. Several authors reported on their initial experience, with both recipient and donor outcomes appearing excellent. As the number of transplant centers performing this procedure increases we look forward to further studies regarding the safety and long-term outcome of this innovative procedure. Studies on viral hepatitis after liver transplantation again focused on the problem of recurrent hepatitis B and hepatitis C. Several small studies found benefit in patients with hepatitis B treated with intramuscular hepatitis B immunoglobulin and lamivudine after transplantation. Although breakthrough replication remains a problem in some patients, these studies offer hope that combination therapy for hepatitis B may provide improved long-term graft survival in these patients. In patients with hepatitis C, several studies focused on identifying risk factors to predict graft recurrence of the virus after liver transplantation. Both cellular rejection and level of viral replication may be important predictors of recurrent hepatitis C virus in the graft. Early treatment reports using interferon and ribavirin suggest that some patients may have a viral response during therapy; however, it is short lived, and tolerance of medication is difficult. Certainly, we look forward to further studies looking at means of prevention and treatment of viral hepatitis in patients undergoing liver transplantation.
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Bodiguel J, Nagy JM, Brown KA, Jamart-Grégoire B. Oxidation of isoniazid by manganese and Mycobacterium tuberculosis catalase-peroxidase yields a new mechanism of activation. J Am Chem Soc 2001; 123:3832-3. [PMID: 11457121 DOI: 10.1021/ja002674f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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