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Occurrence and Patterns of Enterotoxin Genes, spa Types and Antimicrobial Resistance Patterns in Staphylococcus aureus in Food and Food Contact Surfaces in Singapore. Microorganisms 2023; 11:1785. [PMID: 37512957 PMCID: PMC10386305 DOI: 10.3390/microorganisms11071785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/12/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
Staphylococcus aureus contamination of food and food contact surfaces is a public health concern given its virulent and antimicrobial-resistant properties worldwide. In this study, a total of 181 MSSA isolates were analyzed for SE genes, antimicrobial resistance patterns, and spa types. Overall, 24.9% of isolates were positive for SE gene detection, with sea being the most prevalent classical SE (18.8%). The most predominant sample sources for SE gene contamination were hand swabs for sea (6/48), meat dishes for seb (3/14) and seafood dishes for sec (2/24). Antimicrobial resistance was also observed at relatively high frequencies for the clinically important antibiotics penicillin G and ampicillin (both 54.7%), followed by tetracycline (14.9%) and azithromycin (8.8%). In addition, characterization of spa types revealed spa type t5078 to be the most predominant (40.3%), with significant associations between spa types t127 and t5521 and the sea gene. This study offers insights into the enterotoxin gene and antimicrobial resistance profiles of S. aureus in cooked or ready-to-eat food to inform future surveillance and epidemiological studies.
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Creating texturally tuneable, low calorie and palatable noodle-like food assemblies via microfluidics. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Comparison of the sensitivity and specificity of p16/Ki-67 dual staining and HPV DNA testing of abnormal cervical cytology in the detection of histology proven cervical intraepithelial neoplasia grade 2 and above (CIN 2+). THE MALAYSIAN JOURNAL OF PATHOLOGY 2017; 39:257-265. [PMID: 29279588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
INTRODUCTION Human papillomavirus (HPV) testing is used as a means of triaging cervico-vaginal smears with low grade squamous abnormalities or as part of co-testing with cytology. While HPV testing has a high sensitivity, it has a low specificity in detecting cervical intraepithelial neoplasia grade 2 and above (CIN 2+) leading to unnecessary colposcopy referrals. We investigate the accuracy of the p16/Ki-67 dual immunocytochemical stain in determining the presence of CIN 2+ lesions on histology and its potential as a superior biomarker for triage. METHODS Liquid based cervico-vaginal cytology specimens with squamous abnormalities and corresponding histology from 97 women with subsequent colposcopy and biopsy were included. The specimens were then subjected to the dual stain and Roche Cobas 4800 multiplex real time PCR HPV DNA testing. The sensitivity and specificity of the dual stain and HPV testing were calculated using CIN 2+ on histology as a reference standard. RESULTS The sensitivity and specificity of the dual stain in detecting histology proven CIN 2+ was 93.7% and 76.5% while HPV testing was 85.7% and 14.7% respectively. Of the 44 women with ASCUS or LSIL on cytology, the dual stain also reduced the number of unnecessary colposcopy referrals from 27 to 7 when used as a triage marker compared to HPV testing. CONCLUSION p16/Ki-67 dual stain was more sensitive and specific than HPV testing in determining the presence of CIN 2+ on histology. It could triage low grade cervico-vaginal specimens more effectively and potentially help women avoid unnecessary colposcopies. Future studies are needed to further evaluate its role in cervical cancer screening programmes.
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Improving refractive outcomes at extreme axial lengths with the IOLMaster: the optical axial length and keratometric transformation. Br J Ophthalmol 2009; 93:678-83. [DOI: 10.1136/bjo.2008.148452] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Differential expression of splice variant and wild-type parkin in sporadic Parkinson's disease. Neurogenetics 2005; 6:179-84. [PMID: 16086186 DOI: 10.1007/s10048-005-0001-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Altered splicing of parkin under cellular stress could lead to changes in gene expression and altered protein activity. The causative role of parkin in sporadic Parkinson's disease (PD) is unknown. OBJECTIVES We described a parkin splice variant (SV) in the substantia nigra and leukocytes of sporadic PD patients. Using a case control methodology, we investigated the exon 4 SV (E4SV) and wild-type parkin expression in the leukocytes of sporadic PD patients and healthy individuals. METHODS/RESULTS We identified a parkin E4SV in the substantia nigra and leukocytes of sporadic PD patients and controls by reverse transcriptase-polymerase chain reaction (PCR). The exon 4 (122 bp) deletion resulted in a reading frame shift over the junction of exons 3-5 and a stop codon (tga) 17 bp downstream from exon 3. The translated truncated protein was associated with a total loss of the two-RING finger functional domain. Utilizing TaqMan real-time PCR with probes located across the junction of exons 3-4 or 3-5, we demonstrated an over-expression of E4SV/wild-type parkin ratio in the leukocytes of sporadic PD patients compared to age-, gender-, and race-matched controls (p<0.0005). A multivariate regression analysis demonstrated that the ratio of E4SV/wild-type parkin expression increased with age in PD patients, but this was not observed in the controls (p<0.0005). CONCLUSION The relative expression of E4SV/wild type parkin was increased in sporadic PD compared to healthy controls. Based on our observations, further functional studies to determine the pathophysiologic role of E4SV in sporadic PD patients will be of importance.
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Alpha-Synuclein-induzierte Proteinaggregation und Neurodegeneration in vivo sind Parkin-unabhängig. AKTUELLE NEUROLOGIE 2004. [DOI: 10.1055/s-2004-833018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Parkin ubiquitinates the alpha-synuclein-interacting protein, synphilin-1: implications for Lewy-body formation in Parkinson disease. Nat Med 2001; 7:1144-50. [PMID: 11590439 DOI: 10.1038/nm1001-1144] [Citation(s) in RCA: 538] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Parkinson disease is a common neurodegenerative disorder characterized by the loss of dopaminergic neurons and the presence of intracytoplasmic-ubiquitinated inclusions (Lewy bodies). Mutations in alpha-synuclein (A53T, A30P) and parkin cause familial Parkinson disease. Both these proteins are found in Lewy bodies. The absence of Lewy bodies in patients with parkin mutations suggests that parkin might be required for the formation of Lewy bodies. Here we show that parkin interacts with and ubiquitinates the alpha-synuclein-interacting protein, synphilin-1. Co-expression of alpha-synuclein, synphilin-1 and parkin result in the formation of Lewy-body-like ubiquitin-positive cytosolic inclusions. We further show that familial-linked mutations in parkin disrupt the ubiquitination of synphilin-1 and the formation of the ubiquitin-positive inclusions. These results provide a molecular basis for the ubiquitination of Lewy-body-associated proteins and link parkin and alpha-synuclein in a common pathogenic mechanism through their interaction with synphilin-1.
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Isolation of a novel protein tyrosine phosphatase inhibitor, 2-methyl-fervenulone, and its precursors from Streptomyces. JOURNAL OF NATURAL PRODUCTS 2000; 63:1641-1646. [PMID: 11141106 DOI: 10.1021/np000293+] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High-throughput screening identified an extract from Streptomyces sp. IM 2096 with inhibitory activity toward several protein tyrosine phosphatases (PTPs). Four 1,2,4-triazine compounds 2096A-D (1-4) were isolated from this extract and their structures elucidated by interpretation of spectroscopic data and confirmed by degradation and synthesis. The novel glycocyamidine derivatives 1 and 2 are diastereomers and may interconvert. Both are inactive in the PTP inhibition assay. Compounds 1 and 2 are unstable and partially decompose to 3 and glycocyamidine (5) at room temperature. Compound 3, known as MSD-92 or 2-methyl-fervenulone, is a broad-specificity PTP inhibitor with comparable potency to vanadate. The imidazo[4, 5-e]-1,2,4-triazine (4), inactive in the PTP-inhibition assay, may be a degradation product of 3.
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Calmodulin binds to and inhibits the activity of the membrane distal catalytic domain of receptor protein-tyrosine phosphatase alpha. J Biol Chem 2000; 275:30075-81. [PMID: 10893241 DOI: 10.1074/jbc.m004843200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
cDNA expression library screening revealed binding between the membrane distal catalytic domain (D2) of protein-tyrosine phosphatase alpha (PTPalpha) and calmodulin. Characterization using surface plasmon resonance showed that calmodulin bound to PTPalpha-D2 in a Ca(2+)-dependent manner but did not bind to the membrane proximal catalytic domain (D1) of PTPalpha, to the two tandem catalytic domains (D1D2) of PTPalpha, nor to the closely related D2 domain of PTPepsilon. Calmodulin bound to PTPalpha-D2 with high affinity, exhibiting a K(D) approximately 3 nm. The calmodulin-binding site was localized to amino acids 520-538 in the N-terminal region of D2. Site-directed mutagenesis showed that Lys-521 and Asn-534 were required for optimum calmodulin binding and that restoration of these amino acids to the counterpart PTPepsilon sequence could confer calmodulin binding. The overlap of the binding site with the predicted lip of the catalytic cleft of PTPalpha-D2, in conjunction with the observation that calmodulin acts as a competitive inhibitor of D2-catalyzed dephosphorylation (K(i) approximately 340 nm), suggests that binding of calmodulin physically blocks or distorts the catalytic cleft of PTPalpha-D2 to prevent interaction with substrate. When expressed in cells, full-length PTPalpha and PTPalpha lacking only D1, but not full-length PTPepsilon, bound to calmodulin beads in the presence of Ca(2+). Also, PTPalpha was found in association with calmodulin immunoprecipitated from cell lysates. Thus calmodulin does associate with PTPalpha in vivo but not with PTPalpha-D1D2 in vitro, highlighting a potential conformational difference between these forms of the tandem catalytic domains. The above findings suggest that calmodulin is a possible specific modulator of PTPalpha-D2 and, via D2, of PTPalpha.
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Catalytic activation of the membrane distal domain of protein tyrosine phosphatase epsilon, but not CD45, by two point mutations. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1434:275-83. [PMID: 10525146 DOI: 10.1016/s0167-4838(99)00189-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Most, if not all, of the catalytic activity of the tandem catalytic domain-containing receptor-like protein tyrosine phosphatases (PTPs) resides in the membrane proximal domains (D1), with little to no activity associated with the membrane distal domains (D2). Two point mutations in the D2 domain of PTPalpha, which restore invariant amino acids found in the KNRY motif and WPD loop of all active D1 domains, synergistically confer D1-equivalent kinetic properties towards the phosphotyrosine analogue pNPP, and activate PTPalpha-D2 catalysed phosphopeptide hydrolysis (Lim et al., J. Biol. Chem. 273 (1998) 28986-28993; Buist et al., Biochemistry 38 (1999) 914-922). As all D2 domains lack these two D1-invariant amino acids, we have investigated whether other D2 domains are activated by such point mutations. Mutant PTPepsilon-D2, closely related to PTPalpha-D2 and belonging to a subgroup of D2 domains with minimal and conservative substitutions of D1-invariant amino acids, exhibits synergistic activation towards pNPP but not towards a phosphopeptide substrate. CD45-D2, belonging to another subgroup of D2 domains with considerable substitutions in D1-invariant amino acids, is not activated by these mutations, even in the context of a third mutation which restores the minimal essential active site sequence C(X(5))R, indicating that additional defects are sufficient to preclude catalysis. The ability of the KNRY and WPD replacements to activate PTPepsilon-D2 and PTPalpha-D2, but not CD45-D2, in conjunction with the extent and nature of their wild-type amino acid substitutions, suggests that these D2 domains are representative of two functionally distinct groups of D2 domain.
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Targeted disruption of the tyrosine phosphatase PTPalpha leads to constitutive downregulation of the kinases Src and Fyn. Curr Biol 1999; 9:535-8. [PMID: 10339428 DOI: 10.1016/s0960-9822(99)80238-3] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A role for the receptor-like protein tyrosine phosphatase alpha (PTPalpha) in regulating the kinase activity of Src family members has been proposed because ectopic expression of PTPalpha enhances the dephosphorylation and activation of Src and Fyn [1] [2] [3]. We have generated mice lacking catalytically active PTPalpha to address the question of whether PTPalpha is a physiological activator of Src and Fyn, and to investigate its other potential functions in the context of the whole animal. Mice homozygous for the targeted PTPalpha allele (PTPalpha-/-) and lacking detectable PTPalpha protein exhibited no gross phenotypic defects. The kinase activities of Src and Fyn were significantly reduced in PTPalpha-/- mouse brain and primary embryonic fibroblasts, and this correlated with enhanced phosphorylation of the carboxy-terminal regulatory Tyr527 of Src in PTPalpha-/- mice. Thus, PTPalpha is a physiological positive regulator of the tyrosine kinases Src and Fyn. Increased tyrosine phosphorylation of several unidentified proteins was also apparent in PTPalpha-/- mouse brain lysates. These may be PTPalpha substrates or downstream signaling proteins. Taken together, the results indicate that PTPalpha has a dual function as a positive and negative regulator of tyrosine phosphorylation events, increasing phosphotyrosyl proteins through activation of Src and Fyn, and directly or indirectly removing tyrosine phosphate from other unidentified proteins.
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Interconversion of the kinetic identities of the tandem catalytic domains of receptor-like protein-tyrosine phosphatase PTPalpha by two point mutations is synergistic and substrate-dependent. J Biol Chem 1998; 273:28986-93. [PMID: 9786903 DOI: 10.1074/jbc.273.44.28986] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The two tandem homologous catalytic domains of PTPalpha possess different kinetic properties, with the membrane proximal domain (D1) exhibiting much higher activity than the membrane distal (D2) domain. Sequence alignment of PTPalpha-D1 and -D2 with the D1 domains of other receptor-like PTPs, and modeling of the PTPalpha-D1 and -D2 structures, identified two non-conserved amino acids in PTPalpha-D2 that may account for its low activity. Mutation of each residue (Val-536 or Glu-671) to conform to its invariant counterpart in PTPalpha-D1 positively affected the catalytic efficiency of PTPalpha-D2 toward the in vitro substrates para-nitrophenylphosphate and the phosphotyrosyl-peptide RR-src. Together, they synergistically transformed PTPalpha-D2 into a phosphatase with catalytic efficiency for para-nitrophenylphosphate equal to PTPalpha-D1 but not approaching that of PTPalpha-D1 for the more complex substrate RR-src. In vivo, no gain in D2 activity toward p59(fyn) was effected by the double mutation. Alteration of the two corresponding invariant residues in PTPalpha-D1 to those in D2 conferred D2-like kinetics toward all substrates. Thus, these two amino acids are critical for interaction with phosphotyrosine but not sufficient to supply PTPalpha-D2 with a D1-like substrate specificity for elements of the phosphotyrosine microenvironment present in RR-src and p59(fyn). Whether the structural features of D2 can uniquely accommodate a specific phosphoprotein substrate or whether D2 has an alternate function in PTPalpha remains an open question.
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Physical and functional interactions between receptor-like protein-tyrosine phosphatase alpha and p59fyn. J Biol Chem 1998; 273:8691-8. [PMID: 9535845 DOI: 10.1074/jbc.273.15.8691] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We have examined the in vivo activity of receptor-like protein-tyrosine phosphatase alpha (PTPalpha) toward p59(fyn), a widely expressed Src family kinase. In a coexpression system, PTPalpha effected a dose-dependent tyrosine dephosphorylation and activation of p59(fyn), where maximal dephosphorylation correlated with a 5-fold increase in kinase activity. PTPalpha expression resulted in increased accessibility of the p59(fyn) SH2 domain, consistent with a PTPalpha-mediated dephosphorylation of the regulatory C-terminal tyrosine residue of p59(fyn). No p59(fyn) dephosphorylation was observed with an enzymatically inactive mutant form of PTPalpha or with another receptor-like PTP, CD45. Many enzyme-linked receptors are complexed with their substrates, and we examined whether PTPalpha and p59(fyn) underwent association. Reciprocal immunoprecipitations and assays detected p59(fyn) and an appropriate kinase activity in PTPalpha immunoprecipitates and PTPalpha and PTP activity in p59(fyn) immunoprecipitates. No association between CD45 and p59(fyn) was detected in similar experiments. The PTPalpha-mediated activation of p59(fyn) is not prerequisite for association since wild-type and inactive mutant PTPalpha bound equally well to p59(fyn). Endogenous PTPalpha and p59(fyn) were also found in association in mouse brain. Together, these results demonstrate a physical and functional interaction of PTPalpha and p59(fyn) that may be of importance in PTPalpha-initiated signaling events.
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Kinetic analysis of two closely related receptor-like protein-tyrosine-phosphatases, PTP alpha and PTP epsilon. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 245:693-700. [PMID: 9183007 DOI: 10.1111/j.1432-1033.1997.00693.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Among transmembrane protein-tyrosine-phosphatases, the membrane distal catalytic domain (D2) of protein-tyrosine-phosphatase alpha (PTP alpha) is unusual in having low but detectable activity in the absence of the membrane proximal catalytic domain (D1). To investigate the catalytic properties of PTP alpha D2 in association with D1, kinetic parameters of activity were established for PTP alpha D1D2 proteins containing an inactivating point mutation in D1 and/or D2. In this context, D2 activity was unchanged by the presence (N-terminal or C-terminal) or absence of inactive D1, and the presence or absence of inactive D2 affected the velocity but not the Km of D1 catalysis. While D1 appears to be the major catalytic contributor to PTP alpha activity, D2 possesses a significantly higher substrate-specific activity relative to wild-type D1D2 than the D2 domains of other protein-tyrosine-phosphatases. Also, PTP alpha D2 is an active phosphatase with comparable or better efficiency, on the basis of k(cat)/Km criteria, to some of the dual specificity phosphatases. Kinetic parameters of a closely related receptor-like protein-tyrosine-phosphatase, PTP epsilon, were determined. PTP epsilon D1 is the major, if not the only, catalytic moiety of PTP epsilon, and has much higher turnover numbers than D1 of PTP alpha. The PTP epsilon D2 activity is insignificant compared to that of PTP epsilon-D1D2, with lower turnover numbers than PTP alpha D2. Thus, the intrinsic activity of PTP alpha D2 is high compared to other D2 domains and, more outstandingly, its activity relative to D1 appears unique. These are also apparent upon in vitro assay of full-length PTP alpha catalytic mutants expressed in mammalian cells. Together. these results suggest potential catalytic and regulatory roles for PTP alpha D2, and that PTP alpha may be an optimal model transmembrane protein-tyrosine-phosphatase for investigating the former within the cell.
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Abstract
The purpose of this paper is to establish whether there is increased lymphocyte adhesion molecule density in systemic lupus erythematosus (SLE), which could alter the migration pathways and activation thresholds of lymphocytes and thus contribute to the pathogenesis of the disease. We analysed the CD11a, CD29 and CD2 bound antibody molecule (bam) density on the CD4+ and CD8+ CAMhigh (primed) lymphocytes of 28 SLE patients (8 active and 20 inactive by BILAG), using reproducible flow cytometric measurements, standardized with fluorescent beads and antibodies of known fluorescein: protein ratios. In a second patient cohort (17 patients), we investigated whether CD29 density on CD8+ cells correlated with measures of humoral (serum IgG) or cellular (urine neopterin) activation. In the first cohort, 36% of patients had elevated CD29 (beta 1 integrin) density on CD8+ cells. In the second cohort, CD29 density on CD8+ cells was found to be closely associated with total plasma IgG (r = 0.71, P = 0.001), but not with urine neopterin, disease activity (BILAG) or drug treatment. We conclude that CD29 on CD8+ cells is associated with B cell activation in SLE.
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Cervical spondylodiscitis in a patient with ankylosing spondylitis. BRITISH JOURNAL OF RHEUMATOLOGY 1996; 35:1034-6. [PMID: 8883452 DOI: 10.1093/rheumatology/35.10.1034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Rat fibroblast cells overexpressing kinase-inactive human insulin receptors are insulin responsive: influence of growth conditions. Endocrinology 1995; 136:1459-67. [PMID: 7534700 DOI: 10.1210/endo.136.4.7534700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effects of insulin to stimulate metabolic and mitogenic responses were examined in Rat 1 fibroblast cells that overexpressed either normal (HIRc) or kinase-deficient human insulin receptors. When studied at the optimal growth stage for each cell line, insulin-stimulated responses measured in cells containing kinase-defective receptors with a Lys1018-Ala1018 substitution in the ATP-binding site of the kinase domain (A/K1018). Maximal insulin responsiveness for all these effects, measured as fold-increase over basal, was comparable in parental and HIRc cells (1.8- to 2.4-fold increases). Relative insulin responsiveness for all effects was greatest in A/K 1018 cells. One clone (AK-I) expressing a similar number of kinase-inactive receptors as in the HIRc cells displayed maximal responsiveness of 3.6- to 5.5-fold increases. A second A/K cell line containing 1/10 the number of kinase-inactive receptors displayed responsiveness intermediate between AK-I and parental or HIRc cells (1.5- to 4.8-fold increases). Both clones of kinase-deficient A/K1018 cells displayed impaired insulin sensitivity compared with HIRc cells. These findings suggest that expression of insulin receptor kinase activity is a determinant of insulin sensitivity but not necessarily of the final biological responsiveness of cells to insulin.
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Abstract
Lymphocytic vasculitis (LV) characterises systemic lupus erythematosus (SLE) and this potentially reversible lesion, which may be subclinical, may imply overt systemic disease activity. Needle quadriceps muscle biopsy was performed in 26 unselected patients with SLE and the presence of LV in these muscle specimens was compared with SLE disease activity scored using the British Isles Lupus Assessment Group Index (BILAG). Ten of the 22 patients with active disease showed evidence of LV compared with none of the four patients with inactive disease. In the patient group with LV, significantly higher ESR and urine neopterin values were found with P = 0.002 and P = 0.02, respectively compared with patients without LV. Features of vasculitis (as defined by BILAG) were also significantly more common in these patients (P = 0.005). None of the other parameters, including creatine kinase, were significantly different between the two patient subgroups. Thus, LV in needle quadriceps muscle biopsy specimens is a further valuable marker of disease activity in patients with SLE and might provide histological evidence of a systemic vasculitic process in a group of patients with diverse clinical manifestations.
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Investigation of the prevalence and clinical associations of antibodies to human fibronectin in systemic lupus erythematosus. Ann Rheum Dis 1995; 54:117-24. [PMID: 7702398 PMCID: PMC1005533 DOI: 10.1136/ard.54.2.117] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES To assess the prevalence of antibodies to human fibronectin (anti-Fn) in sera of patients with certain connective tissue diseases and to determine their association with disease activity and the pattern of organ involvement in patients with systemic lupus erythematosus (SLE). METHODS A capture enzyme linked immunosorbent assay (ELISA) was developed to quantify anti-Fn antibodies in serum samples from 65 patients with well characterised SLE, 50 with rheumatoid arthritis (RA), 15 with Behçet's disease (BD), 15 with systemic vasculitis and 36 healthy subjects. An anti-Fn antibody titre greater than mean + 3SD of the healthy control log values after back transformation to the normal scale was considered positive. Disease activity in SLE patients was scored using the British Isles Lupus Assessment Group (BILAG) Index. Erythrocyte sedimentation rate (ESR), concentrations of anti-dsDNA antibody, soluble interleukin-2 receptors (sIL-2R), C3, C4, C3 degradation products (C3dg) and immunoglobulin, and antinuclear antibody (ANA) titres were measured in blood samples from SLE patients; neopterin concentration was measured in corresponding urine samples. RESULTS Anti-Fn antibodies were found in 22 of 65 SLE patients (33.8%), seven of 50 with RA (14%), one of 15 with BD (6.6%) and none of the 15 subjects with vasculitis. Thirty SLE patients had active disease and 35 had inactive disease; their median anti-Fn concentrations were 117 u/ml (range 47-450) and 68 u/ml (range 17-334), respectively (p = 0.0001). The presence of anti-Fn did not correlate with immunoglobulin concentrations or ANA titres in these sera. No significant difference was found between SLE patients with disease activity in one major organ system compared with multiple organ involvement, as defined by BILAG (p = 0.19). However, patients with musculoskeletal manifestations had consistently greater anti-Fn concentrations compared with patients with other clinical manifestations. There were significant correlations between amounts of anti-Fn in SLE sera and ESR (rs = 0.25, p = 0.045), sIL-2R (rs = 0.28, p = 0.024) and urine neopterin (rs = 0.3, p = 0.016) but not with serum anti-dsDNA antibody titres, plasma C3, C3dg or C4. However multiple regression analysis showed a low significant correlation only with sIL-2R and BILAG score (p = 0.047 and 0.042, respectively). CONCLUSION Anti-Fn antibodies were detected in 34% of SLE patients and in small proportions of RA and BD patients. An association between serum anti-Fn and disease activity in SLE has been identified and most SLE patients with musculoskeletal involvement had increased anti-Fn antibody concentrations.
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Urine neopterin: a new parameter for serial monitoring of disease activity in patients with systemic lupus erythematosus. Ann Rheum Dis 1994; 53:743-8. [PMID: 7826135 PMCID: PMC1005455 DOI: 10.1136/ard.53.11.743] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To investigate the role of serial measurement of urine neopterin concentration in monitoring the progression of systemic lupus erythematosus (SLE) disease activity scored using the British Isles Lupus Assessment Group (BILAG) index. METHODS We followed prospectively 68 unselected SLE patients for a total of 464 patient months during which 233 separate assessments were carried out. At each assessment, urine neopterin, determined by high performance liquid chromatography, together with erythrocyte sedimentation rate (ESR) and plasma C3, C4, and C3d were measured and the SLE disease activity scored by a single observer. Serial data sets were analysed using time series modelling techniques. RESULTS Single time point analysis showed a significant increase in urine neopterin concentrations in 14 patients who suffered flares of their disease during the study period (p = 0.02). Thirty patients with active disease went into disease remission with significant decreases in their urine neopterin values (p = 0.02). In the time series analysis, a statistically significant association was found between serial concentrations of urine neopterin and BILAG score (r = 0.6, p < 0.05); no other study parameter (ESR and serum C3, C4, and C3d) mirrored SLE disease activity as effectively. CONCLUSIONS This study provides initial evidence that changes in urine concentrations of neopterin are significantly correlated with fluctuations in disease activity over time, scored using the BILAG index, amongst individual patients with SLE. Consequently, serial urine neopterin measurements appear to be clinically useful for monitoring disease activity and may contribute substantially to therapeutic decision making in these patients.
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Muscle biopsy abnormalities in systemic lupus erythematosus: correlation with clinical and laboratory parameters. Ann Rheum Dis 1994; 53:178-82. [PMID: 8154935 PMCID: PMC1005282 DOI: 10.1136/ard.53.3.178] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES To investigate the incidence and significance of Type II fibre atrophy, vessel wall thickening, lymphocytic vasculitis and myositis in needle quadriceps muscle biopsies from patients with systemic lupus erythematosus (SLE) and their correlations with clinical and laboratory parameters. METHODS Needle quadriceps muscle biopsies from 55 patients with SLE and 26 controls were prospectively examined. Clinical and laboratory parameters recorded at the time of muscle biopsy included arthralgia, arthritis, myalgia, proximal weakness, vasculitic rashes, Schirmer test, ENA antibodies, ESR, serum creatine kinase (CK) and plasma C3 degradation products. RESULTS Abnormal muscle biopsies were significantly more frequent in patients with SLE compared with controls (P < 0.005). None of the controls had lymphocytic vasculitis and/or myositis. The difference in incidence between patients with SLE and controls for lymphocytic vasculitis was significant at P < 0.005. Due to the small number of SLE patients with myositis, the difference in incidence for this abnormal finding reached only P = 0.09. In the SLE patient group, lymphocytic vasculitis was associated with significantly higher ESR values (P = 0.007) and higher incidence of arthritis (P = 0.01); and appears to characterise a subset of patients with positive Schirmer tests, anti-Ro and/or anti-La antibodies. Raised serum CK was found to correspond with underlying myositis in patients with SLE and these patients also had an increased incidence of symptoms of proximal weakness and/or anti-RNP antibodies. In contrast, both Type II fibre atrophy and vessel wall thickening failed to correlate with any of the clinical and laboratory parameters studied and appear to be non-specific findings. CONCLUSIONS Abnormal muscle biopsies are common in patients with SLE and the presence of lymphocytic vasculitis and/or myositis signify pathology in these patients. Histopathological abnormalities in needle quadriceps muscle biopsies are further valuable parameters in the assessment of patients with SLE.
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Abstract
Focal myositis is considered a rare self-limiting inflammatory swelling of skeletal muscle. Focal involvement of individual muscle or muscle groups with severe myopathic and inflammatory changes characterizes the histology. We report the development of progressive focal myositis in both upper eyelids of a 34 year old man that responded to immunosuppressive therapy.
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Urine neopterin as a parameter of disease activity in patients with systemic lupus erythematosus: comparisons with serum sIL-2R and antibodies to dsDNA, erythrocyte sedimentation rate, and plasma C3, C4, and C3 degradation products. Ann Rheum Dis 1993; 52:429-35. [PMID: 8323394 PMCID: PMC1005067 DOI: 10.1136/ard.52.6.429] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES--To investigate urine neopterin as a parameter of disease activity in an unselected group of patients with systemic lupus erythematosus (SLE) and to study the relation between urine neopterin and certain patterns of organ disease and differing drug regimens in the treatment of SLE. METHODS--Neopterin was determined by high performance liquid chromatography in 115 early morning urine samples from 68 patients with SLE. Serum soluble interleukin 2 receptor (sIL-2R) and antibodies to double stranded DNA (dsDNA) were determined by enzyme linked immunosorbent assay (ELISA), and the erythrocyte sedimentation rate (ESR), plasma C3, C4, and C3 degradation products (C3dg) were measured in corresponding blood samples. Disease activity was scored using the British Isles Lupus Assessment Group (BILAG) index. RESULTS--Urine neopterin was significantly increased in patients with active and inactive SLE compared with the control group and was significantly higher in patients with active than in those with inactive SLE. Urine neopterin did not distinguish between subsets of patients with SLE with particular patterns of organ disease, as defined by the BILAG index, nor was its level primarily influenced by differing drug regimens. Levels of serum sIL-2R, antibodies to dsDNA, the ESR, and plasma C3, C4, and C3dg were also significantly different between the patients with active and inactive SLE. Unlike urine neopterin there was considerable overlap in the values of these parameters between the two activity groups. Highly significant correlations found between urine neopterin and serum sIL-2R, ESR, and plasma C3, C4, and C3dg suggest the close association of neopterin with clinical activity in SLE. Multivariate logistic regression analysis showed that urine neopterin > 300 mumol/mol creatinine was a highly significant predictor of disease activity with an odds ratio of 3.51. CONCLUSIONS--Determination of urine neopterin, a non-invasive, relatively simple and inexpensive measurement, appears to be the best parameter for assessing and monitoring disease activity and treatment in patients with SLE.
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Pneumocystis carinii pneumonia following immunosuppressive therapy in systemic lupus erythematosus. BRITISH JOURNAL OF RHEUMATOLOGY 1992; 31:643-4. [PMID: 1525634 DOI: 10.1093/rheumatology/31.9.643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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A criterion based audit of inpatient asthma care. Closing the feedback loop. JOURNAL OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON 1992; 26:71-5. [PMID: 1315391 PMCID: PMC5375436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have assessed the care of patients admitted to a specialist respiratory medical ward acutely ill with asthma, using a criterion based audit derived from a standard management protocol already in use in our hospitals. The audit was first performed from 01.01.90 to 31.08.90; after implementing certain changes, the audit was repeated from 1.12.90 to 31.1.91. Special attention was paid in each audit review to pre-admission measures, inpatient management and pre-discharge and follow-up management. During both audit periods, of a total of 78 patients, 74 patients gave a reason for the worsening of their asthma; 59 had had PEF measured and 58 had received systemic steroids before admission; 77 patients had full objective assessment of severity on admission; 76 patients were discharged on oral steroids; 62 had PEF meters for home monitoring; and 65 of the 68 patients who lived in our district were seen again within six weeks as outpatients in the chest clinic. However, only 30/55 (54%) had PEF variability of 20% or less (our criterion for appropriateness of discharge, in the first audit period) and only 32/55 had a written check on their inhaler technique in the first audit period. By relaxing our PEF criterion for discharge (in line with national guidelines), by introducing a stamp for recording that inhaler technique had been checked, and with encouragement and exhortation from senior staff, we improved our performance of meeting the set standards to 17 of 23 (74%) patients for PEF variability and to 22 of 23 (96%) patients for written check on inhaler technique in the second audit period.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
We report the case history of a 57 year old man who has suffered from typical deforming, relapsing polychondritis for 13 years. He has also developed erosive destructive seronegative polyarthritis involving some of his distal interphalangeal, proximal interphalangeal, metacarpophalangeal, intercarpal, wrist, intertarsal and metatarsophalangeal joints. The distribution of joint involvement in the small joints of the hands and feet is asymmetrical. Both hips and knee joints have also been involved necessitating bilateral total hip and right total knee replacement. The articular associations with relapsing polychondritis are discussed.
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An evaluation of different doses of soluble aspirin and aspirin tablets in postoperative dental pain. Br J Clin Pharmacol 1988; 26:463-8. [PMID: 3190996 PMCID: PMC1386569 DOI: 10.1111/j.1365-2125.1988.tb03406.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
1. The efficacy of three different single doses (600, 900 and 1200 mg of soluble aspirin and aspirin tablets) was determined in a randomized placebo-controlled parallel study in 140 patients (70 females) with postoperative pain after removal of impacted third molars. 2. Patients treated with soluble aspirin 600 mg, 900 mg, 1200 mg and aspirin tablet 1200 mg reported significantly less pain (P less than 0.01) throughout the investigation period than those treated with placebo. 3. Overall pain scores after treatment with aspirin tablets 600 and 900 mg did not differ significantly from those after treatment with placebo (P greater than 0.05). 4. On a comparative dose basis, soluble aspirin was significantly more potent (P less than 0.05) than aspirin tablets.
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Thromboxane and inflammatory cell infiltration of the allograft of renal transplant patients. Transplant Proc 1987; 19:3633-6. [PMID: 3313875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Quantitative separation of B-6 vitamers in selected foods by a gas-liquid chromatographic system equipped with an electron-capture detector. J Chromatogr A 1982; 250:86-9. [PMID: 7153303 DOI: 10.1016/s0021-9673(00)95214-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Solubility and absorption spectra of complexes resulting from interaction among human albumin, bromcresol green and detergents. Clin Chim Acta 1974; 52:257-69. [PMID: 4839087 DOI: 10.1016/0009-8981(74)90109-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Normal range estimates of serum chemistry values in adult west Malaysians. THE MEDICAL JOURNAL OF MALAYSIA 1974; 28:154-9. [PMID: 4278202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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An improved automated method for determination of serum albumin using bromcresol green. Am J Clin Pathol 1973; 59:14-21. [PMID: 4688562 DOI: 10.1093/ajcp/59.1.14] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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