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Ahmed N, Bestall JC, Ahmedzai SH, Payne SA, Clark D, Noble B. Systematic review of the problems and issues of accessing specialist palliative care by patients, carers and health and social care professionals. Palliat Med 2004; 18:525-42. [PMID: 15453624 DOI: 10.1191/0269216304pm921oa] [Citation(s) in RCA: 262] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES To determine the problems and issues of accessing specialist palliative care by patients, informal carers and health and social care professionals involved in their care in primary and secondary care settings. DATA SOURCES Eleven electronic databases (medical, health-related and social science) were searched from the beginning of 1997 to October 2003. Palliative Medicine (January 1997-October 2003) was also hand-searched. STUDY SELECTION Systematic search for studies, reports and policy papers written in English. DATA EXTRACTION Included papers were data-extracted and the quality of each included study was assessed using 10 questions on a 40-point scale. RESULTS The search resulted in 9921 hits. Two hundred and seven papers were directly concerned with symptoms or issues of access, referral or barriers and obstacles to receiving palliative care. Only 40 (19%) papers met the inclusion criteria. Several barriers to access and referral to palliative care were identified including lack of knowledge and education amongst health and social care professionals, and a lack of standardized referral criteria. Some groups of people failed to receive timely referrals e.g., those from minority ethnic communities, older people and patients with nonmalignant conditions as well as people that are socially excluded e.g., homeless people. CONCLUSIONS There is a need to improve education and knowledge about specialist palliative care and hospice care amongst health and social care professionals, patients and carers. Standardized referral criteria need to be developed. Further work is also needed to assess the needs of those not currently accessing palliative care services.
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Abstract
Glycation is a major cause of spontaneous damage to proteins in physiological systems. This is exacerbated in diabetes as a consequence of the increase in glucose and other saccharides derivatives in plasma and at the sites of vascular complications. Protein damage by the formation of early glycation adducts is limited to lysine side chain and N-terminal amino groups whereas later stage adducts, advanced glycation endproducts (AGEs), modify these and also arginine and cysteine residues. Metabolic dysfunction in vascular cells leads to the increased formation of methylglyoxal which adds disproportionately to the glycation damage in hyperglycaemia. AGE-modified proteins undergo cellular proteolysis leading to the formation and urinary excretion of glycation free adducts. AGEs may potentiate the development of diabetic complications by activation of cell responses by AGE-modified proteins interacting with specific cell surface receptors, activation of cell responses by AGE free adducts, impairment of protein-protein and enzyme-substrate interactions by AGE residue formation, and increasing resistance to proteolysis of extracellular matrix proteins. The formation of AGEs is suppressed by intensive glycaemic control, and may in future be suppressed by thiamine and pyridoxamine supplementation, and several other pharmacological agents. Increasing expression of enzymes of the enzymatic defence against glycation provides a novel and potentially effective future therapeutic strategy to suppress protein glycation.
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Malik NS, Moss SJ, Ahmed N, Furth AJ, Wall RS, Meek KM. Ageing of the human corneal stroma: structural and biochemical changes. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1138:222-8. [PMID: 1547284 DOI: 10.1016/0925-4439(92)90041-k] [Citation(s) in RCA: 199] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
High and low angle X-ray diffraction patterns from the corneal stroma give information about the mean intermolecular spacing of the collagen molecules and the mean interfibrillar spacing of the collagen fibrils, respectively. X-ray data were collected, using a high intensity synchrotron source, from human corneas and sclera at approximately physiological hydration. The spacings were measured as a function of tissue age. Between birth and 90 years there is an increase in the cross-sectional area associated with each molecule in corneal collagen from approx. 3.04 nm2 to 3.46 nm2, and an increase in scleral collagen from approx. 2.65 nm2 to 3.19 nm2. These changes may be due to an increase in the extent of non-enzymic cross-linking between collagen molecules over the age range. We have investigated this possibility by measuring collagen glycation using the thiobarbituric acid assay and the subsequent advanced glycation end-products (AGEs) using fluorescence emission. The results obtained have shown an age-related increase in glycation and AGEs in both tissues. We have also demonstrated a decrease in the interfibrillar spacing of corneal collagen with increasing age which may be related to changes in the proteoglycan composition of the interfibrillar matrix.
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Ahmed N, Näsman P, Wahlgren NG. Effect of intravenous nimodipine on blood pressure and outcome after acute stroke. Stroke 2000; 31:1250-5. [PMID: 10835440 DOI: 10.1161/01.str.31.6.1250] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The Intravenous Nimodipine West European Stroke Trial (INWEST) found a correlation between nimodipine-induced reduction in blood pressure (BP) and an unfavorable outcome in acute stroke. We sought to confirm this correlation with and without adjustment for prognostic variables and to investigate outcome in subgroups with increasing levels of BP reduction. METHODS Patients with a clinical diagnosis of ischemic stroke (within 24 hours) were consecutively allocated to receive placebo (n=100), 1 mg/h (low-dose) nimodipine (n=101), or 2 mg/h (high-dose) nimodipine (n=94). The correlation between average BP change during the first 2 days and the outcome at day 21 was analyzed. RESULTS Two hundred sixty-five patients were included in this analysis (n=92, 93, and 80 for placebo, low dose, and high dose, respectively). Nimodipine treatment resulted in a statistically significant reduction in systolic BP (SBP) and diastolic BP (DBP) from baseline compared with placebo during the first few days. In multivariate analysis, a significant correlation between DBP reduction and worsening of the neurological score was found for the high-dose group (beta=0.49, P=0. 048). Patients with a DBP reduction of > or =20% in the high-dose group had a significantly increased adjusted OR for the compound outcome variable death or dependency (Barthel Index <60) (n/N=25/26, OR 10. 16, 95% CI 1.02 to 101.74) and death alone (n/N=9/26, OR 4.336, 95% CI 1.131 16.619) compared with all placebo patients (n/N=62/92 and 14/92, respectively). There was no correlation between SBP change and outcome. CONCLUSIONS DBP, but not SBP, reduction was associated with neurological worsening after the intravenous administration of high-dose nimodipine after acute stroke. For low-dose nimodipine, the results were not conclusive. These results do not confirm or exclude a neuroprotective property of nimodipine.
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Meo SA, Alhowikan AM, Al-Khlaiwi T, Meo IM, Halepoto DM, Iqbal M, Usmani AM, Hajjar W, Ahmed N. Novel coronavirus 2019-nCoV: prevalence, biological and clinical characteristics comparison with SARS-CoV and MERS-CoV. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2020; 24:2012-2019. [PMID: 32141570 DOI: 10.26355/eurrev_202002_20379] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Human infections with zoonotic coronavirus contain emerging and reemerging pathogenic characteristics which have raised great public health concern. This study aimed at investigating the global prevalence, biological and clinical characteristics of novel coronavirus, Wuhan China (2019-nCoV), Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection outbreaks. MATERIALS AND METHODS The data on the global outbreak of "2019-nCoV, SARS-CoV, and MERS-CoV" were obtained from World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), concerned ministries and research institutes. We also recorded the information from research documents published in global scientific journals indexed in ISI Web of Science and research centers on the prevalence, biological and clinical characteristics of 2019-nCoV, SARS-CoV, and MERS-CoV. RESULTS Worldwide, SARS-CoV involved 32 countries, with 8422 confirmed cases and 916 (10.87%) casualties from November 2002 to August 2003. MERS-CoV spread over 27 states, causing 2496 cases and 868 (34.77%) fatalities during the period April 2012 to December 2019. However, the novel coronavirus 2019-nCoV spread swiftly the global borders of 27 countries. It infected 34799 people and resulted in 724 (2.08%) casualties during the period December 29, 2019 to February 7, 2020. The fatality rate of coronavirus MERS-CoV was (34.77%) higher than SARS-CoV (10.87%) and 2019-nCoV (2.08%); however, the 2019-nCoV transmitted rapidly in comparison to SARS-CoV and MERS-CoV. CONCLUSIONS The novel coronavirus 2019-nCoV has diverse epidemiological and biological characteristics, making it more contagious than SARS-CoV and MERS-CoV. It has affected more people in a short time period compared to SARS-CoV and MERS-CoV, although the fatality rate of MERS-CoV was higher than SARS-CoV and 2019-nCoV. The major clinical manifestations in coronavirus infections 2019-nCoV, MERS-CoV, and SARS CoV are fever, chills, cough, shortness of breath, generalized myalgia, malaise, drowsy, diarrhea, confusion, dyspnea, and pneumonia. Global health authorities should take immediate measures to prevent the outbreaks of such emerging and reemerging pathogens across the globe to minimize the disease burden locally and globally.
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Ahmed N, Babaei-Jadidi R, Howell SK, Beisswenger PJ, Thornalley PJ. Degradation products of proteins damaged by glycation, oxidation and nitration in clinical type 1 diabetes. Diabetologia 2005; 48:1590-603. [PMID: 15988580 DOI: 10.1007/s00125-005-1810-7] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Accepted: 02/28/2005] [Indexed: 02/02/2023]
Abstract
AIMS/HYPOTHESIS Hyperglycaemia in diabetes is associated with increased glycation, oxidative stress and nitrosative stress. Proteins modified consequently contain glycation, oxidation and nitration adduct residues, and undergo cellular proteolysis with release of corresponding free adducts. These free adducts leak into blood plasma for eventual renal excretion. The aim of this study was to perform a comprehensive quantitative analysis of protein glycation, oxidation and nitration adduct residues in plasma protein and haemoglobin as well as of free adducts in plasma and urine to quantify increased protein damage and flux of proteolytic degradation products in diabetes. METHODS Type 1 diabetic patients (n=21) and normal healthy control subjects (n=12) were studied. Venous blood samples, with heparin anticoagulant, and 24-h urine samples were taken. Samples were analysed for protein glycation, oxidation and nitration adducts by a quantitative comprehensive screening method using liquid chromatography with triple quadrupole mass spectrometric detection. RESULTS In type 1 diabetic patients, the concentrations of protein glycation, oxidation and nitration adduct residues increased up to three-fold in plasma protein and up to one-fold in haemoglobin, except for decreases in pentosidine and 3-nitrotyrosine residues in haemoglobin when compared with normal control subjects. In contrast, the concentrations of protein glycation and oxidation free adducts increased up to ten-fold in blood plasma, and urinary excretion increased up to 15-fold in diabetic patients. CONCLUSIONS/INTERPRETATION We conclude that there are profound increases in proteolytic products of glycated and oxidised proteins in diabetic patients, concurrent with much lower increases in protein glycation and oxidation adduct residues.
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Pai CH, Ahmed N, Lior H, Johnson WM, Sims HV, Woods DE. Epidemiology of sporadic diarrhea due to verocytotoxin-producing Escherichia coli: a two-year prospective study. J Infect Dis 1988; 157:1054-7. [PMID: 3283256 DOI: 10.1093/infdis/157.5.1054] [Citation(s) in RCA: 136] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Hassan MT, van der Lelie D, Springael D, Römling U, Ahmed N, Mergeay M. Identification of a gene cluster, czr, involved in cadmium and zinc resistance in Pseudomonas aeruginosa. Gene 1999; 238:417-25. [PMID: 10570969 DOI: 10.1016/s0378-1119(99)00349-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pseudomonas aeruginosa CMG103 was isolated from a metal-polluted river in Pakistan and displayed a high level of Zn and Cd resistance. An omega-Km transposon mutant of strain CMG103, which showed a substantial decrease in resistance to Zn and Cd, was obtained. A 12.8 kb region determining Zn and Cd resistance in strain CM103 was cloned by complementing the mutant strain, and its nt sequence was determined. Five genes, czrSRCBA, involved in Zn and Cd resistance, were identified. The predicted gene products of czrCBA show a significant similarity with the proteins encoded by the plasmid borne metal resistant determinants czc, cnr and ncc of Ralstonia strains, which determine a chemiosmotic cation-antiporter efflux system. The predicted CzrS and CzrR proteins show a significant similarity to the sensor and regulatory protein, respectively, of two component regulatory systems, such as CopS/CopR and PcoS/PcoR involved in the regulation of plasmid-borne Cu-resistant determinants, and CzcS/CzcR involved in the regulation of czc. The cloned czr region contained downstream of czrCBA additional ORFs whose predicted gene products are similar to proteins involved in catabolism of aromatic compounds. DNA-DNA hybridization indicated strong conservation of czr in other environmental P. aeruginosa isolates and in the P. aeruginosa type strain PAO1, a clinical isolate. This was confirmed by a comparison of the sequence of the CMG103 czr region with the currently available genome sequence of strain PAO1. A high sequence identity (till 99% at the nt level) and organizatory conservation of the czr region of CMG103 was found in PAO1 as well regarding coding sequences as intervening sequences between ORFs. The czr locus was localized between coordinates 2400 and 2550 kb on the physical map of the chromosome of PAO1.
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Ahmed N, Corey M, Forstner G, Zielenski J, Tsui LC, Ellis L, Tullis E, Durie P. Molecular consequences of cystic fibrosis transmembrane regulator (CFTR) gene mutations in the exocrine pancreas. Gut 2003; 52:1159-64. [PMID: 12865275 PMCID: PMC1773762 DOI: 10.1136/gut.52.8.1159] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND AND AIMS We tested the hypothesis that the actual or predicted consequences of mutations in the cystic fibrosis transmembrane regulator gene correlate with the pancreatic phenotype and with measures of quantitative exocrine pancreatic function. METHODS We assessed 742 patients with cystic fibrosis for whom genotype and clinical data were available. At diagnosis, 610 were pancreatic insufficient, 110 were pancreatic sufficient, and 22 pancreatic sufficient patients progressed to pancreatic insufficiency after diagnosis. RESULTS We identified mutations on both alleles in 633 patients (85.3%), on one allele in 95 (12.8%), and on neither allele in 14 (1.9%). Seventy six different mutations were identified. The most common mutation was DeltaF508 (71.3%) followed by G551D (2.9%), G542X (2.3%), 621+1G-->T (1.2%), and W1282X (1.2%). Patients were categorized into five classes according to the predicted functional consequences of each mutation. Over 95% of patients with severe class I, II, and III mutations were pancreatic insufficient or progressed to pancreatic insufficiency. In contrast, patients with mild class IV and V mutations were consistently pancreatic sufficient. In all but four cases each genotype correlated exclusively with the pancreatic phenotype. Quantitative data of acinar and ductular secretion were available in 93 patients. Patients with mutations belonging to classes I, II, and III had greatly reduced acinar and ductular function compared with those with class IV or V mutations. CONCLUSION The predicted or known functional consequences of specific mutant alleles correlate with the severity of pancreatic disease in cystic fibrosis.
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Manne V, Roberts D, Tobin A, O'Rourke E, De Virgilio M, Meyers C, Ahmed N, Kurz B, Resh M, Kung HF. Identification and preliminary characterization of protein-cysteine farnesyltransferase. Proc Natl Acad Sci U S A 1990; 87:7541-5. [PMID: 2217184 PMCID: PMC54783 DOI: 10.1073/pnas.87.19.7541] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ras proteins must be isoprenylated at a conserved cysteine residue near the carboxyl terminus (Cys-186 in mammalian Ras p21 proteins) in order to exert their biological activity. Previous studies indicate that an intermediate in the mevalonate pathway, most likely farnesyl pyrophosphate, is the donor of this isoprenyl group. Inhibition of mevalonate synthesis reverts the abnormal phenotypes induced by the mutant RAS2Val-19 gene in Saccharomyces cerevisiae and blocks the maturation of Xenopus oocytes induced by an oncogenic Ras p21 protein of human origin. These results have raised the possibility of using inhibitors of the mevalonate pathway to block the transforming properties of ras oncogenes. Unfortunately, mevalonate is a precursor of various end products essential to mammalian cells, such as dolichols, ubiquinones, heme A, and cholesterol. In this study, we describe an enzymatic activity(ies) capable of catalyzing the farnesylation of unprocessed Ras p21 proteins in vitro at the correct (Cys-186) residue. This farnesylating activity is heat-labile, requires Mg2+ or Mn2+ ions, is linear with time and with enzyme concentration, and is present in all mammalian cell lines and tissues tested. Gel filtration analysis of a partially purified preparation of protein farnesyltransferase revealed two peaks of activity at 250-350 kDa and 80-130 kDa. Availability of an in vitro protein farnesyltransferase assay should be useful in screening for potential inhibitors of ras oncogene function that will not interfere with other aspects of the mevalonate pathway.
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Ahmed N, Milne PJ, Harris SG. Electrocardiographic data compression via orthogonal transforms. IEEE Trans Biomed Eng 1975; 22:484-7. [PMID: 1184023 DOI: 10.1109/tbme.1975.324469] [Citation(s) in RCA: 111] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Ahmed N, Thornalley PJ. Quantitative screening of protein biomarkers of early glycation, advanced glycation, oxidation and nitrosation in cellular and extracellular proteins by tandem mass spectrometry multiple reaction monitoring. Biochem Soc Trans 2004; 31:1417-22. [PMID: 14641078 DOI: 10.1042/bst0311417] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Glycation of proteins forms fructosamines and AGEs (advanced glycation end products). Oxidative and nitrosative stress leads to the formation of oxidative and nitrosative modifications. The modified amino acid residues formed in these processes are biomarkers of protein damage: some are risk markers and some may be risk factors for disease development. We developed a method for the concurrent quantitative measurement of 16 biomarkers indicative of protein glycation, oxidation and nitrosation damage using LC-MS/MS (LC with tandem MS detection). Underivatized analytes were detected free in physiological fluids and in enzymatic hydrolysates of cellular and extracellular proteins. Hydroimidazolones were the most important glycation biomarkers, and methionine sulphoxide was the most important oxidative biomarker quantitatively; 3-nitrotyrosine was the biomarker of nitrosation. Quantitative screening showed high levels of AGEs in cellular protein and moderate levels in protein of blood plasma. Levels of 3-nitrotyrosine were typically 100-fold lower than this. The major glycation adducts in blood plasma had high renal clearances in normal healthy human subjects, whereas methionine sulphoxide and 3-nitrotyrosine had low renal clearances due to further metabolism. Physiological AGEs in blood plasma were eliminated from the circulation in the kidney and not in the liver. LC-MS/MS peptide mapping was also used to locate the protein biomarkers. These studies reveal that advanced glycation is a significant modification of cellular and extracellular protein. The enzymatic defences against glycation, antioxidants and proteasomal protein degradation inside cells are probable factors regulating biomarker levels of cellular protein.
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Review |
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107 |
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Karachalias N, Babaei-Jadidi R, Ahmed N, Thornalley PJ. Accumulation of fructosyl-lysine and advanced glycation end products in the kidney, retina and peripheral nerve of streptozotocin-induced diabetic rats. Biochem Soc Trans 2003; 31:1423-5. [PMID: 14641079 DOI: 10.1042/bst0311423] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The accumulation of AGEs (advanced glycation end products) in diabetes mellitus has been implicated in the biochemical dysfunction associated with the chronic development of microvascular complications of diabetes--nephropathy, retinopathy and peripheral neuropathy. We investigated the concentrations of fructosyl-lysine and AGE residues in protein extracts of renal glomeruli, retina, peripheral nerve and plasma protein of streptozotocin-induced diabetic rats and normal healthy controls. Glycation adducts were determined by LC with tandem MS detection. In diabetic rats, the fructosyl-lysine concentration was increased markedly in glomeruli, retina, sciatic nerve and plasma protein. The concentrations of N (epsilon)-carboxymethyl-lysine and N (epsilon)-carboxyethyl-lysine were increased in glomeruli, sciatic nerve and plasma protein, and N(epsilon)-carboxymethyl-lysine also in the retina. Hydroimidazolone AGEs derived from glyoxal, methylglyoxal and 3-deoxylglucosone were major AGEs quantitatively. They were increased in the retina, nerve, glomeruli and plasma protein. AGE accumulation in renal glomeruli, retina, peripheral nerve and plasma proteins is consistent with a role for AGEs in the development of nephropathy, retinopathy and peripheral neuropathy in diabetes. High-dose therapy with thiamine and Benfotiamine suppressed the accumulation of AGEs, and is a novel approach to preventing the development of diabetic complications.
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Review |
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Ahmed N, Pansino F, Clyde R, Murthi P, Quinn MA, Rice GE, Agrez MV, Mok S, Baker MS. Overexpression of alpha(v)beta6 integrin in serous epithelial ovarian cancer regulates extracellular matrix degradation via the plasminogen activation cascade. Carcinogenesis 2002; 23:237-44. [PMID: 11872628 DOI: 10.1093/carcin/23.2.237] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent evidence suggests that integrins are involved in the multi-step process of tumour metastasis. The biological relevance of alpha(v) integrins and associated beta-subunits in ovarian cancer metastasis was examined by analysing the expression of these cell surface receptors in nine ovarian cancer cell lines and also in the primary human ovarian surface epithelial cell line (HOSE). beta1, beta3 and beta5 subunits were present in all ten ovarian cell lines. beta6 subunit was present at varying levels in eight out of nine cancer cell lines but was absent in the HOSE cell line. Immunohistochemical staining showed that beta6 was present in both non-invasive (borderline) and high-grade ovarian cancer tissues but was absent in benign and normal ovarian tissue. High alpha(v)beta6 integrin expressing ovarian cancer cell lines had high cell surface expression of uPA and uPAR. Ovarian cancer cell lines expressing high to moderate level of alpha(v)beta6 integrin demonstrated ligand-independent enhanced levels of high molecular weight (HMW)-uPA and pro-matrix metalloproteinase 2 and 9 (pro-MMP-2 and pro-MMP-9) expression in the tumour-conditioned medium. High and moderate expression of alpha(v)beta6 integrin correlated with increased plasminogen-dependent degradation of extracellular matrix which could be inhibited by inhibitors of plasmin, uPA and MMPs or by monoclonal antibody against uPA, MMP-9 or alpha(v)beta6 integrin. These results suggest that endogenous de novo expression of alpha(v)beta6 integrin in ovarian cancer cells may contribute to their invasive potential, and that alpha(v)beta6 expression may play a role in ovarian cancer progression and metastasis.
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Ahmed N, Barker G, Oliva KT, Hoffmann P, Riley C, Reeve S, Smith AI, Kemp BE, Quinn MA, Rice GE. Proteomic-based identification of haptoglobin-1 precursor as a novel circulating biomarker of ovarian cancer. Br J Cancer 2004; 91:129-40. [PMID: 15199385 PMCID: PMC2364749 DOI: 10.1038/sj.bjc.6601882] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Screening for specific biomarkers of early-stage detection of ovarian cancer is a major health priority due to the asymptomatic nature and poor survival characteristic of the disease. We utilised two-dimensional gel electrophoresis (2DE) to identify differentially expressed proteins in the serum of ovarian cancer patients that may be useful as biomarkers of this disease. In this study, 38 ovarian cancer patients at different pathological grades (grade 1 (n=6), grade 2 (n=8) and grade 3 (n=24)) were compared to a control group of eight healthy women. Serum samples were treated with a mixture of Affigel-Blue and protein A (5 : 1) for 1 h to remove high abundance protein (e.g. immunoglobulin and albumin) and were displayed using 11 cm, pH 4–7 isoelectric focusing strips for the first dimension and 10% acrylamide gel electrophoresis for the second dimension. Protein spots were visualised by SYPRO-Ruby staining, imaged by FX-imager and compared and analysed by PDQuest software. A total of 24 serum proteins were differentially expressed in grade 1 (P<0.05), 31 in grade 2 (P<0.05) and 25 in grade 3 (P<0.05) ovarian cancer patients. Six of the protein spots that were significantly upregulated in all groups of ovarian cancer patients were identified by nano-electrospray quadrupole quadrupole time-of-flight mass spectrometry (n-ESIQ(q)TOFMS) and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOFMS) as isoforms of haptoglobin-1 precursor (HAP1), a liver glycoprotein present in human serum. Further identification of the spots at different pathological grades was confirmed by Western blotting using monoclonal antibody against a haptoglobin epitope contained within HAP1. Immunohistochemical localisation of HAP1-like activity was present in malignant ovarian epithelium and stroma but strong immunostaining was present in blood vessels, areas with myxomatous stroma and vascular spaces. No tissue localisation of HAP1-like immunoreactivity was observed in normal ovarian surface epithelium. These data highlight the need to assess circulating concentration of HAP1 in the serum of ovarian cancer patients and evaluate its potential as a biomarker in the early diagnosis of ovarian cancer.
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Research Support, Non-U.S. Gov't |
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Zhou YP, Pena JC, Roe MW, Mittal A, Levisetti M, Baldwin AC, Pugh W, Ostrega D, Ahmed N, Bindokas VP, Philipson LH, Hanahan D, Thompson CB, Polonsky KS. Overexpression of Bcl-x(L) in beta-cells prevents cell death but impairs mitochondrial signal for insulin secretion. Am J Physiol Endocrinol Metab 2000; 278:E340-51. [PMID: 10662719 DOI: 10.1152/ajpendo.2000.278.2.e340] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To study effects of Bcl-x(L) in the pancreatic beta-cell, two transgenic lines were produced using different forms of the rat insulin promoter. Bcl-x(L) expression in beta-cells was increased 2- to 3-fold in founder (Fd) 1 and over 10-fold in Fd 2 compared with littermate controls. After exposure to thapsigargin (10 microM for 48 h), losses of cell viability in islets of Fd 1 and Fd 2 Bcl-x(L) transgenic mice were significantly lower than in islets of wild-type mice. Unexpectedly, severe glucose intolerance was observed in Fd 2 but not Fd 1 Bcl-x(L) mice. Pancreatic insulin content and islet morphology were not different from control in either transgenic line. However, Fd 2 Bcl-x(L) islets had impaired insulin secretory and intracellular free Ca(2+) ([Ca(2+)](i)) responses to glucose and KCl. Furthermore, insulin and [Ca(2+)](i) responses to pyruvate methyl ester (PME) were similarly reduced as glucose in Fd 2 Bcl-x(L) islets. Consistent with a mitochondrial defect, glucose oxidation, but not glycolysis, was significantly lower in Fd 2 Bcl-x(L) islets than in wild-type islets. Glucose-, PME-, and alpha-ketoisocaproate-induced hyperpolarization of mitochondrial membrane potential, NAD(P)H, and ATP production were also significantly reduced in Fd 2 Bcl-x(L) islets. Thus, although Bcl-x(L) promotes beta-cell survival, high levels of expression of Bcl-x(L) result in reduced glucose-induced insulin secretion and hyperglycemia due to a defect in mitochondrial nutrient metabolism and signaling for insulin secretion.
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Escudier M, Ahmed N, Shirlaw P, Setterfield J, Tappuni A, Black MM, Challacombe SJ. A scoring system for mucosal disease severity with special reference to oral lichen planus. Br J Dermatol 2007; 157:765-70. [PMID: 17711534 DOI: 10.1111/j.1365-2133.2007.08106.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND To date, there is only weak evidence for the superiority of any interventions over placebo for the palliation of symptomatic oral lichen planus (LP). Further research involving large placebo-controlled, randomized clinical trials is needed. These will require carefully selected and standardized outcome measures. OBJECTIVES To formulate a scoring system for intraoral LP. METHODS One hundred and fifty-six patients with biopsy-confirmed LP were scored at the first and subsequent visits according to (i) extent of site involvement, (ii) disease activity at each site and (iii) an overall pain score as reported by the patient. Overall differences between clinical variants of LP were analysed using the Kruskal-Wallis test and pairwise differences by the Mann-Whitney U-test. Clinical sensitivity (Wilcoxon signed-rank test) was assessed by scoring patients before and after treatment (n = 23). RESULTS Reticular LP (n = 48) was the commonest single type of clinical presentation, followed by ulcerative (n = 30), atrophic (n = 22), desquamative (n = 18) and plaque (n = 1). The median severity and activity scores were 13/6 (reticular), 39/20 (ulcerative), 20/9 (atrophic) and 23/11 (desquamative). Two or more clinical variants were seen in 37 cases. Statistical significance was observed for differences between clinical variants (P < 0.0001) and variation in scores (P < 0.01) when ulcerative LP was compared with all other types. Clinical sensitivity was statistically significant (P < 0.01), while reproducibility was high and allowed the response to therapy to be easily assessed. CONCLUSIONS It is suggested that this scoring system is easy to use, reproducible and sensitive enough to detect clinical responses to therapy.
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Siddiqi N, Das R, Pathak N, Banerjee S, Ahmed N, Katoch VM, Hasnain SE. Mycobacterium tuberculosis isolate with a distinct genomic identity overexpresses a tap-like efflux pump. Infection 2004; 32:109-11. [PMID: 15057575 DOI: 10.1007/s15010-004-3097-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Accepted: 12/01/2003] [Indexed: 11/29/2022]
Abstract
BACKGROUND One mechanism proposed for drug resistance in Mycobacterium tuberculosis (MTB) is by efflux of the drugs by membrane located pumps. We report a novel and definite association between drug resistance and transcription levels of a tap-like pump (Rv1258c) in a multi-drug resistant MTB patient isolate (ICC154) which possesses a unique genotypic signature. MATERIALS AND METHODS The isolate ICC154 was tested for drug sensitivity. Over-expression of Rv1258c as a function of drug pressure was analyzed by RT-PCR and the strain was typed using fluorescent amplified fragment length polymorhism (FAFLP). RESULT In the presence of rifampicin and ofloxacin, this isolate shows increased transcription of the gene Rv1258c. Genotypic fingerprinting revealed the presence of unique FAFLP markers. CONCLUSION A clear association between drug resistance and overexpression of an efflux protein is evident from our studies. The presence of specific markers has implications in rapid identification of MDR clinical isolates and consequent disease management.
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Research Support, Non-U.S. Gov't |
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Dalmeijer GW, van der Schouw YT, Magdeleyns E, Ahmed N, Vermeer C, Beulens JWJ. The effect of menaquinone-7 supplementation on circulating species of matrix Gla protein. Atherosclerosis 2012; 225:397-402. [PMID: 23062766 DOI: 10.1016/j.atherosclerosis.2012.09.019] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/29/2012] [Accepted: 09/15/2012] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To investigate whether menaquinone-7 (MK-7) supplementation increases carboxylation of MGP. DESIGN A randomized, double-blind, placebo-controlled trial was performed. Sixty participants (40-65 y) were randomly allocated to supplementation of 180 μg/d, 360 μg/d of MK-7 or placebo during 12 weeks. At baseline, after 4 and 12 weeks, desphospho-uncarboxylated MGP (dp-ucMGP), desphospho-carboxylated MGP (dp-cMGP) and total uncarboxylated MGP (t-ucMGP) were measured by ELISA techniques. Furthermore, the ratio of uncarboxylated osteocalcin (ucOC) to carboxylated osteocalcin (cOC) was used as proxy of vitamin K status and various cardiovascular risk factors were measured. RESULTS Dp-ucMGP decreased significantly and dose-dependently in the 180 μg and 360 μg MK-7 supplementation groups (P time*treatment < 0.001) after 12 weeks, by 31% and 46% respectively, while dp-ucMGP levels remained unchanged after placebo treatment. The osteocalcin ratio also decreased significantly after 12-week supplementation with 180 μg (60%) and 360 μg (74%) MK-7 (P time*treatment < 0.001), while levels remained unchanged after placebo treatment. These results indicate improved vitamin K status and good compliance to the study treatment. Changes over time of dp-cMGP (p = 0.42) and t-ucMGP (p = 0.23) levels did not differ between treatment arms. Other cardiovascular risk factors did not differ between treatments arms. CONCLUSIONS Menaquinone supplementation dose-dependently decreases dp-ucMGP concentrations, but does not affect other MGP species. Dp-ucMGP may serve as a non-invasive marker of vitamin K status.
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Randomized Controlled Trial |
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Abstract
A study of primary epithelial neoplasms of the appendix (with the exception of classical carcinoids), produced 24 adenocarcinomas and 42 benign lesions from the files of the Laboratory of Surgical Pathology of Columbia University. Invasive adenoarcinomas were often complicated by appendicitis and were then unexpectedly discovered during appendectomy. In one third of the cases the carcinomas were found in juxtaposition to adenomatous lesions of the appendix. Well-differentiated adenocarcinomas of the colonic type generally had a better prognosis than signet-ring cell (or microglandular) tumors. The most reliable criterion for correlating prognosis was the Duke's method of staging. Since invasive adenocarcinomas of the appendix can metastasize to regional lymph nodes, treatment should ideally consist of ileocolectomy.
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Abstract
OBJECTIVE To evaluate the relationship between high initial blood pressure and functional outcome in patients with acute stroke. DESIGN An observational study based on the data from the Intravenous Nimodipine West European Stroke Trial (INWEST). INWEST was a placebo-controlled randomized study terminated prematurely; subsequent analysis found a correlation between diastolic BP (DBP) reduction caused by high-dose nimodipine and unfavourable outcome. Subjects. Of the 295 patients with acute ischaemic stroke (within 24 h) recruited in the INWEST, 265 were included in this analysis [n = 92 for placebo, n = 93 for low-dose nimodipine (1-mg h(-1)) and n=80 for high-dose nimodipine (2-mg h(-1))]. Definition. Initial BP was defined as BP at the time of randomization. Normal initial BP (NIBP)=systolic BP (SBP) 120-160 and DBP 60-90 mmHg (n=126). Four alternatives were defined as high initial BP (HIBP): (1) >160/90 (n=126), (2) >170/95 (n=106), (3) >180/100 (n=63), (4) >190/105 (n=45). Main outcome measures. Combined death or dependency (DD) (Barthel index < 60) at 21 days. RESULTS In multiple logistic regression analyses, the odds ratio [OR] for DD at day 21 was significantly higher in patients with any definition of HIBP than with NIBP. For all patients, OR and 95% confidence intervals [CI] for 160/90 versus NIBP=3.1, 1.3-7.3, respectively; for 170/95=3.3, 1.4-8.1; for 180/100=7.0, 2.1-22.8; for 190/105=3.7, 1.1-12.4. For only placebo patients, OR and 95% CI for 160/90=4.8, 1.2-19.3; for 170/95=4.4, 1.1-17.8; for 180/100=12.7, 2.2-74.7; for 190/105=5.6, 1.1-30.0. The outcome was similar at 24 weeks but did not reach statistical significance for the placebo patients. CONCLUSION Patients with HIBP had a poor functional outcome after acute stroke.
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Clinical Trial |
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Sammons J, Ahmed N, El-Sheemy M, Hassan HT. The role of BMP-6, IL-6, and BMP-4 in mesenchymal stem cell-dependent bone development: effects on osteoblastic differentiation induced by parathyroid hormone and vitamin D(3). Stem Cells Dev 2006; 13:273-80. [PMID: 15186723 DOI: 10.1089/154732804323099208] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human bone marrow-derived mesenchymal stem cells (MSCs) represent an ideal source for cell therapy for inherited and degenerative diseases, bone and cartilage repair, and as target for gene therapy. The role of the combination of human parathyroid hormone (PTH) and vitamin D(3) in bone formation and mineralization has been established in several osteoblast cell culture studies. The aim of the present study was to evaluate the role of this hormonal combination alone and in the presence of bone morphogenetic protein-4 (BMP-4) or-6 (BMP-6) in inducing osteogenic differentiation of human MSC. Human MSC derived from adult normal bone marrow that are positive for CD29, CD44, CD105, and CD166 and negative for CD14, CD34, and CD45, were treated with the PTH and 1,25-dihydroxyvitamin D(3) in the presence and absence of recombinant human BMP-4 or BMP6. PTH and vitamin D(3) induced high levels of expression of two key markers of bone formation: osteocalcin and alkaline phosphatase by MSCs. BMP-6 but not BMP-4 increased osteocalcin expression induced by PTH and vitamin D(3). Both BMPs enhanced calcium formation in MSC cultures and this response was potentiated by PTH and vitamin D(3). The present results revealed a novel potent effect of PTH and vitamin D(3) plus BMPs in inducing bone development by human MSCs. These results may facilitate therapeutic utility of MSCs for bone disease and help clarify mechanisms involved in stem cell-mediated bone development.
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Journal Article |
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Zekri J, Ahmed N, Coleman RE, Hancock BW. The skeletal metastatic complications of renal cell carcinoma. Int J Oncol 2001; 19:379-82. [PMID: 11445855 DOI: 10.3892/ijo.19.2.379] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Of the 103 patients with advanced renal cell carcinoma 31 (30%) developed symptomatic radiologically confirmed skeletal metastases. These were typically lytic, predominantly affecting the axial skeleton and associated with considerable skeletal morbidity. Solitary bone lesions occurred in 14 (45%) of patients. The median survival of patients with bone metastases was 12 months. Hypercalcaemia was common in patients both with (29%) and without (44%) bone metastases. The number and rate of skeletal related events was similar to that seen from bone metastases from breast cancer. It would therefore be appropriate to evaluate the effectiveness of bisphosphonate treatment for reducing skeletal morbidity in advanced renal cell cancer with bone metastases.
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Zahid S, Khan R, Oellerich M, Ahmed N, Asif AR. Differential S-nitrosylation of proteins in Alzheimer's disease. Neuroscience 2013; 256:126-36. [PMID: 24157928 DOI: 10.1016/j.neuroscience.2013.10.026] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 12/24/2022]
Abstract
Numerous studies have provided evidence regarding the involvement of protein S-nitrosylation in the progression of Alzheimer's disease (AD) pathology and its implication in the formation and accumulation of misfolded protein aggregates. The identification of S-nitrosylated proteins can be a major step toward the understanding of mechanisms leading to neuronal degeneration. The present study targeted S-nitrosylated proteins in AD hippocampus, substantia nigra and cortex using the following work-flow that combines S-nitrosothiol-specific antibody detection, classical biotin switch method labeled with fluorescence dye followed by electrospray ionization quadrupole time of flight tandem MS (ESI-QTOF MS/MS) identification. Endogenous nitrosocysteines were identified in 45 proteins, mainly involved in metabolism, signaling pathways, apoptosis and redox regulation as assigned by REACTOME and KEGG pathway database analysis. Superoxide dismutase (SOD2) [Mn], fructose-bisphosphate aldolase C (ALDOC) and voltage-dependent anion-selective channel protein 2 (VDAC2) showed differential S-nitrosylation signal, not previously reported in AD regions. Extensive neuronal atrophy with increased protein S-nitrosylation in AD regions is also evident from immunofluorescence studies using S-nitrosocysteine antibody. A number of plausible cysteine modification sites were predicted via Group-based Prediction System-S-nitrosothiols (GPS-SNO) 1.0 while STRING 8.3 analysis revealed functional annotations in the modified proteins. The findings are helpful in characterization of functional abnormalities and may facilitate the understanding of molecular mechanisms and biological function of S-nitrosylation in AD pathology.
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Research Support, Non-U.S. Gov't |
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Shashidharan P, Clarke DD, Ahmed N, Moschonas N, Plaitakis A. Nerve tissue-specific human glutamate dehydrogenase that is thermolabile and highly regulated by ADP. J Neurochem 1997; 68:1804-11. [PMID: 9109504 DOI: 10.1046/j.1471-4159.1997.68051804.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Glutamate dehydrogenase (GDH), an enzyme that is central to the metabolism of glutamate, is present at high levels in the mammalian brain. Studies on human leukocytes and rat brain suggested the presence of two GDH activities differing in thermal stability and allosteric regulation, but molecular biological investigations led to the cloning of two human GDH-specific genes encoding highly homologous polypeptides. The first gene, designated GLUD1, is expressed in all tissues (housekeeping GDH), whereas the second gene, designated GLUD2, is expressed specifically in neural and testicular tissues. In this study, we obtained both GDH isoenzymes in pure form by expressing a GLUD1 cDNA and a GLUD2 cDNA in Sf9 cells and studied their properties. The enzymes generated showed comparable catalytic properties when fully activated by 1 mM ADP. However, in the absence of ADP, the nerve tissue-specific GDH showed only 5% of its maximal activity, compared with approximately 40% showed by the housekeeping enzyme. Low physiological levels of ADP (0.05-0.25 mM) induced a concentration-dependent enhancement of enzyme activity that was proportionally greater for the nerve tissue GDH (by 550-1,300%) than of the housekeeping enzyme (by 120-150%). Magnesium chloride (1-2 mM) inhibited the nonactivated housekeeping GDH (by 45-64%); this inhibition was reversed almost completely by ADP. In contrast, Mg2+ did not affect the nonstimulated nerve tissue-specific GDH, although the cation prevented much of the allosteric activation of the enzyme at low ADP levels (0.05-0.25 mM). Heat-inactivation experiments revealed that the half-life of the housekeeping and nerve tissue-specific GDH was 3.5 and 0.5 h, respectively. Hence, the nerve tissue-specific GDH is relatively thermolabile and has evolved into a highly regulated enzyme. These allosteric properties may be of importance for regulating brain glutamate fluxes in vivo under changing energy demands.
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