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Rahman B, El-Damanhoury HM, Sheela S, Ngo HC. Effect Of Calcium Silicate, Sodium Phosphate, and Fluoride on Dentinal Tubule Occlusion and Permeability in Comparison to Desensitizing Toothpaste: An In Vitro Study. Oper Dent 2021; 46:641-649. [PMID: 35507903 DOI: 10.2341/20-008-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2020] [Indexed: 11/23/2022]
Abstract
This study compared the ability of a calcium silicate-, sodium phosphate-, and fluoride-based (CSSPF) toothpaste (TP) in promoting dentinal tubule occlusion and reducing dentin permeability with that of other commercially available antisensitivity TPs. Seventy-eight dentin discs (1.0±0.1 mm thick) were prepared from the midcoronal area and were treated with 37% phosphoric acid for 2 minutes; then they were randomly divided into six groups according to treatments: No treatment [positive control (PC)], entirely covered with nail varnish [negative control (NC)], hydroxyapatite (HAP)-containing TP [Desensin Repair (DES)], NovaMin-based [Sensodyne Repair & Protect (SEN)], CSSPF-based TP [Regenerate Advanced (REG)], sodium monofluorophosphate, potassium citrate, zinc citrate TP [Signal Sensitive Expert (SIG)]. Dentin permeability was tested by the dye percolation method (DP%). Scanning electron microscope (SEM) micromorphological and energy dispersive X-ray elemental analysis (EDX) of the dentin surfaces were done following each treatment. Results were analyzed using one-way analysis of variance (ANOVA) followed by Tukey post hoc test at a 95% confidence level (α=0.05). All the tested groups showed higher DP% than NC and lower percolation than the PC (p<0.05). REG and SIG were statistically comparable, and showed significantly lower DP% (p<0.05) than SEN and DES. None of the TPs tested was able to obliterate the lumen of the dentinal tubules (DT) completely. REG exhibited the highest weight percentage of calcium deposition, followed by SEN. Compared to the tested desensitizing TPs, CSSPF-based TPs demonstrated equal or less dentin permeability and better DT occlusion.
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Affiliation(s)
- B Rahman
- Betul Rahman, associate professor, Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, UAE
| | - H M El-Damanhoury
- *Hatem M El-Damanhoury, associate professor, Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, UAE
| | - S Sheela
- Soumya Sheela, post-doctoral research associate, Sharjah Institute of Medical Research, University of Sharjah, Sharjah, UAE
| | - H C Ngo
- Hien C Ngo, professor, Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, UAE
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Summerhayes RJ, Rahman B, Morgan GG, Beresin G, Moreno C, Wright JM. Meta-analysis of small for gestational age births and disinfection byproduct exposures. Environ Res 2021; 196:110280. [PMID: 33035558 DOI: 10.1016/j.envres.2020.110280] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Some epidemiological studies show associations between disinfection byproducts (DBPs) and adverse developmental outcomes. OBJECTIVES We undertook a meta-analysis of epidemiological studies on maternal exposure to trihalomethanes (THMs) and haloacetic acids (HAAs) and risk of small for gestational age (SGA) birth. METHODS We identified forty-five publications including two reports and five theses via a 2020 literature search. Nineteen study populations from 16 publications met the inclusion criteria and were systematically evaluated. Effect measures were pooled using random effects meta-analytic methods along with cumulative, sub-group and meta-regression analyses to examine between-study heterogeneity and variation in risk across different DBP measures. RESULTS We detected a small increased risk for SGA with exposure to the sum of four (i.e., THM4) THM4 (odds ratio (OR) = 1.07; 95%CI: 1.03, 1.11), chloroform (OR = 1.05; 95%CI: 1.01, 1.08), bromodichloromethane (OR = 1.08; 95%CI: 1.05, 1.11) and the sum of the brominated THM4 (OR = 1.05; 95%CI: 1.02, 1.09). Larger ORs were detected for the sum of five haloacetic acids (i.e., HAA5) (OR = 1.12; 95%CI: 1.01, 1.25), dichloroacetic acid (OR = 1.25; 95%CI: 1.01, 1.41) and trichloroacetic acid (OR = 1.21; 95%CI: 1.07, 1.37). We detected larger SGA risks for several THM4 among the prospective cohort and case-control studies compared to retrospective cohorts and for the SGA3/5% (vs. SGA10%) studies. The THM4 meta-regression showed associations between SGA and the total quality score based on categorical or continuous measures. For example, an OR of 1.03 (95%CI: 1.01, 1.06) was detected for each 10-point increase in the study quality score based on our systematic review. CONCLUSIONS We detected a small increased risk of SGA based on 18 THM4 study populations that was comparable to a previous meta-analysis of eight THM4 study populations. We also found increased risks for other THM4 and HAA measures not previously examined; these results were robust after accounting for outliers, publication bias, type of SGA classification, different exposure windows, and other factors.
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Affiliation(s)
| | - B Rahman
- University of Sydney, School of Public Health and University Centre for Rural Health, Australia
| | - G G Morgan
- University of Sydney, School of Public Health and University Centre for Rural Health, Australia
| | - G Beresin
- Massachusetts Department of Public Health, USA
| | - C Moreno
- Oak Ridge Associated Universities, USA
| | - J M Wright
- US EPA, Center for Public Health and Environmental Assessment, USA.
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Rahman B, Side L, Gibbon S, Meisel SF, Fraser L, Gessler S, Wardle J, Lanceley A. Moving towards population-based genetic risk prediction for ovarian cancer. BJOG 2018; 124:855-858. [PMID: 28217902 DOI: 10.1111/1471-0528.14603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2017] [Indexed: 12/16/2022]
Affiliation(s)
- B Rahman
- Department of Women's Cancer, EGA Institute for Women's Health, University College London, London, UK
| | - L Side
- Department of Women's Cancer, EGA Institute for Women's Health, University College London, London, UK.,North East Thames Regional Genetics Service, London, UK
| | - S Gibbon
- UCL Anthropology, University College London, London, UK
| | - S F Meisel
- Department of Behavioural Science and Health, Institute of Epidemiology and Health Care, University College London, London, UK
| | - L Fraser
- Department of Women's Cancer, EGA Institute for Women's Health, University College London, London, UK
| | - S Gessler
- Department of Women's Cancer, EGA Institute for Women's Health, University College London, London, UK
| | | | - A Lanceley
- Department of Women's Cancer, EGA Institute for Women's Health, University College London, London, UK
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Abstract
We consider a globally coupled network of active (oscillatory) and inactive (nonoscillatory) oscillators with distributed-delay coupling. Conditions for aging transition, associated with suppression of oscillations, are derived for uniform and gamma delay distributions in terms of coupling parameters and the proportion of inactive oscillators. The results suggest that for the uniform distribution increasing the width of distribution for the same mean delay allows aging transition to happen for a smaller coupling strength and a smaller proportion of inactive elements. For gamma distribution with sufficiently large mean time delay, it may be possible to achieve aging transition for an arbitrary proportion of inactive oscillators, as long as the coupling strength lies in a certain range.
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Affiliation(s)
- B Rahman
- Department of Mathematics, University of Sussex, Falmer, Brighton BN1 9QH, England, United Kingdom
| | - K B Blyuss
- Department of Mathematics, University of Sussex, Falmer, Brighton BN1 9QH, England, United Kingdom
| | - Y N Kyrychko
- Department of Mathematics, University of Sussex, Falmer, Brighton BN1 9QH, England, United Kingdom
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Fatema K, Zwar NA, Milton AH, Rahman B, Awal ASMN, Ali L. Cardiovascular risk assessment among rural population: findings from a cohort study in a peripheral region of Bangladesh. Public Health 2016; 137:73-80. [PMID: 27036981 DOI: 10.1016/j.puhe.2016.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 01/20/2016] [Accepted: 02/15/2016] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The incidences of non-communicable diseases including cardiovascular diseases (CVDs) is increasing in Bangladesh. The reasons for this increasing trend need to be explored. The aim of this study is to assess the risk of CVDs among a peripheral rural Bangladeshi population and to explore the sociodemographic, anthropometric and clinical variables associated with increased risk. STUDY DESIGN Cohort study. METHODS From a cohort of 190,471 individuals of all ages, originally included in a diabetic eye disease program initiated in 2008-2009, a purposive sub-cohort of 66,710 individuals, aged 31-74 years was recruited. During 2011-2012 these participants were assessed for CVDs using the WHO's risk assessment tool designed for primary care settings in low resource societies. Participant characteristics associated with higher risk were explored using univariable and multivariable regression analysis. RESULTS Out of all (95.5% participation rate) participants 1170 (1.84%) were found to be at high risk for CVD. The prevalence of hypertension (HTN), pre-HTN, obesity, underweight and self-reported DM were 8.9%, 15.2%, 9.6%, 7.8% and 0.5% respectively, among the study population. In multivariable regression analysis female sex, older age, temporary housing structure (i.e., tin shed), extremes of BMI (both underweight and obese) and central obesity were associated with higher risk for CVDs. CONCLUSIONS The prevalence of CVD risk factors and high CVD risk individuals in this cohort was found to be lower than previous studies. It may be the effects of urbanization are yet to reach this relatively traditional rural population. This study adds to the literature on use of the WHO risk assessment tool.
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Affiliation(s)
- K Fatema
- Department of Epidemiology, Bangladesh University of Health Sciences (BUHS), 125/1 Darus Salam, Mirpur, Dhaka 1216, Bangladesh; The School of Public Health and Community Medicine, Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - N A Zwar
- The School of Public Health and Community Medicine, Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - A H Milton
- Centre for Clinical Epidemiology and Biostatistics (CCEB), The School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Newcastle, NSW 2008, Australia.
| | - B Rahman
- The School of Public Health and Community Medicine, Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - A S M N Awal
- ORBIS International, Apartment No, B4 & C4, Plot #1, Road #137, Gulshan, Dhaka 1212, Bangladesh.
| | - L Ali
- Department of Biochemistry and Cell Biology, BUHS, 125/1 Darus Salam, Mirpur, Dhaka 1216, Bangladesh.
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Bui C, Rahman B, Heywood AE, MacIntyre CR. A Meta-Analysis of the Prevalence of Influenza A H5N1 and H7N9 Infection in Birds. Transbound Emerg Dis 2016; 64:967-977. [DOI: 10.1111/tbed.12466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Indexed: 12/30/2022]
Affiliation(s)
- C. Bui
- School of Public Health and Community Medicine; University of New South Wales; Sydney NSW Australia
| | - B. Rahman
- School of Public Health and Community Medicine; University of New South Wales; Sydney NSW Australia
| | - A. E. Heywood
- School of Public Health and Community Medicine; University of New South Wales; Sydney NSW Australia
| | - C. R. MacIntyre
- School of Public Health and Community Medicine; University of New South Wales; Sydney NSW Australia
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Jose H, Rawstorne P, Rahman B, Dolan K. P11.25 Timor-leste national size estimates and behavioural data for key populations at risk of hiv and other stis. Br J Vener Dis 2015. [DOI: 10.1136/sextrans-2015-052270.473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Wilde A, Chan HN, Rahman B, Meiser B, Mitchell PB, Schofield PR, Green MJ. A meta-analysis of the risk of major affective disorder in relatives of individuals affected by major depressive disorder or bipolar disorder. J Affect Disord 2014; 158:37-47. [PMID: 24655763 DOI: 10.1016/j.jad.2014.01.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/19/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND To conduct a meta-analysis to estimate the incidence of major depressive disorder (MDD) and bipolar disorder (BD) in first-degree relatives (FDRs) of probands affected by MDD or BD. The risk for MDD in FDR of BD probands and vice versa is also investigated. METHODS A systematic review of case-control and cohort studies, which were published between 1977 and 2012; reported relative risks (RR) or odd ratios (OR) or equivalent raw data; made an explicit distinction between MDD and BD; used operational diagnostic criteria; and reported systematic proband recruitment and ascertainment of relatives. Studies were obtained by electronic MEDLINE and EMBASE searches and hand-searching. Estimates were derived from pooled data using random effects methods. RESULTS Of an initial sample of 241 articles, 22 were eligible for inclusion. For FDRs of one proband with MDD compared to healthy control probands, estimates for MDD were OR=2.14 (95% CI 1.72-2.67), increasing to OR=3.23 (95% CI 2.11-4.94) for two MDD probands. For FDRs of one BD proband compared to healthy control probands, estimates for BD were OR=7.92 (95% CI 2.45-25.61), and OR=6.58 (95% CI 2.64-16.43) for FDRs of two BD probands. CONCLUSIONS These findings support previously published data indicating strong familiality for both MDD and BD. Data will be useful in providing individuals with a family history of MDD or BPD with tailored risk estimates.
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Affiliation(s)
- A Wilde
- School of Psychiatry, University of New South Wales, NSW 2052, Australia; Black Dog Institute, Sydney, NSW 2031, Australia.
| | - H-N Chan
- School of Psychiatry, University of New South Wales, NSW 2052, Australia; Black Dog Institute, Sydney, NSW 2031, Australia; Department of Psychiatry, Singapore General Hospital, 169608, Singapore
| | - B Rahman
- School of Public Health and Community Medicine, University of New South Wales, NSW 2052, Australia
| | - B Meiser
- Prince of Wales Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
| | - P B Mitchell
- School of Psychiatry, University of New South Wales, NSW 2052, Australia; Black Dog Institute, Sydney, NSW 2031, Australia
| | - P R Schofield
- Neuroscience Research Australia, Sydney, NSW 2031, Australia; School of Medical Sciences, University of New South Wales, NSW 2052, Australia
| | - M J Green
- School of Psychiatry, University of New South Wales, NSW 2052, Australia; Black Dog Institute, Sydney, NSW 2031, Australia; Neuroscience Research Australia, Sydney, NSW 2031, Australia
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Rahman B, Alderman N, Oliver C. Use of the structured descriptive assessment to identify possible functions of challenging behaviour exhibited by adults with brain injury. Neuropsychol Rehabil 2013; 23:501-27. [DOI: 10.1080/09602011.2013.787938] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Rahman B, Oliver C, Alderman N. Descriptive analysis of challenging behaviours shown by adults with acquired brain injury. Neuropsychol Rehabil 2010; 20:212-38. [DOI: 10.1080/09602010903021097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ishida H, Rahman B, Kashino S. Morpholinium 2-chloro-4-nitrobenzoate, 2-chloro-5-nitrobenzoate and 4-chloro-3-nitrobenzoate. Acta Crystallogr C 2001; 57:1450-3. [PMID: 11740114 DOI: 10.1107/s0108270101016389] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2001] [Accepted: 10/03/2001] [Indexed: 11/10/2022] Open
Abstract
Morpholinium 2-chloro-4-nitrobenzoate, C4H10NO+*C7H3ClNO4-, (I), crystallizes in a non-centrosymmetric space group. The cations and anions are connected by N-H...O hydrogen bonds to afford a 2(1) helical chain. Morpholinium 2-chloro-5-nitrobenzoate, C4H10NO+*C7H3ClNO4-, (II), and morpholinium 4-chloro-3-nitrobenzoate, C4H10NO+*C7H3ClNO4-, (III), both crystallize in a centrosymmetric space group. In (II) and (III), two cations and two anions are held together by N-H.O hydrogen bonds to form a centrosymmetric ring with graph-set descriptor R4(4)(12).
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Affiliation(s)
- H Ishida
- Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan.
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Ishida H, Rahman B, Kashino S. 2:1 complexes of 2-chloro-4-nitrobenzoic acid and 2-chloro-5-nitrobenzoic acid with pyrazine. Acta Crystallogr C 2001; 57:876-9. [PMID: 11443273 DOI: 10.1107/s0108270101007016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2001] [Accepted: 04/27/2001] [Indexed: 11/10/2022] Open
Abstract
2-chloro-4-nitrobenzoic acid and 2-chloro-5-nitrobenzoic acid form O--H...N hydrogen bonds with pyrazine to afford 2:1 complexes of 2C7H4ClNO4*C4H4N2, (I) and (II), respectively, that are located on inversion centers. The 2C7H4ClNO4*C4H4N2 units in both complexes are connected by weak C--H...O hydrogen bonds; the units build a three-dimensional hydrogen-bond network in (I) and a ribbon structure in (II).
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Affiliation(s)
- H Ishida
- Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan.
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Abstract
Regeneration of reduced nicotinamide adenine dinucleotide phosphate (NADPH) is essential for the activity of glutathione redox cycling during cellular peroxide detoxification. In order to test for a function of astroglial glycogen to serve as endogenous precursor for glucose-6-phosphate, the substrate for the regeneration of NADPH by the pentose phosphate pathway, the content of glycogen in astroglia-rich primary cultures derived from the brains of newborn rats was determined after application of peroxides. In the presence of hydrogen peroxide or cumene hydroperoxide in concentrations of 200 microM glycogen was mobilized with a half-life of 16 min in incubation medium containing 20 mM glucose, whereas in the absence of peroxides the glycogen content decreased more slowly with a half-life of 42 min. After 30 min of incubation with or without peroxides 30 and 73%, respectively, of the initial glycogen content was found. The degree of glycogen mobilization was reduced by lowering the initial concentration of the peroxides. These results demonstrate that in astroglial cells (i) glucosyl residues of glycogen are mobilized after application of peroxides despite the presence of exogenous glucose, and (ii) that the demand for glucose-6-phosphate as substrate for NADPH regeneration via the pentose phosphate pathway can, at least partially, be met by mobilization of glycogen.
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Affiliation(s)
- B Rahman
- Physiologisch-chemisches Institut der Universität, Hoppe-Seyler-Strasse 4, D-72076, Tübingen, Germany
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Rahman B, Schneider HP, Bröer A, Deitmer JW, Bröer S. Helix 8 and helix 10 are involved in substrate recognition in the rat monocarboxylate transporter MCT1. Biochemistry 1999; 38:11577-84. [PMID: 10471310 DOI: 10.1021/bi990973f] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Transport of lactate, pyruvate, and the ketone bodies, acetoacetate and beta-hydroxybutyrate, is mediated in many mammalian cells by the monocarboxylate transporter MCT1. To be accepted as a substrate, a carboxyl group and an unpolar side chain are necessary. Site-directed mutagenesis of the rat MCT1 was used to identify residues which are involved in substrate recognition. Helices 8 and 10 but not helix 9 were found to contain critical residues for substrate recognition. Mutation of arginine 306 to threonine in helix 8 resulted in strongly reduced transport activity. Concomitantly, saturable transport was transformed into a nonsaturable dependence of transport activity on lactate concentration, suggesting that binding of the substrate was strongly impaired. Furthermore, proton translocation in the mutant was partially uncoupled from monocarboxylate transport. Mutation of phenylalanine 360 to cysteine in helix 10 resulted in an altered substrate side chain recognition. In contrast to the wild-type transporter, monocarboxylates with more bulky and polar side chains were recognized by the mutated MCT1. Mutation of selected residues in helix 9 and helix 11 (C336A, H337Q, and E391Q) did not cause alterations of the transport properties of MCT1. It is suggested that substrate binding occurs in the carboxy-terminal half of MCT1 and that helices 8 and 10 are involved in the recognition of different parts of the substrate.
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Affiliation(s)
- B Rahman
- Physiologisches Institut der Universität, Tübingen, Germany
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Bröer S, Schneider HP, Bröer A, Rahman B, Hamprecht B, Deitmer JW. Characterization of the monocarboxylate transporter 1 expressed in Xenopus laevis oocytes by changes in cytosolic pH. Biochem J 1998; 333 ( Pt 1):167-74. [PMID: 9639576 PMCID: PMC1219569 DOI: 10.1042/bj3330167] [Citation(s) in RCA: 244] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several laboratories have investigated monocarboxylate transport in a variety of cell types. The characterization of the cloned transporter isoforms in a suitable expression system is nevertheless still lacking. H+/monocarboxylate co-transport was therefore investigated in monocarboxylate transporter 1 (MCT1)-expressing Xenopus laevis oocytes by using pH-sensitive microelectrodes and [14C]lactate. Superfusion with lactate resulted in intracellular acidification of MCT1-expressing oocytes, but not in non-injected control oocytes. The basic kinetic properties of lactate transport in MCT1-expressing oocytes were determined by analysing the rates of intracellular pH changes under different conditions. The results were in agreement with the known properties of the transporter, with respect to both the dependence on the lactate concentration and the external pH value. Besides lactate, MCT1 mediated the reversible transport of a wide variety of monocarboxylic acids including pyruvate, D,L-3-hydroxybutyrate, acetoacetate, alpha-oxoisohexanoate and alpha-oxoisovalerate, but not of dicarboxylic and tricarboxylic acids. The inhibitor alpha-cyano-4-hydroxycinnamate bound strongly to the transporter without being translocated, but could be displaced by the addition of lactate. In addition to changes in the intracellular pH, lactate transport also induced deviations from the resting membrane potential.
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Affiliation(s)
- S Bröer
- Physiologisch-chemisches Institut der Universität, Hoppe-Seyler-Strasse 4, D-72076 Tübingen, Federal Republic of
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Bröer S, Rahman B, Pellegri G, Pellerin L, Martin JL, Verleysdonk S, Hamprecht B, Magistretti PJ. Comparison of lactate transport in astroglial cells and monocarboxylate transporter 1 (MCT 1) expressing Xenopus laevis oocytes. Expression of two different monocarboxylate transporters in astroglial cells and neurons. J Biol Chem 1997; 272:30096-102. [PMID: 9374487 DOI: 10.1074/jbc.272.48.30096] [Citation(s) in RCA: 276] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The transport of lactate is an essential part of the concept of metabolic coupling between neurons and glia. Lactate transport in primary cultures of astroglial cells was shown to be mediated by a single saturable transport system with a Km value for lactate of 7.7 mM and a Vmax value of 250 nmol/(min x mg of protein). Transport was inhibited by a variety of monocarboxylates and by compounds known to inhibit monocarboxylate transport in other cell types, such as alpha-cyano-4-hydroxycinnamate and p-chloromercurbenzenesulfonate. Using reverse transcriptase-polymerase chain reaction and Northern blotting, the presence of mRNA coding for the monocarboxylate transporter 1 (MCT1) was demonstrated in primary cultures of astroglial cells. In contrast, neuron-rich primary cultures were found to contain the mRNA coding for the monocarboxylate transporter 2 (MCT2). MCT1 was cloned and expressed in Xenopus laevis oocytes. Comparison of lactate transport in MCT1 expressing oocytes with lactate transport in glial cells revealed that MCT1 can account for all characteristics of lactate transport in glial cells. These data provide further molecular support for the existence of a lactate shuttle between astrocytes and neurons.
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Affiliation(s)
- S Bröer
- Physiologisch-chemisches Institut der Universität, Hoppe-Seyler Str. 4, D-72076 Tübingen, Germany.
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Rahman MM, Caglayan F, Rahman B. Periodontal health parameters in patients with chronic renal failure and renal transplants receiving immunosuppressive therapy. J Nihon Univ Sch Dent 1992; 34:265-72. [PMID: 1287154 DOI: 10.2334/josnusd1959.34.265] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The periodontal status of 54 renal transplant recipients and 52 patients with chronic renal failure receiving hemodialysis was evaluated and compared with that of systemically healthy subjects matched for age, sex, social status and the number of teeth present. The renal transplant recipients had been receiving immunosuppressive (IS) drug therapy since the time of transplantation. Both of the renal patient groups had significantly higher plaque index scores than the respective controls. By contrast, the renal transplant recipients showed significantly lower periodontal scores and pocket depths. However, there was no significant difference between the hemodialysis group and the corresponding healthy controls with regard to mean periodontal index score and pocket depth. No significant differences could be found among the three groups with regard to mean sulcular bleeding index score or gingival index score. Within the IS group, no relationship was found between the duration of drug therapy and the various periodontal parameters. The observed variations among the groups studied appear to suggest modulation of periodontal condition by both general health status in patients with chronic renal failure and the IS agents used in renal transplant recipients.
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Affiliation(s)
- M M Rahman
- Department of Periodontology, Dicle University, Diyarbakir, Turkey
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Rahman B, Rahman MA, Hassan Z. Variation of copper and ceruloplasmin levels with liver function tests in schizophrenic patients. Biomedicine 1978; 29:238-41. [PMID: 747731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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