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Bazargan-Hejazi S, Ahmadi A, Shirazi A, Ainy E, Djalalinia S, Fereshtehnejad SM, Jahanmehr N, Kiadaliri A, Moradi-Lakeh M, Parsaeian M, Pourmalek F, Rahimi K, Sepanlou SG, Tehrani A, Malekzadeh R, Naghavi M. The Burden of Road Traffic Injuries in Iran and 15 Surrounding Countries: 1990-2016. Arch Iran Med 2018; 21:556-565. [PMID: 30634852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/07/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The Global Burden of Disease (GBD) Study provides estimates of deaths, years of life lost (YLL), years of life lived with disability (YLD), and disability-adjusted life years (DALYs) due to 249 causes of death, 315 diseases and injuries, and 79 behavioral, environmental, occupational, and metabolic risk factors in 195 countries, territories, and regions by sex and 20 age categories in 195 countries and regions since 1990. In this study, we aimed to present the burden of road traffic injuries (RTIs) in Iran and 15 surrounding countries in 1990-2016. METHODS The standard Cause of Death Ensemble modeling (CODEm) is used to estimate deaths due to all causes of injury by age, sex, country and year. A range of 27 causes is used for estimating non-fatal health outcomes based on inpatient and outpatient datasets using DisMod-MR 2.0. Disability-adjusted life years (DALYs) estimate quantify the total burden of years lost due to premature death or disability and was computed by summing the fatal burden and non-fatal burden associated with a cause (i.e., YLL+YLD). RESULTS In 2016, age-standardized transport injuries in Iran accounted for 35.6 (UI: 29.64-43.44) deaths per 100000 compared to 60.8 (UI: 51.04-72.49) in 1990. Transport injury became the fourth leading cause of death in Iran in 2016, up from the 5th leading cause of death in 1990. The burden of RTIs was mainly caused by motor vehicles and motorcycles and mostly affected the economically productive age groups (15-49), males and children, especially those at school age. Afghanistan with 59.14 deaths (52.09-66.8) and UAE with 53.71 deaths (36.59-72.77) had the largest transport injury death rates per 100000. From 1990 to 2016, Iran had -2.06 annual percent change in transport death rates. The lowest annual percent change is reported for Turkmenistan at -3.43. While Pakistan, UAE and Qatar had the highest annual percent change in transport injury. Across all countries, the observed-to-expected ratios for transport injury death rates varied considerably in 2016.The UAE had the largest age-standardized ratios of observed-to-expected rate (2.93), followed by Oman (2.39), Saudi Arabia (2.23), Afghanistan (2.04) and Iran (1.95). CONCLUSIONS RTIs continue to be a public health burden in Iran and its neighboring countries, even though, there is evidence for decline in RTIs across all countries except Pakistan. The most frequent sub-causes of death and injury are the motor vehicle, motorcycle, and pedestrian injuries. The most vulnerable road users are children and young adults.
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Affiliation(s)
- Shahrzad Bazargan-Hejazi
- Professor, College of Medicine, Department of Psychiatry, Charles R. Drew University of Medicine and Science, and David Geffen School of Medicine, University of California at Los Angeles (UCLA), USA
| | - Alireza Ahmadi
- Department of Anesthesiology, Critical & Pain Management, Kermanshah University of Medical Sciences (KUMS), Kermanshah, Iran
| | - Anaheed Shirazi
- Charles R. Drew University of Medicine and Science, College of Medicine, Los Angeles, California, USA
| | - Elaheh Ainy
- Safety Promotion and Injury Prevention Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shirin Djalalinia
- Deputy of Research and Technology, Ministry of Health and Medical Education and NCDRC EMRI, Tehran University of Medical Science, Tehran, Iran
| | | | - Nader Jahanmehr
- Safety Promotion and Injury Prevention Research Center, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Aliashgher Kiadaliri
- Clinical Epidemiology Unit, Orthopedics, Department of Clinical Sciences Lund, Lund University, Sweden
| | - Maziar Moradi-Lakeh
- Associate Professor in Community Medicine, Department of Community Medicine, School of Medicine, Iran University of Medical Sciences and Health Services, Tehran, Iran
| | - Mahboubeh Parsaeian
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Farshid Pourmalek
- School of Population and Public Health, University of British Colombia, Vancouver, BC, Canada
| | - Kazem Rahimi
- Associate Professor of Cardiovascular Medicine, University of Oxford, Deputy Director, The George Institute for Global Health, Director, Deep Medicine program, Oxford Martin School, University of Oxford, Honorary Consultant Cardiologist, Oxford University Hospitals NHS Foundation Trust
| | - Sadaf G Sepanlou
- Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Arash Tehrani
- Deputy of Research of Preventive Medicine and Public Health Research Center, Assistant professor of Community Medicine Department, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Malekzadeh
- Professor of Medicine, Digestive Disease Research Institute, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - Mohsen Naghavi
- Professor of Global Health, Institute for Health Metrics and Evaluation (IHME), University of Washington, Seattle, USA
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White Z, Milad N, Tehrani A, Sellers S, Bernatchez PN. Statins, Cholesterol and Muscle Damage: an Illusion? ATHEROSCLEROSIS SUPP 2018. [DOI: 10.1016/j.atherosclerosissup.2018.04.170] [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: 10/14/2022]
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Javanbakht M, Jamshidi AR, Baradaran HR, Mohammadi Z, Mashayekhi A, Shokraneh F, Rezai Hamami M, Yazdani Bakhsh R, Shabaninejad H, Delavari S, Tehrani A. Estimation and Prediction of Avoidable Health Care Costs of Cardiovascular Diseases and Type 2 Diabetes Through Adequate Dairy Food Consumption: A Systematic Review and Micro Simulation Modeling Study. Arch Iran Med 2018; 21:213-222. [PMID: 29738265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 01/31/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Recent evidence from prospective cohort studies show a relationship between consumption of dairy foods and cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM). This association highlights the importance of dairy foods consumption in prevention of these diseases and also reduction of associated healthcare costs. The aim of this study was to estimate avoidable healthcare costs of CVD and T2D through adequate dairy foods consumption in Iran. METHODS This was a multistage modelling study. We conducted a systematic literature review in PubMed and EMBASE to identify any association between incidence of CVD and T2DM and dairy foods intake, and also associated relative risks. We obtained age- and sex-specific dairy foods consumption level and healthcare expenditures from national surveys and studies. Patient level simulation Markov models were constructed to predict the disease incidence, patient population size and associated healthcare costs for current and optimal dairy foods consumption at different time horizons (1, 5, 10 and 20 years). All parameters including costs and transition probabilities were defined as statistical distributions in the models, and all analyses were conducted by accounting for first and second order uncertainty. RESULTS The systematic review results indicated that dairy foods consumption was inversely associated with incidence of T2DM, coronary heart disease (CHD) and stroke. We estimated that the introduction of a diet containing 3 servings of dairy foods per day may produce a $0.43 saving in annual per capita healthcare costs in Iran in the first year due to saving in cost of CVD and T2DM treatment. The estimated savings in per capita healthcare costs were $8.42, $39.97 and $190.25 in 5, 10 and 20-years' time, respectively. Corresponding total aggregated avoidable costs for the entire Iranian population within the study time horizons were $33.83, $661.31, $3,138.21 and $14,934.63 million, respectively. CONCLUSION Our analysis demonstrated that increasing dairy foods consumption to recommended levels would be associated with reductions in healthcare costs. Further randomized trial studies are required to investigate the effect of dairy foods intake on cost of CVD and T2DM in the population.
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Affiliation(s)
- Mehdi Javanbakht
- Health Economics Group, Institute of Health & Society, Newcastle University, UK
| | - Ahmad Reza Jamshidi
- Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Reza Baradaran
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Iran
| | - Zahra Mohammadi
- Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Atefeh Mashayekhi
- Health Economics Group, Institute of Health & Society, Newcastle University, UK
| | | | - Mohsen Rezai Hamami
- Health Economics and Health Technology Assessment, Institute of Health and Wellbeing, University of Glasgow, UK
| | - Raziyeh Yazdani Bakhsh
- Health Information Management, Health Management and Economic Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossien Shabaninejad
- Department of Health Services Management, School of Health Management and Information Sciences, Iran University of Medical Sciences, Iran
| | - Sajad Delavari
- Health Human Resources Research Center, School of Management & Information Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Arash Tehrani
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Iran
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Motevalian SA, Haddadi M, Akbari H, Khorramirouz R, Saadat S, Tehrani A, Rahimi-Movaghar V. Strengthening injury surveillance system in iran. Chin J Traumatol 2016; 14:348-53. [PMID: 22152138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE To strengthen the current Injury Surveillance System (IS System) in order to better monitor injury conditions, improve protection ways and promote safety. METHODS At first we carried out a study to evaluate the frameworks of IS System in the developed countries. Then all the available documents from World Health Organization, Eastern Mediterranean Regional Organization, as well as Minister of Health and Medical Education concerning Iran were reviewed. Later a national stakeholder's consultation was held to collect opinions and views. A national workshop was also intended for provincial representatives from 41 universities to identify the barriers and limitations of the existing program and further to strengthen injury surveillance. RESULTS The evaluation of the current IS System revealed many problems, mainly presented as lack of accurate pre- and post-hospital death registry, need of precise injury data registry in outpatient medical centers, incomplete injury data registry in hospitals and lack of accuracy in definition of variables in injury registry. The five main characteristics of current IS System including flexibility, acceptability, simplicity, usefulness and timeliness were evaluated as moderate by experts. CONCLUSIONS Major revisions must be considered in the current IS System in Iran. The following elements should be added to the questionnaire: identifier, manner of arrival to the hospital, situation of the injured patient, consumption of alcohol and opioids, other involved participants in the accident, intention, severity and site of injury, side effects of surgery and medication, as well as one month follow-up results. Data should be collected from 10% of all hospitals in Iran and analyzed every 3 months. Simultaneously data should be online to be retrieved by researches.
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Jett K, Chohan H, Cui J, Tehrani A, Friedman J, Breemen C, Esfandiarei M. Impairment of Vascular Function in a Mouse Model of Neurofibromatosis Type 1. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.638.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kimberly Jett
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Harleen Chohan
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Jason Cui
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Arash Tehrani
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Jan Friedman
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Cornelis Breemen
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Mitra Esfandiarei
- Department of Anesthesiology, Pharmacology, & TheraputicsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Biomedical Sciences ProgramMidwestern UniversityGlendaleArizonaUnited States
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Paddock ML, Sagle L, Tehrani A, Beatty JT, Feher G, Okamura MY. Mechanism of proton transfer inhibition by Cd(2+) binding to bacterial reaction centers: determination of the pK(A) of functionally important histidine residues. Biochemistry 2003; 42:9626-32. [PMID: 12911304 DOI: 10.1021/bi0346648] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bacterial photosynthetic reaction center (RC) uses light energy to catalyze the reduction of a bound quinone molecule Q(B) to quinol Q(B)H(2). In RCs from Rhodobacter sphaeroides the protons involved in this process come from the cytoplasm and travel through pathways that involve His-H126 and His-H128 located near the proton entry point. In this study, we measured the pH dependence from 4.5 to 8.5 of the binding of the proton transfer inhibitor Cd(2+), which ligates to these surface His in the RC and inhibits proton-coupled electron transfer. At pH <6, the negative slope of the logarithm of the dissociation constant, K(D), versus pH approaches 2, indicating that, upon binding of Cd(2+), two protons are displaced; i.e., the binding is electrostatically compensated. At pH >7, K(D) becomes essentially independent of pH. A theoretical fit to the data over the entire pH range required two protons with pK(A) values of 6.8 and 6.3 (+/-0.5). To assess the contribution of His-H126 and His-H128 to the observed pH dependence, K(D) was measured in mutant RCs that lack the imidazole group of His-H126 or His-H128 (His --> Ala). In both mutant RCs, K(D) was approximately pH independent, showing that Cd(2+) does not displace protons upon binding in the mutant RCs, in contrast to the native RC in which His-H126 and His-H128 are the predominant contributors to the observed pH dependence of K(D). Thus, Cd(2+) inhibits RC function by binding to functionally important histidines.
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Affiliation(s)
- M L Paddock
- Department of Physics 0319, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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Adelroth P, Paddock ML, Tehrani A, Beatty JT, Feher G, Okamura MY. Identification of the proton pathway in bacterial reaction centers: decrease of proton transfer rate by mutation of surface histidines at H126 and H128 and chemical rescue by imidazole identifies the initial proton donors. Biochemistry 2001; 40:14538-46. [PMID: 11724567 DOI: 10.1021/bi011585s] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The pathway for proton transfer to Q(B) was studied in the reaction center (RC) from Rhodobacter sphaeroides. The binding of Zn(2+) or Cd(2+) to the RC surface at His-H126, His-H128, and Asp-H124 inhibits the rate of proton transfer to Q(B), suggesting that the His may be important for proton transfer [Paddock, M. L., Graige, M. S., Feher, G. and Okamura, M. Y. (1999) Proc. Natl. Acad. Sci. U.S.A. 96, 6183-6188]. To assess directly the role of the histidines, mutant RCs were constructed in which either one or both His were replaced with Ala. In the single His mutant RCs, no significant effects were observed. In contrast, in the double mutant RC at pH 8.5, the observed rates of proton uptake associated with both the first and the second proton-coupled electron-transfer reactions k(AB)(()(1)()) [Q(A)(-)(*)Q(B)-Glu(-) + H(+) --> Q(A)(-)(*)Q(B)-GluH --> Q(A)Q(B)(-)(*)-GluH] and k(AB)(()(2)()) [Q(A)(-)(*)Q(B)(-)(*) + H(+) --> Q(A)(-)(*)(Q(B)H)(*) --> Q(A)(Q(B)H)(-)], were found to be slowed by factors of approximately 10 and approximately 4, respectively. Evidence that the observed changes in the double mutant RC are due to a reduction in the proton-transfer rate constants are provided by the observations: (i) k(AB)(1) at pH approximately pK(a) of GluH became biphasic, indicating that proton transfer is slower than electron transfer and (ii) k(AB)(2) became independent of the driving force for electron transfer, indicating that proton transfer is the rate-limiting step. These changes were overcome by the addition of exogenous imidazole which acts as a proton donor in place of the imidazole groups of His that were removed in the double mutant RC. Thus, we conclude that His-H126 and His-H128 facilitate proton transfer into the RC, acting as RC-bound proton donors at the entrance of the proton-transfer pathways.
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Affiliation(s)
- P Adelroth
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
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Tehrani A, Wheeler-Schilling TH, Guenther E. Coexpression patterns of mGLuR mRNAs in rat retinal ganglion cells: a single-cell RT-PCR study. Invest Ophthalmol Vis Sci 2000; 41:314-9. [PMID: 10634636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
PURPOSE Eight different subunits of metabotropic glutamate receptors (mGluRs) are known to date. mGluRs have been linked to an extensive list of neuromodulatory effects, depending on which intracellular or membrane-bound effector system is activated. Activation of mGluRs can influence neuronal activity and can result in changes of intracellular Ca2+ homeostasis-that is, changes in factors that are known to be crucial for cellular differentiation and cell death. Because mGluRs are known in modulating both intracellular and intercellular activities, this study was designed to determine which types of mGluRs are coexpressed in a neuron and whether distinct coexpression patterns can be found that reflect the different physiological requirements of a neuron at different stages of development and to learn whether neuronal injury results in adaptive changes of mGluR expression. METHODS Juvenile and adult rat retinal ganglion cells (RGCs) and adult RGCs after axotomy were analyzed for their gene expression pattern of mGluRs by single-cell reverse transcription-polymerase chain reaction (RT-PCR). RESULTS Adult RGCs predominantly expressed one or two different mGluR mRNAs, whereas juvenile RGCs coexpressed two and more. mGluR3, -5, and -7 mRNAs were found more frequently in juvenile than in adult RGCs. mGluR6 was detected in juvenile RGCs in low abundance but never in adult RGCs. However, mGluR6 was expressed in adult RGCs after axotomy. mGluR1 and -7 were also found more frequently in axotomized RGCs than in the adult control group. CONCLUSIONS All types of mGluR mRNAs are expressed in RGCs. This is in contrast with previous in situ hybridization and immunohistochemical studies in which expression of mGluR3, -5, and -6 was not reported. The expression of some mGluR mRNAs seems to be developmental, although no distinct copatterns were found.
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Affiliation(s)
- A Tehrani
- Department of Pathophysiology of Vision and Neuro-Ophthalmology, University Eye Hospital, Tübingen, Germany
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Abstract
Polyhydroxyalkanoate (PHA) cellular inclusions consist of polyesters, phospholipids, and proteins. Both the polymerase and the depolymerase enzymes are active components of the structure. Recently, proteins associated with these inclusions have been described in a number of bacterial species. In order to further clarify the structure and function of these proteins in relation to polymer inclusions, ultrastructural studies of isolated polymer inclusions were initiated. The surface boundary characteristics of polymer inclusions, produced by several genera of bacteria, two different Pseudomonas putida deletion mutants and by Escherichia coli recombinants, were examined. The recombinant E. coli carried either the PHB biosynthesis operon (phaCAB) from Ralstonia eutropha alone, or both this operon and a gene encoding an inclusion surface protein of R. eutropha (phaP). The results support two suggestions: (i) specific genes in the PHA gene cluster code for the proteins forming the surface boundary arrays which characterize the polymer inclusion; and (ii) transfer of such a gene would result in subcellular compartmentalization of accumulating polymer. Although the proteins appear to serve a similar function among different genera, nevertheless, the different surface proteins are encoded by a variety of non-homologous genetic sequences.
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Affiliation(s)
- E S Stuart
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, USA.
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Foster LJ, Stuart ES, Tehrani A, Lenz RW, Fuller RC. Intracellular depolymerase and polyhydroxyoctanoate granule integrity in Pseudomonas oleovorans. Int J Biol Macromol 1996; 19:177-83. [PMID: 8910058 DOI: 10.1016/0141-8130(96)01125-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [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: 02/03/2023]
Abstract
When polyhydroxyoctanoate (PHO) was produced by Pseudomonas oleovorans during a regimen of intermittent feeding on octanoic acid, there was a significant change in both the polymer associated proteins and the composition of the enclosed polymer. The polymer granules were isolated with their protein coat intact and the enzymatic hydrolysis of the polymer within this cell free system was determined. The degradation rate for the PHO in these native granules reached a maximum of 1.17 mg/h at an optimum pH of 9 when incubated at 30 degrees C. A study of the effect of various inhibitors on depolymerase activity suggested that the enzyme most likely has disulfide linkages and serine residues at its active site. Ultrastructure studies suggested this loss of enzyme activity was correlated with significant organizational degeneration in the proteins associated with the PHO inclusion body. Once solubilized from the granule, the depolymerase itself remained enzymatically active, and addition of this released material to other granule preparations increased the rate of polymer granule degradation. Similarly, when colloidal suspensions of purified, amorphous PHO were placed in contact with that depolymerase, they also underwent rapid degradation. In contrast, when crystalline solvent-cast PHO films were placed in contact with this enzyme, no degradative activity was observed.
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Affiliation(s)
- L J Foster
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst 01003-4505, USA
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Abstract
Six subjects wore intraoral devices carrying bovine enamel blocks covered with a layer of Streptococcus mutans. They swished solutions of 5% glucose or maltose, or sols or gels of 3, 5, 10, 15, or 20% gelatinized wheat starch in the mouth for 3 X 1 min. Demineralization was measured after 45 min by determining the change in iodide permeability (delta Ip) of the enamel. Spittings of the administered materials and samples of saliva, taken at intervals during the test, were analyzed for maltose, and the time of clearance was calculated. Demineralization was greatest for glucose followed by maltose, the starch gels, and the sols. The latter gave close to zero scores. The salivary clearance time increased with increase in concentration of the starch. Although the starch was hydrolyzed rapidly in the mouth, its oral retentiveness was greater than that of the maltose rinse. Demineralization was closely correlated with the final pH of the S. mutans cell layer. The data indicate that the starch in baked or cooked foods may have a significant demineralization potential and that it enhances oral retentiveness.
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Tehrani A, Goulet D, Brudevold F, Attarzadeh F. Enamel demineralization and the length of intra-oral exposure to different concentrations of glucose or sucrose. J Dent Res 1986; 65:139-45. [PMID: 3455970 DOI: 10.1177/00220345860650021001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Six subjects wore intra-oral devices carrying eight bovine enamel blocks which were covered with a layer of S. mutans. They rinsed their mouths for five sec, one min, or multiples of one min with a 5 or 10% glucose (G) solution. Demineralization was measured after 45 min by determining the change in iodide permeability (delta Ip) of the enamel. In addition, saliva samples, taken at intervals during the test, were analyzed for G, and the time of clearance (tc) was calculated. Demineralization scores (delta Ip) were consistently greater from the 10% than from the 5% G solution. Both solutions produced an increase in delta Ip with an increase in the rinsing time (tr). The G remaining in saliva after the rinse did not significantly affect delta Ip. The delta Ip scores showed good correlation with the final pH of the S. mutants cell mass, r = -0.77. For each rinse solution, the scores also showed good correlations with tr (r = 0.87 and 0.79) and much weaker correlations with tr + tc (r = 0.44 and 0.53). Continuous in vitro exposure to 1, 5, or 10% solutions of sucrose (S) in saliva for 30 min or more caused a linear increase in delta Ip with time with no concentration effects. A linear increase was also observed in vivo when a one-minute mouth-rinse with 10% solution of S was administered every 30 min. The findings indicate that significant demineralization may occur while carbohydrate foods are consumed, and that brushing the teeth or rinsing the mouth after meals may not be as effective against caries as is generally believed.
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Abstract
The clearance of glucose from saliva was compared with that from spaces located in an intra-oral appliance. The spaces (N = 8) were similar in shape and size to posterior interdental spaces and could be sampled with a microsyringe without removing the appliance from the mouth. The subjects (N = 5) rinsed their mouths with solutions of 5, 10, or 25% glucose. Samples were obtained from a pair of spaces and from saliva at standard intervals and were analyzed for glucose. The rate of glucose clearance was consistently slower from the spaces than from bulk saliva, as shown by higher concentrations and longer clearance times for the spaces. The clearance curves were similar in shape and were rectilinear when the logarithms of the concentrations were plotted against time. The rate of clearance from the spaces appears to be characteristic for an individual, as was also true of salivary clearance.
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Brudevold F, Tehrani A, Attarzadeh F, Goulet D, van Houte J. Effect of some salts of calcium, sodium, potassium, and strontium on intra-oral enamel demineralization. J Dent Res 1985; 64:24-7. [PMID: 3855415 DOI: 10.1177/00220345850640010401] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A newly-developed intra-oral enamel demineralization test was used to evaluate the effect of supplementation of a 10% sucrose solution with various components on enamel demineralization induced by the sucrose. Five human subjects wore a palatal prosthesis holding eight blocks of subsurface bovine enamel covered with a layer of S. mutans cells. The test involved rinsing with sucrose solution or with sucrose solution supplemented with 0.162 mol/l of different calcium salts or equivalent concentrations of Na-, K-, and Sr salts; rinsing was for one min at times zero and 45 min of the 90-minute test period. Ca-propionate, Ca-acetate, and Ca-levulinate completely inhibited sucrose-induced enamel demineralization; Ca-chloride, Ca-lactate, and Ca-ascorbate gave from 65-75%, and K-acetate, Na-lactate, and Sr-lactate 39, 25, and 18% inhibition, respectively. Consideration of the anion dissociation constants and the Ca-anion association constants of the salts suggests that the observed inhibition is caused mainly by common ion effects and, to a lesser extent, by buffer effects.
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Brudevold F, Goulet D, Tehrani A, Attarzadeh F, van Houte J. Intraoral demineralization and maltose clearance from wheat starch. Caries Res 1985; 19:136-44. [PMID: 2581692 DOI: 10.1159/000260840] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Tehrani A, Brudevold F, Attarzadeh F, van Houte J, Russo J. Enamel demineralization by mouthrinses containing different concentrations of sucrose. J Dent Res 1983; 62:1216-7. [PMID: 6581198 DOI: 10.1177/00220345830620120801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Intra-oral enamel demineralization tests, involving rinsing with sucrose solutions (5, 1, 0.5, or 0.3%) at varying frequencies during a 1.5-hour period, showed that demineralization was a function of the total sugar dose (frequency of rinsing times concentration). Two rinses with a 5% solution caused demineralization, nine rinses were needed in the case of a 0.5% solution, and none occurred after nine rinses with a 0.3% solution. Remineralization was also observed and apparently occurred after exhaustion of the sucrose supply.
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Abstract
Mouthrinses with 5% solutions of different sugars were tested for their demineralizing effect on blocks of bovine enamel covered with a layer of S. mutans cells and carried in a palatal prosthesis. The extent of demineralization, as measured by the permeability of the enamel to iodide, was similar for fructose, glucose, and sucrose, less for maltose and lactose, and least for galactose.
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Abstract
Blocks of bovine enamel subjected to de- and remineralization were measured for changes in permeability to iodide and urea. Results were similar, indicating that the diffusion pathways for the two species were comparable, and that sites for iodide binding did not appear to exit.
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Brudevold F, Tehrani A, Cruz R. The relationship among the permeability to iodide, pore volume, and intraoral mineralization of abraded enamel. J Dent Res 1982; 61:645-8. [PMID: 6953092 DOI: 10.1177/00220345820610050501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The results indicate that Ip measurements are fairly closely related to the pore volume of the enamel to a depth of about 13 micrometer. A previous finding - that intraoral exposure produced substantial mineralization of abraded enamel after one h, and a slower rate of mineralization during the next two h - was confirmed, and it was shown that the rate of mineralization decreased with a decrease in the pore volume of the enamel. The rapid rate of intraoral mineralization represents a powerful mechanism for maintaining a fully mineralized enamel surface. The sensitivity of the Ip method demonstrated in this study, and the finding that Ip measurements relate to the pore volume of the enamel, coupled with previous findings that the increase in Ip produced by mild acid etching of intact enamel is proportional with the amount of dissolved Ca, indicate that the method provides valid measurement of intraoral de- and remineralization.
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Abstract
The iodide permeability (Ip) of abraded bovine enamel increased after short exposure to an acid buffer and decreased after short exposure to a mineralizing solution. Intraoral exposure gave a marked decrease in Ip after one h and a continued lesser decrease after two and three h. In vitro exposure to fresh and dialyzed saliva and various undersaturated solutions indicated that the intraoral decrease was due to mineralization rather than to pellicle formation. Analysis of the data also indicated that part of the mineral formed intraorally was more loosely bound to the enamel than that formed from an inorganic mineralizing solution. The rapid rate of the initial phase of intraoral mineralization shown in this study reveals a powerful mechanism for protecting the dentition against demineralization.
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