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Sohail A, Chishti FUDA, Manzar S, Zahid N, Ahmad F, Rafiq T. Can dynamic elastic therapy be established as the standard protocol of closed reduction for moderately displaced extracapsular condylar fractures? Oral Maxillofac Surg 2024; 28:385-391. [PMID: 37185928 DOI: 10.1007/s10006-023-01154-6] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 04/19/2023] [Indexed: 05/17/2023]
Abstract
OBJECTIVE This study was conducted with the aim to establish standard technique of closed reduction (CR) and compare functional outcomes in patients of moderately displaced unilateral extracapsular condylar fractures. MATERIAL AND METHODS This study is a retrospective randomized controlled trial, conducted at a tertiary care hospital setting from August, 2013 to November, 2018. Patients of unilateral extracapsular condylar fractures with ramus shortening < 7mm and deviation < 35° were divided in two groups by drawing lots and were treated by dynamic elastic therapy and maxillomandibular fixation (MMF). Mean and standard deviation were calculated for quantitative variables, and one way analysis of variance (ANOVA) and Pearson's Chi-square test were used to determine significance of outcomes between two modalities of CR. P value < 0.05 was taken as significant. RESULTS The numbers of patients treated by dynamic elastic therapy and MMF were 76 (38 in each group). Out of which 48 (63.15%) were male and 28 (36.84%) were female. The ratio of male to female was 1.7:1. The mean ± standard deviation (SD) of age was 32 ± 9.57 years. In patients treated by dynamic elastic therapy, the mean ± SD (at 6-month follow-up) of loss of ramus height (LRH), maximum incisal opening (MIO) and opening deviation were 4.6mm ± 1.08mm, 40.4mm ± 1.57mm and 1.1mm ± 0.87mm respectively. Whereas, LRH, MIO and opening deviation were 4.6mm ± 0.85mm, 40.4mm ± 2.37mm and 0.8mm ± 0.63mm respectively by MMF therapy. One-way ANOVA was statistically insignificant (P value > 0.05) for above mentioned outcomes. Pre-traumatic occlusion was achieved in 89.47% of patients by MMF and in 86.84% patients by dynamic elastic therapy. Pearson's Chi-square test was statistically insignificant (p value < 0.05) for occlusion. CONCLUSION Parallel results were obtained for both modalities; thus, the technique as dynamic elastic therapy, which promotes early mobilization and functional rehabilitation, can be favored as standard technique of closed reduction for moderately displaced extracapsular condylar fractures. This technique eases patients' stress associated with MMF and prevents ankylosis.
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Affiliation(s)
- Aqib Sohail
- Dental College, Lahore Medical & Dental College, Lahore, Pakistan
| | | | - Saadia Manzar
- Department of Oral & Maxillofacial Surgery, Rashid Latif Dental College/Rashid Latif Medical Complex, Lahore, Pakistan.
| | - Nighat Zahid
- Department of Oral & Maxillofacial Surgery, Lahore Medical & Dental College, Lahore, Pakistan
| | - Fareed Ahmad
- Department of Oral Medicine, CMH Lahore Medical College & Institute of Dentistry, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Tayyaba Rafiq
- Department of Oral & Maxillofacial Surgery, Lahore Medical & Dental College, Lahore, Pakistan
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Ammara A, Sobia A, Nureen Z, Sohail A, Abid S, Aziz T, Nahaa MA, Rewaa SJ, Ahellah MJ, Nouf SAA, Nehad AS, Manal YS, Amnah AA, Majid A, Abdulhakeem SA, Anas SD, Saad A. Revolutionizing the effect of Azadirachta indica extracts on edema induced changes in C-reactive protein and interleukin-6 in albino rats: in silico and in vivo approach. Eur Rev Med Pharmacol Sci 2023; 27:5951-5963. [PMID: 37458623 DOI: 10.26355/eurrev_202307_32947] [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] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
OBJECTIVE The aim of the present study is to determine the in vivo and in silico anti-inflammatory effect of Azadirachta indica (A. indica) in carrageenan-induced rats and its blood biomarkers. A. indica (Neem) is a widely used medicinal plant across the world, especially in Pakistan. Neem leaves have been traditionally used for the synthesis of drugs and treatment of a wide variety of diseases. MATERIALS AND METHODS In this study, sixty albino rats (160-200 g) were divided into 4 groups: control (group I), standard (group II), ethanolic and aqueous (group III and IV) at doses of 50, 100, 200 and 400 mg/kg. RESULTS Ethanolic and aqueous extracts showed maximum inhibition in paw size at the 5th hour (400 mg/kg). Similarly, biomarkers measured, including Interleukin-6 and C-reactive protein, exhibited significant anti-inflammatory activity at the highest dose of 400 mg/kg in both experimental groups but were more distinct in the group treated with ethanolic extracts. Correlation between C-reactive protein (CRP) and inter-leukin-6 (IL-6) showed positive correlation in group III, while negative in group IV. Similarly, positive and negative correlations were observed between CRP biomarkers and paw size in group III and IV, and the same results were also shown in the case of IL-6 and paw size. In molecular docking, the binding energy value of protein CRP and IL-1β with the identified ligands quercetin and nimbosterol showed (-8.2 kcal/mol and -7.7 kcal/mol) the best binding affinity as compared to standard drug diclofenac with -7.0 kcal/mol binding energy respectively. CONCLUSIONS In conclusion, in silico and in vivo analysis revealed that the extracts of A. indica leaves can be used as an effective drug to manage inflammation.
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Affiliation(s)
- A Ammara
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Lahore, Punjab, Pakistan.
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Khan RU, Khan M, Sohail A, Ullah R, Iqbal A, Ahmad B, Khan IU, Tariq A, Ahmad M, Said A, Ullah S, Ali A, Rahman MU, Zaman A, Bilal H. Efficacy of pentamidine-loaded chitosan nanoparticles as a novel drug delivery system for Leishmania tropica. Trop Biomed 2022; 39:511-517. [PMID: 36602209 DOI: 10.47665/tb.39.4.003] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.
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Affiliation(s)
- R U Khan
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan
| | - M Khan
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan
| | - A Sohail
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan
| | - R Ullah
- Department of Dairy Technology, Faculty of Veterinary and Animal Sciences, University of Agriculture Dera Ismail Khan, Pakistan
| | - A Iqbal
- Faculty of Veterinary and Animal Sciences, Gomal University, Dera Ismail Khan, Pakistan
| | - B Ahmad
- Department of Animal Sciences, Faculty of Veterinary and Animal Sciences, MNS University of Agriculture Multan, Punjab, 25000, Pakistan
| | - I U Khan
- Faculty of Veterinary and Animal Sciences, Gomal University, Dera Ismail Khan, Pakistan
| | - A Tariq
- Directorate of Livestock and Dairy Development Department, Khyber Pakhtunkhwa, Pakistan
| | - M Ahmad
- Department of Animal Sciences, Quaid-E Azam University Islamabad, Pakistan
| | - A Said
- Department of Parasitology, University of Agriculture Faisalabad, Pakistan
| | - S Ullah
- Department of Biochemistry, Hazara University Mansehra, Pakistan
| | - A Ali
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan
| | - M U Rahman
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan
| | - A Zaman
- Faculty of Veterinary and Animal Sciences, Gomal University, Dera Ismail Khan, Pakistan
| | - H Bilal
- Second Affiliated Hospital of Shantou University Medical College, Shantou, China
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Prielhofer R, Lindner C, Sohail A, Reininger M, Graumann K. Development of Scalable Stem Cell Cultivation Processes in Bioreactors. CHEM-ING-TECH 2022. [DOI: 10.1002/cite.202255185] [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: 11/07/2022]
Affiliation(s)
| | - C. Lindner
- Phoenestra GmbH Hafenstr. 47–51 4020 Linz Austria
| | - A. Sohail
- Phoenestra GmbH Hafenstr. 47–51 4020 Linz Austria
| | - M. Reininger
- Phoenestra GmbH Hafenstr. 47–51 4020 Linz Austria
| | - K. Graumann
- Phoenestra GmbH Hafenstr. 47–51 4020 Linz Austria
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Loong L, Ponnampalavanar S, Lai P, Syed Omar S, Sohail A, Wong P, Ong HC, Kukreja A, Ng R, Tan L, Tan C, Lee C, Lim K, Thursky K, James R. Antimicrobial prescribing trends and appropriateness in a tertiary teaching hospital in Malaysia. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.263] [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: 11/25/2022] Open
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Mehmood S, Khan A, Bilal M, Sohail A, Iqbal H. Aptamer-based biosensors: a novel toolkit for early diagnosis of cancer. Materials Today Chemistry 2019. [DOI: 10.1016/j.mtchem.2019.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Choudhry A, Younis M, Sohail A, Choudhry A, Abd-rabu R, Crye M, Green R, Wallen J. Medical Malpractice in Bronchoscopy: Failure to Diagnose and Treat Remains the Top Reason for Litigation. A72. ADVANCES IN INTERVENTIONAL PULMONARY 2019. [DOI: 10.1164/ajrccm-conference.2019.199.1_meetingabstracts.a2363] [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] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
- A.J. Choudhry
- Surgery, SUNY Upstate University, Syracuse, NY, United States
| | - M. Younis
- Medicine, University of Missouri, Kansas City, MO, United States
| | - A. Sohail
- Medicine, University of Lahore, Lahore, Pakistan
| | - A. Choudhry
- Medicine, Capital health, Trenton, NJ, United States
| | - R. Abd-rabu
- Cardiothoracic Surgery, Mayo Clinic, Rochester, MN, United States
| | - M. Crye
- Surgery, SUNY Upstate University, Syracuse, NY, United States
| | - R. Green
- Surgery, SUNY Upstate University, Syracuse, NY, United States
| | - J. Wallen
- Surgery, SUNY Upstate University, Syracuse, NY, United States
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Majeed A, Latif A, Kapoor V, Sohail A, Florita C, Georgescu A, Zangeneh T. Resistant Cytomegalovirus Infection in Solid-organ Transplantation: Single-center Experience, Literature Review of Risk Factors, and Proposed Preventive Strategies. Transplant Proc 2018; 50:3756-3762. [PMID: 30586840 DOI: 10.1016/j.transproceed.2018.02.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 02/17/2018] [Indexed: 01/21/2023]
Abstract
BACKGROUND Cytomegalovirus (CMV) infection causes morbidity and mortality in solid-organ transplant recipients. Drug-resistant CMV is an emerging problem with poor survival outcomes and limited therapeutic options. In this study we comprehensively address the issue of drug resistance in CMV when compared with standard therapies, such as ganciclovir (GCV) and foscarnet. METHODS We conducted a retrospective review of adult patients diagnosed with CMV after solid-organ transplant at our center between 2013 and 2017, and identified 7 resistant CMV cases. To study risk factors in the published literature, we performed an extensive database search. RESULTS All patients had documented UL97 mutations, and 3 patients harbored both UL97 and UL54 mutations. For cases with increasing viral load or failure to achieve clinical improvement despite optimal therapy, genetic resistance testing was carried out. Patients received GCV and foscarnet combination therapy. As an adjunct, CMV immunoglobulin, cidofovir, and leflunomide were added. Risk factors, including donor+/recipient- serostatus, persistent high viral replication, prolonged therapeutic GCV exposure (>2.5 months), and allograft rejection, were assessed. CONCLUSION Patients at risk, especially those with D+/R- serostatus, should be judiciously monitored for resistance. Prolonged intravenous GCV exposure increases the risk for development of drug resistance. Therefore, precise guidelines are required for prevention of long-term GCV/VGCV exposure. Investigation regarding interferon-gamma release assay and adoptive transfer of T cells in diagnosed CMV patients is warranted to improve future prophylactic and management strategies against CMV, with a potential to reduce the requirement for available toxic antiviral drugs.
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Affiliation(s)
- A Majeed
- Division of Infectious Diseases, Department of Medicine, University of Arizona, Tucson, Arizona.
| | - A Latif
- Department of Medicine, University of Arizona, Tucson, Arizona
| | - V Kapoor
- Department of Medicine, University of Arizona, Tucson, Arizona
| | - A Sohail
- Department of Medicine, University of Arizona, Tucson, Arizona
| | - C Florita
- Division of Infectious Diseases, Department of Medicine, University of Arizona, Tucson, Arizona
| | - A Georgescu
- Division of Infectious Diseases, Department of Medicine, University of Arizona, Tucson, Arizona
| | - T Zangeneh
- Division of Infectious Diseases, Department of Medicine, University of Arizona, Tucson, Arizona
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Sair A, Masud T, Sohail A, Rafique A. Microbiological variation amongst fresh and minimally processed vegetables from retail establishers - a public health study in Pakistan. Food Res 2017. [DOI: 10.26656/fr.2017.6.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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10
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Sohail M, Hume M, Byrd J, Nisbet D, Ijaz A, Sohail A, Shabbir M, Rehman H. Effect of supplementation of prebiotic mannan-oligosaccharides and probiotic mixture on growth performance of broilers subjected to chronic heat stress. Poult Sci 2012; 91:2235-40. [DOI: 10.3382/ps.2012-02182] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Imran MA, Sohail A, Shahid N. EXACT SOLUTIONS FOR OSCILLATING MOTION OF A SECOND-GRADE FLUID ALONG AN EDGE WITH MIXED BOUNDARY CONDITIONS. CHEM ENG COMMUN 2012. [DOI: 10.1080/00986445.2011.636849] [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: 10/28/2022]
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Ames H, Mingolla E, Sohail A, Chandler B, Gorchetchnikov A, Leveille J, Livitz G, Versace M. The Animat: New Frontiers in Whole Brain Modeling. IEEE Pulse 2012; 3:47-50. [DOI: 10.1109/mpul.2011.2175638] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bhatti S, Aman-ur-Rehman A, Sohail A, Randhawa I, Hyder S. 6611 Hepatocellular carcinoma: a retrospective analysis of 276 cases. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)71332-1] [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: 10/20/2022] Open
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14
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Bautè AV, Sohail A. Renal artery stenosis: clinical picture, frequency, and management. J S C Med Assoc 1998; 94:306-9. [PMID: 9689782] [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] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Our review has demonstrated a high prevalence of RAS in the elderly population, particularly the group affected by atherosclerosis, as well as disclosing the potential benefits of early diagnosis, treatments, and the associated morbidity/mortality of each corrective intervention.
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Affiliation(s)
- A V Bautè
- Division of Cardiovascular Diseases, University of South Carolina School of Medicine, Columbia 29208, USA
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Abstract
The BamHI restriction-modification system contains a third gene, bamHIC, which positively regulates bamHIR. Similar small genes from other systems were tested in vivo for their ability to cross-complement. C.BamHI protein was identified, purified, and used to raise polyclonal antibodies. Attempts to detect other C proteins in cell extracts by cross-reactivity with C.BamHI antibodies proved unsuccessful.
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Affiliation(s)
- C L Ives
- New England Biolabs, Beverly, Massachusetts 01915, USA
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16
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Abstract
The bamHIC gene, controlling the BamHI restriction-modification (R-M) system can functionally be replaced by providing pvuIIC or smaIC in trans. C.BamHI, the protein product encoded by bamHIC, has been purified and shown to bind a 345-bp DNA fragment within the BamHI R-M system.
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Affiliation(s)
- A Sohail
- New England Biolabs, Beverly, MA 01915, USA
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Mushtaq R, Naeem S, Sohail A, Riazuddin S. BseRI a novel restriction endonuclease from a Bacillus species which recognizes the sequence 5'...GAGGAG...3'. Nucleic Acids Res 1993; 21:3585. [PMID: 8346041 PMCID: PMC331471 DOI: 10.1093/nar/21.15.3585] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 01/30/2023] Open
Affiliation(s)
- R Mushtaq
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
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Abstract
Deamination of 5-methylcytosine in DNA results in T/G mismatches. If unrepaired, these mismatches can lead to C-to-T transition mutations. The very short patch (VSP) repair process in Escherichia coli counteracts the mutagenic process by repairing the mismatches in favor of the G-containing strand. Previously we have shown that a plasmid containing an 11-kilobase fragment from the E. coli chromosome can complement a chromosomal mutation defective in both cytosine methylation and VSP repair. We have now mapped the regions essential for the two phenotypes. In the process, we have constructed plasmids that complement the chromosomal mutation for methylation, but not for repair, and vice versa. The genes responsible for these phenotypes have been identified by DNA sequence analysis. The gene essential for cytosine methylation, dcm, is predicted to code for a 473-amino-acid protein and is not required for VSP repair. It is similar to other DNA cytosine methylases and shares extensive sequence similarity with its isoschizomer, EcoRII methylase. The segment of DNA essential for VSP repair contains a gene that should code for a 156-amino-acid protein. This gene, named vsr, is not essential for DNA methylation. Remarkably, the 5' end of this gene appears to overlap the 3' end of dcm. The two genes appear to be transcribed from a common promoter but are in different translational registers. This gene arrangement may assure that Vsr is produced along with Dcm and may minimize the mutagenic effects of cytosine methylation.
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Affiliation(s)
- A Sohail
- Cold Spring Harbor Laboratory, New York 11724
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Affiliation(s)
- A S Bhagwat
- Department of Chemistry, Wayne State University, Detroit, MI 48202
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20
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Abstract
Three peaks of methyltransferase activity specific for MNNG alkylated DNA have been identified from extracts of chemically adapted M. luteus. They are designated as TI to TIII in order to their elution from a Sephadex G-75 column. The first one of these peaks has been purified to homogeneity. TI, is an inducible, unusually salt resistant, heat labile protein which corrects O6-methylguanine in alkylated DNA by the transfer of the O6-alkyl group to a cysteine amino acid in the TI protein. There is a stoichiometric relationship between the loss of O6-methylguanine from the DNA and the production of S-methylcysteine. Partially purified TII & TIII proteins show specificity for O4-alkylthymine and methyl phosphotriesters respectively. The mode of repair by the isolated methyltransferases is similar yet there is no competition for substrate specificity. The apparent molecular weights of TI, TII & TIII proteins are 31Kd, 22Kd, and 13Kd respectively.
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Affiliation(s)
- S Riazuddin
- Centre for Advanced Molecular Biology, University of the Punjab, Lahore, Pakistan
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21
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Abstract
Five peaks of DNA glycosylase activity showing a preference for MNNG alkylated DNA have been identified from extracts of adapted M. luteus. They are numerically designated as GI to GV in order of their decreasing molecular weights. The first two of these peaks have been highly purified. GI, is a constitutive heat labile protein, 35% stimulated by the presence of 50 mM NaCl, acts exclusively on 3 MeA residues in alkylated DNA, 60-70% inhibited by the presence of 2 mM free 3MeA and has been designated as 3MeA DNA glycosylase enzyme. GII, which is an inducible protein, is heat stable, 28% inhibited by the presence of 50 mM NaCl, removes 3MeA, 3MeG, 7MeA & 7MeG with different efficiency, and has been designated as 3,7 methylpurine DNA glycosylase enzyme. The rate of release of 3 methylpurines is 30 times that of 7MeG. There is no activity of either enzyme on O2-MeC, O2-MeT, O4-MeT or O6-MeG. The apparent molecular weights of GI and GII proteins are 28 Kd and 22 Kd respectively.
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Abstract
The dcm locus of Escherichia coli K-12 has been shown to code for a methylase that methylates the second cytosine within the sequence 5'-CC(A/T)GG-3'. This sequence is also recognized by the EcoRII restriction-modification system coded by the E. coli plasmid N3. The methylase within the EcoRII system methylates the same cytosine as the dcm protein. We have isolated, from a library of E. coli K-12 DNA, two overlapping clones that carry the dcm locus. We show that the two clones carry overlapping sequences that are present in a dcm+ strain, but are absent in a delta dcm strain. We also show that the cloned gene codes for a methylase, that it complements mutations in the EcoRII methylase, and that it protects EcoRII recognition sites from cleavage by the EcoRII endonuclease. We found no phage restriction activity associated with the dcm clones.
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