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Shaldam M, Tawfik H, Elmansi H, Belal F, Yamaguchi K, Sugiura M, Magdy G. Synthesis, crystallographic, DNA binding, and molecular docking/dynamic studies of a privileged chalcone-sulfonamide hybrid scaffold as a promising anticancer agent. J Biomol Struct Dyn 2023; 41:8876-8890. [PMID: 36310097 DOI: 10.1080/07391102.2022.2138551] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/15/2022] [Indexed: 10/31/2022]
Abstract
In the present study, a drug-like molecular hybrid structure between chalcone and sulfonamide moieties was synthesized and characterized. The structural peculiarities of the synthesized hybrid were further verified by means of single crystal X-ray crystallography. Furthermore, its biological activity as an anticancer agent was evaluated. The synthesized model of chalcone-sulfonamide hybrid 3 was found to have potent anticancer properties against the studied cancer cell lines. Hence, the in vitro binding interaction of hybrid 3 with Calf thymus DNA (CT-DNA) was studied at a simulated physiological pH to confirm its anticancer activity for the first time. This was investigated by applying different spectroscopic techniques, ionic strength measurements, viscosity measurements, thermodynamics, molecular dynamic simulation and molecular docking studies. The obtained results showed a clear binding interaction between hybrid 3 and CT-DNA with a moderate affinity via a minor groove binding mechanism. The binding constant (Kb) at 298 K calculated from the Benesi-Hildebrand equation was found to be 3.49 × 104 M-1. The entropy and enthalpy changes (ΔS0 and ΔH0) were 204.65 J mol-1 K-1 and 35.08 KJ mol-1, respectively, indicating that hydrophobic interactions constituted the major binding forces. The results obtained from molecular docking and dynamic simulation studies confirmed the minor groove binding interaction and the stability of the formed complex. This study can contribute to further understanding of the molecular mechanism of hybrid 3 as a potential antitumor agent and can also guide future clinical and pharmacological studies for rational drug design with enhanced or more selective activity and greater efficacy.[Figure: see text]Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Moataz Shaldam
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt
| | - Haytham Tawfik
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Heba Elmansi
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Fathalla Belal
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Koki Yamaguchi
- Faculty of Pharmaceutical Sciences, Sojo University, Kumamoto, Japan
| | - Masaharu Sugiura
- Faculty of Pharmaceutical Sciences, Sojo University, Kumamoto, Japan
| | - Galal Magdy
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt
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Elkeran AAEF, El-Midany T, Tawfik H. A Sweep-Line Algorithm and Its Application to Spiral Pocketing.(Dept.M). MEJ Mansoura Engineering Journal 2021; 26:14-21. [DOI: 10.21608/bfemu.2021.146094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Greeff K, Dènes B, Tawfik H. Cardiovascular effects of (+)- and (-)-tranylcypromine compared to other monoamine oxidase inhibitors. Mod Probl Pharmacopsychiatry 2015; 19:220-30. [PMID: 6408408 DOI: 10.1159/000407519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Tawfik H. Treating the whole patient. Br Dent J 2013; 215:103. [DOI: 10.1038/sj.bdj.2013.744] [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: 11/09/2022]
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Tawfik H, Abu-Seida AM, Hashem AA, Nagy MM. Regenerative potential following revascularization of immature permanent teeth with necrotic pulps. Int Endod J 2013; 46:910-22. [PMID: 23480261 DOI: 10.1111/iej.12079] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 02/02/2013] [Indexed: 02/05/2023]
Abstract
AIM To assess the regenerative potential of immature teeth with necrotic pulps following revascularization procedure in dogs. METHODOLOGY Necrotic pulps and periapical pathosis were created by infecting 108 immature teeth, with 216 root canals in nine mongrel dogs. Teeth were divided into three equal groups according to the evaluation period. Each group was further subdivided into six subgroups according to the treatment protocol including MTA apical plug, revascularization protocol, revascularization enhanced with injectable scaffold, MTA over empty canal. All root canals were disinfected with a triple antibiotic paste prior to revascularization with the exception of control subgroups. After disinfection, the root length, thickness and apical diameter were measured from radiographs. Histological evaluation was used to assess the inflammatory reaction, soft and hard tissue formation. RESULTS In the absence of revascularization, the length and thickness of the root canals did not change over time. The injectable scaffold and growth factor was no more effective than a revascularization procedure to promote tooth development following root canal revascularization. The tissues formed in the root canals resembled periodontal tissues. CONCLUSION The revascularization procedure allowed the continued development of roots in teeth with necrotic pulps.
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Affiliation(s)
- H Tawfik
- Endodontic Department, Faculty of Dentistry, Ainshams University, Cairo, Egypt
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Hegazi EM, Khafagi WE, Konstantopoulou MA, Schlyter F, Raptopoulos D, Shweil S, Abd El-Rahman S, Atwa A, Ali SE, Tawfik H. Suppression of leopard moth (Lepidoptera: Cossidae) populations in olive trees in Egypt through mating disruption. J Econ Entomol 2010; 103:1621-1627. [PMID: 21061961 DOI: 10.1603/ec09435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae), is a damaging pest for many fruit trees (e.g., apple [Malus spp.], pear [Pyrus spp.] peach [Prunus spp.], and olive [Olea]). Recently, it caused serious yield losses in newly established olive orchards in Egypt, including the death of young trees. Chemical and biological control have shown limited efficiency against this pest. Field tests were conducted in 2005 and 2006 to evaluate mating disruption (MD) for the control of the leopard moth, on heavily infested, densely planted olive plots (336 trees per ha). The binary blend of the pheromone components (E,Z)-2,13-octadecenyl acetate and (E,Z)-3,13-octadecenyl acetate (95:5) was dispensed from polyethylene vials. Efficacy was measured considering reduction of catches in pheromone traps, reduction of active galleries of leopard moth per tree and fruit yield in the pheromone-treated plots (MD) compared with control plots (CO). Male captures in MD plots were reduced by 89.3% in 2005 and 82.9% in 2006, during a trapping period of 14 and 13 wk, respectively. Application of MD over two consecutive years progressively reduced the number of active galleries per tree in the third year where no sex pheromone was applied. In all years, larval galleries outnumbered moth captures. Fruit yield from trees where sex pheromone had been applied in 2005 and 2006 increased significantly in 2006 (98.8 +/- 2.9 kg per tree) and 2007 (23 +/- 1.3 kg per tree) compared with control ones (61.0 +/- 3.9 and 10.0 +/- 0.6 kg per tree, respectively). Mating disruption shows promising for suppressing leopard moth infestation in olives.
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Affiliation(s)
- E M Hegazi
- Department of Economic Entomology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
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Tawfik H, Huang R, Samy M, Nagar A. On the Use of Intelligent Systems for the Modelling of Financial Literacy Parameters. Journal of Information Technology Research 2009. [DOI: 10.4018/jitr.2009062902] [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] [Indexed: 11/08/2022]
Abstract
Research has shown that more young people lack good financial literacy and make poor financial decisions. Financial literacy is not only important for individuals, but also for families, financial institutions, and the entire economy. In this paper, artificial neural networks (ANNs) and support vector machines (SVMs) are used as tools to model the financial literacy levels of young university students across Australia and three Western European countries. The goal was to ascertain the students’ level of financial knowledge in relation to the use of credit card and loan facilities based on a number of input parameters such as age, gender and educational level. Sensitivity analysis is applied to determine the relative contribution of each input parameter to the overall financial literacy model. The experiments show that ANNs and SVMs exhibit promising results and capabilities for effectively modeling financial literacy. Our findings indicate that the main determinants of young people’s level of financial literacy include educational level, length of employment, age, and credit card status – in terms of the use of credit card facilities, and gender, living status and credit card status – in terms of the use of loan facilities.
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Affiliation(s)
| | | | - M. Samy
- Liverpool Hope University, UK
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Hegazi E, Khafagi WE, Konstantopoulou M, Raptopoulos D, Tawfik H, El-Aziz GMA, El-Rahman SMA, Atwa A, Aggamy E, Showeil S. Efficient Mass-Trapping Method As an Alternative Tactic for Suppressing Populations of Leopard Moth (Lepidoptera: Cossidae). Annals of the Entomological Society of America 2009; 102:809-818. [DOI: 10.1603/008.102.0507] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Abstract
The leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae), is a xylophagous species that has become a serious pest in the olive (Olea spp.) orchards in Egypt. Both chemical and biological control have scored poorly against this pest and additional methods are needed. A simple, but efficient UV-light-pheromone sticky trap (“Hegazi model”) was devised for leopard moth mass trapping. Activity of leopard moth and efficiency of pheromone-baited, light, and pheromone and light traps were evaluated. The combination of light and sex pheromone was optimally attractive to leopard moth populations in olive orchards. A comparison between light traps baited with sex pheromone in mass-trapping method and conventional controls (insecticidal and physical removal of larvae) in heavily infested plots was carried out between 2002 and 2005. Leopard moths have long flight period, starting in mid-May and lasting until early November. Females of leopard moths were rarely trapped, but all had eggs. In mass-trapping plot, the seasonal captures and active galleries diminished from one year to the next, which may indicate the effectiveness of the method. From May 2003 to October 2005 greater reduction in total counts of active galleries was observed in mass-trapping plot compared with those recorded in the control field, in which chemical sprays and manual killing were performed. Yield from trees in mass-trapping field was significantly increased in comparison to control trees. The study strongly recommends the use of mass-trapping method instead of pesticides against the leopard moths, not only to control them but also to mass trap and monitor other lepidopterous pests of olive trees.
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Affiliation(s)
| | - W E Khafagi
- Plant Protection Research Institute, Alexandria, 21616 Egypt
| | - M Konstantopoulou
- Chemical Ecology and Natural Products Laboratory, NCSR “Demokritos”, Ag. Paraskevi, 15310, Athens, Greece
| | - D Raptopoulos
- Chemical Ecology and Natural Products Laboratory, NCSR “Demokritos”, Ag. Paraskevi, 15310, Athens, Greece
| | - H Tawfik
- Plant Protection Research Institute, Alexandria, 21616 Egypt
| | - G M Abd El-Aziz
- Plant Protection Research Institute, Alexandria, 21616 Egypt
| | | | - A Atwa
- Plant Protection Research Institute, Cairo, 5646 Egypt
| | - E Aggamy
- Faculty of Agriculture, Cairo University, 5415 Egypt
| | - S Showeil
- Plant Protection Research Institute, Alexandria, 21616 Egypt
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Abstract
Background External genital warts (EGWs, condylomata acuminata) are a common, highly contagious disease caused by human papillomavirus (HPV), predominantly HPV 6 and HPV 11. Green tea catechins have been identified for their immunostimulatory, antiproliferative and antitumour properties. Two phase III trials evaluated treatment of EGWs with ointment containing a mixture of green tea catechins (Polyphenon E), U.S. adopted name: sinecatechins). Objectives To obtain additional data on the efficacy and safety of Polyphenon E ointment in the treatment of EGWs from two randomized, double-blind, vehicle-controlled trials. Methods Men and women aged > or = 18 years (n = 1005), with two to 30 EGWs (12-600 mm(2) total area) applied vehicle (G(Veh); n = 207), Polyphenon E ointment 10% (G(10%); n = 401) or Polyphenon E ointment 15% (G(15%); n = 397) three times daily until complete clearance of all EGWs (baseline + new EGWs) or for a maximum of 16 weeks. Results A total of 1004 patients were evaluable for safety and 986 for efficacy; 838 completed treatment after 16 weeks. Complete clearance of all EGWs was obtained in 53.6% (G(10%)) and 54.9% (G(15%)) of patients with Polyphenon E vs. vehicle (35.4%) (P < 0.001). Statistically significant differences in clearance rates appeared after 6 weeks of active treatment. Odds ratios vs. G(Veh) for G(10%) [2.10; 95% confidence interval (CI) 1.49-2.98] and G(15%) (2.22; 95% CI 1.57-3.14) indicated about a twofold higher chance of complete clearance under active treatment. Time to complete clearance was shorter with active treatment (hazard ratios 1.57 and 1.87, respectively, for G(10%) and G(15%) vs. G(Veh) groups; P < 0.001). Recurrence rates during follow-up were low and similar across groups: 5.8%, 6.8% and 6.5% (G(Veh), G(10%) and G(15%) groups, respectively). Adverse events were evenly distributed across groups ( approximately 30% of patients). Severe local signs were more frequent but moderate in the active treatment groups (1.5%, 9.2% and 13.5% for G(Veh), G(10%) and G(15%) groups, respectively). Conclusions Polyphenon E ointment is effective and well tolerated in the treatment of EGWs.
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Affiliation(s)
- S Tatti
- The Hospital Clinicas, Universidad de Buenos Aires, Av. Cordoba 2351, Buenos Aires 1120, Argentina
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Patel M, Tawfik H, Myint Y, Brocklehurst D, Nicholson JW. Factors affecting the ability of dental cements to alter the pH of lactic acid solutions. J Oral Rehabil 2008. [DOI: 10.1111/j.1365-2842.2000.00607.x] [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: 11/28/2022]
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Stockfleth E, Beti H, Orasan R, Grigorian F, Mescheder A, Tawfik H, Thielert C. Topical Polyphenon®E in the treatment of external genital and perianal warts: a randomized controlled trial. Br J Dermatol 2008; 158:1329-38. [DOI: 10.1111/j.1365-2133.2008.08520.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Elghazaly H, Tawfik H, Mahrous M, Meshref MM, Sakr A, Haddad N. Vinorelbine and capecitabine combination as first-line treatment in patients with metastatic breast cancer: Final results of a multicentric trial in Egypt. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.1125] [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: 11/20/2022] Open
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Gross G, Meyer KG, Pres H, Thielert C, Tawfik H, Mescheder A. A randomized, double-blind, four-arm parallel-group, placebo-controlled Phase II/III study to investigate the clinical efficacy of two galenic formulations of Polyphenon E in the treatment of external genital warts. J Eur Acad Dermatol Venereol 2007; 21:1404-12. [PMID: 17958849 DOI: 10.1111/j.1468-3083.2007.02441.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Clinical efficacy and safety of Polyphenon(R) E, a defined green tea extract, in external genital warts. DESIGN Randomized, double-blind, placebo-controlled study for up to 12 weeks with a 12-week treatment-free follow-up. SETTING Twenty-eight hospitals and practices in Germany and Russia. PATIENTS Two hundred forty-two outpatients (125 men, 117 women) with 2 to 30 warts (total wart area, 12-600 mm(2)). Intervention(s) Topical application of Polyphenon E 10% Cream, Polyphenon E 15% Ointment or placebo to all external genital warts three times a day. MAIN OUTCOME MEASURE(S) Measurement of total wart area and local reactions/adverse events. RESULTS For 15% ointment, statistically significant differences to placebo were achieved regarding complete clearance of all baseline external genital warts (61.0% vs. 40.5% in males, 56.8% vs. 34.1% in females; combined gender: P = 0.0066) and 75% to 100% clearance (80.8% vs. 51.8%; P = 0.0001) in both the intent-to-treat and per-protocol populations. For 10% cream, 53.8% males and 39.5% females achieved complete clearance. Recurrence rates 12 weeks after end of treatment were 10.6%, 11.8% and 10.3% for 15% ointment, 10% cream and placebo, respectively. Adverse events were observed in only 7.9% of patients, with no serious adverse events or deaths reported. Local skin reactions were generally mild to moderate and resolved with continued treatment without sequelae. CONCLUSIONS Polyphenon(R) E 15% ointment, composed of a defined green tea extract, proved to be efficacious and safe for both gender in the treatment of external genital warts.
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Affiliation(s)
- G Gross
- Department of Dermatology and Venereology, University of Rostock, Rostock, Germany.
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Ghazali R, Hussain AJ, Liatsis P, Tawfik H. The application of ridge polynomial neural network to multi-step ahead financial time series prediction. Neural Comput Appl 2007. [DOI: 10.1007/s00521-007-0132-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abdel-Halim I, Sabri A, Tawfik H, Gasmi J. Pre-operative chemotherapy with navelbine (N) and anthracycline in locally advanced breast cancer (LABC): A multicentric Egyptian phase II trial. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)90850-6] [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: 11/29/2022] Open
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El-Salahy EM, Ahmed MI, El-Gharieb A, Tawfik H. New scope in angiogenesis: role of vascular endothelial growth factor (VEGF), NO, lipid peroxidation, and vitamin E in the pathophysiology of pre-eclampsia among Egyptian females. Clin Biochem 2001; 34:323-9. [PMID: 11440734 DOI: 10.1016/s0009-9120(01)00230-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [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: 11/19/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate the role of VEGF, NO, MDA, and Vitamin E in the pathophysiology of preeclampsia (PE) among Egyptian women. PATIENTS AND METHODS Our study included 20 pregnant women with mild PE, 40 pregnant women with severe PE, 20 normal control women and 20 normal control pregnant women. Plasma from all women were subjected to estimation of VEGF using ELISA kit, estimation of nitrates (as end product of NO) and MDA by chemical methods and measurement of Vitamin E using HPLC. RESULTS The obtained data from this study revealed that, VEGF may be used as a useful marker for PE which is elevated in plasma of women with PE (mild and severe) compared to controls. VEGF could differentiate between PE and controls at a cut-off value of: 70 ng/mL with a sensitivity of 95% and a specificity of 90%. Moreover, at a cut-off value of 250 ng/mL, VEGF could discriminate mild PE from severe PE with a sensitivity of 77.5% and a specificity of 85%. With respect to nitrate levels, they were significantly elevated in normal pregnant women compared with normal controls. Meanwhile, nitrate levels showed a highly significant decrease in PE in relation to both controls, explaining the vasoconstriction and high blood pressure occurring in preeclamptic women. Correlation analysis revealed significant inverse correlation between nitrate levels and VEGF. Lipid peroxidation as indicated by MDA was enhanced in preeclamptic women as compared to healthy controls. The increase in MDA levels was correlated to the severity of PE. A highly significant fall in vitamin E as an antioxidant-scavenging vitamin was seen in preeclamptic women as compared to the controls. Also, a significant drop in the vitamin level was found in severe PE in comparison to mild PE. The oxidant/antioxidant correlation was illustrated by the inverse correlation between vitamin E and MDA(r = -0.837, p = 0.000). CONCLUSION The findings from this study indicated that VEGF may be used as a clinically useful biomarker for PE for better diagnosis, to differentiate between mild and severe PE, and may also be a target for therapeutic intervention of PE. The increase in levels of VEGF together with reduction in NO levels could confirm the existence of vascular reactivity and endothelial disturbance in PE. The decrease in the vasodilator, NO may in part lead to the vasospasm of preeclampsia, which consequently produces hypoxia. The latter may be a cause of an elevation of VEGF (angiogenic factor) levels in PE. Meanwhile, elevated levels of lipid peroxides together with impaired antioxidant defense mechanisms may play a role in the etiology of PE.
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Affiliation(s)
- E M El-Salahy
- Oncology Diagnostic Unit, Biochemistry Department, Ain Shams Faculty of Medicine, Abbassia, Cairo, Egypt 11566.
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Abstract
Two related studies have been carried out to determine the effect of (a) powder:liquid ratio and (b) relative amounts of cement on the extent of buffering of a lactic acid storage solution using zinc polycarboxylate and glass-ionomer cements (both water-activated). The effect of varying the powder:liquid ratio was found to be slight and not statistically significant. On the other hand, increasing the numbers of specimens in a given volume of storage solution was found to have a significant influence on the final pH (at the 0.0005 level of significance). The fact that powder:liquid ratio did not affect the final pH led to the conclusion that attack occurs mainly at the matrix of these cements, confirming previous findings about the acid erosion process. The finding that increasing the relative amount of cement to acid storage solution strongly influenced pH suggested that, under clinical conditions, buffering would be important. When five specimens were used, the final pH corresponded to that of arrested caries, from which it was concluded that these cements have the ability to be cariostatic in vivo.
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Affiliation(s)
- M Patel
- Department of Dental Biomaterials Science, Guy's, King's, St Thomas' Dental Institute, King's College, London, UK
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Schlieper P, Tawfik H. Antiarrhythmic activity of alpha-tocopherol nicotinate and related compounds and their physico-chemical properties. Arzneimittelforschung 1987; 37:920-3. [PMID: 3675687] [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: 01/06/2023]
Abstract
The effect of alpha-tocopherol nicotinate (Renascin), alpha-tocopherol and dodecanoic acid (lauric acid) on the positive inotropic action of ouabain and digoxin and on cardiac glycoside induced arrhythmias has been tested in isolated guinea-pig left atria and in anaesthetized guinea-pigs. alpha-Tocopherol nicotinate and dodecanoic acid significantly decrease the positive inotropic action of digoxin, but not that of ouabain in isolated guinea-pig atria. Ouabain and digoxin induced arrhythmias are suppressed by the three compounds in isolated guinea-pig atria and in anaesthetized guinea-pigs: alpha-tocopherol nicotinate has the highest antiarrhythmic activity followed by dodecanoic acid and alpha-tocopherol. These results are further evidence for the dissociation between the positive inotropic and arrhythmogenic action of cardiac glycosides. The antiarrhythmic activity of the three compounds and the physico-chemical properties, as measured in liposomes, are compared with that of quinidine and aprindine. As nicotinic acid does not show any effect on cardiac glycoside induced arrhythmias, the ester linkage in alpha-tocopherol nicotinate seems to be of particular importance for its antiarrhythmic activity.
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Affiliation(s)
- P Schlieper
- Institut für Pharmakologie, Universität Düsseldorf, Fed. Rep. of Germany
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Schlieper P, Tawfik H. Comparative studies of cardiodepressant drugs on contraction dynamics and electrophysiological parameters of cardiac tissues at pH 7.4 and 9. J Pharm Pharmacol 1987; 39:517-21. [PMID: 2886619 DOI: 10.1111/j.2042-7158.1987.tb03169.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of propranolol, amethocaine (tetracaine), lignocaine (lidocaine), procaine and benzocaine on force of contraction and action potential parameters of guinea-pig left atria and papillary muscles have been investigated at pH 7.4 and 9. All the drugs decreased the force of contraction of both preparations. Their biological activities correlated with their lipid/buffer partition coefficients and with their ability to change the surface potential of liposomes. The sequence of activities is as follows: propranolol greater than amethocaine greater than lignocaine greater than benzocaine greater than procaine. Uncharged benzocaine had no effect on the liposome surface charge. Biological and physicochemical effects obtained at pH 9 were higher than those observed at pH 7.4. Action potential amplitude and Vmax were decreased by all the drugs except benzocaine. At pH 9, the action potential duration was generally shortened, except by amethocaine and procaine; both caused a prolongation of the action potential at 90% repolarization.
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Tawfik H, Greeff K, Schlieper P. Pharmacodynamic specification and membrane stabilising action of a homologous series of silasympathomimetics. Arzneimittelforschung 1986; 36:916-8. [PMID: 3741524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The pharmacodynamic effect of a homologous series of aminomethyldimethyl-(methoxyphenyl)-silane derivatives have been tested on isolated guinea-pig left atria. All molecules increase the force of contraction to different degrees by a partly direct and partly indirect mechanism (measured on atria isolated from reserpine treated guinea-pigs). The positive inotropic effect is reduced by bupranolol. Furthermore the compounds show an antagonistic effect to orciprenaline. The membrane stabilising action is lowest for those compounds showing the highest inotropic effects and vice versa.
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Abstract
In this study the pharmacological effects of seven semisynthetic cardenolides have been investigated and compared with those of 11 natural cardiac glycosides. These compounds are of different potency on electrically driven isolated guinea-pig atria. Their concentration response curves showed different slopes, which could be an indication of varying therapeutic range. The pharmacodynamics of these compounds on isolated guinea-pig atria are in good correlation with the data obtained from binding studies on guinea-pig ventricular homogenate as well as that obtained from comparative experiments on Na+,K+-ATPase activity inhibition.
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