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Rizk M, Belal F, Ibrahim F, Ahmed S, Sheribah ZA. LC of pharmaceutically important halogenated 8-hydroxyquinolines after precolumn derivatization with Pd (II). J Pharm Biomed Anal 2002; 27:813-20. [PMID: 11814722 DOI: 10.1016/s0731-7085(01)00504-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An accurate, sensitive, and selective reversed phase high performance liquid chromatographic (HPLC) method was developed for the analysis of two halogenated 8-hydroxyquinoline derivatives; clioquinol (CQN) and iodoquinol (IQN). The proposed method depends on the complexation ability of the studied compounds with Pd(II) ions. Reversed phase chromatography was conducted using a 300 x 3.9 mm i.d. stainless steel column packed with 10 microm Bondclone phenyl at ambient temperature. A solution containing 0.005% w/v of Pd(II)-chloride in a mixture of acetonitrile-methanol-water (3:3:4 v/v/v) of pH 3.7 as a mobile phase pumped at a flow rate of 0.75 ml min(-1). UV-detection was performed at 282 and 285 nm for CQN and IQN, respectively. The method showed excellent linearity in the range 0.05-1.8 and 0.1-3.0 microg ml(-1) with limit of detection (S/N=2) 4.8 ng ml(-1) (1.57 x 10(-8) M) and 6.4 ng ml(-1) (1.61 x 10(-8) M) for CQN and IQN, respectively. The suggested method was successfully applied for the analysis of the studied drugs in bulk with average% recoveries of 99.68+/-0.44 for CQN and 99.65+/-0.53 for IQN. The proposed method was successfully applied for the analysis of the studied drugs in single or combined dosage forms with average% recoveries of 99.41+/-0.51-100.02+/-0.63. The proposed method could be used successfully for the determination of the studied compounds in the presence of their degradation product as they could be eluted with different retention times. The presence of metronidazole (MNZ) or tolnaftate (TFT) with the studied drugs does not affect their accurate determination. The results obtained were favorably compared with those obtained by the reference method. The results were satisfactorily, accurate, and precise.
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Walash MI, Belal F, Ibrahim F, Hefnawy M, Eid M. LC determination of dinitrosopiperazine in simulated gastric juice. J Pharm Biomed Anal 2001; 26:1003-8. [PMID: 11600313 DOI: 10.1016/s0731-7085(01)00509-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A simple and specific reversed phase HPLC method for the determination of dinitrosopiperazine in simulated gastric juice using UV detection was reported. The chromatographic resolution of the analyte and the internal standard isosorbide dinitrate was performed without extraction from the gastric juice on a reversed phase ODS column. Isocratic elution was carried out with methanol-0.02 M sodium dihydrogen phosphate (60:40 v/v, pH 3.0) at a flow rate of 1.0 ml min(-1) with UV detection at 238 nm. The calibration graph was linear over the concentration range 0.072-2.88 microg ml(-1) of dinitrosopiperazine with minimum detectability (S/N=2) of 0.01 microg ml(-1) (8 x 10(-8) M). Inter-day and intra-day precisions calculated as % RSD were in the range 0.32-0.38% and 0.19-0.25% respectively. Inter-day and intra-day accuracies calculated as % error were in the range 0.18-0.21 and 0.08-0.11% respectively. The proposed method was successfully applied to the study of the possible in-vivo production of DNPZ under the standard nitrosation conditions recommended by WHO.
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Rizk M, Belal F, Ibrahim F, Ahmed S, el-Enany NM. Voltammetric determination of praziquantel in tablets and biological fluids. ARZNEIMITTEL-FORSCHUNG 2001; 51:673-8. [PMID: 11556129 DOI: 10.1055/s-0031-1300099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A simple method is described for the determination of praziquantel (CAS 55268-74-1) in its pure form, tablet formulations and biological fluids. The proposed method depends upon the polarographic activity of praziquantel at the dropping mercury electrode (DME) in Britton Robinson buffers, whereby a well-defined catholic wave is produced over the pH range 7-12. The wave was characterized as being irreversible diffusion-controlled with limited adsorption properties. The diffusion current constant (Id) was 0.56 +/- 0.004 (n = 11). The current-concentration relationship was found to be rectilinear over the range 8-48, 3.2-38.4 and 0.48-20 micrograms.ml-1 using direct current (DCt), differential pulse polarographic (DPP) and alternating current (ACt) odes, respectively, with minimum detection limit (S/N = 2) of 0.32 microgram.ml-1 (1.02 x 10(-6) mol/l and 0.02 microgram.ml-1 (6.4 x 10(-8) mol/l) for DPP and ACt modes respectively. The average percent recovery was favourably compared to a reference method with a satisfactory standard deviation. The proposed method was applied to spiked human urine and plasma. The percentage recoveries were 99.33 +/- 0.79 and 98.23 +/- 0.53, respectively.
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Rizk M, Belal F, Ibrahim F, Ahmed S, Sheribah ZA. Derivative spectrophotometric analysis of 4-quinolone antibacterials in formulations and spiked biological fluids by their Cu(II) complexes. J AOAC Int 2001; 84:368-75. [PMID: 11324600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A derivative UV-spectrophotometric analytical procedure was developed for determination of three 4-quinolone antibacterials: norfloxacin (NFX), ciprofloxacin (CFX), and sparfloxacin (SFX). The method depends on the complexation of Cu(II) with the studied compounds in aqueous medium. A third order, measurement was applied for their quantification. A linear correlation was established between the amplitude of the peak and concentration for all the studied drugs in the range of 15-80, 35-120, and 200-700 ng/mL, with minimum detectability (S/N = 2) of 1.0, 1.3, and 5.1 ng/mL for NFX, CFX, and SFX, respectively. The method was successfully applied for accurate, sensitive, and selective determination of the studied drugs in bulk and tablets formulation with average percentage recoveries of 99.22 +/- 0.55 to 100.33 +/- 1.60. The results obtained were favorably compared with those of the reference method. The method was also used to determine sparfloxacin in spiked human plasma and urine. The results obtained were satisfactory, accurate, and precise.
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Rizk M, Belal F, Ibrahim F, Ahmed S, El-Enany NM. Voltammetric analysis of certain 4-quinolones in pharmaceuticals and biological fluids. J Pharm Biomed Anal 2000; 24:211-8. [PMID: 11130200 DOI: 10.1016/s0731-7085(00)00401-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The voltammetric behaviour of Enrofloxacin (I), Sparfloxacin (II) and Fleroxacin (III) was studied using direct current (DCt), differential pulse (DPP) and alternating current (ACt). All the drugs manifest cathodic waves in Britton Robinson buffer over the pH range of 4.0-11.98. The waves were characterized as being irreversible, diffusion-controlled with limited adsorption properties. The diffusion current concentration relationships were found to be rectilinear over the ranges 4 x 10(-5) x 10(-4) M, 1 x 10(-5)-2 x 10(-4) M, 1 x 10(-5)-4 x 10(-4) M using DCt mode for I, II and III, respectively and 1 x 10(-6)-4 x 10(-5) M, 1 x 10(-6)-1 x 10(-4) M, and 2 x 10(-6)-8 x 10(-5) M, using DPP mode for I, II and III respectively, with minimum detectability (S/N = 3) of 1 x 10(-7) M for I, II and 2 x 10(-7) M for III. The proposed method was successfully applied to the determination of the studied compounds either per se or in formulations and biological fluids. The results obtained were concordant to those given using reference methods.
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Belal F, Walash MI, Ibrahim F, Hefnawy M, Eid M. Voltammetric determination of N,N'-dinitrosopiperazine in simulated gastric juice. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2000; 55:694-9. [PMID: 11204944 DOI: 10.1016/s0014-827x(00)00093-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A voltammetric method has been developed for the determination of N,N'-dinitrosopiperazine (DNPZ) in simulated gastric juice. The method is based on measuring the differential pulse polarographic peak produced in pH 3 Britton Robinson buffer. A well defined, diffusion-controlled cathodic wave was obtained at -0.77 V versus Ag/AgCl over the range 0.4-24 microg/ml with minimum detectability (S/N = 2) of 0.072 microg/ml (5 x 10(-7) M). The proposed method was successfully applied to study the possible in vivo production of the nitroso-derivatives of piperazine under the standard nitrosation reaction conditions recommended by WHO. The method has some distinct advantages over the reported GC methods.
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Rizk M, Belal F, Ibrahim F, Ahmed SM, El-Enany NM. A simple kinetic spectrophotometric method for the determination of oxamniquine in formulations and spiked biological fluids. J Pharm Biomed Anal 2000; 23:503-13. [PMID: 10933544 DOI: 10.1016/s0731-7085(00)00320-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A simple and sensitive kinetic method for the determination of oxamniquine in pharmaceutical preparations and biological fluids was developed. The procedure is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time of 20 min. The absorbance of the colored manganate ions was measured at 610 nm. Alternatively, the decrease in the absorbance of potassium permanganate after addition of the drug was measured at 525 nm. The absorbance concentration plots in both procedures were rectilinear over the range 0.5-4 microg ml(-1). The concentration of oxamniquine is calculated using the corresponding calibration equation for the fixed-time method. The determination of oxamniquine by fixed-concentration and rate-constant methods was feasible with the calibration equations obtained but the fixed time method had been found to be more applicable. Both procedures were applied to the determination of oxamniquine in formulations. The results obtained were in good agreement with those obtained using the official method. The fixed time method of 20 min was further applied to spiked human urine and plasma, the recoveries (%) were 100.94 +/- 0.57 and 98.07 +/- 0.88 for urine and plasma, respectively, at 610 nm, and 97.51 +/- 1.27 and 95.69 +/- 1.23 for urine and plasma, respectively, at 525 nm.
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Rizk M, Belal F, Ibrahim F, Ahmed SM, El-Enany NM. A Simple Kinetic Spectrophotometric Method For The Determination of Certain 4-Quinolones in Drug Formulations. Sci Pharm 2000. [DOI: 10.3797/scipharm.aut-00-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An accurate simple and selective kinetic procedure for the determination of certain 4-quinolones namely, norfloxacin (I), ofloxacin (II), enrofloxacin (III), fleroxacin (IV), ciprofloxacin (V) and pefloxacin (VI) is described. The procedure is based on reacting the studied compounds in acidic media (0.1 M HCL) with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in presence of cerium (IV) ammonium sulphate as an oxidant at room temperature for a fixed time of 20 min. for (I), (III), 12 min for (II) and 30 min for IV , V and VI, then the absorbance of the reaction product is measured at 630 nm. The concentration of the studied compounds is computed using the corresponding calibration curve equation for the fixed-time method. The absorbance-concentrations plot is rectilinear over the range 20-100 ug.ml-1 for (I), 2 - 20 ug.ml-1 for (II), 10 - 74 ug.ml-1 for (III), 10 - 60 ug.ml-1 for IV, 10 - 50 ug.ml-1 for IV and 8 - 40 ug.ml-1 for VI. The determination of the studied compounds by the fixed-concentration and rate constant methods is feasible with the calibration equation obtained, but the fixed-time method proved to be more applicable. The procedure was applied successfully to commercial tablets and ampoules and the results obtained were compared statistically with the reference methods.
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109
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Rizk M, Belal F, Ibrahim F, Ahmed S, el-Enany N. Spectrofluorimetric analysis of certain 4-quinolone in pharmaceuticals and biological fluids. PHARMACEUTICA ACTA HELVETIAE 2000; 74:371-7. [PMID: 10812936 DOI: 10.1016/s0031-6865(00)00025-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A highly sensitive spectrofluorimetric procedure is developed for the analysis of certain 4-quinolone antibiotics: sparfloxacin (I), oxolonic acid (II), flumequine (III) and enrofloxacin (IV) in their pharmaceutical dosage forms or in biological fluids. This procedure is based upon the intrinsic fluorescence in acetonitrile for sparfloxacin or upon the highly enhanced fluorescence obtained by the interaction of the drugs with AlCl3. The optimum pH for the maximum fluorescence intensity is 8-8.5 for I, 5-6 for II, III and pH 3.5 for IV. The different experimental parameters that affect the fluorescence intensity were carefully studied and incorporated into the procedure.
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110
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Dahniya MH, Hanna RM, Grexa E, Cherian MJ, Niazy MN, Badr S, Ibrahim F, al-Othman AN. Percutaneous drainage of tuberculous iliopsoas abscesses under image guidance. AUSTRALASIAN RADIOLOGY 1999; 43:444-7. [PMID: 10901956 DOI: 10.1046/j.1440-1673.1999.00709.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most intra-abdominal and other types of fluid collections are now successfully drained percutaneously under image guidance. The utility of percutaneous drainage of tuberculous abscesses, especially those associated with osseous changes, is, however, less well established. Six patients with tuberculous iliopsoas abscesses were successfully managed by percutaneous drainage combined with antituberculous therapy. The abscesses were bilateral in one patient and unilateral in the other five. Drainage was by needle aspiration under ultrasound (US) guidance in one patient, and by catheter under CT guidance in the other patients. Three patients had associated osseous changes. There were no procedural complications. Tuberculous iliopsoas abscess can be successfully treated by percutaneous drainage and appropriate antituberculous therapy.
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Rizk M, Belal F, Ibrahim F, Ahmed SM, el-Enany NM. Fluorimetric determination of oxamniquine in biological fluids. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 1999; 54:47-50. [PMID: 10321028 DOI: 10.1016/s0014-827x(98)00091-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A highly sensitive and specific fluorimetric method was developed for the determination of oxamniquine in biological fluids (urine and plasma). The proposed method is based on the reduction of oxamniquine using zinc/calcium chloride to obtain its nitroso derivative. The latter is then allowed to react with 2-cyanoacetamide to get a highly fluorescent product. The different experimental parameters affecting the intensity of the fluorescence were carefully studied and incorporated into the procedure. Under the described conditions, the method is applicable over the concentration range of 0.08-0.88 microgram/ml with a minimum detectability (S/N = 2) of 8 ng/ml. The percentage recoveries from spiked urine and plasma were 99.75 +/- 1.58 and 97.46 +/- 0.44%, respectively.
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112
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el-Nawawy A, Soliman T, el-Azzouni O, Abbassy AA, Massoud MN, Marzouk S, Ibrahim F, Helal L. Interleukin-1-beta, tumor necrosis factor-alpha, insulin secretion and oral glucose tolerance in non-diabetic siblings of children with IDDM. Indian J Pediatr 1998; 65:455-60. [PMID: 10771998 DOI: 10.1007/bf02761143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Recent reports suggest that the pancreas participates in tumor necrosis factor alpha (TNF-A) production during stress, and that the islets are predominantly responsible for such synthesis. In vitro TNF-A and interleukin 1-beta (IL-1-beta) inhibit insulin release from islet beta-cells. We measured the circulating levels of IL-1-beta, TNF-A and islet cell antibody (ICA) in 30 children with IDDM (10 of them at their first presentation), 30 of their non-diabetic siblings, and 30 normal age-matched children. In the non-diabetic children we investigated the early phase of insulin release after intravenous bolus of glucose and evaluated tolerance to oral glucose (OGTT). IL-1-beta and TNF-A concentrations were significantly higher in IDDM-siblings (31.8 +/- 7.7 pg/ml and 650 +/- 155 pg/ml respectively) versus normal children (21.2 +/- 6.4 pg/ml and 383 +/- 122 pg/ml respectively). IL-1-beta and TNF-A concentrations did not differ significantly between the diabetic children and healthy age-matched controls. ICA were detected in 60% of the recently diagnosed diabetic children vs. 30% of those with longer duration of diabetes (3.1 +/- 1.2 years). Despite the significantly high prevalence of ICA in the recently diagnosed children with IDDM, their IL-1-beta and TNF-A concentrations were lower than those for the normal children. In experimental animals these cytokines can induce round cell infiltration (insulinitis) and inhibit insulin secretion by beta-cell. The presence of significantly higher concentrations of these cytokines in IDDM siblings, with high prevalence of ICA (16%), was associated with normal oral glucose tolerance and normal peak insulin response (60 +/- 10.4 mlU/ml) after i.v. glucose bolus compared to normal children (52.3 +/- 9.5 mlU/ml). However, after 2 years of follow up, one of them developed IDDM and another developed IGT but none of the normal controls developed abnormal glucose tolerance. It appears that the process of autoimmune aggression against beta-cells, and its effect on insulin release and glucose homeostasis, is a slow and chronic process. However, the production of these cytokines and consequently the degree of beta-cell destruction, in a genetically susceptible subject, might be enhanced by several factors including viral infections. In summary, IL-1-beta and TNF-A levels can be used as indicators of continuing autoimmune aggression against beta-cells before the development of extensive beta-cell destruction.
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Kazanji M, Ibrahim F, Fiette L, Bomford R, De Thé G. Role of the genetic background of rats in infection by HTLV-I and HTLV-II and in the development of associated diseases. Int J Cancer 1997; 73:131-6. [PMID: 9334820 DOI: 10.1002/(sici)1097-0215(19970926)73:1<131::aid-ijc20>3.0.co;2-i] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three aspects of the rat model of HTLV-I/II infection were investigated. (i) The efficacy of HTLV-I-transformed rat cell lines in infecting different strains of rats: WKY and Lewis HTLV-I-transformed cell lines were injected into adult WKY, Lewis and Brown Norway rats, representing syngeneic and allogeneic combinations. The HTLV-I provirus was not detected in peripheral-blood mononuclear cells (PBMC) from these rats 18 weeks after inoculation, showing that HTLV-I-transformed rat cells are not suitable for virus challenge in vaccination experiments. Rats inoculated with Lewis HTLV-I-transformed cells produced an antibody response to HTLV-I, which was higher in allogeneic (WKY and Brown Norway) than in syngeneic rats. (ii) The susceptibility of rats to HTLV-II infection: After human HTLV-II-producing cells (MO) were injected into adult WKY rats, the HTLV-II provirus was detected in PBMC 12 weeks later. Sequencing of a portion of this provirus confirmed its identity with the HTLV-II from MO cells. (iii) The role of MHC haplotype in susceptibility to neurological disease in rats inoculated as newborns with HTLV-I: The hypothesis that the RT-Ik haplotype confers susceptibility was tested by inoculating newborn OKA (RT-Ik), WKY (RT-Il), Lewis (RT-Il) and Fischer 344 (RT-I lvl) rats with human HTLV-I-producing cells (MT-2). Eighteen months later, only the WKY rats showed histological abnormality of the spinal cord, without clinical paralysis. Fischer 344 rats developed cutaneous tumors and OKA rats mammary tumors. The HTLV-I provirus was not detected in these tumors.
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Mahieux R, Ibrahim F, Mauclere P, Herve V, Michel P, Tekaia F, Chappey C, Garin B, Van Der Ryst E, Guillemain B, Ledru E, Delaporte E, de The G, Gessain A. Molecular epidemiology of 58 new African human T-cell leukemia virus type 1 (HTLV-1) strains: identification of a new and distinct HTLV-1 molecular subtype in Central Africa and in Pygmies. J Virol 1997; 71:1317-33. [PMID: 8995656 PMCID: PMC191187 DOI: 10.1128/jvi.71.2.1317-1333.1997] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To gain new insights on the origin, evolution, and modes of dissemination of human T-cell leukemia virus type I (HTLV-1), we performed a molecular analysis of 58 new African HTLV-1 strains (18 from West Africa, 36 from Central Africa, and 4 from South Africa) originating from 13 countries. Of particular interest were eight strains from Pygmies of remote areas of Cameroon and the Central African Republic (CAR), considered to be the oldest inhabitants of these regions. Eight long-term activated T-cell lines producing HTLV-1 gag and env antigens were established from peripheral blood mononuclear cell cultures of HTLV-1 seropositive individuals, including three from Pygmies. A fragment of the env gene encompassing most of the gp21 transmembrane region was sequenced for the 58 new strains, while the complete long terminal repeat (LTR) region was sequenced for 9 strains, including 4 from Pygmies. Comparative sequence analyses and phylogenetic studies performed on both the env and LTR regions by the neighbor-joining and DNA parsimony methods demonstrated that all 22 strains from West and South Africa belong to the widespread cosmopolitan subtype (also called HTLV-1 subtype A). Within or alongside the previously described Zairian cluster (HTLV-1 subtype B), we discovered a number of new HTLV-1 variants forming different subgroups corresponding mainly to the geographical origins of the infected persons, Cameroon, Gabon, and Zaire. Six of the eight Pygmy strains clustered together within this Central African subtype, suggesting a common origin. Furthermore, three new strains (two originating from Pygmies from Cameroon and the CAR, respectively, and one from a Gabonese individual) were particularly divergent and formed a distinct new phylogenetic cluster, characterized by specific mutations and occupying in most analyses a unique phylogenetic position between the large Central African genotype (HTLV-1 subtype B) and the Melanesian subtype (HTLV-1 subtype C). We have tentatively named this new HTLV-1 genotype HTLV-1 subtype D. While the HTLV-1 subtype D strains were not closely related to any known African strain of simian T-cell leukemia virus type 1 (STLV-1), other Pygmy strains and some of the new Cameroonian and Gabonese HTLV-1 strains were very similar (>98% nucleotide identity) to chimpanzee STLV-1 strains, reinforcing the hypothesis of interspecies transmission between humans and monkeys in Central Africa.
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el Nawawy A, Soliman AT, el Azzouni O, Abbassy AA, Massoud MN, Marzouk S, Ibrahim F, Helal L. Interleukin-1-beta, tumour necrosis factor-alpha, islet-cell antibody, and insulin secretion in children with thalassemia major on long-term blood transfusion. J Trop Pediatr 1996; 42:362-4. [PMID: 9009565 DOI: 10.1093/tropej/42.6.362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In vitro, cytokines like interleukin-1-beta (IL-1-B) and tumour necrosis factor-alpha (TNF-A) inhibit insulin release and can destroy islet B-cells. We measured blood levels of IL-1-B, TNF-A, and islet cell antibody (ICA) in 20 children with IDDM, 20 of their non-diabetic siblings, 20 children with thalassemia major on long-term hypertransfusion therapy and iron chelation, and 10 normal age-matched children. In the non-diabetic and thalassemic children we investigated the early phase of insulin release after i.v. glucose (0.5 g/kg, 30 per cent solution) and evaluated tolerance to oral glucose (1.75 g/ kg). Circulating IL-1-B and TNF-A concentrations were significantly higher in IDDM-siblings (33.7 +/- 12.7 pg/ml and 655 +/- 165 pg/ml, respectively) v. normal children (21.1 +/- 6.4 pg/ml and 383 +/- 122 pg/ml, respectively). Thalassemic children had no detectable circulating ICA. The prevalence of ICA was 30 per cent in children with IDDM and 60 per cent of their siblings. Impaired oral glucose tolerance was detected in five children with thalassemia (25 per cent), but in none of the IDDM-siblings. The early phase of insulin release was significantly depressed in thalassemic children (peak insulin = 29.2 +/- 5.1 mIU/ml) v. normal children (52.3 +/- 9.5 mIU/ml) and IDDM-siblings (45.3 +/- 12.4 mIU/ml). It appears that thalassemic children had significantly decreased insulin secretion and impaired glucose tolerance, however, the mechanism of B-cell dysfunction is not mediated by ICA nor by cytokines.
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Ibrahim F, Hojman D, Kreiner AJ, Roussière B, Sauvage J, Bourgeois C, Korichi A, Davidson J, Davidson M, Debray M, Deloncle I, Knipper A, Marguier G, Oms J, Perrin N, Porquet MG, Sergolle H, Somacal H. Rotational high spin structures in doubly-odd 184Au. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 53:1547-1556. [PMID: 9971101 DOI: 10.1103/physrevc.53.1547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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117
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Ibrahim F, de Thé G, Gessain A. Isolation and characterization of a new simian T-cell leukemia virus type 1 from naturally infected celebes macaques (Macaca tonkeana): complete nucleotide sequence and phylogenetic relationship with the Australo-Melanesian human T-cell leukemia virus type 1. J Virol 1995; 69:6980-93. [PMID: 7474117 PMCID: PMC189617 DOI: 10.1128/jvi.69.11.6980-6993.1995] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A study of simian T-cell leukemia virus type 1 (STLV-1) infection in a captive colony of 23 Macaca tonkeana macaques indicated that 17 animals had high human T-cell leukemia virus type 1 (HTLV-1) antibody titers. Genealogical analysis suggested mainly a mother-to-offspring transmission of this STLV-1. Three long-term T-cell lines, established from peripheral blood mononuclear cell cultures from three STLV-1-seropositive monkeys, produced HTLV-1 Gag and Env antigens and retroviral particles. The first complete nucleotide sequence of an STLV-1 (9,025 bp), obtained for one of these isolates, indicated an overall genetic organization similar to that of HTLV-1 but with a nucleotide variability for the structural genes ranging from 7.8 to 13.1% compared with the HTLV-1 ATK and STLV-1 PTM3 Asian prototypes. The Tax and Rex regulatory proteins were well conserved, while the pX region, known to encode new proteins in HTLV-1 (open reading frames I and II), was more divergent than that in the ATK strain. Furthermore, a fragment of 522 bp of the gp21 env gene from uncultured peripheral blood mononuclear cell DNAs from five of the STLV-1-infected monkeys was sequenced. Phylogenetic trees constructed with the long terminal repeat and env (gp46 and gp21) regions demonstrated that this new STLV-1 occupies a unique position within the Asian STLV-1 and HTLV-1 isolates, being, by most analyses, related more to the Australo-Melanesian HTLV-1 topotype than to any other Asian STLV-1. These data raise new hypotheses on the possible interspecies viral transmission between monkeys carrying STLV-1 and early Australoid settlers, ancestors of the present day Australo-Melanesian inhabitants, during their migrations from the Southeast Asian land mass to the greater Australian continent.
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Abstract
In order to demonstrate the presence of Helicobacter pylori in the metaplastic epithelium of Barrett's oesophagus and to evaluate its possible association with this entity, we examined 29 cases of Barrett's oesophagus where concomitant antral biopsies were also available. These cases were compared with an equal number of age and sex matched controls of uncomplicated reflux oesophagitis. H. pylori was present in 11 of 29 cases of Barrett's oesophagus (38%). No increase in the frequency of H. pylori antral gastritis was found in patients of Barrett's oesophagus compared to the control group of uncomplicated reflux oesophagitis. The positivity of Barrett's oesophagus for H. pylori correlated with the presence of H. pylori antral gastritis (P < 0.05), although in two cases of H. pylori-positive Barrett's oesophagus antral biopsies were negative for H. pylori. No difference was found in the severity of inflammatory and dysplastic changes of H. pylori-positive and H. pylori-negative Barrett's oesophagus. Presence of H. pylori does not seem to alter the natural history of Barrett's oesophagus.
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119
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Ibrahim F, Fiette L, Gessain A, Buisson N, de-Thé G, Bomford R. Infection of rats with human T-cell leukemia virus type-I: susceptibility of inbred strains, antibody response and provirus location. Int J Cancer 1994; 58:446-51. [PMID: 8050826 DOI: 10.1002/ijc.2910580324] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The susceptibilities of different strains of inbred rats to infection with the human T-cell leukemia virus (HTLV-I) after inoculation of human HTLV-I producer cell lines were compared. The Fisher F344 and Brown Norway strains developed the highest antibody response to HTLV-I, while the Lewis and BB strains were low responders. Antibodies against the HTLV-I gag proteins, and env gp21 but not env gp46, were detected in Western blots with sera from HTLV-I-infected Fischer F344 and Brown Norway rats. These sera were inactive in an in vitro syncytium-formation inhibition test. The HTLV-I provirus was detected by polymerase chain reaction in all Fischer F344, and some Lewis and Brown Norway rats, but not in the BB, which lack CD8+ T lymphocytes. The most frequent locations of the HTLV-I provirus in the Fischer F344, Lewis and Brown Norway rats at 12 weeks after infection were the peripheral blood mononuclear cells (PBMC) and spinal cord. In a second experiment in Brown Norway rats, the provirus was again detected in the PBMC of rats at 12 weeks, but not at 22 weeks, and among the other organs tested at 22 weeks the sympathetic nerve ganglia were positive. It is concluded that HTLV-I infection occurs in adult rats, but is suppressed with time.
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Abstract
Thirty-two patients with 35 ureteric injuries encountered during gynaecological surgery are presented. Their mean age was 41 years. Eight ureteric injuries were recognized during surgery, the nature and sites of injury were diagnosed peroperatively using an illuminated size 5 F ureteric probe (Storz) passed through a cystoscope. Three ureteric injuries were diagnosed during convalescence as continuous drainage of urine or urinoma collection, while three patients developed total anuria due to ligation of both ureters. Eighteen patients presented with late urinary fistulae, being uretero-uterine in 8 and ureterovaginal in 10. The ureteric injury occurred during emergency Caesarean section in 15 patients, the indication for Caesarean section being obstructed prolonged labour in 70% of them. Twelve urinary fistulae followed hysterectomy. Intravenous urography, antegrade and retrograde ureterography were useful methods of locating the sites of the fistulae. Ureteroneocystostomy was performed in 18 patients, utilizing a Boari flap in 3 and a bladder psoas hitch in 2. Other methods of treatment are discussed. The mean follow-up was 3 years.
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Díaz-Berenguer JA, Ibrahim F. [Evaluation of a rapid technique for detecting the type A Streptococcus antigen (Test Pack Strep A)]. Aten Primaria 1992; 9:245-9. [PMID: 1498218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE To test a rapid technique of Antigen Detection (TAD) of Type A Betahemolitic Streptococci (BHSA) in Acute Tonsillitis (AT), comparing it with and using as a point of reference traditional Blood Agar Cultivation (BAC). Additionally, the use of Clinical Data as a method of supposed Diagnosis was studied. DESIGN Prospective observational study. SITE. Health Primary Care (Maspalomas Health Centre). PATIENTS AND OTHER PARTICIPANTS 118 patients between the ages of 1 and 71 affected by AT. MEASUREMENTS AND MAIN RESULTS There was a proportion of 13.56% BHSA in the AT of our sample, with a Confidence Interval (CI) of 95% (7.38-19.74) using the BAC; and 17.80% with a CI of 95% (10.90-24.70) using the TAD. The following values were obtained for the TAD: Sensitivity (S) of 93.75%, Specificity (Sp) of 94.12%, Positive Predictive Value (PPV) of 71.43% and Negative Predictive Value (NPV) of 98.9%. Of the clinical variables studied, only the presence/absence of Exudate and Adenopathies were linked to the presence of BHSA in the Cultivations (p less than 0.05 and p less than 0.01 respectively); with, however, inconclusive S, Sp, PPV and PNV values. CONCLUSIONS We found insufficient correlation between clinical findings and the presence of BHSA to consider it a valid method of supposed diagnosis. There was however a statistical link between the presence of Exudate and local Adenopathies, and a positive result in the cultivation. The TAD is shown to be a rapid method, easy to use, and highly reliable for the discovery of the presence of BHSA in AT.
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Belal F, Ibrahim F, El-Din MS, Taras MFE. N,N-dibromodiethylbarbituric acid as an analytical reagent. Part 1. Determination of some pharmaceutically important hydrazine derivatives. Analyst 1991. [DOI: 10.1039/an9911601085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ibrahim F, Belal F, Hassan SM, Aly FA. Spectrophotometric determination of some MAO inhibitors using 7,7,8,8-tetracyanoquinodimethane and iodine monochloride. J Pharm Biomed Anal 1991; 9:101-7. [PMID: 1873301 DOI: 10.1016/0731-7085(91)80132-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two simple and sensitive spectrophotometric methods are described for the assay of three MAO inhibitors: isocarboxazid, tranylcypromine sulphate and iproniazid phosphate. The first method is based on the formation of a highly coloured stable radical anion between the drug as an n-donor and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a pi-electron acceptor. Beer's law is obeyed in the concentration range 0.2-3, 0.2-4 and 0.5-4 micrograms ml-1 for isocarboxazid, tranylcypromine sulphate and iproniazid phosphate, respectively. The second method involves the use of iodine monochloride (ICl) as an sigma-acceptor. It was found that ICl reacts quantitatively only with isocarboxazid and tranylcypromine sulphate; with iproniazid phosphate results were very poor. Beer's law is obeyed in the concentration range 2-20 micrograms ml-1 for both drugs. The optimum experimental parameters for colour production in each case were determined. The percentage recoveries obtained were in accordance with those obtained by the official methods. The proposed methods are characterized by high sensitivity.
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Belal F, Ibrahim F, El-Brashy A. Bromometric determination of some pharmaceutically important antimony(III) compounds. Microchem J 1990. [DOI: 10.1016/0026-265x(90)90138-u] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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