Green inhibitor of carbon steel corrosion in 1 M hydrochloric acid: Eruca sativa seed extract (experimental and theoretical studies).

The adsorption activity and inhibition effect of Eruca sativa seed extract as a green inhibitor for the dissolution of carbon steel in 1 M hydrochloric acid solution were investigated. In this study, we used a chemical technique (gravimetric method), electrochemical techniques, electrical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques, and theoretical studies. In addition to these techniques, we examined the surface morphology of the carbon steel utilizing different methods. The measurements of the polarization technique indicate that this extract acts as a mixed-type inhibitor. Thermodynamic parameters were calculated and discussed. The adsorption of Eruca sativa seed extracts on the alloy obeys the Langmuir and Henry adsorption isotherms. The extract gives an excellent inhibition efficiency 94.8% by a gravimetric method at 0.3 g L-1 from the extract. The relationship between the calculated % IE from experiments and the theoretical studies was established.

Production of monoclonal antibodies against Rift Valley fever virus Application for rapid diagnosis tests (virus detection and ELISA) in human sera.

This paper describes the production and characterization of RVFV monoclonal antibodies. The characteristics of 32 out of 55 ELISA and/or IFA positive monoclonal antibodies were determined, including the RVFV components against which they are directed. One monoclonal antibody recognized the nucleoprotein, 15 the Gc and 16 the Gn. Among the latter ones, five monoclonal antibodies possess another specificity and recognized both Gn and either the nucleoprotein (four of them) or the NSs protein (one). To validate the use of these monoclonal antibodies for diagnosis tests, a pool of monoclonal antibodies reacting with the structural proteins was prepared and used successfully to detect RVFV from cell culture as well as viral antigen-antibody complex in ELISA.

Complete coding sequence of the Alkhurma virus, a tick-borne flavivirus causing severe hemorrhagic fever in humans in Saudi Arabia.

To date, tick-borne flaviviruses responsible for hemorrhagic fever in humans have been isolated in Siberia (Omsk hemorrhagic fever virus), India (Kyasanur Forest disease virus, KFDV), and in Saudi Arabia (Alkhurma virus, ALKV). Prior to this study, only partial coding sequences of these severe pathogens had been determined. We report here the complete coding sequence of ALK virus, which was determined to be 10,248 nucleotides (nt) long, and to encode a single 3,416 amino acid polyprotein. Independent analyses of the complete polyprotein and the envelope protein provided genetic and phylogenetic evidence that ALKV belongs to the tick-borne flavivirus group, within which it is most closely related to KFDV. Analysis of structural genes, genetic distances, and evolutionary relationship indicate that ALKV and KFDV derived from a common phylogenetic ancestor and constitute two genetic subtypes of the same virus species according to current genetic criteria of classification.

Virologic and serologic surveillance for dengue fever in Jeddah, Saudi Arabia, 1994-1999.

Dengue fever infection was first documented in Jeddah, Saudi Arabia, by virus isolation of dengue type 2 virus in 1994 at the virology laboratory of Dr. Soliman Fakeeh Hospital. Dengue virus surveillance was established after that time. Blood samples were collected from 985 patients (710 male patients and 275 female patients) with suspected cases of dengue from February 1994 to December 1999. Dengue virus isolates were obtained in 207 patients (21%; 162 male patients and 45 female patients). Dengue type 2 was the predominant serotype (138 of 207 isolates, 66.7%), followed by dengue type 1 with (56 of 207 isolates, 27%) and dengue type 3 (13 of 207 isolates, 6.3%). The largest number of isolates (186 of 207 isolates, 90%) was in 1994, a year during which there was a dengue epidemic. In the next 5 years, 1995-1999, only 21 isolates (10%) were isolated. Immunoglobulin M capture enzyme-linked immunosorbent assay was positive in 160 acute samples; 52 of them were from virus culture-positive cases and 108 (11%) from culture-negative cases. The total number of cases diagnosed by both methods was 315 (32%). The prevalence of dengue immunoglobulin G antibodies, as assessed on the basis of immunofluorescent assay, hemagglutination inhibition titers > or = 1/20, or both, in the acute samples was 314 (32%) of 985, indicating past Flavivirus infection. Two patients died, one man with dengue hemorrhagic fever and one woman with dengue shock syndrome. Both fatal dengue cases were due to infection with type 2 virus. All other cases were simple dengue fever. To our knowledge, this is the first report confirming the circulation of 3 dengue serotypes in Jeddah.

Hepatitis C: prevalence and common genotypes among ethnic groups in Jeddah, Saudi Arabia.

The presence of antibodies to hepatitis C virus (HCV) was examined using a third-generation ELISA in 3,350 serum samples obtained from patients visiting different outpatient clinics, preoperative patients, and women visiting for ante-natal care at the Dr. Fakeeh hospital in Jeddah, Saudi Arabia from January to September 1998. The population included mainly Saudis, Egyptians, and Yemenis, and patients from other Middle East and Asian countries. The prevalence of HCV infection was 5.87% among Saudis, 22.54% among Egyptians, and 2.12% among Yemenis. The prevalence among patients from other Middle East and Asian countries were 3.38% and 4.98%, respectively. The overall prevalence among the studied group was 6.75%. Genotyping of isolates from Saudi Arabia showed that the prevalences of types 4, la, 1b, and 2 were 45.9%, 40.6%, 10.85%, and 2.7%, respectively. Genotyping of isolates from Egypt showed that type 4 was the major type among Egyptians (91.6%), while types 1a and 1b each had prevalences of 4.2%.