Microcystin levels in irrigation water and field-vegetable plants, and food safety risk assessment: A case study from Egypt.

Microcystin (MC), a hepatotoxin that is harmful to human health, has frequently increased in freshwaters worldwide due to the increase in toxic cyanobacterial blooms. Despite many studies reported the human exposure to MC through drinking water, the potential transfer of this toxin to human via consumption of vegetables grown on farmlands that are naturally irrigated with contaminated water has not been largely investigated. Therefore, this study investigates the presence of MC in irrigation water and its potential accumulation in commonly consumed vegetables from Egyptian farmlands. The results of toxin analysis revealed that all irrigation water sites contained high MC concentrations (1.3-93.7 µg L-1) along the study period, in association with the abundance of dominant cyanobacteria in these sites. Meanwhile, MCs were detected in most vegetable plants surveyed, with highest levels in potato tubers (1100 µg kg-1 fresh weight, FW) followed by spinach (180 µg kg-1 FW), onion (170 µg g-1 FW), Swiss chard (160 µg kg-1 FW) and fava bean (46 µg kg-1 FW). These MC concentrations in vegetables led to estimated daily intake (EDI) values (0.08-1.13 µg kg bw-1 d-1 for adults and 0.11-1.5 µg kg bw-1 d-1 for children), through food consumption, exceeding the WHO recommended TDI (0.04 µg kg bw-1 d-1) for this toxin. As eutrophic water is widely used for irrigation in many parts of the world, our study suggests that cyanotoxins in irrigation waters and agricultural plants should be regularly monitored to safeguard the general public from inadvertent exposure to harmful toxins via food consumption.

Ecological studies on Al-Khadoud Spring, Al-Hassa, Saudi Arabia.

Al-Khadoud spring is one of the most important water resources in Al-Hassa Governorate, Saudi Arabia. However, much of its biotic information is still unknown. This study presented preliminary ecological information of this aquatic body. Regarding to macrophytes, a total of eight species were observed along the study sites. These species include two submerged aquatic plants (Potamogeton pectinatus L. and Ceratophyllum demersum L.). The common distributed species are Phragmites australis (Cav.) Trimex Steud and Cyperus rotundus (L.). On the other hand, a total of 20 algal genera were recorded with 7 genera of Chlorophyceae, 8 of Bacillariophyceae, 4 of Cyanophyceae and one of Euglenophyceae. The common phytoplankton occurred in all three investigated sites were Chlorella vulgaris, Mougeotia sp., Oscillatoria sp. and Actinastrum sp. Regarding to the biotic fauna, different forms of unicellular zooplankton such as Paramecium and Amoeba were recorded. Invertebrates such as freshwater insects and some freshwater snails were documented in the study sites including Melanodies tuberculata, Melanopsis praemorsa and Lymnaea auricularia. As regard to vertebrates, one species of fish, Aphanius dispar, dominate the spring basin and its extended channels.

Carticaine versus lidocaine for peribulbar anesthesia in cataract surgery.

PURPOSE: To compare carticaine 4% and lidocaine 2% for peribulbar anesthesia in cataract surgery. SETTING: Ain Shams and Cairo University Hospitals, Cairo, Egypt. METHODS: This prospective double-blind randomized study comprised 200 cataract patients assigned to 1 of 2 groups of 100 each based on type of anesthesia: carticaine 4% or lidocaine 2%. The efficacy, safety, and duration of the motor and the analgesic block produced by carticaine 4% adrenaline hyaluronidase mixture and lidocaine 2% adrenaline hyaluronidase mixture used as peribulbar anesthesia were compared. The mean time for satisfactory block, need for supplementary injections, incidence of intraoperative and postoperative pain, and postoperative complications were evaluated. The data were analyzed using the Student t test and Mann-Whitney U test for intergroup differences. The chi-square or Fisher exact test was used to assess eye movement scores, the need for supplementary injections, the onset of postoperative pain, and the incidence of postoperative complications. RESULTS: The mean time for satisfactory anesthesia was 7.5 minutes +/- 1.68 (SD) for lidocaine 2% and 2.5 +/- 1.53 minutes for carticaine 4% (P <.001). The need for supplementary injections was 28% in the lidocaine group and 4% in the carticaine group (P <.001). The mean onset of postoperative pain was 2.00 +/- 0.86 hours in the lidocaine group and 5.52 +/- 1.80 hours in the carticaine group (P <.05). There were no cases of postoperative neurotoxicity or extraocular muscle dysfunction in either group. CONCLUSIONS: Carticaine 4% adrenaline hyaluronidase mixture was an effective and safe agent for peribulbar anesthesia. It was more efficient than lidocaine 2% adrenaline hyaluronidase mixture in the onset and quality of anesthesia as well as postoperative analgesia.