imam mekkawy | Assiut University (original) (raw)

Papers by imam mekkawy

Tissue and Cell, 2011

In the present work, the destructive effects of the 4-nonylphenol on one of the most economically... more In the present work, the destructive effects of the 4-nonylphenol on one of the most economically important Nile fishes namely African catfish (Clarias gariepinus) were studied. Apoptosis, erythrocytes alterations, micronucleus test and blood parameters count were used as biological indicators to detect those effects. After exposure to sublethal concentrations of 4-nonylphenol (0, 0.05, 0.08 and 0.1 mg/l), apoptotic red blood cells with many malformations and micronuclated erythrocytes were recorded. Decrease in the blood parameters such as red blood cells (RBCs), hemoglobin (Hb), package cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC), platelets, white blood cells (WBCs), lymphocytes, basophils, monocytes and increase in mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), neutrophils, eosinophils indicated the negative effects of 4-nonylphenol. It was concluded that, the 4-nonylphenol caused genotoxicity in erythrocytes with many malformations in shape and number indicated with other blood parameters.

The parasites infecting the internal organs of Oreochromis niloticus and Tilapia zillii. It also ... more The parasites infecting the internal organs of Oreochromis niloticus and Tilapia zillii. It also deals with the impact of these parasites either on the infected tissues or on the whole biology of the fishes under study. The specimens were collected from three different water bodies; the River Nile, El-Foadia stream and El-Mora canal in Sohag. Were examined gills, liver, gonads, spleen and intestine for the parasitic infection. This revealed the presence of eight species of genus Myxobolus, One species related to genus Sphaerospora was described new species, spores related to genus Trichodina were detected in gills, Monogenean and Digenia worms were isolated from Oreochromis niloticus and Tilapia zillii. The impact of parasites was clear on the various tissues and led to the tissue damage and destruction of some of the cell. vary the intensity of the spread of the parasite on the environment in which it resides Fish. There is a clear relationship between the length of the fish and de...

ABSTRACT The presence of the genetic toxic chemicals in the aquatic environment increased. This s... more ABSTRACT The presence of the genetic toxic chemicals in the aquatic environment increased. This study aimed using the random amplified polymorphic DNA (RAPD-PCR) assay to investigate the genotoxic effects of 4-nonylphenol in adults and embryos of African catfish Clarias gariepinus. After exposure of adults and embryos to sublethel concentrations of 4-nonylphenol (0, 0.05, 0.08, and 0.1 mg/l) for 15 days, DNA was extracted for RAPD assay. The RAPD pattern from catfish exposed to 4-nonylphenol displayed some changes in polymorphism band patterns including disappearance and appearance of bands. Cluster method was used to indicate the distinct distance between the band patterns of exposed fish and the control. In conclusion, the RAPD-PCR is method can be used as an investigation tools for the evaluation of the genetic damage of the catfish induced by the exposure to 4-nonylphenol.

Page 1. 8 Histopathological Alterations in some Body Organs of Adult Clarias gariepinus (Burchell... more Page 1. 8 Histopathological Alterations in some Body Organs of Adult Clarias gariepinus (Burchell, 1822) Exposed to 4-Nonylphenol Alaa El-Din H. Sayed1*, Imam A. Mekkawy1,2 and Usama M. Mahmoud1 1Zoology Department ...

In present work, some biochemical characteristics of the catfish, Clarias gariepinus were studied... more In present work, some biochemical characteristics of the catfish, Clarias gariepinus were studied under the effect of different sublethal doses of 4-nonylphenol (0, 0.05, 0.08 and 0.1 mgl-1). Liver enzymes ALT and AST increased insignificantly at P<0.05 whereas the ALP decreased insignificantly. The activities of G6PDH showed significant increase with the increased sublethel doses of 4-nonylphenol while the activities of LDH decreased insignificantly with increase of such doses. The concentrations of serum glucose and total cholesterol significantly increased after exposure to 4-nonylphenol, although Hyperglycemia is evident. The kidney function parameters such as total serum protein and uric acid increased insignificantly after exposure to 4-nonylphenol in comparison with the control fish whereas creatinine exhibited significant increase (P<0.05). Some serum ions decreased significantly (HCO 3 and Na +) or insignificantly (Cu +2 , Cl and Ca +2) and others increased significantly (Fe +2) or insignificantly (K +) under 4-nonylphenol stress on C. gariepinus. Increased serum anion gap was associated with increased hyperglycemia and insignificant hypocalcemia. Such increased gap referred to nonylphenolinduced metabolic acidosis. The adverse impact of the sublethal doses of 4-nonylphenol on the molecular structure of the protein was evident by electrophoresis. In conclusion, in addition to its tissue-specific estrogenic effects, 4-nonylphenol has non-estrogenic adverse effects on liver and kidney functions through activation of other metabolism-related genes distinct from estrogenresponsive genes.

In the present work, heavy metal distribution and the corresponding damage in some organs of Bagr... more In the present work, heavy metal distribution and the corresponding damage in some organs of Bagrus bajad collected from Assiut, Egypt were studied. The residues of Copper, Zinc, Cadmium, Manganese, Iron and Lead were determined. Variability in such residues among different localities and organs was analyzed reflecting different patterns of distribution and magnitudes. Kidney and/or gills represent the primary site for collection of certain metals. In spite of a good condition of the aquatic ecosystems studied, accumulation of some metals such as Cd and Pb in fish tissues was above the permissible level reflecting the past history. Corresponding damages in gills, kidney, liver and muscles were evaluated in terms of lipid peroxidation (LPO) and DNA fragmentation reflecting the impact of heavy metals on the molecular level of cell structure of Bagrus bajad.

In the present study heavy metal distribution and the corresponding tissue damage in some organs ... more In the present study heavy metal distribution and the corresponding tissue damage in some organs of Oreochromis niloticus collected from Assiut, Egypt were investigated. The residues of Copper, Zinc, Cadmium, Manganese, Iron and Lead were estimated. Variability in such residues among different localities, sediments and organs was analyzed reflecting different patterns of distribution and magnitudes. Kidneys, gills or liver act as the primary site for accumulation of certain metals. In spite of a good status of the aquatic ecosystems studied, accumulation of some metals such as Cu, Cd, Fe and Mn in fish tissues was above the permissible limits reflecting fish past history, organ specificity and variability of aquatic ecosystem status. Corresponding damages in gills, kidneys, liver and muscles were evaluated in terms of lipid peroxidation (LPO) and DNA fragmentation reflecting the impact of heavy metals on the molecular level of cell structure of Oreochromis niloticus. The results of the present study concerning with accumulation of heavy metals in fish organs and sediments, were compared with those recorded by other authors in different localities for the River Nile and other localities of the world. Analytical procedures Digestion of samples Reagents Standard solutions of Cu, Zn, Cd, Fe, Mn and Pb were prepared from commercial stock standard solutions (Merck) at concentrations of 1000 mg/l. Double deionised water was used throughout. Working standard solutions were prepared by dilution of stock standard solution with the addition of hydrochloric acid, so that the acid concentration in working standard solutions matched the acid concentration in digested solutions. All reagents used were analytical-reagent grade. Samples preparation Two grams of gills, kidneys, Liver and muscles were weighed in quartz-glass crucibles, dried in a drying oven at 105° C and ashed overnight at 450° C ± 25° C in a programmable furnace. According to Zlatka et al. (2005) the ash was dissolved in diluted hydrochloric acid/nitric acid (1/1, v/v). The solution was evaporated to dryness. The remains were redissolved with diluted hydrochloric acid (1/10, v/v), filtered into a 50 ml volumetric flask and diluted with water to the mark.

The aim of the present investigation is to determine the toxicological effects of mercury chlorid... more The aim of the present investigation is to determine the toxicological effects of mercury chloride on haematological parameters of the widely consumed African catfish, Clarias gariepinus. Adult specimens of Clarias gariepinus were exposed to a sublethal concentrations (0.04 and 0.12 ppm) of mercury chloride for 7, 14, 21 and 28 days. Blood samples were obtained from caudal circulation and used for the measurement of red (RBC) and white (WBC) blood cell counts, haematocrite (Hct), haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Empirical data of results obtained were subjected to statistical analysis of variance (ANOVA) to test the effects of mercury, selenium, vitamin E and exposure periods. The mean values of RBC's, Hct, Hb, MCH and MCHC were significantly decreased from the control values, while mean values of MCV, WBC and lymphocytes were significantly increased from the c...

The present study investigated effects of environmental relevant concentrations of 4-nonylphenol ... more The present study investigated effects of environmental relevant concentrations of 4-nonylphenol (0.05 to 0.08 to 0.1 mg/l) on the reproduction and embryonic developmental stages of catfish (Clarias gariepinus). To determine the effect of 4-nonylphenol on reproduction; catfish were exposed to three concentrations of 4-nonylphenol in a flow-through-system during spawning period (some for one week and other for two weeks). At an estimated 4-nonylphenol concentration the fertilization rate and hatching rate were significantly decreased with 4-nonylphenol concentrations increasing while the incubation period, the mortality rate and malformed embryos ratio were increased. Also, the development of embryos and larvae was affected by 4-nonylphenol in terms of morphological changes and histopathological alterations.

The presence of the genetic toxic chemicals in the aquatic environment increased. This study aime... more The presence of the genetic toxic chemicals in the aquatic environment increased. This study aimed using the random amplified polymorphic DNA (RAPD-PCR) assay to investigate the genotoxic effects of 4-nonylphenol in adults and embryos of African catfish Clarias gariepinus. After exposure of adults and embryos to sublethel concentrations of 4-nonylphenol (0, 0.05, 0.08, and 0.1 mg/l) for 15 days, DNA was extracted for RAPD assay. The RAPD pattern from catfish exposed to 4-nonylphenol displayed some changes in polymorphism band patterns including disappearance and appearance of bands. Cluster method was used to indicate the distinct distance between the band patterns of exposed fish and the control. In conclusion, the RAPD-PCR is method can be used as an investigation tools for the evaluation of the genetic damage of the catfish induced by the exposure to 4-nonylphenol.

the parasites infecting the internal organs of Oreochromis niloticus and Tilapia zillii. It also ... more the parasites infecting the internal organs of Oreochromis niloticus and Tilapia zillii. It also deals with the impact of these parasites either on the infected tissues or on the whole biology of the fishes under study. The specimens were collected from three different water bodies; the River Nile, El-Foadia stream and El-Mora canal in Sohag. Were examined gills, liver, gonads, spleen and intestine for the parasitic infection. This revealed the presence of eight species of genus Myxobolus, One species related to genus Sphaerospora was described new species, spores related to genus Trichodina were detected in gills, Monogenean and Digenia worms were isolated from Oreochromis niloticus and Tilapia zillii. The impact of parasites was clear on the various tissues and led to the tissue damage and destruction of some of the cell. vary the intensity of the spread of the parasite on the environment in which it resides Fish. There is a clear relationship between the length of the fish and de...

Pakistan Journal of Biological Sciences, 2013

British Journal of Pharmaceutical Research, 2013

Aims: Study the release of fluconazole from different O/W creams and PEG ointments. Study Design:... more Aims: Study the release of fluconazole from different O/W creams and PEG ointments. Study Design: In this study, different formulations were prepared with changing one of the added excipients and study the effect of this change on the drug release and then the selected formulations were subjected to antifungal activity study.

Toxicology and Environmental Health Sciences, 2012

The present investigation aimed to determine the toxicological effects of mercury chloride on bio... more The present investigation aimed to determine the toxicological effects of mercury chloride on biochemical parameters of the widely consumed African catfish, Clarias gariepinus. Adult specimens of Clarias gariepinus were exposed to sublethal concentrations (0.04 and 0.12 ppm) of mercury chloride for 7, 14, 21 and 28 days. Empirical data of results obtained were subjected to statistical analysis of variance (ANOVA) to test the effects of mercury, selenium, vitamin E and exposure periods. The mean values of Na + , Urea, Creatinine, AST, ALT and ALP were significantly increased from the control values, while mean values of K + , Glucose and Triglyceride were significantly decreased from the control values. Selenium and Vitamin E supplementation play appositive role in detoxification of mercury toxicity specially the low dose. The results suggest that mercury chloride can negatively affect the physiology of fish. It was observed that supplementation of selenium and vitamin E decreases the toxic effect of mercury.

Scientia Marina, 2006

Much of the existing knowledge of the mechanisms involved in teleost fertilisation is based on a ... more Much of the existing knowledge of the mechanisms involved in teleost fertilisation is based on a few small model species that have no commercial value. Research is therefore urgently required to address mechanisms involved in fertilisation in species of great commercial value. In this study, the ultrastructural morphological variations in the surface of the egg of Clarias gariepinus were recorded before and after fertilisation by using electron microscopy. The outer surface of the unfertilised egg was smooth, whereas the fertilised egg acquired a network of projections on the vegetal hemisphere. Moreover, different patterns of ornamentation on the egg surface were evident. This pattern of ornamentation varied with the progress of embryonic development. The micropyle of the C. gariepinus egg consisted of a funnel-shaped vestibule, from the bottom of which a cylindrical micropylar canal extended. The micropylar canal decreased in diameter after completion of fertilisation, forming a micropylar disc. The sperm behaviour on the egg surface was oriented towards any depression on the chorion surface. The chorion of ovulated eggs consisted of one layer. After fertilisation the chorion was differentiated into three layers: the double-layered coat, the zona radiata externa and the zona radiata interna. Four protein subunits of the chorion of C. gariepinus were identified by SDS-PAGE. IR-spectra obtained from C. gariepinus chorion revealed that the vibration of chorion proteins exhibited different weak activities in the IR-spectra with minor difference between pre-and post-fertilisation chorion proteins.

Journal of Photochemistry and Photobiology B: Biology, 2007

In the present work, the destructive effects of Ultraviolet-A radiation on the African Catfish, C... more In the present work, the destructive effects of Ultraviolet-A radiation on the African Catfish, Clarias gariepinus was revealed in terms of total protein, cholesterol, glucose, hemoglobin and erythrocytic indices, differential blood cell counting, heamatocrite, creatinine level, Aspartic Amino Transferase, Alanine Amino Transferase and Alkaline Phosphatase. These destructive effects were also confirmed by histopathological changes in liver, blood corpuscles and skin.

Journal of Photochemistry and Photobiology B: Biology, 2013

In the present study the protective role of quince leaf extract against the adverse impacts of ul... more In the present study the protective role of quince leaf extract against the adverse impacts of ultraviolet radiation-A (UVA) on some tissues of Clarias gariepinus (Burchell, 1822) was considered. Fishes were classified into four groups: control, UVR-treated group (for 3days/for 3h/day), UVR-treated group (for 3days/for 3h/day) with adding 10ml of quince extract, and UVR-treated group (for 3days/for 3h/day) with adding 20ml of quince leaf extract. Blood smears and sections of the liver, and skin were processed routinely for H &amp;amp;amp;amp;amp;amp; E paraffin embedding technique. Some UVA-induced malformations were recorded in the red blood cells including crenated cells (Cr), Acanthocytes (Ac), tear drop-like cells (Tr) and sickle cells (Sk). Also, UVA-induced disorganization of the normal architecture of hepatic tissues with lipidosis was evident. Hypertrophy and vacuolated club cells were recorded in skin exposed to UVA. In conclusion, quince leaf extract has a valuable antioxidant protective role to prevent and/or repair the histopathological changes induced by UVA.

Journal of Fisheries and Aquatic Science, 2013

Journal of Applied Ichthyology, 2008

Embryonic development of Clarias gariepinus was studied from oocyte activation to the end of endo... more Embryonic development of Clarias gariepinus was studied from oocyte activation to the end of endogenous feeding (164 h post-fertilization, 164 h-PF). The ontogeny of the eyes, the ear, the heart, the digestive tract and the notochord were described histologically: (i) eyes were not pigmented at hatching (40 h-PF) and the anlage of the retina was observed at 96 h-PF. At 164 h-PF, the pigmented epithelium was distinguished as a single layer of cubical cells and the outer nuclear layer was composed of cones; (ii) the inner ear was oval-shaped and two otoliths and a sensory epithelium were differentiated at hatching. Three semicircular canals with rudimentary cristae developed until 96 h-PF, leading to a fully developed auditory vesicle at 120 h-PF; (iii) at 40 h-PF, a beating heart appeared as a thin-walled tube and at 72 h-PF no blood elements were recorded in the two-chambered heart. The four compartments (bulbus arteriosus, ventricle, atrium, sinus venosus) and mature blood elements were found only at 144 h-PF; (iv) the hatchlings possessed an undifferentiated digestive system, and differentiation of a buccal cavity, oesophagus and intestine was only recorded 96 h-PF. The connection between the oesophagus and the intestine and the anus opened at 144 h-PF; (v) the notochord in newly hatched embryos was composed of vacuolated cells and a peripheral layer of notochordal epithelium inside a fibrous sheath. Subsequently, vacuolated cells proliferated and notochordal epithelium changed from cubical to squamous cells. Eye differentiation was concomitant with first feeding, thus suggesting a key role of visual senses in feeding behaviour.