Azza M. A. Ibrahim

Tumor necrosis factor alpha-308 and Lymphotoxin alpha+252 genetic polymorphisms and the susceptibility to non-Hodgkin lymphoma in Egypt.

Genetic polymorphism within the regulatory regions of tumor necrosis factor-alpha (TNF-α) and Lymphotoxin-alpha (LT-α) may be involved in the development of lymphoid malignancies. The aim of the current study was to investigate the effect of TNFα-308 and LTα+252 genetic polymorphism on susceptibility to non-Hodgkin lymphoma (NHL) in Egypt. Genotyping of the studied genes by restriction fragment length polymorphism polymerase chain reaction was conducted on 84 NHL and 100 healthy controls and revealed that TNFα-308 homotype (AA) was significantly higher in NHL patients and conferred sixfold increased risk of NHL (OR=5.9, 95%CI=2.3-16.1). Moreover, TNFα/LTα high-producer haplotypes were significantly higher in NHL patients and conferred increased risk of NHL (OR=4.59, 95%CI=2.19-9.42).

Monoclonal antibody‐based ELISA for the detection of ethyl parathion

An enzyme‐linked immunosorbent assay (ELISA) using a monoclonal antibody for the detection of ethyl parathion has been developed. The assay is capable of detecting ethyl parathion in water or milk in the range 0.001–40 μg ml‐1. The specificity of the technique was studied by inhibition assay. Cross‐reactivity with related compounds showed that the antibody reacted with ethyl parathion, methyl parathion and reduced parathion but did not react significantly with the structurally related compounds paraxon, p‐nitrophenol, malathion and dimethoate. Cross‐reactions at 40 μg gl‐1, the highest concentration assayed, produced inhibition by paraxon (40%), p‐nitrophenol (30%), malathion (15%) and dimethoate (0%).

Application of an aldrin and dieldrin ELISA to the detection of pesticides in eggs

This paper details the results obtained when a number of egg samples, collected in Egypt from different races of chicken were analyzed for the presence of the organochlorine insecticides aldrin and dieldrin. A simple ELISA was used for the detection and quantification of aldrin and dieldrin. The test was modified for application in this high protein system. Pesticide was detected in 83–352% (14/17) of the samples at levels ranging from 0.006 to 0.7 ppm (0.006 to 0.7 μg ml‐1). People eating eggs containing these amounts of pesticides which are above the World Health Organisation average daily intake levels would be at increased risk.

Chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in vitro

Different therapeutic techniques have been developed for regeneration of articular cartilage injuries, but none has provided an optimal solution to their treatment. Human umbilical cord blood‐mesenchymal Stem Cells (HUCB‐MSCs) have been considered as promising alternative cell source for cartilage repair. Objectives: Examining the success rate of MSCs isolation from HUCB as well as chondrogenic differentiation potential of HUCB‐MSCs in vitro. Materials and methods: 32 UCB samples were collected, in addition to 5 bone marrow (BM) and 5 peripheral blood (PB) samples, taken as reference controls. Samples were used for mononuclear cells isolation from which MSCs were expanded under complete aseptic conditions, were verified morphologically and through the presence of CD44 and CD105, and absence of CD34. Results: Success rate of UCB‐MSCs isolation was (25%), a rate that was lower than those of PB (40%) and BM (80%). Accordingly, certain input parameters have been recommended for successful MSCs isolation from UCB. On selecting samples in which recommended parameters were fulfilled, success rate was increased to 72%. This was together with providing optimal experiment conditions; mainly type of expansion medium, success rate reached 80%. Then, successfully expanded MSCs were subjected to chondrogenic differentiation by culturing in pelleted micromass system in presence of transforming growth factor beta‐1 and chondrogenic medium devoid of fetal bovine serum to evaluate their ability to undergo chondrogenesis. Differentiation was verified microscopically using special stains, and proved by reverse transcriptase‐polymerase chain reaction for expression of aggrecan and collagen II genes. In conclusion, in vitro differentiation into chondrocytes is possible from HUCB‐MSCs. Microsc. Res. Tech. 78:667–675, 2015.

Detection of aldrin and dieldrin in egyptian milk samples using a competitive ELISA

A number of milk samples collected in Egypt from different animal species and at different locations were analyzed for the presence of the organochloride pesticides aldrin and dieldrin. A simple competitive enzyme‐linked immunosorbent assay (ELISA) was used for the detection and quantification of aldrin and dieldrin in milk samples from different species: buffalo, cow, goat, sheep and donkey. Pesticides were detected in 62.5% (10/16) of the buffalo milk samples, 73.33% (11/15) of the cows’ milk samples, 25% (3/12) of the goats’ milk samples, 71.42% (5/7) of the sheeps’ milk samples and 66–66% (2/3) of the donkeys’ milk samples.

Detection of dieldrin in milk by (ELISA)

Polyclonal antibodies against an aldrin/dieldrin immunogen have been raised in rabbits and used as the basis of an enzyme‐linked immunosorbent assay (ELISA). This assay can detect dieldrin in milk in the range 5 μg ml ‐1 to Ing ml ‐1 reliably. This range differs in skimmed and semi‐skimmed milk, and in cream, reflecting the differences in fat content between these samples.

Development of an Indirect Competitive ELISA for Aldrin/Dieldrin in Human Milk Samples Collected in Egypt

Human milk samples (80) collected from 10 different cities in Egypt were tested for aldrin/dieldrin using an indirect enzyme‐linked immunosorbent assay (ELISA). Pesticides were detected in 73 of the 80 samples (91.25%) at levels ranging from 0.005 to 28 μg ml‐1. These results present evidence for the persistence (or continued use) of these pesticides in Egyptian agriculture and their transmission through the food chain. More significantly the levels of pesticide in maternal milk (0.006–28 ppm) represent an unacceptably high level for infant intake; the maximum average daily intake is 0.0001 mg kg‐1 body weight (WHO, 1972).

Detection of porcine pepsin in rennet mixtures used in cheese making by ELISA

An ELISA for the detection of porcine pepsin has been developed. Porcine pepsin was detected using this assay at concentrations of ≥ 1 μg ml‐1. Other cheese rennetting agents, such as bovine rennet or Mucor miehei rennet did not cross‐react in the assay either separately or in mixtures. The ELISA was used for the determination of porcine pepsin at concentrations of 1% (10 μg ml‐1) and over in combination with bovine rennet/M. miehei rennet mixtures. The effects on the assay of samples which had been subjected to a pH range between 5.0 and 7.0 (which may be encountered during the storage of rennet mixtures and in cheese making procedures), were tested. Similarly pre‐incubation of porcine pepsin in the presence of NaCl up to 10%, conditions encountered in certain salty cheese preparations, had no subsequent effect on the sensitivity of the assay when such samples were tested. Milk proteins showed no cross‐reactivity with the anti‐porcine pepsin and increasing concentrations of casein to 75 mg ml‐1 caused no...

Quantification by ELISA of Aldrin/Dieldrin in river Nile water and tap water samples collected in Egypt

An indirect competitive ELISA was developed for the quantitative analysis of aldrin/dieldrin. This has been used to monitor the levels of these pesticides in water samples collected in Egypt. The detection range of the aldrin/dieldrin assay in water was 5–10 ppm without enhancement. River Nile water samples and tap water samples (n = 25) were collected from 25 stations in 16 different governorates in Egypt. Pesticides were detected in 10 of the 25 Nile water samples (40%) at levels from 10 to 110 ppb. In tap water samples, pesticides were not detected at levels greater than the lower limit of the assay. The technique described provides a rapid, economical, highly sensitive and specific method of analysis that is relatively simple to perform and interpret. It will be extremely useful in monitoring levels of pesticides in water used for human consumption.

Indirect competitive ELISA for the quantitative and qualitative analysis of aldrin/dieldrin in egyptian milk samples from different farm animal species

The development of a simple, indirect, competitive ELISA is described for the detection and quantification of aldrin/dieldrin in Egyptian milk samples obtained from farm animals of different species used in dairy production in Egypt (buffalo, cow, goat and sheep) and from donkey milk. Milk samples (53) were collected from 18 stations in 16 different governorates in Egypt. The detection limit for aldrin/dieldrin in milk was 10 ppb—5 ppm without enhancement. Aldrin/dieldrin was detected in the following number of milk samples: buffalo, 62.5% (10/16); cow, 73.33% (11/15); goat, 66.66% (8/12); sheep, 71.428% (5/7); and donkey, 66.66% (2/3). The values reflect the lipophilic nature of these pesticides. The assay is rapid, sensitive, simple to perform and excellent for screening.