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Featured researches published by Nehal A. Afifi.


Research in Veterinary Science | 1996

Effect of subclinical lead toxicity on the immune response of chickens to Newcastle disease virus vaccine

Youssef Sa; Ahmed A. El-Sanousi; Nehal A. Afifi; A.M.A El-Brawy

The effect of lead acetate (20 and 40 mg kg-1 bodyweight daily) administered via the crop from day old to 56 days of age on the immune response to Newcastle disease virus vaccine (NDVV, La Sota strain) was studied in 354 Lohman chickens. Lead decreased the mitogenic response of peripheral blood lymphocytes (PBL) to phytohaemagglutinin-P (PHA-P) in birds vaccinated with NDVV. It also decreased the weights of the bursa of Fabricius, the thymus glands and the spleen relative to bodyweight. Lead administration decreased the antibody titre to NDVV in the vaccinated groups. The percentage mortality due to a challenge with a virulent velogenic Newcastle disease virus was higher in the lead intoxicated birds.


Research in Veterinary Science | 1997

Kinetic disposition, systemic bioavailability and tissue distribution of apramycin in broiler chickens

Nehal A. Afifi; A. Ramadan

Apramycin was administered to chickens orally, intramuscularly and intravenously to determine blood concentration, kinetic behaviour, bioavailability and tissue residues. Single doses of apramycin at the rate of 75 mg kg-1 body weight were given to broiler chickens by intracrop, i.m. and i.v. routes. The highest serum concentrations of apramycin were reached 0.20 and 0.76 hours after the oral and i.m. doses with an absorption half-life (t1/2(ab.)) of 0.10 and 0.19 hours and an elimination half life (t1/2(beta)) of 1.22 and 2.31 hours respectively. The systemic bioavailability was 2.0 and 58 per cent after intracrop and i.m. administration, respectively, indicating poor absorption of the drug when given orally. Following i.v. injection, the kinetics of apramycin was described by a two-compartment open model with a (t1/2(alpha)) of 1.5 hours, (t1/2(beta)) of 2.1 hours. Vd(ss) (volume of distribution) of 4.82 litre kg-1 and C1(B) (total body clearance) of 1.88 litre kg-1 hour-1. The serum protein-binding of apramycin was 26 per cent. The highest tissue concentrations of apramycin were present in the kidneys and liver. No apramycin residues were detected in tissues after six hours except in the liver and kidneys following intracrop dosing and kidneys following i.m. administration.


Journal of Chromatography B | 2017

Quantification of bupivacaine hydrochloride and isoflupredone acetate residues in porcine muscle, beef, milk, egg, shrimp, flatfish, and eel using a simplified extraction method coupled with liquid chromatography–triple quadrupole tandem mass spectrometry

Sang-Hyun Cho; Jin-A Park; Weijia Zheng; A. M. Abd El-Aty; Seong-Kwan Kim; Jeong-Min Choi; Hee Yi; Soo-Min Cho; Nehal A. Afifi; Jae-Han Shim; Byung-Joon Chang; Jin-Suk Kim; Ho-Chul Shin

In this study, a simple analytical approach has been developed and validated for the determination of bupivacaine hydrochloride and isoflupredone acetate residues in porcine muscle, beef, milk, egg, shrimp, flatfish, and eel using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A 0.1% solution of acetic acid in acetonitrile combined with n-hexane was used for deproteinization and defatting of all tested matrices and the target drugs were well separated on a Waters Xbridge™ C18 analytical column using a mobile phase consisting of 0.1% acetic acid (A) and 0.1% solution of acetic acid in methanol (B). The linearity estimated from six-point matrix-matched calibrations was good, with coefficients of determination ≥0.9873. The limits of quantification (LOQs) for bupivacaine hydrochloride and isoflupredone acetate were 1 and 2ngg-1, respectively. Recovery percentages in the ranges of 72.51-112.39% (bupivacaine hydrochloride) and 72.58-114.56% (isoflupredone acetate) were obtained from three different fortification concentrations with relative standard deviations (RSDs) of <15.14%. All samples for the experimental work and method application were collected from the local markets in Seoul, Republic of Korea, and none of them tested positive for the target drugs. In conclusion, a simple method using a 0.1% solution of acetic acid in acetonitrile and n-hexane followed by LC-MS/MS could effectively extract bupivacaine hydrochloride and isoflupredone acetate from porcine muscle, beef, milk, egg, shrimp, flatfish, and eel samples.


Research in Veterinary Science | 1992

Effect of pantothenic acid on disposition kinetics and tissue residues of sulphadimidine in chickens

A. Ramadan; M.S.M. Hanafy; Nehal A. Afifi

Sulphadimidine was administered to chickens via the intracrop route to determine plasma concentrations of the unchanged sulphonamide and its acetylated derivatives, kinetic disposition, tissue residues and acetylation. The sulphadimidine was given alone (group 1) at a dose of 200 mg kg-1 bodyweight. Pantothenic acid was given via the intracrop route at a dose of 100 mg kg-1 bodyweight one hour before (group 2) and six hours after (group 3) sulphadimidine administration (200 mg kg-1 bodyweight intracrop). The highest plasma concentrations of sulphadimidine in groups 1, 2 and 3 were reached in 1.73, 1.62 and 1.71 hours, respectively, following intracrop administration. In birds of groups 1, 2 and 3 no sulphadimidine was detected at 72, 24 and 48 hours, respectively, following its administration. Estimation of sulphadimidine in most of the body tissues revealed that all tissues examined had lower concentrations than plasma. In chickens given pantothenic acid (groups 2 and 3) before and after sulphadimidine administration, an increase in the concentration of N4 acetylated derivatives of sulphadimidine was observed compared with birds given sulphadimidine alone (group 1).


Canadian Journal of Physiology and Pharmacology | 2017

Trigonelline attenuates hepatic complications and molecular alterations in high-fat high-fructose diet-induced insulin resistance in rats

Nehal A. Afifi; Amer Ramadan; Emad Y. Erian; Dalia O. Saleh; Ahmed A. Sedik; Manal Badawi; Walid El Hotaby

The present study aimed to evaluate the effect of trigonelline (TRG) on the hepatic complications associated with high-fat high-fructose (HFHF) diet-induced insulin resistance (IR) in rats. IR was induced by giving a saturated fat diet and 10% fructose in drinking water to rats for 8 weeks. Insulin-resistant rats were orally treated with TRG (50 and 100 mg/kg), sitagliptin (SIT; 5 mg/kg), or a combination of TRG (50 mg/kg) and SIT (5 mg/kg) for 14 days. Liver homogenates were used for assessment of hepatic lipids, oxidative stress biomarkers, and inflammatory cytokines. Histopathological and DNA cytometry examinations were carried out for hepatic and pancreatic tissues. Hepatic tissues were examined using Fourier-transform infrared spectroscopy for assessment of any molecular changes. Results of the present study revealed that oral treatment of insulin-resistant rats with TRG or TRG in combination with SIT significantly decreased homeostatic model assessment of IR, hepatic lipids, oxidative stress biomarkers, and the inflammatory cytokines. TRG or TRG in combination with SIT ameliorated the histopathological, DNA cytometry, and molecular alterations induced by a HFHF diet. Finally, it can be concluded that TRG has beneficial effects on the hepatic complications associated with IR due to its hypoglycemic effect and antioxidant potential.


business information systems | 2018

Extending BPSim Based on Workflow Resource Patterns

Nehal A. Afifi; Ahmed Awad; Hisham M. Abdelsalam

The improper modeling of human resources spotted within business process simulation approaches affect appropriate evaluation of dynamic business processes behavior over time. The BPSim standard is acknowledged as a first step towards streamlining the experience of business process simulation and providing a tool independent exchange format for so-called simulation scenarios. Unfortunately, BPSim is not fully elaborated regarding the resource perspective. This paper introduces RBPSim, an extension of BPSim inspired by the well-known Workflow Resource Patterns. Moreover, the paper provides refined inter and intra-relationships among Workflow Resource Patterns to guide a modular implementation within simulation tools.


Canadian Journal of Physiology and Pharmacology | 2018

Hepatoprotective influence of quercetin and ellagic acid on thioacetamide-induced hepatotoxicity in rats

Nehal A. Afifi; Marwa A. Ibrahim; Mona K. Galal

Despite all the studies performed to date, therapy choices for liver injuries are very few. Therefore, the search for a new treatment that could safely and effectively block or reverse liver injuries remains a challenge. Quercetin (QR) and ellagic acid (EA) had potent antioxidant and anti-inflammatory activities. The current study aimed at evaluating the potential hepatoprotective influence of QR and EA against thioacetamide (TAA)-induced liver toxicity in rats and the underlying mechanism using silymarin as a reference drug. Fifty mature male rats were orally treated daily with EA and QR in separate groups for 45 consecutive days, and then were injected with TAA twice with 24 h intervals in the last 2 days of the experiment. Administration of TAA resulted in marked elevation of liver indices, alteration in oxidative stress parameters, and significant elevation in expression level of fibrosis-related genes (MMP9 and MMP2). Administration of QR and EA significantly attenuated the hepatic toxicity through reduction of liver biomarkers, improving the redox status of the tissue, as well as hampering the expression level of fibrosis-related genes. In this study, QR and EA were proved to attenuate the hepatotoxicity through their antioxidant, metal-chelating capacity, and anti-inflammatory effects.


Proceedings of the International Conference on Antimicrobial Research (ICAR2010) | 2011

Effect of Paracetamol on the Pharmacokinetics of Cephalexin in Dogs

Nehal A. Afifi; M. Atef; K. Abo-EL-Sooud; N. El-Mokadem

The pharmacokinetics of single oral dose (20 mg kg b.wt.) of cephalexin alone and concomitantly with paracetamol was studied in normal healthy dogs. Moreover, the effect of simultaneous co-administration during five continuous days of treatment on hepato-renal functions was also evaluated. Cephalexin was rapidly absorbed from the gastrointestinal tract and the calculated peak serum concentration of cephalexin Cmax was 16.47 μg ml -1 attained at 1.96 h (tmax). Paracetamol treatment significantly decreased the cephalexin concentrations from 30 minutes till 4 hours post administration. Paracetamol significantly lowered the peak serum concentration and the area under the concentration curve AUC of cephalexin. The relative bioavailability (Fr) of cephalexin with paracetamol was 76.65%. The percents of cephalexin protein binding in normal dogs serum either alone or in combination with paracetamol were 15.60, and 14.24 % respectively, indicating that the co-administration were significantly decreased the binding tendency. Following multiple doses of cephalexin alone, AP, ALT and AST activities, urea and creatinine were significantly increased till the fifth day then returning to the normal level. While concomitant administration of cephalexin with paracetamol induced transient significantly increases in the concentrations of urea and creatinine during the treatment period. Therefore, concomitant use of paracetamol with cephalexin may require close monitoring for clinical consequence of potential drug interaction.


Fish & Shellfish Immunology | 1994

The effect of ascogen on the immune response of tilapia fish to Aeromonas hydrophila vaccine.

A. Ramadan; Nehal A. Afifi; M.M. Moustafa; A.M. Samy


Veterinary World | 2012

Pharmacokinetics and bioavailability of tulathromycin following intravenous, intramuscular and subcutaneous administrations in healthy rabbits -

K. Abo-EL-Sooud; Nehal A. Afifi; A M Abd El-Aty

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Jae-Han Shim

Chonnam National University

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