The course of infection with Toxoplasma gondii RH strain in mice pre-vaccinated with gamma irradiated tachyzoites.

Toxoplasma gondii is a ubiquitous protozoan of major medical and veterinary importance. Its treatment is difficult since the available drugs have severe side effects and reactivation may occur anytime. Vaccination with irradiated parasites exhibits ideal characteristics for vaccine development. In our experimental mice model, the protection against challenge with the virulent RH strain was assessed, using 255Gy irradiated tachyzoites. Eighty mice were allocated into 3 groups: naive control group, challenged with virulent RH tachyzoites group and a third group which is challenged with 1 × 106 irradiated tachyzoites, administered as two biweekly doses intraperitoneally. Protection was tested by challenging vaccinated mice with the virulent type RH tachyzoites 30 days after the 2nd vaccination dose. The assessment was built on qualitative clinical, quantitative parasitological, histopathological parameters and measurement of serum Nitric Oxide (NO). The results showed prolonged survival rate, absence of tachyzoites in the peritoneal aspirate by counting, absence of tachyzoites in all examined organs by impression smears, amelioration of histopathological changes in the liver, spleen, brain and lung specimens and increase of the serum NO level in the vaccinated group. Therefore, we propose that irradiated Toxoplasma tachyzoites confer protection for challenged mice and could be an alternative immunization schedule for vaccine development especially for who are at risk of severe immunosuppression.

Coupling of a streamlined solid-liquid extraction protocol with LC-ESI-MS/MS for the regular oversight of illegal bromate additive use: An accurate and sensitive determination method in preliminary and bakery products.

A reliable solid-liquid extraction protocol coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry in the negative-ion mode was developed and validated for illegal bromate determination in preliminary and bakery products. Crude and dried-treated samples were directly extracted with acetonitrile-water (4:1, v/v). Bromate was determined using a Phenomenex Synergi™ Polar reversed-phase column and MS/MS under multiple reaction monitoring. The chosen solvent efficiently extracted bromate with all applied extraction-assisting techniques (p > 0.05). Although this assay avoids cleanup procedures, matrix effect of <-11% was achieved. Rapid bromate separation in only 8 min was attained by a reversed-phase column. In both commodities, linearity range, R2, recovery%, repeatability, intermediate precision, LOD and LOQ results were 0.05-100 ng mL-1, >0.9999, 88.6-103%, 2.93-9.80% and 9.64-10.10%, 0.015 µg kg-1 and 0.05 µg kg-1, respectively. Out of 288 tested real samples, 13.9% of violations were observed. This high-sensitivity protocol offers effective oversight and consumer protection.

Development and Validation of a Modified QuEChERS protocol Coupled to Liquid Chromatography-Tandem Mass Spectrometry for the Rapid and Accurate Determination of Acrylamide in Cereal-Based Baby Foods.

BACKGROUND: With the widespread consumption by children of cereal-based baby food, acrylamide contamination is a prevalent risk that may have carcinogenic consequences. OBJECTIVE: This study aims to develop and validate a modified QuEChERS protocol (quick, easy, cheap, effective, rugged, and safe) without solvent exchange, followed by rapid separation and accurate determination of acrylamide in cereal-based baby foods using reversed-phase (RP)-LC-MS/MS. METHODS: Samples were extracted using a modified QuEChERS protocol of the AOAC version and cleaned up with basic alumina. Separation was performed on a Phenomenex® Kinetex C18 column (100 Å × 3.5 µm × 4.6 mm × 150 mm) using a gradient elution program with a mobile phase of 10 mM ammonium formate-methanol. Determinations were conducted using electrospray ionization (ESI)-MS/MS in positive-ion mode. RESULTS: Basic alumina yielded clean extracts, resulting in acceptable recovery percentages and a tolerable matrix effect (ME) <5%. This allowed extraction without a solvent exchange step. Efficient separation was achieved at a retention time (tR) of 3.39 ± 0.05 min employing an RP-C18 column with core-shell properties in a relatively short analysis run time of only 5 min. Trueness, precision, LOD, LOQ, linearity range, and R2 results were 92.5-104.6%, RSD ≤12.2%, 5 µg/kg, 20 µg/kg, 4.0-1000.0 µg/kg, and > 0.9999, respectively. The test method applicability was demonstrated by proficiency testing (PT) and 50 real samples of cereal-based baby foods. Most of the tested samples were in violation of acrylamide's established European Union benchmark (40 µg/kg). CONCLUSION: Acetate-buffered QuEChERS protocol in conjunction with optimized amounts of basic alumina was confirmed as an efficient extraction protocol for acrylamide from cereal-based baby foods resulting in optimal method performance. Successful selection of the RP-C18 column is key for selective separation for acrylamide in a relatively short analysis run time. HIGHLIGHTS: The modified AOAC QuEChERS protocol with a dispersive solid phase extraction (d-SPE) of basic alumina assisted in reducing the ME to tolerable levels while maintaining acceptable method performance. The use of an RP-C18 column with core-shell properties enabled a rapid and accurate acrylamide determination.

Breast cancer involvement of the nipple-areola complex and implications for nipple-sparing mastectomies: a retrospective observational study in 137 patients.

INTRODUCTION: Nipple-sparing mastectomy (NSM) has gained much attention by enhancing the aesthetic outcome in breast carcinoma patients. The aim of this study was to assess the prevalence of malignant affection of the nipple-areola complex (NAC) in breast carcinoma patients and its correlation with prognostic factors for breast cancer. PATIENTS AND METHODS: This study included 137 female patients diagnosed with breast carcinoma at different disease stages who were admitted to our surgical oncology unit at Suez Canal University Hospital from June 15, 2014 to January 25, 2017. We excluded patients with evidence of nipple involvement as ulceration or patients with previous breast surgery with periareolar incisions. This study was designed to test the hypothesis that the NAC can be spared in certain selected patients. All studied participants provided a full history and underwent general and local clinical examinations, pre-operative laboratory tests, and radiological and pathological evaluations. RESULTS: The mean age of the study population was 47.39 ± 8.01 years. Among the patients, the NAC was affected in 12 (11.40%) patients. Patients with NAC involvement showed a significantly larger tumor size of more than 4 cm and a shorter tumor-nipple distance of less than 2 cm (p = 0.000). Lymph node metastasis was associated with NAC involvement (p = 0.001), with increased risk when more than 10 lymph nodes were involved (p = 0.007). Lymphovascular invasion was a significant predictor of NAC involvement (p = 0.014). Multifocal as well as multicentric tumors were significantly associated with NAC involvement (p = 0.016 and 0.003, respectively). NAC involvement was more likely in Estrogen receptor (ER) and Progesterone receptor (PR) patients than in ER+ and PR+ patients (p = 0.000), while Human epidermal receptor (HER+) patients were more likely to have NAC involvement than HER patients (p = 0.000). Additionally, stage ΙΙΙ cancer was significantly associated with NAC involvement (p = 0.041), and histological grade III disease carried a greater risk than grade I disease of NAC involvement (p = 0.008). CONCLUSION: The incidence of NAC affection among breast carcinoma patients who underwent mastectomy and axillary clearance was associated with important parameters, such as tumor size, areola edge-tumor distance, lymph node affection, hormonal receptor status and lymphovascular invasion. Accordingly, NAC-preserving surgeries could be tailored to patients with favourable tumor characteristics.

Determination of Formaldehyde by HPLC with Stable Precolumn Derivatization in Egyptian Dairy Products.

Formaldehyde is one of the most dangerous chemical compounds affecting the human health; exposure to it from food may occur naturally or by intentional addition. In this study a high performance liquid chromatography method for determination of formaldehyde in dairy products was described. The dairy samples were reacted and extracted with a warmed organic solvent in the presence of derivatizing agent 2,4-dinitrophenylhydrazine (DNPH) and formaldehyde; the mixture was centrifuged and followed by diode array detection. The method is validated and gives average recovery of formaldehyde at the three different levels 0.1, 5.0, and 10.0 mg/kg varied between 89% and 96%. The method is linear from the limit of quantification 0.1 mg/kg up to 10 mg/kg levels. This method is intended for formaldehyde analyses in dairy products simply with stable derivatization, minimum residue loss, excellent recovery, and accurate results with a sensitive limit of detection 0.01 mg/kg. 90 dairy samples from milk, cheese, and yogurt were investigated from seven Egyptian governorates and all samples were free from formaldehyde.

Reliable HPLC determination of aflatoxin m1 in eggs.

Aflatoxin M1 is the foremost metabolite of aflatoxin B1 in humans and animals, which may be present in animal products from animals fed with aflatoxin B1 contaminated feed. In this study a high performance liquid chromatography method for determination of aflatoxin M1 in eggs was described. The egg samples were diluted with warmed water and the toxin was immunoextracted followed by fluorescence detection. The average recovery of aflatoxin M1 at the three different levels 0.05, 0.1, and 0.5 µ g/kg varied between 87% and 98%. The method is linear from the limit of quantification 0.05 µ g/kg up to 3 µ g/kg levels. This method is intended for aflatoxin M1 analyses in eggs simply with minimum toxin lose, excellent recovery, and accurate results with the limit of detection 0.01 µ g/kg.