In this study, level IIb lymph node metastasis was only found in association with tongue carcinoma. Although this region may be preserved in elective SOHND in patients with SCC of the oral cavity, it should be included whenever the tongue is the primary site.

Aflatoxin is a common contaminant of foods, particularly in the staple diets of many developing countries. To evaluate adverse effects of aflatoxin B1 (AFB1) toxicity on health status in the Nile tilapia Oreochromis niloticus, fish were fed diet contaminated with either 20 or 100 ppb AFB1 for 6 or 12 weeks. Growth indices, survival rate and hepatosomatic index (HSI) were assessed. Blood samples were collected for hematological profiles (e.g. RBCs and WBC count, Hb content). Liver enzyme activity; aspartate aminotransferase (AST), alanine aminotransferase (ALT) as well as alkaline phosphatase (ALP), were evaluated and toxin residues in the liver and musculature were detected. Liver histopathological investigations were carried out, whereas antioxidant glutathione peroxidase (GPx) and glutathione S-transferase (GST) gene expression were determined in this tissue by semi-quantitative RT-PCR. Furthermore, to test the fish immune status, challenge against Aeromonas hydrophila was conducted. Results indicated that 100 ppb AFB1 negatively impacted O. niloticus weight gain, feed efficiency, hematological profiles, HSI as well as liver histopathology, while increase in AST, ALT, ALP liver enzymes activity was evidenced. Further, the expression of liver GPx and GST down-regulated and AFB1 residues were always detected in the liver and only in the musculature in fish fed 100 ppb AFB1 for 12 weeks. The ability of fish to withstand A. hydrophila infection was remarkably lowered. Overall, the results herein demonstrate the toxic effects of AFB1 in O. niloticus. The observed alterations in fish status, especially in the liver coincide well with the expected oxidative stress resulting from the AFB1 toxicity. ª 2015 The Egyptian German Society for Zoology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Hydrogel-based polymers are represented by those hydrophilic polymers having functional groups in their chain such as amine (NH2), hydroxyl [-OH], amide (-CONH-, -CONH2), and carboxyl [COOH]. These hydrophilic groups raise their potential to absorb fluids or aqueous solution more than their weights. This physicochemical mechanism leads to increased hydrogel expansion and occupation of larger volume, the process which shows in swelling behavior. With these unique properties, their use for biomedical application has been potentially raised owing also to their biodegradability and biocompatibility. Chitosan as a natural copolymer, presents a subject for hydrogel structures and function. This review aimed to study the structure as well as the function of chitosan and its hydrogel properties.

In this study, we examined the prevalence and molecular characteristics of Cryptosporidium in buffalo, dairy cattle and sheep in different farms at Kafr El Sheikh Province, Egypt. Rectal fecal samples, including 466 samples from buffalo, 1697 from cattle and 120 from sheep, were collected from different ages and screened by modified Ziehl-Neelsen acid-fast microscopy for detection of Cryptosporidium oocysts. All studied farms were positives with an overall prevalence of 1.29% in buffalo (4.17% in claves versus 0.48% in adults), 7.07% in cattle (6.90% in calves versus 10.20% and 6.10% in heifers and adults, respectively) and 2.50% in sheep (4.40% in lambs versus 1.30% in adults). PCR-RFLP analyses of small-subunit rRNA genes from positive specimens revealed the occurrence of C. parvum and C. ryanae in buffalo; C. parvum, C. ryanae, C. bovis and C. andersoni in cattle and only C. xiaoi in sheep. Genotypes distribution showed that C. ryanae was the dominant species (60.0%) followed by C. parvum (40.0%) in buffalo calves. Meanwhile, in cattle calves, C. parvum was the commonest species (74.23%) followed by C. ryanae (16.10%) and C. bovis (9.70%). Subtyping of C. parvum based on sequence analysis of the polymorphic 60 kDa glycoprotein gene locus showed the presence of subtypes IIdA20G1 and IIaA15G1R1 in both buffalo and cattle calves, addressing the potential role of calves in zoonotic cryptosporidiosis in Egypt.

Objectives: It was the aim of this study to determine whether level IIB lymph nodes can be saved in elective neck dissection as a treatment for patients with squamous cell carcinoma (SCC) of the larynx. We present a prospective analysis of a case series. Methods: Thirty-one patients with SCC of the larynx and without palpable lymph nodes at the neck who underwent an elective neck dissection were prospectively studied. The incidence of micrometastasis to level IIB lymph nodes after performing elective neck dissection was evaluated by nested reverse transcription polymerase chain reaction for cytokeratin (CK)19 and CK20 as well as by pathological examination. Results: Nested reverse transcription polymerase chain reaction for CK19 and CK20 mRNA presented similar results but differed from the pathological examination. Of the 31 patients, 6 (19%) by pathological analysis and 9 (29%) by molecular analysis had lymph nodes positive for metastatic SCC. By molecular analysis, only 1 of the 31 patients had involvement of level IIB lymph nodes. Conclusions: This region may be preserved in elective neck dissection in patients with SCC of the larynx, so that accessory nerve dysfunction can be minimized and operative time can be saved.