In higher vertebrates, considerable progress has been made in understanding the endocrine regulation of puberty; however, in teleosts, the regulatory mechanisms of spermatogenesis during the first annual cycle remain unclear. The present study was conducted to understand the regulatory mechanisms of spermatogenesis throughout the different stages of the first spermatogenic cycle and to check the ability of various steroids and hormones to induce in vitro spermatogonial proliferation in Japanese huchen (Hucho perryi ). The results indicate that the serum level of 11-ketotestosterone (11-KT) was positively associated with germ cell type; the level first began to rise with the appearance of late-type B spermatogonia and continued to increase gradually throughout the active spermatogenic stages and spermiogenesis, reaching a peak value 2 wk before spawning, and then declined. During the spermatogenic stages, the serum concentration of 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-DP) was undetectable. Only a small peak was detected with the appearance of spermatocytes and spermatids, and at the time of spawning, the level increased dramatically, reaching its maximum value with the onset of milt production. Despite the high variation in serum levels of 17beta-estradiol (E2) both between months and among the individuals, E2 was found during the whole reproductive cycle. From these results, we concluded that 1) 11-KT is necessary for the initiation of spermatogenesis and sperm production, and it probably plays a role in spermiation, 2) 17alpha,20beta-DP is essential for the final maturation stage, could play a significant role in the mitosis phase and meiosis process, and probably participates in the regulation of spawning behavior, and 3) estrogen is an indispensable male hormone that plays a physiological role in some aspects of testicular functions, especially during the mitotic phase. The three steroids were also able to induce DNA synthesis, spermatogonial renewal, and/or spermatogonial proliferation in vitro.

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In the current study, a significant amount of ulvan was extracted from Ulva lactuca collected from Alexandria coastline, Egypt, using a simple extraction method. According to the chemical analysis, the obtained polysaccharide content is estimated to be 36.50 g/100 g with a high sulfate content of 19.72%. Physio-chemically, the FTIR analysis confirmed the presence of sulfated groups attached to the carbohydrate backbone. The GC–MS results revealed the presence of various monosaccharides with relative abundances in the order: fucopyranose (22.09%) > L-rhamnose (18.17%) > L-fucose (17.46%) > rhamnopyranose (14.29%) > mannopyranose (8.59%) > α-D-glactopyranose (7.64%) > galactopyranose (6.14%) > β-arabinopyranose (5.62%). In addition, the SEM–EDX depicted an amorphous architecture with a majority wt% for the elements of C, O, and S. The partially purified ulvan demonstrated potent antimicrobial activity against some fish and human pathogenic microbes. The inhibition zone diameter ranged from 11 to 18 mm. On the other hand, the prepared ulvan-chitosan hydrogel significantly improved the antimicrobial activity as the inhibition zone diameter ranged from 12 to 20. Moreover, when compared to the controls, the extracted ulvan demonstrated anti-fouling properties and successfully disrupted the biofilm formed on a glass slide submerged in seawater.

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Introduction: The X-ray repair cross-complementing 1 (XRCC1) enzyme plays an important role in the DNA repair pathway. XRCC1 polymorphism increased the risk of human oral squamous cell carcinoma. Loading of thymoquinone on gold nanoparticles as a drug carrier, had revealed a superior anti-cancer effect as a chemotherapeutic agent in DMBA-induced OSCC. Aim of the work: This study aimed to evaluate the expression of DNA repair enzyme X-ray repair cross-complementing 1 (XRCC1) following treatment of induced oral cancer in hamster buccal pouch with thymoquinone (TQ) only and loaded on gold nanoparticles (AuNps). Materials and methods: Sixty male Syrian golden hamsters were divided into 4 groups: Group A: (negative control). The left pouches of the rest of animals were painted with the carcinogen DMBA (3times / week/ 12 weeks), then: Group B: (positive control), Group C: painted and injected intraperitoneally (i.p) with TQ only (3 times/week for 6 and 12 weeks). Group D: painted with TQ loaded on AuNps (3 times/week for 6 and 12 weeks). After euthanization, all pouches were surgically excised, fixed and processed for H&E and XRCC1 immunohistochemical stains. Results: Groups B, C1, C2, and D1 showed well-differentiated squamous cell carcinoma with low intensity of immune staining. Groups D2 showed remarkable regression of tumors both clinically and histologically with high intensity of IHC staining. Conclusion: Loading of TQ at low concentration (0.001 mg/kg) on AuNps /12 weeks was a promising chemotherapeutic combination, through enhancing XRCC1 expression to regress the carcinogenesis process. This effect could be due to the anti-oxidant, free-radicle scavenging effect and enhancing apoptosis by TQ.