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Despite the growing awareness on the importance of gut microbiomes, understanding marine mammal gut microbiomes remains limited due to difficulties in sampling. Spotted dolphins (Stenella attenuata) are widely spread oceanic cetaceans, and there is a gap in knowledge regarding their gut microbiology. In this study, we opportunistically collected samples from both wild and human-cared spotted dolphins in the southern waters of Hainan Island, China. This provided the opportunity to examine the composition and diversity of the gut microbial communities of this cetacean species. Since these dolphins inhabit a similar water environment, different food sources might be the primary factor distinguishing the gut microbiomes of wild and human-cared populations, offering valuable experimental material to investigate potential differences in gut microbial community structure among marine mammals in similar environments but with varying food sources. We found that the gastrointestinal microbial community structure of wild and human-cared dolphins demonstrated significant differences, both overall and at specific locations. However, no significant difference was observed in the microbial diversity of their gastrointestinal tracts, indicating that the disparities primarily lie in microbiota composition. Additionally, we detected numerous potentially pathogenic bacteria, suggesting a comprehensive future study of marine mammal gut microbiology. Such a study might involve determining health indicator factors associated with these microbiomes. Our study not only supplements information on the gut microbiology of spotted dolphins but also delves into the similarities and differences in gastrointestinal microbial communities within the same marine mammal species when food source variations play a significant role in their lives.

Abstract Objective To explore the application of magnetic resonance imaging (MRI) in the evaluation of radiation-induced sinusitis (RIS), MRI-based scoring system was used to evaluate the development regularity, characteristics and influencing factors of RIS in nasopharyngeal carcinoma (NPC) patients. Patients and methods A retrospective analysis was performed by collecting the clinical and MRI data of 346 NPC patients to analyze the characteristics and prognosis of RIS. The predictive model was constructed according to the influencing factors of RIS. Results (1) In the 2-year follow-up after radiotherapy (RT), there was significant change in L-M score in both groups of NPC patients (sinusitis before RT group: p = 0.000 vs. non-sinusitis before RT group: p = 0.000). After 6 months of RT, the L-M scores of the two groups tended to plateau (sinusitis before RT group: p = 0.311 vs. non-sinusitis before RT group: p = 0.469). (2) The prevalence of sinusitis in two groups of NPC patients (without or with sinusitis before RT) was 83% vs. 93%, 91% vs. 99%, 94% vs. 98% at 1, 6 and 24 months after RT, respectively. (3) In the patients without sinusitis before RT, the incidence of sinusitis in maxillary and anterior/posterior ethmoid, sphenoid and frontal sinuses was 87.1%, 90.0%/87.1%, 49.5%, 11.8% respectively, 1 month after RT. (4) A regression model was established according to the univariate and multivariate analysis of the factors related to RIS (smoking history: p = 0.000, time after RT: p = 0.008 and TNM staging: p = 0.040). Conclusion (1) RIS is a common complication in NPC patients after RT. This disorder progressed within 6 months after RT, stabilized and persisted within 6 months to 2 years. There is a high incidence of maxillary sinus and ethmoid sinus inflammation in NPC patients after RT. (2) Smoking history, time after RT and TNM staging were significant independent risk factors for RIS. (3) The intervention of the risk factors in the model may prevent or reduce the occurrence of RIS in NPC patients.

Generally, a species is defined as an independent unit that is reproductively isolated from others. However, deviations from this definition are not uncommon. For example, cross-fertilization in pinnipeds has been reported among at least 10 species. Herein, we describe an unexpected hybridization that occurred between female gray seals (Halichoerus grypus) and male spotted seals (Phoca largha) in the presence of adult male gray seals in a mixed-species seal population under human care. To our knowledge, these are the first cases of gray and spotted seal hybrids ever reported. The three hybridized offspring had the appearance of a gray seal body and a spotted seal head. Microsatellite DNA markers were employed as genetic evidence to further support the hybridization events. Our study suggests a natural preference for interspecies hybridization between female gray seals and male spotted seals in human care. Following that, potential causes of cross-species hybridization, including female preference, male competition, and some other factors, are discussed. [ABSTRACT FROM AUTHOR]