A Retrospective Cohort Study of Risk Factors for Descending Necrotizing Mediastinitis Caused by Multispace Infection in the Maxillofacial Region.

PURPOSE: Descending necrotizing mediastinitis (DNM) has been the most common life-threatening complication of multispace infection (MSI) in the maxillofacial region owing to the lack of a timely diagnosis and treatment. We assessed the clinical characteristics and diagnosis of odontogenic MSI and evaluated the risk factors for DNM caused by MSI. PATIENTS AND METHODS: We performed a retrospective cohort study of inpatients with MSI in the maxillofacial region from January 2012 to October 2016. The patients were classified into a non-DNM group and a secondary DNM group. The information collected included gender, age, systemic comorbidities, source of maxillofacial infection, computed tomography imaging data, and laboratory test results. Univariate analysis (t test and χ2 test, or the Fisher exact test) and logistic regression analysis were applied. RESULTS: A total of 296 patients were included. The mortality was 6.3%. On univariate analysis, the following factors were statistically significant: gender (P = .001); age (P = .003); source of infection (P = .004); number of affected spaces (P < .001); involvement of the parotid space (P < .001), submandibular space (P < .001), subgingival space (P < .001), pterygomandibular space (P < .001), parapharyngeal space (P < .001), and retropharyngeal space (P < .001); and percentage of neutrophils (P < .001). On multivariate analysis, the parapharyngeal space (P = .008), source of infection (P = .037), and number of affected spaces (P < .001) were statistically significant. CONCLUSIONS: Glandular infection, parapharyngeal space involvement, and the presence of multiple affected spaces were risk factors for DNM. Clinicians should vigilantly watch for these factors during clinical treatment and effective measures taken to prevent the occurrence of DNM as soon as possible.

Isolation and characterization of drought-responsive genes from peanut roots by suppression subtractive hybridization

Background Peanut (Arachis hypogaea L.) is an important economic and oilseed crop. Long-term rainless conditions and seasonal droughts can limit peanut yields and were conducive to preharvest aflatoxin contamination. To elucidate the molecular mechanisms by which peanut responds and adapts to water limited conditions, we isolated and characterized several drought-induced genes from peanut roots using a suppression subtractive hybridization (SSH) technique. Results RNA was extracted from peanut roots subjected to a water stress treatment (45% field capacity) and from control plants (75% field capacity), and used to generate an SSH cDNA library. A total of 111 non-redundant sequences were obtained, with 80 unique transcripts showing homology to known genes and 31 clones with no similarity to either hypothetical or known proteins. GO and KEGG analyses of these differentially expressed ESTs indicated that drought-related responses in peanut could mainly be attributed to genes involved in cellular structure and metabolism. In addition, we examined the expression patterns of seven differentially expressed candidate genes using real-time reverse transcription-PCR (qRT-PCR) and confirmed that all were up-regulated in roots in response to drought stress, but to differing extents. Conclusions We successfully constructed an SSH cDNA library in peanut roots and identified several drought-related genes. Our results serve as a foundation for future studies into the elucidation of the drought stress response mechanisms of peanut.