[Clinical management and prognosis for descending necrotizing mediastinitis].

Objective: To investigate the clinical characteristics, treatment experiences and prognostic factors for descending necrotizing mediastinitis (DNM). Methods: A retrospective analysis was performed on the data of 22 patients with DNM diagnosed and treated in Henan Provincial People's Hospital from January 2016 to August 2022, including 16 males and 6 females, aged 29-79 years. After admission, all patients underwent CT scanning of the maxillofacial, cervical, and thoracic regions to confirm their diagnoses. Emergency incision and drainage were performed. The neck incision was treated with continuous vacuum sealing drainage. According to the prognoses, the patients were divided into cure group and death group, and the prognostic factors were analyzed. SPSS 25.0 software was used to analyze the clinical data. Rusults: The main complaints were dysphagia (45.5%, 10/22) and dyspnea (50.0%, 11/22). Odontogenic infection accounted for 45.5% (10/22) and oropharyngeal infection accounted for 54.5% (12/22). There were 16 cases in the cured group and 6 cases in the death group, with a total mortality rate of 27.3%. The mortality rates of DNM typeⅠand typeⅡwere respectively 16.7% and 40%. Compared with the cured group, the death group had higher incidences for diabetes, coronary heart disease and septic shock (all P<0.05). There were statistically significant differences between the cure group and the death group in procalcitonin level (50.43 (137.64) ng/ml vs 2.92 (6.33) ng/ml, M(IQR), Z=3.023, P<0.05) and acute physiology and chronic health evaluation Ⅱ(APACHEⅡ) score (16.10±2.40 vs 6.75±3.19, t=6.524, P<0.05). Conclution: DNM is rare, with high mortality, high incidence of septic shock, and the increased procalcitonin level and APACHE Ⅱ score combined diabetes and coronary heart disease are the poor prognostic factors for DNM. Early incision and drainage combined with continuous vacuum sealing drainage technique is a better way to treat DNM.

[Positional relationship between branches of the facial nerve and the plane of angulus oris: an anatomical study].

Objective: To investigate the relationship between the inferior buccal branch and mandibular marginal branch of the facial nerve in the plane of angulus oris. Methods: Twenty unilateral adults cadaveric heads were dissected. In the vicinity of the posterior border of mandibular ramus, the positional relationship between mandibular marginal branch and the plane of angulus oris, the inferior buccal branch and the plane of angulus oris was recoded and analyzed. Results: In 18 of the 20 samples, the plane of angulus oris was between the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. In one sample, the plane of angulus oris was below the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. Another sample was excluded because the starting points of the inferior buccal branch and mandibular marginal branch were in front of the posterior border of mandibular ramus. The distance from the intersection of the posterior border of mandibular ramus and the plane of angulus oris to the intersection of inferior buccal branch and the plane of angulus oris was (14.96±8.55) mm. Conclusions: In most cases studied, the plane of angulus oris is between the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. Along the plane of angulus oris, within 1.0 cm anterior to the posterior border of mandibular ramus, it is a relatively safe place for surgical approach.

Two designs of platysma myocutaneous flap for reconstruction of oral and facial defects following cancer surgery.

This study evaluates the effects of two different designs of platysma myocutaneous flap, vertical and transverse, used in the reconstruction of defects following the excision of oral and facial tumors. Modified radical neck dissection or selected neck dissection was also performed. Out of the 48 patients, vertical and transverse platysma myocutaneous flaps were used for 41 and 7, respectively. The postoperative outcome for the vertical flaps was 37 cases surviving, two cases of complete necrosis, and two cases of partial necrosis. With the transverse flaps, six survived and there was one case of complete necrosis. The success rate was 90.2% and 85.7% for the vertical and the transverse flap, respectively. The form and function of recipient sites were well recovered. In conclusion, the platysma myocutaneous flap has clinical value in selected patients needing reconstruction of small and medium-sized intraoral or facial defects. It is recommended that the vertical design be used for reconstruction of buccal mucosa defects, and the transverse design for mouth-floor and facial defects.

A vector projection method for predicting supersecondary motifs.

For the 11 types of most frequently occurring supersecondary motifs, we used a new method--the vector projection method--to predict a protein's supersecondary structure. In a training set of peptides and a test set of peptides we obtained a satisfactory result, with a prediction accuracy of about 90%. The high prediction accuracy indicates that this method is reasonable for predicting the folding motifs of proteins. This work provides insight into the problem of predicting a protein's local structure accurately, and is of particular value in protein modeling, prediction, and molecule design.

Magnetic resonance imaging evaluation of the effects of ageing on grey-white ratio in the human brain.

A previous neuropathological report noted a non-linear pattern of change in cerebral grey-white matter ratio during ageing. In that report, grey-white ratio decreased from age 20 to age 50, then increased in elderly subjects. The objective of the current study was to attempt to replicate this pattern of age-related change in the grey-white ratio in living human subjects using quantitative magnetic resonance imaging segmentation analysis. We measured the grey-white ratio in 78 subjects between the ages of 19 and 77 years, using a computer segmentation algorithm with magnetic resonance images. In agreement with the previous neuropathological report, the current in vivo magnetic resonance study found that the grey-white ratio declined from age 20 to age 50, then increased in elderly subjects.

Decreased regional cortical gray matter volume in schizophrenia.

OBJECTIVE: The authors hypothesized that cortical gray matter volume reduction in schizophrenia is greatest in the heteromodal association cortex. This area comprises a highly integrated, reciprocally interconnected system that coordinates higher order cortical functions. METHOD: Total brain and regional gray matter volumes were calculated in 46 schizophrenic patients and 60 age and sex-matched comparison subjects by using magnetic resonance images. Disease specificity was examined by assessing 27 patients with bipolar disorder. Approximations to the dorsolateral prefrontal cortex, inferior parietal lobule, and superior temporal gyrus were selected as regions of interest for the heteromodal association cortex. Occipital and sensorimotor areas were used as comparison regions to test the hypothesis for regional specificity. RESULTS: Gray matter volume was reduced in schizophrenic patients in index regions even after covariance for overall brain volume, sex, and age. Bipolar disorder patients did not exhibit heteromodal gray matter reduction. Comparison regions did not differ among the three groups. Global gray matter volume was not different among groups after covariance for global brain volume. Comprehensive individual region post hoc analysis found no additional gray matter differences. CONCLUSIONS: These findings support the theory of disproportionate reduction of gray matter volume in the heteromodal association cortex specific to schizophrenia.

MR volume segmentation of gray matter and white matter using manual thresholding: dependence on image brightness.

PURPOSE: To describe a quantitative MR imaging segmentation method for determination of the volume of cerebrospinal fluid, gray matter, and white matter in living human brain, and to determine the method's reliability. METHODS: We developed a computer method that allows rapid, user-friendly determination of cerebrospinal fluid, gray matter, and white matter volumes in a reliable manner, both globally and regionally. This method was applied to a large control population (N = 57). RESULTS: Initially, image brightness had a strong correlation with the gray-white ratio (r = .78). Bright images tended to overestimate, dim images to underestimate gray matter volumes. This artifact was corrected for by offsetting each image to an approximately equal brightness. After brightness correction, gray-white ratio was correlated with age (r = -.35). The age-dependent gray-white ratio was similar to that for the same age range in a prior neuropathology report. Interrater reliability was high (.93 intraclass correlation coefficient). CONCLUSIONS: The method described here for gray matter, white matter, and cerebrospinal fluid volume calculation is reliable and valid. A correction method for an artifact related to image brightness was developed.