Development and validation of a diagnostic model for predicting cervical lymph node metastasis in laryngeal and hypopharyngeal carcinoma.

Objectives: The lymph node status is crucial for guiding the surgical approach for patients with laryngeal and hypopharyngeal carcinoma (LHC). Nonetheless, occult lymph node metastasis presents challenges to assessment and treatment planning. This study seeks to develop and validate a diagnostic model for evaluating cervical lymph node status in LHC patients. Materials and methods: This study retrospectively analyzed a total of 285 LHC patients who were treated at the Department of Otolaryngology Head and Neck Surgery, Daping Hospital, Army Medical University, from January 2015 to December 2020. Univariate and multivariate logistic regression analyses were employed to construct the predictive model. Discrimination and calibration were used to assess the predictive performance of the model. Decision curve analysis (DCA) was performed to evaluate the clinical utility of the model, and validation was conducted using 10-fold cross-validation, Leave-One-Out Cross Validation, and bootstrap methods. Results: This study identified significant predictors of lymph node metastasis in LHC. A diagnostic predictive model was developed and visualized using a nomogram. The model demonstrated excellent discrimination, with a C-index of 0.887 (95% CI: 0.835-0.933). DCA analysis indicated its practical applicability, and multiple validation methods confirmed its fitting and generalization ability. Conclusion: This study successfully established and validated a diagnostic predictive model for cervical lymph node metastasis in LHC. The visualized nomogram provides a convenient tool for personalized prediction of cervical lymph node status in patients, particularly in the context of occult cervical lymph node metastasis, offering valuable guidance for clinical treatment decisions.

Developmental Times of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) at Constant Temperatures and Applications in Forensic Entomology.

The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16-34°C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D0 = 9.07 ± 0.54°C and K = 3991.07 ± 187.26 h °C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala.

The effect of dietary fat levels on the size and development of Chrysomya megacephala (Diptera: Calliphoridae).

Variation in the type of tissue that larvae feed on can produce marked differences in developmental rate and body size, which can compromise predictions of minimum postmortem interval. A series of experiments were conducted to investigate the effect of fat content in the diet on larval growth in Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), an important forensic blowfly species in China. Bionomical parameters such as body size, development time, mortality, and sex ratio were observed. The results indicated that fat content in the diet has a dramatic effect on the body size and larval development. More dietary fat content was beneficial for development of larvae in first and early second instar. But it was adverse in the later third instar. Significantly, a high-fat diet resulted in increased development rates and the production of undersized larvae and adults. Overall mortality of larvae and pupa was higher when more fat was added to the diet, but sex ratio of adults was not negatively affected. This study highlights that the fat content in the diet should be considered in the entomological research and forensic application when estimating minimum postmortem interval on the basis of larval body size and developmental stage.

[Low volume amplification in single cell separation and inspection].

OBJECTIVE: To establish optimal amplification conditions with the application of 0.2 mL test tube in single cell separation and inspection. METHODS: Oral epithelium cell suspension was prepared. Five or ten cells were collected with 0.2 mL test tube. Then DNA were amplified with Identifiler Plus kit in three different conditions in which the proteinase K addition, gold enzyme concentration in PCR reaction, and PCR reaction cycles were adjusted separately. Finally the detection rate, allelic dropout rate and artificial alleles were compared among the groups. RESULTS: In these 3 different conditions: addition of proteinase K, addition of 0.4 microL gold enzyme in PCR reaction, and use of 32 cycles, the detection rate was higher and allelic dropout rate was lower than the other conditions. CONCLUSION: In single cell separation and inspection, the usage of 0.2 mL test tube could be an effective supplement to chip-low volume amplification.

Bartonella quintana infections in captive monkeys, China.

Bartonella quintana has been considered to be specifically adapted to humans. Our isolation of the organism from 2 of 36 captive rhesus macaques in China and finding antibodies against B. quintana in 12 of 33 indicates that the reservoir hosts of B. quintana may include primates other than humans.