[Risk factor analysis on body mass rebound after laparoscopic sleeve gastrectomy and establishment of a nomogram prediction model].

Objective: To investigate the potential independent risk factors of body mass rebound following laparoscopic sleeve gastrectomy (LSG) and construct a nomogram prediction model based on these factors. Methods: In this retrospective observational study, patients with obesity who had undergone LSG at the Department of Gastrointestinal Surgery of the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University between January 2015 and July 2017 were retrospectively enrolled. These patients were divided according to their status of postoperative body mass rebound. The inclusion criteria were patients aged between 16 and 65 years who had undergone LSG bariatric surgery with surgical indications according to the 2014 Chinese Guidelines for the Surgical Management of Obesity and Type 2 Diabetes Mellitus. The exclusion criteria were patients who had undergone other bariatric surgeries, who were taking weight-loss drugs or drugs that affected their body weight, who had severe gastroesophageal reflux and hiatal hernia, who were pregnant, who had incomplete clinical data, and who were lost to follow-up or were followed up for <3 years. In total, 241 patients with obesity (69 males and 172 females) who had undergone LSG surgery were enrolled. The mean age and body mass index (BMI) were (29.9±5.8) years and (40.8±4.8) kg/m2, respectively. The patients were followed up till July 2022, with a focus on their body weight. Postoperative body mass rebound was defined as a percentage increase of ≥10% from the nadir body mass, which was the lowest body mass during the 3-year follow-up period. The body weight rebound following LSG and its influencing factors were observed, based on which a nomogram model was constructed and evaluated. The relationships between the patients' basic data, clinical indicators, preoperative hematological indicators, postoperative indicators, and body weight rebound following LSG were analyzed via univariate analysis. Independent risk factors were further screened by multivariate logistic regression analysis. Factors with a statistically significant difference were included into the nomogram prediction model. Moreover, the model was internally (modeling set) and externally (validation set, 80 baseline data-matched patients with obesity from our center) validated using receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) via R software. ROC curve analysis was used to analyze the predictive and cutoff values of the measurement data for body mass rebound. Results: Overall, 90 patients (37.3%) exhibited postoperative body weight rebound, with the lowest BMI of (29.5±2.6) kg/m2 and time to reach the lowest BMI of (15.4±2.3) months; 151 patients (62.7%) did not exhibit body weight rebound, with the lowest BMI of (29.8±2.3) kg/m2 and time to reach the lowest BMI of (14.7±2.1) months. The results of univariate analysis showed that BMI, depression, anxiety, C-reactive protein (CRP) levels, systemic immune inflammatory index (SII), prognostic nutritional index (PNI), and albumin/fibrinogen ratio (AFR) were associated with body weight rebound following LSG with statistically significant differences (all P<0.05). The results of multivariate regression analyses suggested that depression [odds ration (OR) = 1.31, 95% confidence interval (CI): 1.08-1.62, P=0.010], preoperative CRP levels of ≥8 mg/L (OR = 1.34, 95% CI: 1.09-1.69, P=0.007), SII (OR = 0.58, 95% CI: 0.41-0.86, P=0.013), PNI (OR = 2.06, 95% CI: 1.03-4.21, P=0.007), and AFR (OR: 0.49, 95% CI: 0.33-0.69, P=0.011) were five independent risk factors for body mass rebound. A nomogram prediction model was constructed based on the multivariate analysis results. The scores of PNI, SII, AFR, CRP, and depression were 92.5, 100, 72.5, 25, and 27.5, respectively. The total score was calculated by adding the individual scores of each risk factor, which was used to calculate the probability of body mass rebound following LSG. The evaluation results of the nomogram model showed a C-index of 0.713 and 0.762, sensitivity of 0.656 and 0.594, and specificity of 0.715 and 0.909 in the modeling and validation sets, respectively. The calibration curve analysis and DCA indicated that the nomogram model has a good predictive value for body mass rebound after LSG. Conclusion: Preoperative depression, CRP of ≥8 mg/L, SII, PNI, and AFR were independent risk factors for body mass rebound following LSG. Hence, the nomogram prediction model based on these factors can effectively predict body mass rebound in patients undergoing LSG.

Simulation study of a high-order mode terahertz radiation source based on an orthogonal grating waveguide and multiple sheet electron beams.

Generally, it is difficult for the common backward wave oscillator (BWO) to produce powerful THz radiation when the operating frequency increases to a high level such as over 1 THz due to the very small structural dimensions. The concept of generating powerful THz radiation from the interaction between high-order mode THz wave and multiple sheet electron beams is a promising solution to address the issue. For the high-order mode operation, a novel orthogonal grating waveguide is proposed, which is relatively ease of fabrication compared with the overmoded structure based on the double staggered grating waveguide. A high-order mode BWO based on the orthogonal grating waveguide and multiple sheet electron beams is studied by simulations. Particle-in-cell simulations show that the BWO can provide over 1.08 W power in the frequency range of 1.18-1.30 THz. Such a methodology opens up a new way to extend the BWO's operating frequency to a higher level and provides a potential solution for developing compact powerful THz radiation sources with wide tunable bandwidth.

[Effect of huoxue tablet on the rheology of erythrocyte in primary hypertension].

OBJECTIVE: To explore the effect of Huoxue Tablet on the rheology of erythrocyte and the therapeutic effect in treating primary hypertension. METHODS: Seventy-five cases of primary hypertension patients were randomly divided into 3 groups. Group I was treated by Huoxue Tablet, group II was treated by composite Danshen tablet, group III was treated by placebo. Erythrocytes deformability and aggregation were determined by laser diffractometry apparatus before and after treatment. RESULTS: After treated by Huoxue Tablet for 5-6 weeks. The authors found that deformability of erythrocyte was increased, the aggregation of erythrocyte, the whole blood viscosity and the blood pressure were reduced. The clinical symptoms were relieved. CONCLUSIONS: Huoxue Tablet can obviously improve the rheology of erythrocyte of the primary hypertension and relieve the clinical symptoms. It can be used as a supplementary medicine in treating primary hypertension.

[Study on mast cells in experimental silicosis].

Quantitative and ultrastructural changes of mast cells (MC) were studied in rat lungs after inhalation of quartz particles. The number of degranulating MC was remarkably increased two weeks and 4 weeks after quartz inhalation (P < 0.05). The average number of the MC per unit area (mm2 of tissue section) and distribution in both experimental and control groups were similar and the mast cells were mainly distributed in the subpleural, perivascular and peribronchial connective tissues. The average number of MC per unit area significantly increased with pulmonary fibrosis three months later. Most of them infiltrated in the fibrotic alveolar septa and fibrotic areas, and the number of degranulating MC was also remarkably increased (P < 0.05). In addition, electronic microscopy showed that mast cells came into contact with fibroblast-like cells and the mast cells usually became degranulated in appearance. These results suggest that there is a close relationship between MC and silicotic fibrosis.

[Changes in type II alveolar epithelial cells in experimental allergic alveolitis].

Changes of type II alveolar epithelial cells (type II cells) were studied in experimental allergic alveolitis by using enzyme histochemical, electron microscopic and morphometric techniques. The results showed that the number of type II cells increased obviously after exposed to thermoactinomyces vulgaris (TV). The peak was on the 15th day and then decreased gradually till to normal on the 180th day. Type II cells could be divided into two populations in TV-treated rats, namely, the large type II cells and the small type II cells. The former ones bore a diameter larger than the value of mean + 2.58s and mean indicated the mean value of type II cells diameters of the controls. The large type II cells are known to be the hypertrophic cells.

Intraerythrocytic parasites and red cell deformability: Plasmodium berghei and Babesia microti.

In the studies reported here, we examined the effects of two intraerythrocytic parasites (Plasmodium berghei and Babesia microti) on the deformability of their host red cells. Red cell deformability was assessed by three criteria: 1) the prevalence of tank-treading (the tank-tread-like movement of the red cell membrane around its cytoplasmic contents), 2) elongation under fluid shear stress (the steady-state length: width ratio), and 3) the time required for the red cell to reduce its steady-state elongation by 63.2% after the abrupt release of the shear stress (the characteristic shape-recovery time). Trophozoite-stage parasites of both species reduced the prevalence of tank-treading. Ring- and trophozoite-stage parasites of both species reduced steady-state elongation, and ring-stage P. berghei prolonged the shape-recovery time. These results suggest that altered red cell deformability is a common feature of infection with intraerythrocytic parasites.

Effects of Chinese medicinal herbs on hemorheology in diabetics.

There was a statistically significant increase in whole blood viscosity, plasma viscosity, erythrocyte filterability index and hematocrit in diabetics with "Qi Yin deficiency and blood stasis" syndrome. After treatment with "Yi Qi Yang Yin Hou Xue" prescription there was a statistically significant improvement in hemorheological properties and a slight decrease in fasting blood glucose.