BACKGROUND:The Twin-block orthodontic appliance is commonly used for the correction of Class Ⅱ malocclusion.Its mechanism of action in stimulating mandibular growth has been confirmed in many studies,but its impact on maxillary growth is not very clear. OBJECTIVE:By establishing a finite element model to analyze the stress distribution of the maxillary complex,surrounding bone sutures,and maxillary dentition in patients with Class Ⅱ malocclusion wearing Twin-block orthodontic appliances. METHODS:One patient with Class Ⅱ malocclusion who underwent orthodontic treatment at Qingdao Hospital/Qingdao Municipal Hospital of Shandong Rehabilitation University was selected.The bite force data of the patient when wearing the Twin-block orthodontic appliance was measured,and CBCT data were collected.A finite element model was established,including the maxillary complex,peripheral sutures,Twin-block orthodontic appliance,and maxillary dentition.ABAQUS software was used to simulate the stress distribution in the maxilla and maxillary dentition when the patient was wearing the Twin-block appliance. RESULTS AND CONCLUSION:The equivalent stress on the maxillary anterior teeth was significantly smaller than that on the posterior teeth,and the maximum equivalent stress on both sides of the teeth were 4.797 5 Mpa and 8.716 1 Mpa,respectively,which were located at the first premolar.The maximum displacements were presented at the maxillary incisors on both sides of the teeth,which were 0.080 5 mm and 0.081 0 mm,respectively.The maximum equivalent stress on the bone suture was 1.284 Mpa,which was mainly concentrated in the pterygopalatine suture and the frontal-maxillary suture on both sides,and there was almost no difference in the force of the rest of bone sutures;the maximum displacement of the bone suture was 0.07 mm,with the pterygopalatine suture having the largest displacement,followed by the frontal-maxillary suture.The maximal equivalent stress on the maxillary complex was 27.18 Mpa,which was mainly concentrated on both sides of the anterior pyriform foramen of the maxilla,around the nasofrontal suture and around the pterygopalatine suture at the posterior part of the jaws.The maximal displacement of the maxilla was 0.07 mm,which was mainly concentrated on the maxillary alveolar bone.All these findings show that the occlusal force acts on the maxillary complex through the Twin-block appliance,resulting in clockwise rotation of the maxilla and steepening of the dentition plane.Measures should be taken to compensate for this tendency,for example,by considering maxillary molar elongation and intrusion in the process of occlusion,which are not only able to flatten the occlusal plane,but facilitate the mandibular protraction,thereby further improving Class Ⅱ malocclusion orthodontic treatment.

BACKGROUND:Most of the studies on combined orthodontic-orthognathic treatment of skeletal class Ⅲ malocclusions have focused on the improvement of the patient's lateral appearance and recovery in the later stages of the treatment,while there are fewer studies observing the microcosmic nature of the alveolar bone remodeling of the lower anterior teeth. OBJECTIVE:To evaluate the therapeutic effect of lower anterior tooth decompensation and alveolar bone remodeling in patients with skeletal class Ⅲ malocclusion before and after orthodontic-orthognathic treatment based on oral X-ray lateral films and oral cone-beam CT. METHODS:From January 2015 to May 2023,15 patients with skeletal class Ⅲ malocclusion who underwent orthodontic-orthognathic surgery at Qingdao Hospital of Rehabilitation University were enrolled.All patients underwent lateral cephalography and cone beam computed tomography before and after treatment.Cephalometric measurement items related to the angle and line distance,lip/lingual bone cracking length(d-La/d-Li)and bone cracking/bone fenestration of the lower anterior teeth before and after treatment were measured. RESULTS AND CONCLUSION:Lateral X-ray films showed that the amount of alveolar bone remodeling after decompensation of the lower anterior teeth showed significant changes compared to before treatment.The root of the tooth moved significantly towards the center of the alveolar bone,and the specific data was closer to normal data,but there were still some differences compared with normal individuals.Based on the cone-beam CT measurement,the bone cracking/bone fenestration length and width of the alveolar bone were improved in almost all the teeth after orthodontic-orthognathic combined treatment,alveolar bone remodeling in some teeth even reached the level of healthy individuals.Before treatment,most patients often experienced bone fenestration/cracking on the lip/lingual side of the lower incisor due to compensatory tooth growth.However,during the preoperative orthodontic stage,decompensation triggered alveolar bone remodeling and significant changes in tooth angle.Preoperative orthodontic treatment caused the upper anterior teeth to retract and the lower anterior teeth to tilt and control the root,but the amount of decompensation before surgery was often insufficient.In the orthognathic surgery stage,the jaw was removed through the positioning guide plate,the maxilla moved forward,and the mandible retreated.During the postoperative orthodontic process,the effect of fine adjustment was better.Although there is a certain degree of recurrence trend in the position of teeth and jawbones,the postoperative orthodontic treatment is closer to the normal value.

BACKGROUND:Temporomandibular joint disorders are closely related to high stress in temporomandibular joint.With the change of molar position after tooth reduction extraction,the establishment of new occlusal relationship often leads to the change of internal stress environment of the temporomandibular joint. OBJECTIVE:To analyze the stress distribution of temporomandibular joint in patients undergoing orthodontic reduction tooth extraction with different degrees of molar forward movement using the three-dimensional finite element model of the maxillary complex and temporomandibular joint. METHODS:A case of individual normal occlusal patient was selected from the Orthodontics Department of Qingdao Municipal Hospital,Shandong Province,and the finite element models of 1/3 anterior molar space(extraction of four second premolar teeth)before and after reduction and 2/3 anterior molar space(extraction of 4 second premolar teeth)after reduction were established based on the cone-beam CT and MRI data.ABAQUS software was used to analyze the stress distribution of various parts of the temporomandibular joint during the interposition of tooth tips. RESULTS AND CONCLUSION:The stress distribution of the condyle,articular disc,and osteoarticular fossa in the model before and after the reduction was basically the same.The stress of the condyle was mainly distributed in the anterior and apical part of the condyle,the stress of the articular disc was mainly distributed in the middle band and lateral part of the articular disc,and the stress of the articular fossa was mainly concentrated in the anterior and apical part of the articular fossa.However,the equivalent stress value of the condyle,articular disc and articular fossa decreased after reduction.After orthodontic reduction extraction,the equivalent stress values of condyle and articular disc in the 1/3 anterior molar space model were smaller than those in the 2/3 anterior molar space model.From the perspective of biomechanics,orthodontic reduction extraction can reduce the stress of the temporomandibular joint and provide a good biomechanical environment.

Objective:To investigate the microsurgical efficacy of large primary intracranial solitary fibrous tumor and influencing factors for its prognoses.Methods:From January 2010 to December 2022, 47 patients with large primary intracranial solitary fibrous tumor admitted to and accepted microsurgery in Department of Neurosurgery, Wuhan Central Hospital and Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, were enrolled. The clinical data, microsurgical efficacy and follow-up results of these patients were retrospectively analyzed, and influencing factors for total resection and prognoses were determined.Results:Thirty-two patients had tumor within the supratentorial region and 15 in the mandibular region, including 24 with sinus involved tumor. According to 2021 WHO Classification of Tumors of the Central Nervous System, 5 patients (10.6%) had grading 1, 32 (68.1%) grading 2, and 10 (21.3%) grading 3. Total resection was achieved in 31 patients (66.0%) and subtotal resection in 16 patients (34.0%). Postoperative complications, such as intraoperative hemorrhage, distant epidural hematoma and subcutaneous effusion, occurred in 7 patients (14.9%) and they were cured after secondary hematoma removal or conservative treatment; residual limb mobility disorder occurred in 3 patients, visual impairment in 3, and postoperative seizures in 2. Adjuvant radiotherapy was performed in 13 patients (27.7%). Follow-up was performed for (69.1±29.6) months and 29 patients (61.7%) had recurrent tumors (6 with intracranial and extracranial metastases and 4 deaths). Mean progression-free survival was (57.5±25.1) months; the 1-, 3-, and 5-year progression-free survival rates were 95.7%, 87.2%, and 59.6%, respectively. Sinus involvement was the independent influencing factor for total tumor resection; and total resection was an independent protective factor for progression-free survival for large primary intracranial solitary fibrous tumor ( HR=4.291, 95% CI: 1.555-11.838, P=0.005). Conclusion:Patients with large primary intracranial solitary fibrous tumor have a high recurrent risk after surgery; and gross-total resection should be strived to prevent tumor recurrence.

Corona virus disease 2019 (COVID-19) is an acute respiratory infectious disease with strong contagiousness, strong variability, and long incubation period. The probability of misdiagnosis and missed diagnosis can be significantly decreased with the use of automatic segmentation of COVID-19 lesions based on computed tomography images, which helps doctors in rapid diagnosis and precise treatment. This paper introduced the level set generalized Dice loss function (LGDL) in conjunction with the level set segmentation method based on COVID-19 lesion segmentation network and proposed a dual-path COVID-19 lesion segmentation network (Dual-SAUNet++) to address the pain points such as the complex symptoms of COVID-19 and the blurred boundaries that are challenging to segment. LGDL is an adaptive weight joint loss obtained by combining the generalized Dice loss of the mask path and the mean square error of the level set path. On the test set, the model achieved Dice similarity coefficient of (87.81 ± 10.86)%, intersection over union of (79.20 ± 14.58)%, sensitivity of (94.18 ± 13.56)%, specificity of (99.83 ± 0.43)% and Hausdorff distance of 18.29 ± 31.48 mm. Studies indicated that Dual-SAUNet++ has a great anti-noise capability and it can segment multi-scale lesions while simultaneously focusing on their area and border information. The method proposed in this paper assists doctors in judging the severity of COVID-19 infection by accurately segmenting the lesion, and provides a reliable basis for subsequent clinical treatment.
Humans ; COVID-19/diagnostic imaging* ; Respiratory Rate ; Tomography, X-Ray Computed

Objective     To explore the timing and safety of limited-period lung cancer surgery in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods     Clinical data of of patients infected with COVID-19 undergoing lung cancer surgery (an observation group) in the Department of Thoracic Surgery of Guangdong Provincial People's Hospital, the Department of Thoracic Surgery of General Hospital of Southern Theater Command of PLA, and the Department of Cardiothoracic Surgery of the First Affiliated Hospital of Guangdong Pharmaceutical University from December 2022 to January 2023 were retrospectively analyzed and compared with patients who underwent surgery during the same period but were not infected with COVID-19 (a control group), to explore the impact of COVID-19 infection on lung cancer surgery. Results     We finally included 110 patients with 73 patients in the observation group (28 males and 45 females at age of 52.62±12.80 years) and 37 patients in the control group (22 males and 15 females at age of 56.84±11.14 years). The average operation time of the observation group was longer than that of the control group, and the incidence of anhelation was higher than that of the control group (P<0.05). There were no statistcal differences in blood loss, length of hospital stay, moderate or above fever rate, degree of cough and chest pain, or blood routine between the two groups. Conclusion    It is safe and feasible to perform lung cancer surgery early after recovery for COVID-19 patients with lung cancer.

ObjectiveTo study the brain network during balance control tasks in older adults. MethodsFrom January to April, 2022, 22 healthy young adults and 20 healthy older adults were recruited from the Fifth Affiliated Hospital of Guangzhou Medical University and communities. They were asked to finish standing tasks on the plantar pressure plate with eyes opening and closing, while the functional connectivities (FC) of prefrontal cortex (PFC) and primary motor cortex (PMC) were measured with functional near-infrared spectroscopy. ResultsCompared with the young adults, the area of the ellipse (Z = -2.884, P < 0.01) and the maximum swing (Z = -2.481, P < 0.05) increased in the older adults as eyes closing. During the standing task, the intra-FC of left (t = 2.978, P < 0.01) and right (Z = -3.123, P < 0.01) PFC decreased in the older adults, and the inter-FC of right PMC to left PFC (t = 2.087, P < 0.05) and right PFC to left PFC (t = 3.471, P < 0.001) decreased, too. ConclusionThe FC of PFC decreased in healthy older adults during balance control tasks, which may be a indicator for aging brain.

Objective:To explore the risk factors involved in gastritis, gastric intraepithelial neoplasia (GIN) and gastric cancer in Shihezi area.Methods:A total of 7 110 Han nationality patients who underwent gastroscopy at the First Affiliated Hospital of Shihezi University School of Medicine from January 2012 to December 2016 were selected as the research subjects. The data of patients were obtained through medical records and questionnaires. After excluding diseases related to esophagus and duodenum, a total of 4 429 cases were included in the retrospective analysis. Of which, 4 249 were gastritis, 93 were GIN, and 87 were gastric cancer. χ2 test, rank-sum test or Fisher exact probability method were used to analyze the differences of various factors in gastritis, GIN and gastric cancer. Univariate and multivariate logistic regression analysis were used to screen the risk factors for gastritis progression to GIN and gastric cancer. Results:χ2 test and rank sum test showed that there were statistically significant differences in gender, age, history of digestive diseases and distribution of Helicobacter pylori ( HP) infection among the groups of gastritis, GIN and gastric cancer ( P<0.05). The proportion of HP infection decreased gradually with the disease severity. Multivariate logistic regression analysis showed that male ( P<0.001, OR=2.251, 95% CI: 1.461-3.470), elderly ( P<0.001, OR=4.829, 95% CI: 2.241-10.409), a family history of gastric cancer ( P=0.002, OR=3.227, 95% CI: 1.537-6.774) and a history of digestive diseases ( P=0.034, OR=1.644, 95% CI: 1.037-2.607) were independent risk factors for gastritis progression to GIN. Male ( P<0.001, OR=3.254, 95% CI: 2.026-5.225), middle-aged ( P=0.022, OR=2.688, 95% CI: 1.153-6.265) and elderly ( P=0.002, OR=4.734, 95% CI: 1.750-12.807) were independent risk factors for gastritis progression to gastric cancer. In stratified analysis to exclude age and gender, smoking ( P=0.028, OR=4.060, 95% CI: 1.160-14.202) was found to be a risk factor for gastritis progression to GIN in young adults, and obesity ( P=0.032, OR=3.869, 95% CI: 1.121-13.356) was found to be a risk factor for gastritis progression to gastric cancer in women. Conclusion:The degree of HP infection in gastric tissues is negatively correlated with the severity of gastric diseases, suggesting that HP infection may be an early event inducing gastric cancer. Male, the elderly, people with a family history of gastric cancer and a history of digestive diseases, and young smokers in Shihezi are more likely to develop GIN, and male, middle-aged, elderly, and obese women are at increased risk of gastric cancer.

Diabetic nephropathy is a microvascular complication in the advanced stage of diabetes. About 20%-40% of patients with diabetes will progress to diabetic nephropathy. And worldwide, diabetic nephropathy has become the leading cause of end-stage renal disease. Animal model is a useful tool to study the pathogenesis and treatment of diabetic nephropathy. Currently, the commonly used diabetic nephropathy models all simulate partial characteristics of human diabetic nephropathy in different degrees of pathophysiology. However, the research on diabetic nephropathy has not achieved considerable progress. The main obstacle is that there is no effective animal model that can fully simulate all the characteristics of human diabetic nephropathy. In this paper, the animal models of diabetic nephropathy were reviewed from the aspects of modeling mechanism, pathophysiology, their advantages and disadvantages.

Hyperhomocysteinemia (Hhcy) is an independent risk factor for Alzheimer's disease (AD). Visual dysfunction is commonly found and is positively correlated with the severity of cognitive defects in AD patients. Our previous study demonstrated that Hhcy induces memory deficits with AD-like tau and amyloid-β (Aβ) pathologies in the hippocampus, and supplementation with folate and vitamin B12 (FB) prevents the Hhcy-induced AD-like pathologies in the hippocampus. Here, we investigated whether Hhcy also induces AD-like pathologies in the retina and the effects of FB. An Hhcy rat model was produced by vena caudalis injection of homocysteine for 14 days, and the effects of FB were assessed by simultaneous supplementation with FB in drinking water. We found that Hhcy induced vessel damage with Aβ and tau pathologies in the retina, while simultaneous supplementation with FB remarkably attenuated the Hhcy-induced tau hyperphosphorylation at multiple AD-related sites and Aβ accumulation in the retina. The mechanisms involved downregulation of amyloid precursor protein (APP), presenilin-1, beta-site APP-cleaving enzyme 1, and protein phosphatase-2A. Our data suggest that the retina may serve as a window for evaluating the effects of FB on hyperhomocysteinemia-induced Alzheimer-like pathologies.
Alzheimer Disease ; etiology ; metabolism ; pathology ; therapy ; Amyloid beta-Peptides ; metabolism ; Animals ; Dietary Supplements ; Disease Models, Animal ; Folic Acid ; therapeutic use ; Homocysteine ; Hyperhomocysteinemia ; complications ; metabolism ; pathology ; therapy ; Male ; Rats, Sprague-Dawley ; Retina ; metabolism ; pathology ; Retinal Vessels ; metabolism ; pathology ; Vitamin B 12 ; therapeutic use ; tau Proteins ; metabolism