Role of Trace Cadmium Exposure on the Development of Occlusal Traumatic Temporomandibular Arthritis.

OBJECTIVE: To investigate whether heavy metal cadmium acts as a risk factor for temporomandibular joint disorder disease and to study its pathogenic mechanism. METHODS: A total of 57 rats were allocated into 6 distinct groups, distinguished by 2 interventions: occlusal elevation and cadmium water gavage. These groups included a blank control group, occlusal elevation group, occlusal elevation + 0.42 mg/mL cadmium water gavage group, occlusal elevation + 4.2 mg/mL cadmium water gavage group, no occlusal elevation + 0.42 mg/mL cadmium water gavage group, and no occlusal elevation + 4.2 mg/mL cadmium water gavage group. The impact of cadmium exposure on cartilage oxidative stress was evaluated through the assessment of SOD, CAT, GST, and GSH-Px enzyme activities. In addition, the influence of cadmium exposure on alterations in the extracellular matrix and inflammatory mediators was examined by analyzing the expression levels of type II collagen, protein aggregation polysaccharide, glycosaminoglycan, IL1ß, IL-6, and TNF-α. Histologic examination of the condylar process cartilage of rats in the occlusal elevation + cadmium water gavage group was conducted to ascertain the occurrence of osteoarthritis. RESULTS: The variance in the expression levels of inflammatory factors did not demonstrate statistical significance between the occlusal elevation group and the blank control group; however, statistical significance was observed between the occlusal elevation + cadmium water gavage group and both the control and occlusal elevation groups. CONCLUSION: The severity of inflammation and condylar lesions correlates directly with the concentration of cadmium.

Anterior Segment Biometry During Accommodation After Posterior Chamber Phakic Implantable Collamer Lens Implantation.

PURPOSE: To evaluate the dynamic changes in anterior segment parameters during accommodation following Implantable Collamer Lens (ICL) implantation with swept-source optical coherence tomography (SS-OCT). METHODS: Under the accommodation of 0.00 diopters (D), 3.00 D, and maximum amplitude, SS-OCT was used to examine the anterior segment parameters, including ICL vault, ICL depth (the distance between the corneal endothelium and the posterior surface of ICL), crystalline lens thickness, anterior chamber depth, and various parameters of the anterior chamber angle, comprising angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. RESULTS: During accommodation, the ICL vault showed a significant decrease from baseline (536 ± 278 µm) to 3.00 D (522 ± 281 µm), followed by an increase from 3.00 D to maximum amplitude (548 ± 306 µm) (analysis of variance [ANOVA], P < .001). Four eyes (2.61%) exhibited a decrease in ICL vault to less than 100 µm (47 ± 32 µm) at maximum accommodation. The ICL depth decreased significantly as accommodation increased (ANOVA, P < .001). Crystalline lens thickness increased, whereas anterior chamber depth decreased during accommodation (ANOVA, P < .001). The anterior chamber angle widened during 3.00 D of accommodation but narrowed at maximum accommodation, leading to significant changes in the angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle during accommodation (ANOVA, P < .001 for all). CONCLUSIONS: The anterior segment, including ICL vault and anterior chamber angle, undergo significant dynamic changes during accommodation. These accommodative changes may require careful monitoring for the surgery design of ICL implantation. [J Refract Surg. 2024;40(3):e164-e172.].

Correlation study of functional magnetic resonance index and clinicopathological features of rectal cancer.

PURPOSE: To investigate the correlation between DCE-MRI, R2*, IVIM, and clinicopathological features of rectal cancer. METHODS: This was a prospective study, enrolling 42 patients with rectal cancer, 20 of whom underwent rectal mesorectal excision. Dynamic contrast-enhanced magnetic resonance imaging scanning was performed preoperatively in all patients, and additional preoperative scanning of R2* imaging and intravoxel incoherent motion was performed in those who underwent surgery. Artificially delineate the ROI around the tumor. Functional magnetic resonance index parameters Ktrans, Ve, R2*, D, D*, and f were estimated by computer software to analyze postoperative pathological reports of patients undergoing total mesenteric resection. Correlation and significance analyses of imaging metrics and pathologic features were performed by GraphPad Prism 9 to assess statistical significance. RESULTS: DEC-MRI, R2*, and IVIM have certain application values in the distance from the lower margin of the tumor to the anorectal ring, imaging T stage and N stage, tumor markers CEA and CA199, immunohistochemical indexes Ki-76 and P53, lymph node cancer metastasis, and rectal fascia status (P < 0.05). CONCLUSION: DEC-MRI, R2*, and IVIM provide reliable quantitative parameters for preoperative clinicopathological evaluation of patients with rectal cancer.