Langerhans cell histiocytosis（LCH）is an inflammatory myeloid neoplasm characterized by aberrant differentiation or proliferation of mononuclear phagocytes. Orbital involvement，termed orbital LCH（OLCH），typically presents with periorbital masses，eyelid edema，and localized osteolytic lesions. Besides，optic nerve involvement may cause diplopia，visual impairment and so on，significantly impairing quality of life. Central nervous system-Langerhans cell histiocytosis（CNS-LCH），including central diabetes insipidus and neurodegeneration，may cause irreversible sequelae such as diabetes insipidus，progressive tremor，and ataxia，severely impacting prognosis. Current management of OLCH and its association with CNS-LCH remain controversial.The Histiocyte Society considers OLCH to be one of the risk factors for CNS-LCH，and therefore should receive 6 months of systemic chemotherapy to prevent sequelae. However，conflicting evidence suggests an unclear relationship between OLCH and CNS-LCH progression，with studies demonstrating favorable outcomes in isolated orbital cases treated through localized approaches（surgical excision，curettage，or intralesional corticosteroid injection）.Patients with unifocal OLCH exhibit favorable prognosis and potential for spontaneous resolution，and may could spare from systemic chemotherapy to avoid related adverse effects.

OBJECTIVE: To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. MATERIALS AND METHODS: Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2-7 and L2-4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. RESULTS: The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2-5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62-0.94; males: r = 0.63-0.94) and lumbar vertebrae (males: r = 0.93-0.98; females: r = 0.82-0.97) were statistically significant at each age group. CONCLUSION: The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.
Aging ; Asian Continental Ancestry Group* ; Bone Density* ; Cervical Vertebrae ; Female ; Healthy Volunteers ; Humans ; Linear Models ; Lumbar Vertebrae* ; Male ; Sex Characteristics ; Spine

BACKGROUND:How to construct tissue-engineered periodontal tissue through efficient combination of scaffold materials and seed cells in vitro is an important direction of current research.
OBJECTIVE:To compare the cellseeding efficiency of traditional static seeding method and col agen enclose seeding method to select a more appropriate seeding method for cellattach.
METHODS:Gingival fibroblasts from dogs at certain concentrations were seeded onto polylactic acid-chitosan-gelatin scaffolds with gradient and uniform pore sizes using the traditional static seeding method and col agen enclose seeding method, respectively. The number of adherent cells was counted to calculate the seeding efficiency for data comparison. RESULTS AND CONCLUSION:The cellseeding efficiency of the col agen enclose seeding method was higher than that of the traditional static seeding method (P<0.01). The col agen enclose seeding method can significantly improve the seeding efficiency and increase cellinitial concentration on the scaffold, and this method can be used for gingival tissue engineering.