Objective:To investigate the clinicopathological and molecular characteristics of neurocutaneous melanosis in children caused by NRAS gene variants.Methods:Three cases of neurocutaneous melanosis from Children's Hospital of Fudan University (case 1 and case 2) and Shanghai Children′s Hospital, School of Medicine Shanghai Jiaotong University (case 3) from July 2022 to February 2023 were collected. The clinical, histopathological, immunohistochemical and genetic results of three patients were retrospectively analyzed. The literatures were reviewed.Results:The patients were all female, aged 5, 4 and 3 years, respectively. The patients presented with severe headache with other symptoms of increased intracranial pressure. Physical examination showed multiple congenital melanocytic nevi throughout the body. Imaging examination showed intracranial masses, which were located in the right cerebellum, pineal gland and left temporal lobe, respectively. The maximum diameters were 39.1 mm, 72.8 mm and 52.2 mm, respectively. Histologically, the tumor showed diffuse sheets of round or oval-shaped cells arranged in nests, with marked nuclear atypia, eosinophilic cytoplasm, dark nuclei, and prominent nucleoli. Giant tumor cells were seen and mitotic figures were easily observed. There were hemorrhage and necrosis. Pigment granules were found in the cytoplasm and stroma in case 1 and case 2. Immunohistochemically, the tumor cells showed diffuse and strong staining of SOX10, S-100, HMB45 and Melan A, but did not express GFAP and CKpan. The Ki-67 proliferation index ranged from 30% to 80%. Genetic testing showed that case 1 and case 2 had NRAS Q61K matation, and case 3 had NRAS Q61R mutation. Case 1 and case 3 underwent complete resection of the tumor combined with chemotherapy. Case 2 was diagnosed by biopsy and underwent resection after chemotherapy and radiotherapy. All patients were followed up for 18, 21 and 25 months, respectively. All patients died due to complications such as increased intracranial pressure and hydrocephalus.Conclusions:Neurocutaneous melanosis is a congenital neurocutaneous syndrome caused by abnormal development of embryonic neuroectodermal melanoblasts. Most cases are associated with somatic mutations of NRAS gene. Clinicians should pay attention to the skin manifestations and neuroimaging examination in patients with unexplained intracranial hypertension or epilepsy. The diagnosis of neurocutaneous melanosis depends on histopathology and genetic testing.

Objective:To investigate the clinicopathological and molecular characteristics of neurocutaneous melanosis in children caused by NRAS gene variants.Methods:Three cases of neurocutaneous melanosis from Children's Hospital of Fudan University (case 1 and case 2) and Shanghai Children′s Hospital, School of Medicine Shanghai Jiaotong University (case 3) from July 2022 to February 2023 were collected. The clinical, histopathological, immunohistochemical and genetic results of three patients were retrospectively analyzed. The literatures were reviewed.Results:The patients were all female, aged 5, 4 and 3 years, respectively. The patients presented with severe headache with other symptoms of increased intracranial pressure. Physical examination showed multiple congenital melanocytic nevi throughout the body. Imaging examination showed intracranial masses, which were located in the right cerebellum, pineal gland and left temporal lobe, respectively. The maximum diameters were 39.1 mm, 72.8 mm and 52.2 mm, respectively. Histologically, the tumor showed diffuse sheets of round or oval-shaped cells arranged in nests, with marked nuclear atypia, eosinophilic cytoplasm, dark nuclei, and prominent nucleoli. Giant tumor cells were seen and mitotic figures were easily observed. There were hemorrhage and necrosis. Pigment granules were found in the cytoplasm and stroma in case 1 and case 2. Immunohistochemically, the tumor cells showed diffuse and strong staining of SOX10, S-100, HMB45 and Melan A, but did not express GFAP and CKpan. The Ki-67 proliferation index ranged from 30% to 80%. Genetic testing showed that case 1 and case 2 had NRAS Q61K matation, and case 3 had NRAS Q61R mutation. Case 1 and case 3 underwent complete resection of the tumor combined with chemotherapy. Case 2 was diagnosed by biopsy and underwent resection after chemotherapy and radiotherapy. All patients were followed up for 18, 21 and 25 months, respectively. All patients died due to complications such as increased intracranial pressure and hydrocephalus.Conclusions:Neurocutaneous melanosis is a congenital neurocutaneous syndrome caused by abnormal development of embryonic neuroectodermal melanoblasts. Most cases are associated with somatic mutations of NRAS gene. Clinicians should pay attention to the skin manifestations and neuroimaging examination in patients with unexplained intracranial hypertension or epilepsy. The diagnosis of neurocutaneous melanosis depends on histopathology and genetic testing.

Objective:To investigate whether silencing signal transducer and activator of transcription 6 (STAT6) with siRNA can inhibit eosinophilic inflammation of sinonasal mucosa in a mouse model of eosinophilic chronic rhinosinusitis (ECRS).Methods:The study was conducted from March to September in 2022. Forty-eight female BALB/c mice were randomly divided into four groups: the control group, the Vehicle (transfection reagent)-treated group, the Scramble siRNA (Control siRNA)-treated group, and the STAT6 siRNA-treated group, with twelve mice in each group. An ovalbumin (OVA)-staphylococcal enterotoxin B (SEB)-induced ECRS murine model was established. SiRNA prepared in Lipofectamine was locally administered to the nasal cavity. After administration, samples of the peripheral blood and sinonasal mucosa were collected. Eosinophils in peripheral blood were detected by hematology analyzer. Total and OVA-specific IgE (OVA-sIgE) in serum were detected by enzyme-linked immunosorbent assay (ELISA). Mucosal levels of cytokines and chemokines, including interleukin (IL)-5, IL-17A, interferon-γ (IFN-γ) and eotaxin-1, were also measured using ELISA. Mucosal histological changes of eosinophil infiltration were examined using hematoxylin, and eosin staining, and tissue eosinophil count was performed using a microscope under a high-power field (HPF). Tissue expression of STAT6 and phosphorylated STAT6 (p-STAT6) was detected with the western blot method. Immunofluorescence staining was used to localize the expression of p-STAT6 in sinonasal mucosa. Statistical analysis was conducted using SPSS 18.0 software.Results:Peripheral blood eosinophil count, percentage of peripheral blood eosinophil, total serum IgE level, and serum OVA-sIgE level in the STAT6 siRNA-treated group [(0.318±0.045)×10 3/μl, (3.667±0.479)%, (102.070±13.205) ng/ml, and (38.870±7.352) ng/ml] were significantly different from those of the Vehicle-treated group [(0.532±0.049)×10 3/μl, (6.710±1.061)%, (203.102±29.653) ng/ml, and (74.575±6.432) ng/ml, Z value was -2.56, -2.24, -2.40, and -2.56, respectively, all P<0.05] and Scramble siRNA-treated group [(0.493±0.036)×10 3/μl, (5.858±0.872)%, (189.964±30.042) ng/ml, and (80.935±8.358) ng/ml, Z value was -2.17, -2.08, -2.24, and -2.72, respectively, all P<0.05]. Besides, IL-5 and eotaxin-1 levels in the STAT6 siRNA-treated group [(312.279±34.281) pg/ml and (25.297±4.323) pg/ml] were significantly lower than those in the Vehicle-treated group [(689.667±31.905) pg/ml and (68.278±6.485) pg/ml, Z value was -2.73 and -2.88, respectively, both P<0.01] and Scramble siRNA-treated group [(661.783±42.094) pg/ml and (63.015±7.416) pg/ml, Z value was -2.72 and -2.81, respectively, both P<0.01]. Tissue eosinophil count in sinonasal mucosa was (29.132±4.163)/HPF in the STAT6 siRNA-treated group, and were significantly less than those in the Vehicle-treated group [(78.050±7.912)/HPF, Z=-2.88, P<0.01] and Scramble siRNA-treated group [(73.864±8.671)/HPF, Z=-2.72, P<0.01]. The expression level of STAT6 protein (0.105±0.021) was significantly decreased in the mice treated with STAT6 siRNA compared with PBS, Vehicle, and Scramble siRNA (0.232±0.037, 0.243±0.039, and 0.228±0.032, Z value was -2.25, -2.49, and -2.56, respectively, all P<0.05). Corresponding, p-STAT6 protein level (0.292±0.038) was markedly decreased by the introduction of STAT6 siRNA, the difference was statistically significant as compared with the Vehicle-and Scramble siRNA-treated groups (0.613±0.046 and 0.641±0.050, Z value was -2.81 and -2.88, respectively, both P<0.01). Immunofluorescence staining showed that p-STAT6 was mainly located in the nucleus of nasal epithelial cells and inflammatory cells. The green fluorescence of p-STAT6 expression in sinonasal mucosa in the STAT6 siRNA-treated group was weaker than that in the Vehicle-and Scramble siRNA-treated groups. Conclusion:Intranasal administration of STAT6 siRNA can significantly downregulate STAT6 expression, decrease p-STAT6 level, and prohibit the development of Th2-skewed ECRS.

Objective To explore mechanical property changes of methyl vinyl silicone rubber modified by ferric nanoparticles and its dispersed phase.Methods Mechanical properties such as Shore A hardness,tensile strength,elongation at break,tearing rate of permanent deformation and tearing strength of pre-prepared ironic nanoparticle enhanced silicone rubber and carbon-coated ferric particle reinforced silicone rubber were tested according to national standards.A thermal field emission scanning electron microscope (TFE-SEM) was used to investigate the morphology of both surface and fracture of the composite materials and to observe the dispersion of ferric nanoparticles in them.Results Mean values of Shore A hardness,tensile strength,elongation at break,tearing permanent deformation rate and tear strength of modified composites increased with the increasing amounts of ferric nanoparticles,however,when the quota of ironic nanoparticles in the composite formula were greater than 17 phr,carbon-coated ferric nanoparticles more than 19 phr,the mean values of tensile strength of two composites stopped increasing and presented the declining trend.When the quota of ferric nanoparticles in the formula exceeding 15 phr,the mean values of elongation at break and tear strength began to decrease in the formula ratio of silicone rubber/ferric nanoparticles up to 85:15,while the Shore A hardness of samples increased all the way.Ferric nanoparticles dispersed evenly on the surface of composites.Nanopowder aggregation in the fracture surface of both composites could be observed at the formula ratio of 85:15 of silicone rubber/iron nanoparticle and 87:13 of silicone rubber/carbon-coated iron specimen.Conclusion Effect of iron nanapareticles and carbon-coated ferric nanoparticles on the mechanical properties of the reinforced methyl vinyl silicone rubber depends on the nanoparticle size,additive amount and agglomeration.