The orientational projections of the sensory fibres of axillary nerve to the substantia gelationsa (SG) of the spinal cord in rats were studied in accordance with the principle of transgangionic degeneration by using acid phosphatase technique. It was found that the afferent fibers of the axillary nerve projected chiefly to SG from the upper part of C_6 to the lower part of C_8 longitudinally. In a few rats, projections extended to the lower part of C_5 and upper part of T_1. In comparison with the available studies, a tendency of backward localization was noted. As to their transverse projections, the afferent fibres of the axillary nerve were found outside of the midline of SG, and mainly located in the lateral half of SG, at the 1/3 of median and the 1/3 of interior region. In the segments of C_7C_8 of some rats, the medial. 1/2 of the lateral half of SG was projected. It was found that the projection column from up downward had a tendency of extension toward lateral portion.

The orientational projections of sensory fibres of median nerve to the Substantia Gelatinosa (SG) of the spinal cord in rats were studied in accordance with the principle of transganglion degeneration by using the acid phosphatase technique. It was found longitudinally that the afferent fibres of the median nerve projected chiefly to SG from the upper part of C_5 to middle part of T_1. In a few rats, projections extended to middle and lower part of C_4 and lower part of T_1. In comparison with the records in anatomy literature and data from researches with HRP technique, a tendency of pre-positioning was noted. The regional projections of the afferent fibres of median nerve were found within the centre line of SG, and mainly in the region of the medial 1/4-1/2 of the medial half. In the segments of C_7-T_1 of a few rats, the whole area of the medial half of SG was projected. In observing the projections of the afferent fibres of median nerve, it was found that they have a tendency of lateralward increase from cranial portion to caudal portion.

The orientational projections of sensory fibres of radial nerve and ulnar nerve to the substantia gelatinosa(SG) of the spinal cord in rats were studied in accordance with the principle of transganglion degeneration by using the acid phosphatase technique.It was found that the affeernt fibers of the radial nerve projected chiefly to SG, from the upper part of C_6 to the middle part of T_1 longitudinally; the ulnar nerves projected chiefly to SG from the middle part of C_6 to the middle part of T_1.In their transverse projections,the afferent fibres of the radial nerve were mainly found in the region of the whole area of the middle 1/3 of SG; and the afferent fibres of ulnar nerve were found within the centre line of SG, and mainly in the region of the lateral 1/2～3/4 at medial half. In summary, radial nerve projected to the lateral region and ulnar nerve to the medial region of SG.

Background and Aims:Methylenetetrahydrofolate dehydrogenase 1(MTHFD1)is essential in various tumors.However,the role of MTHFD1 in pancreatic cancer remains unclear.This study was conducted to explore the expression and clinical significance of MTHFD1 in pancreatic cancer through bioinformatics analysis and clinical sample validation,as well as to analyze its potential mechanisms of action in pancreatic cancer. Methods:The GEPIA2 online platform was used to analyze the differential expression of MTHFD1,survival,and pathological stage in TCGA pancreatic cancer data,examining the relationship between MTHFD1 expression and clinicopathologic features of pancreatic cancer patients.Univariate and multivariate analyses were performed using the Cox proportional hazards model on TCGA data.GO,KEGG,and GSEA analyses were conducted to predict the possible mechanisms of MTHFD1 in pancreatic cancer.The expression of MTHFD1 in 80 cases of pancreatic cancer and adjacent tissues was detected using immunohistochemistry,qRT-PCR,and Western blot and its expression with clinicopathologic characteristics was analyzed. Results:In the TCGA database,MTHFD1 expression in pancreatic cancer tissues was significantly higher than in normal tissues(P＜0.05).High expression of MTHFD1 was significantly associated with poor prognosis in pancreatic cancer patients(P=0.007).TCGA data indicated a close correlation between MTHFD1 expression and tumor stage(P＜0.05).MTHFD1 expression was identified as an independent prognostic factor for pancreatic cancer(HR=1.777,P=0.01).GO,KEGG,and GSEA analyses showed that MTHFD1 was related to the cell cycle,and correlation heatmaps indicated a strong association between the MTHFD1 gene and the cell cycle.In the TIMER database,MTHFD1 expression level was significantly correlated with various immune cells,including B cells,CD8+T cells,CD4+T cells,macrophages,neutrophils,and dendritic cells(all P＜0.05).The GDSC database revealed that patients with low MTHFD1 expression were more sensitive to various therapeutic agents than those with high expression.In clinical pancreatic cancer specimens,the positive expression rate of MTHFD1 and its mRNA and protein levels were significantly higher in cancer tissues than in adjacent tissues(all P＜0.05).MTHFD1 expression was associated with tumor differentiation,clinical stage,lymph node metastasis,and neural infiltration(all P＜0.05).Patients with high MTHFD1 expression had significantly shorter overall survival than those with low expression(P＜0.05). Conclusion:MTHFD1 is highly expressed in pancreatic cancer tissues and is associated with poor prognosis.It may participate in the occurrence and development of pancreatic cancer through the cell cycle and is related to the infiltration of tumor immune cells.