Objective To investigate the involvement of apoptosis in the lesions of patients with psoriasis. Methods The apoptosis was detected with terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL), and the expression of p53, PCNA and apoptosis suppressing protein bcl 2 was assessed with immunoperoxidase technique in psoriatic lesions and normal skin. Results A large number of keratinocytes showing biochemical and morphologic features of cells undergoing apoptosis were observed in all the suprabasal layers of the psoriatic epidermis. The plaques from all patients analysed showed marked increase in the number of PCNA positive cells in the middle and basal keratinocytes, and a dramatic reduction in the number of bcl 2 positive cells in the basal cell layer. Conclusion The increased apoptosis of keratinocytes in the lesions of psoriasis might be a homeostatic mechanism to the hyperplasia of cells.

Spinal cord injury and regeneration involves transcriptional activity of many genes, of which many remain unknown. Using the rat spinal cord full- transection model, bioinformatics, cloning, expression assays, fusion proteins, and transfection techniques, we identified and characterized one such differentially expressed gene, termed scirr1 (spinal cord injury and/or regeneration related gene 1). Fourteen orthologs were found in 13 species from echinoderm to insect and human by Blast search of NCBI protein reference sequence database. However, no further information is available for these homologues. Using whole-mount in situ hybridization, mouse scirr1 mRNA was expressed temporally and spatially in accordance with the early development sequence of the central nervous system. In adult rat spinal cord, expression of scirr1 mRNA was localized to neurons of gray matter by in situ hybridization. Using immunohistochemistry, SCIRR1 protein was found to be up-regulated and expressed more highly in spinal cord neurons farther from the epicenter of injury. Although the precise function of SCIRR1 is unknown, its unique pattern of expression during CNS early development and up-regulation after spinal cord injury suggest that SCIRR1 should be involved in the succeeding injury and/or repair processes of the injured spinal cord. Also, the typical F-box and leucine-rich repeat (LRR) architecture of rat SCIRR1 indicated that it may play an important substrate recruiting role in the pleiotropic ubiquitin/proteasome pathway. All these make scirr1 a new interesting start to study the spinal cord injury and regeneration mechanism.
Amino Acid Sequence ; Animals ; Base Sequence ; Brain/embryology/metabolism ; Embryo, Mammalian/metabolism ; F-Box Proteins/*biosynthesis ; Gene Expression Regulation, Developmental ; Male ; Mice ; Molecular Sequence Data ; Organ Specificity ; PC12 Cells ; Phylogeny ; Rats ; Rats, Wistar ; Spinal Cord/embryology/metabolism ; Spinal Cord Injuries/*metabolism ; Up-Regulation

Background N-nitrosamines, a group of by-products of drinking water disinfection, have strong cytotoxicity to mammals. N-nitrosamines in drinking water are at the ng·L⁻¹ level, and its accurate qualitative and quantitative analysis is difficult, so it is necessary to develop a sensitive and accurate method to determine N-nitrosamines in drinking water. Objective To establish a solid phase extraction-gas chromatography tandem mass spectrometry (GC-MS/MS) method for simultaneous determination of 10 kinds of N-nitrosamines in drinking water. To apply the established method to determine the levels of 10 kinds of N-nitrosamines in drinking water in Nanjing, and to understand the pollution status. Methods Coconut charcoal solid phase extraction (SPE) cartridge and HLB Pro SPE cartridge were compared for the extraction efficiency of 10 N-nitrosamines in drinking water. A coconut charcoal SPE cartridge and a HLB Pro SPE cartridge were concatenated using a SPE connector, and then formed two combinations: coconut charcoal (top)-HLB Pro (bottom) and HLB Pro (top)-coconut charcoal (bottom), to extract the spiked samples, and combined with direct and independent elution ways to obtain the best extraction efficiency. From November to December 2021, 9 raw water, 10 finished water, and 7 tap water samples were collected from 9 municipal water supply units in Nanjing with 1 L brown glass sampling bottles. An 1.0 L drinking water sample was added with the isotope internal standard to prepare a test sample containing an isotope internal standard concentration of 25 ng·L⁻¹. The automatic SPE instrument loaded all the 1.0 L drinking water samples to the tandem SPE cartridge of the HLB Pro (top)-coconut charcoal (bottom) at the rate of 15 mL·min⁻¹. After extraction, the HLB Pro SPE cartridge and coconut charcoal SPE cartridge were transferred to the solid phase extraction vacuum device and eluted with 10 mL of dichloromethane respectively, then the dichloromethane eluents were combined, and concentrated to about 1.0 mL by nitrogen blowing after a small amount of the upper aqueous phase was removed. The concentrated solution was detected by GC-MS/MS and quantified by isotope internal standard method. Results The comparison of sample spike recovery experiments showed that coconut charcoal solid phase extraction (SPE) cartridge and HLB Pro SPE cartridge presented highcomplementarity for the extraction efficiency of 10 N-nitrosamines in drinking water. Using HLB Pro (top)-coconut charcoal (bottom), independent elution, and combined with eluents, the optimal extraction efficiency was obtained. Under these conditions, by GC MS/MS, the 10 N-nitrosamines showed a good linear relationship within the range of 2–50 ng·L⁻¹, the correlation coefficients were all greater than 0.9996, the method detection limit was 0.149–0.211 ng·L⁻¹, and the limit of quantification was 0.596–0.844 ng·L⁻¹. At the spiked concentrations of 5.0, 15, and 30 ng·L⁻¹, the average recoveries of the 10 kinds of N-nitrosamines were 88.0%–104.8%, and the relative standard deviations were 1.22%–4.87%. When applying the method to determine the concentrations of the 10 N-nitrosamines in Nanjing drinking water, the results showed that the 10 N-nitrosamines were positive in different degrees in raw water, finish water, and terminal water, the detection rates were 0%–100%, and the concentrations were ND–27.6 ng·L⁻¹. Conclusion This tandem solid phase extraction-gas chromatography tandem mass spectrometry method can achieve simultaneous determination of a variety of N-nitrosamines in drinking water with high sensitivity and high throughput.