Objective To investigate the effect induced by specific inducible nitric oxide synthase (iNOS) inhibitor 1 400 W on nasopharyngeal carcinoma CNE-2 cells lines and its mechanism.Methods CNE-2 cells were treated by different concentrations of 1 400 W,diamminedichloroplatinum (DDP),and both chemicals.Cell counting kit-8 (CCK-8) was used to examine the viability of cells.Quantitative realtime polymerase chain reaction (qRT-PCR) was applied to detect the iNOS mRNA expression.Results The expression of iNOS mRNA was down-regulated by 1400W and was positively correlated with inhibitionrate of cell proliferation.1 400 W inhibits proliferation of CNE-2 cell in a concentration-dependent manner.The proliferation inhibition rate of CNE-2 cells treated by 1 400 W combined with DDP was not enhanced.Conclusions Specific inducible nitric oxide synthase inhibitor 1 400 W can exerts anti-tumor effect though inhibiting the expression of iNOS mRNA;The mechanism of chemosensitization induced by iNOS inhibitor on CNE-2 cells may be closely related level of down-regulation of iNOS expression.

Objective To investigate the prevalence of Cryptosporidium infection and the distribution of parasite species and genotypes among HIV-positive individuals in Jiangxi Province. Methods HIV-positive individuals' sociodemographic and clinical data were collected from three AIDS designated hospitals in Jiangxi Province from January 2022 to March 2023. Subjects' stool samples were collected, and genomic DNA was extracted from stool samples. Nested PCR assay was performed based on the small subunit ribosomal RNA (SSU rRNA) gene of Cryptosporidium, and Cryptosporidium gp60 gene was amplified in stool samples positive for the SSU rRNA gene. The second-round PCR amplification product was checked with 1.5% agarose gel electrophoresis, and the products of suspected positive amplifications were sequenced, followed by sequence alignment. The phylogenetic tree was created using the Neighbor-Joining method with the software MEGA 11.0, to characterize the species, genotypes and sub-genotypes of Cryptosporidium. Results A total of 382 HIV-positive individuals were enrolled, with two cases identified with Cryptosporidium infection (0.52% prevalence), and both cases had no abdominal pain or diarrhea. Following sequencing and sequence alignment, the gene sequences of these two Cryptosporidium isolates shared 99.76% and 99.88% similarity with the gene sequence of C. meleagridis isolates. Phylogenetic analysis based on the Cryptosporidium SSU rRNA gene sequence identified the species of these two Cryptosporidium-positive stool samples as C. meleagridis. Following nested PCR amplification of the Cryptosporidium gp60 gene, sequencing and sequence alignment, the two C. meleagridis isolates were characterized as III eA17G2R1 and III bA25G1R1a sub-genotypes, and the sub-genotype III bA25G1R1a was firstly described in humans. Conclusion The prevalence of Cryptosporidium is low among HIV-positive individuals in Jiangxi Province. The likelihood of Cryptosporidium infection cannot be neglected among HIV-positive individuals without diarrhea.