[Key microbial monitoring and clinical analysis of bloodstream infections and CRO colonization after hematopoietic stem cell transplantation in hematological patients].

Objective: To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients. Methods: We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison. Results: The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM (P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM (P=0.035) . Conclusion: This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

Abnormal expression of PTEN and PIK3CA in pemetrexed-resistant human pancreatic cancer cell line Patu8988.

The aim of this study was to investigate the expression of PTEN and PIK3CA in the pemetrexed-resistant human pancreatic cancer cell line Patu8988, and to evaluate their effects on the biological behavior of pancreatic cancer cells. PTEN and PIK3CA gene and protein expressions were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot, respectively, in a pemetrexed-resistant pancreatic cancer cell line and in the parent strain of the pancreatic cancer cells. The discrepancies between the two types of cell lines were detected by a transwell test. RT-PCR and western blot analyses revealed that PTEN and PIK3CA were overexpressed in the pemetrexed-resistant pancreatic cancer cell line. PTEN and PIK3CA were shown to be upregulated by 89 and 76% (western blot), respectively, in the pemetrexed-resistant cell line, compared to the normal pancreatic cancer cell line. The migratory and invasive abilities of the pemetrexed-resistant pancreatic cancer cell were significantly reduced compared to those of the parent strain (P < 0.05; transwell assay). Both PTEN and PIK3CA expression was abnormally enhanced in the pemetrexed-resistant cell line Patu8988; the co-existence of high levels of PTEN and PIK3CA in the pemetrexed-resistant pancreatic cancer line cells induced a significant decrease in their migratory and invasive capacities. This suggested that the mechanism of pemetrexed resistant may be affected by PTEN and PIK3CA, and that these may alter the biological behavior of cancer cells.

Complete mitochondrial genome of the Chinese Hwamei Garrulax canorus (Aves: Passeriformes): the first representative of the Leiothrichidae family with a duplicated control region.

The Chinese Hwamei Garrulax canorus, a member of the family Leiothrichidae, is commonly found in central and southern China, northern Indochina, and on Hainan Island. In this study, we sequenced the complete mitochondrial genome of G. canorus. The circular mitochondrial genome is 17,785 bp in length and includes 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and two ribosomal RNA genes. In addition, two copies of highly similar putative control regions were observed in the mitochondrial genome. As found in other vertebrates, most of the genes are coded on the H-strand, except for one protein-coding gene (nad6; NADH dehydrogenase subunit 6) and eight tRNA genes (tRNA(Gln), tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr), tRNA(Ser(UCN)), tRNA(Pro), and tRNA(Glu)). All the protein-coding genes start with ATG, with the exception of cox1 (cytochrome oxidase subunit 1), which starts with GTG. All tRNA genes have the potential to fold into the typical clover-leaf structure. Conserved sequences in three domains were observed in the two putative control regions. These results provide basic information for future phylogenetic analyses among species of the order Passeriformes.

Phylogeny of major lineages of galliform birds (Aves: Galliformes) based on complete mitochondrial genomes.

Complete mitochondrial DNA sequences have been used successfully to estimate phylogenetic relationships among animal taxa, and for studies of population genetics and molecular evolution. We made phylogenetic analyses of 22 species of Galliformes, with two species of Anseriformes as outgroups, using maximum likelihood (ML), maximum parsimony (MP) and Bayesian inference (BI) methods based on the nucleotide dataset and the corresponding amino acid dataset of 13 concatenated protein-coding genes. The consensus phylogenetic trees supported monophyly of Galliformes, Phasianidae (nucleotide and amino acid: posterior probabilities 1.00 in BI, bootstrap value > 99% in ML and MP), Coturnicinae, and Gallininae (nucleotide and amino acid: posterior probabilities 1.00 in BI, bootstrap value > 85% in ML and MP), but failed to demonstrate monophyly of Pavoninae and Phasianinae. Our results also support a sister-group relationship between megapodes and all other galliforms. We found that Arborophilinae is basal to the balance of the Phasianidae. Moreover, we suggest that the turkey should be classified in the Phasianinae of Phasianidae. Although the relationships among the various lineages of the Galliformes remain controversial, these results should be useful for further study.

Characterization of the complete mitochondrial genome of the Rock pigeon, Columba livia (Columbiformes: Columbidae).

The rock pigeon (Columba livia), or Rock dove, is a member of the bird family Columbidae. We mapped the complete mitochondrial genome of the Rock pigeon. The mitochondrial genome of this species is a circular molecule of 17,229 bp in length, encoding a standard set of 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, plus a putative control region, demonstrating a structure very similar to that of other birds. As found in other vertebrates, most of these genes are coded on the H-strand, except for NADH dehydrogenase subunit 6 (nad6) and eight tRNA genes (Gln, Ala, Asn, Cys, Tyr, Ser(UCN), Pro, Glu). The AT skew and GC skew of the whole genome, protein-coding genes, tRNA, rRNA, and the control region were calculated for the complete mitochondrial genomes of 30 avian species, representing 29 orders. All protein-coding genes initiated with ATG, except for cox1 and nad5, which began with GTG. One extra nucleotide 'C' was present in NADH dehydrogenase subunit 3 (nad3). All tRNA gene sequences have the potential to fold into typical cloverleaf secondary structures. Within the control region, conserved sequences were identified in three domains. Although the conserved blocks, such as ETAS1, ETAS2, CSB1, CSB1-like, and boxes C, D, E, and F, are readily identifiable in the C. livia control region, the typical origin of H-strand replication (O(H)), CSB2 and CSB3 could not be detected. These results provide basic information for phylogenetic analyses of birds, especially Columbiformes species.

Therapeutic efficacy of sustained drug release from chitosan gel on local inflammation.

The model anti-inflammatory drug prednisolone (PS) was retained in chitosan (CS) gel beads, which were prepared in a 10% aqueous amino acid solution (pH 9.0). Sustained release of PS from the CS gel beads was observed. Carrageenan solution was injected into air pouches (AP), which were prepared subcutaneously on the dorsal surface of mice, in order to induce local inflammation. CS gel beads retaining PS were then implanted into the AP to investigate the therapeutic efficacy of sustained PS release against local inflammation. In vivo PS release from CS gel beads was governed by both diffusion of the drug and degradation of the gel matrix. Sustained drug release by CS gel beads allowed the supply of the minimum effective dose and facilitated prolonged periods of local drug presence. Inflammation indexes were significantly reduced after implantation of CS gel beads when compared with injection of PS suspension. Thus, extension of the duration of drug activity by CS gel beads resulted in improved therapeutic efficacy. These observations indicate that CS gel beads are a promising biocompatible and biodegradable vehicle for treatment of local inflammation.