Three mutants with Tn5-B21 insertion in tonB3 (PA0406) of Pseudomonas aeruginosa exhibited defective twitching motility and reduced assembly of extracellular pili. These defects could be complemented with wild-type tonB3
The distribution of 19 major virulence genes and the presence of plasmids were surveyed in 141 Legionella pneumophila serogroup (SG) 1 isolates from patients and water in Queensland, Australia. The results showed that 16 of the virulence genes examined were present in all isolates, suggesting that they are life-essential genes for isolates in the environment and host cells. The 65 kb pathogenicity island identified originally in strain Philadelphia-1 T was detected more frequently in isolates from water (44?2 %) than in those from patients (2?7 %), indicating that the 65 kb DNA fragment may aid the survival of L. pneumophila in the sampled environment. However, the low frequency of the 65 kb fragment in isolates from patients suggests that the pathogenicity island may not be necessary for L. pneumophila to cause disease. Plasmids were not detected in the L. pneumophila SG1 isolates from patients or water studied. There was an association of both lvh and rtxA with the virulent and predominant genotype detected by amplified fragment length polymorphism, termed AF1, whereas the avirulent common isolate from water termed AF16 did not have lvh or rtxA genes, with the exception of one isolate with rtxA. It was found that a PCR detection test strategy with lvh and rtxA as pathogenesis markers would be useful for determining the infection potential of an isolate. INTRODUCTIONLegionellae, the aetiologic agents of legionellosis, are ubiquitous worldwide in rivers and lakes (Fliermans et al., 1981), as well as in man-made water systems such as cooling towers and spas (Fields et al., 2002). The vast majority of cases of legionellosis are caused by Legionella pneumophila, mostly serogroup (SG) 1 strains (Yu et al., 2002). To understand the pathogenicity of L. pneumophila, a number of virulence genes of L. pneumophila have been wellcharacterized and extensively reviewed (Cianciotto, 2001;Dowling et al., 1992). The virulence factors characterized include genes required for the whole infection process, such as bacterial cell attachment to host cells, survival and intracellular replication and cell-to-cell spread. The products of genes involved in the initial attachment to host cells and early stages of intracellular infection include type IV pili, the 60 kDa heat-shock protein Hsp60, the poreformation protein RtxA, the macrophage infectivity potentiator Mip and the macrophage-specific infectivity protein MilA (Cianciotto & Fields, 1992;Cirillo et al., 2001;Garduń o et al., 1998;Harb & Abu Kwaik, 2000). The genes required for bacterial survival and intracellular replication are a group of genes called icm (intracellular multiplication) or dot (defect in organelle trafficking) (Vogel et al., 1998). They form a type IV secretion system to deliver effectors to host cells to control organelle trafficking . A number of effectors have been characterized, including RalF (Nagai et al., 2002), LidA (Conover et al., 2003) and LepA/B (Chen et al., 2004) and other recently identified effectors (Shohdy et al., 2005).In addition, the typ...
Loving‐kindness and compassion meditation (LKCM) was a promising intervention for improving life satisfaction, but previous findings have been inconsistent. The current study provides a systematic review and meta‐analysis, including 23 empirical studies on LKCM with life satisfaction as an outcome variable. The primary meta‐analysis indicated that LKCM significantly enhanced life satisfaction in pre‐post design (g = 0.312, k = 15, n = 451), but the significance disappeared in the additional meta‐analysis based on randomized controlled trials (g = 0.106, k = 6, n = 404). Moderator analyses found significant effects for type of control (i.e., the effects of LKCM were inferior to active control group, but superior to waitlist condition), but not for other moderators (i.e., participant type, previous meditation experience, specific protocol, components of LKCM, combination with mindfulness mediation, and intervention length). Narrative review identified self‐compassion and positive emotions as important mediators. The practice time of LKCM had indirect but not direct association with life satisfaction. The findings supported that LKCM is promising in increasing life satisfaction, but more studies are needed to investigate the effects with more rigorous designs. Future studies should investigate other potential mechanisms and clarify whether LKCM change the reality or the perception of life.
To investigate the association between the susceptibility to cervical cancer and the single nucleotide polymorphisms of 5 tumor necrosis factor-α promoter genes (rs361525, rs1800629, rs1800750, rs1799964, and rs673) in Chinese women. A total of 946 peripheral blood samples were collected from women of Han Ethnicity in Shandong province. Of them, 452 were diagnosed with cervical squamous cell carcinomas. The study also included a control group of 494 healthy women. The targeted single nucleotide polymorphisms were analyzed by TaqMan probe method. (1) The rate of high-risk subtype human papillomavirus infection in exfoliated cervical epithelial cells was significantly higher in patients with cervical cancer than the control group (91.4% vs 10.3%, P < .01). The rate of human papillomavirus infection was lower in patients with carcinoma in situ than those with invasive carcinoma (77.9% vs 95.4%, P < .01). (2) There was a significant difference for rs361525 genotype (CC/CT/TT) between the control, carcinoma in situ, and invasive carcinoma groups (P < .001). Both rs1800629 and rs1799964 genotypes (both GG/GA/AA) were also different between these groups (P < .001 and P < .001). (3) The allele frequencies of rs361525, rs1800629, and rs1799964 were significantly correlated with the diagnosis of cervical cancer. The frequency of T allele in rs361525 was significantly higher for cervical cancer group (10.8%) than control group (3.8%; odds ratio = 3.04, 95% confidence interval = 1.76-5.25, P < .01). The frequency of A allele in rs1800629 was significantly higher for cervical cancer (29.9%) than control group (14.2%; odds ratio = 2.58, 95% confidence interval = 1.87-3.56, P < .01). The frequency of A allele in rs1799964 was also higher for cervical cancer group (38.3%) than control group (16.4%; odds ratio = 1.43, 95% confidence interval = 1.07-1.91, P < .05). The rs361525, rs1800629, and rs17999645 were significantly correlated with the diagnosis of cervical cancer.
Calcium channel, voltage-dependent, alpha-2/delta subunit 1 (CACNA2D1) gene encodes a member of the alpha-2/delta subunit family, proteins are accessory molecules associated with voltage-gated calcium channels, and increase the density at the plasma membrane of calcium channels activated by high voltage. The main objective of the present study was to identify polymorphisms of CACNA2D1 gene, and to analyze associations between these polymorphisms and carcass and meat quality traits in cattle. In this study, through PCR-SSCP and DNA sequencing methods, two new allelic variant corresponding to the C→G and G→T mutations at positions 526740 and 537917 in the exon25 and exon35 of bovine CACNA2D1 gene, respectively, could be detected. SNP C526740G is a nonsynonymous mutation, resulting in a Cysteine (Cys) to Tryptophan (Trp) amino acid replacement and SNP G537917T resulting in an Aspartic (Asp) to Tyrosine (Tyr) amino acid replacement. The gene-specific SNP markers association analysis was investigated. The C526740G was significantly associated with Meat color (MC) (P=0.0297) and Backfat thickness (BF) (P<0.001). The G537917A indicated significant association with Dressing percentage (DP) (P=0.0485). No significant association, however, was detected between any of the marker genotype and other traits measured in this study. Results from this study initially suggested that CACNA2D1 gene is one of the potential candidate genes influencing carcass and meat quality traits and gene-specific SNPs may be a useful marker for MAS programs in cattle breeding.
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