333 research outputs found
Preterm infants harbour diverse Klebsiella populations, including atypical species that encode and produce an array of antimicrobial resistance- and virulence-associated factors
Klebsiella spp. are frequently enriched in the gut microbiota of preterm neonates, and overgrowth is associated with necrotizing enterocolitis (NEC), nosocomial infections and late-onset sepsis. Little is known about the genomic and phenotypic characteristics of preterm-associated Klebsiella as previous studies have focussed on recovery of antimicrobial-resistant isolates or culture independent molecular analyses. The aim of this study was to better characterize preterm-associated Klebsiella populations using phenotypic and genotypic approaches. Faecal samples from a UK cohort of healthy and sick preterm neonates (n=109) were screened on MacConkey agar to isolate lactose positive Enterobacteriaceae. Whole-genome sequences were generated for Klebsiella spp., and virulence and antimicrobial resistance genes identified. Antibiotic susceptibility profiling, and in vitro macrophage and iron assays were undertaken for the Klebsiella strains. Metapangenome analyses with a manually curated genome dataset were undertaken to examine diversity of Klebsiella oxytoca and related bacteria in a publicly available shotgun metagenome dataset. Approximately one-tenth of faecal samples harboured Klebsiella spp. (Klebsiella pneumoniae, 7.3 %; Klebsiella quasipneumoniae, 0.9 %; Klebsiella grimontii, 2.8 %; Klebsiella michiganensis, 1.8 %). Isolates recovered from NEC- and sepsis-affected infants and those showing no signs of clinical infection (i.e. 'healthy') encoded multiple -lactamases. No difference was observed between isolates recovered from ‘healthy’ and sick infants with respect to in vitro siderophore production (all encoded enterobactin in their genomes). All K. pneumoniae, K. quasipneumoniae, K. grimontii and K. michiganensis faecal isolates tested were able to reside and persist in macrophages, indicating their immune evasion abilities. Metapangenome analyses of published metagenomic data confirmed our findings regarding the presence of K. michiganensis in the preterm gut. There is little difference in the phenotypic and genomic characteristics of Klebsiella isolates recovered from 'healthy' and sick infants. Identification of -lactamases in all isolates may prove problematic when defining treatment regimens for NEC or sepsis, and suggests ‘healthy’ preterm infants contribute to the resistome. Refined analyses with curated sequence databases are required when studying closely related species present in metagenomic data
Comparative transcriptomics reveals the conserved building blocks involved in parallel evolution of diverse phenotypic traits in ants
Background: Reproductive division of labor in eusocial insects is a striking example of a shared genetic background giving rise to alternative phenotypes, namely queen and worker castes. Queen and worker phenotypes play major roles in the evolution of eusocial insects. Their behavior, morphology and physiology underpin many ecologically relevant colony-level traits, which evolved in parallel in multiple species. Results: Using queen and worker transcriptomic data from 16 ant species we tested the hypothesis that conserved sets of genes are involved in ant reproductive division of labor. We further hypothesized that such sets of genes should also be involved in the parallel evolution of other key traits. We applied weighted gene co-expression network analysis, which clusters co-expressed genes into modules, whose expression levels can be summarized by their 'eigengenes'. Eigengenes of most modules were correlated with phenotypic differentiation between queens and workers. Furthermore, eigengenes of some modules were correlated with repeated evolution of key phenotypes such as complete worker sterility, the number of queens per colony, and even invasiveness. Finally, connectivity and expression levels of genes within the co-expressed network were strongly associated with the strength of selection. Although caste-associated sets of genes evolve faster than non-caste-associated, we found no evidence for queen-or worker-associated co-expressed genes evolving faster than one another. Conclusions: These results identify conserved functionally important genomic units that likely serve as building blocks of phenotypic innovation, and allow the remarkable breadth of parallel evolution seen in ants, and possibly other eusocial insects as well.Peer reviewe
Graft-vs-tumor effect in patients with advanced nasopharyngeal cancer treated with nonmyeloablative allogeneic PBSC transplantation
While nonmyeloablative peripheral blood stem cell transplantation (NST) has shown efficacy against several solid tumors, it is untested in nasopharyngeal cancer (NPC). In a phase II clinical trial, 21 patients with pretreated metastatic NPC underwent NST with sibling PBSC allografts, using CY conditioning, thymic irradiation and in vivo T-cell depletion with thymoglobulin. Stable lymphohematopoietic chimerism was achieved in most patients and prophylactic CYA was tapered at a median of day +30. Seven patients (33%) showed partial response and three (14%) achieved stable disease. Four patients were alive at 2 years and three showed prolonged disease control of 344, 525 and 550 days. With a median follow-up of 209 (4–1147) days, the median PFS was 100 days (95% confidence interval (CI), 66–128 days), and median OS was 209 days (95% CI, 128–236 days). Patients with chronic GVHD had better survival—median OS 426 days (95% CI, 194–NE days) vs 143 days (95% CI, 114–226 days) (P=0.010). Thus, NST may induce meaningful clinical responses in patients with advanced NPC
Visual Inspection of Acetic Acid (VIA) to Detect PreCancerous Cervical Cancer in Rural Areas of Sarawak
Introduction: Cervical cancer is still the leading cause of gynaecological cancer in Sarawak. Low awareness on cervical screening and logistic problems are the main reasons for delay in diagnosis, especially in rural areas. Although pap smear screening had been implemented for decades, failure to get early treatment and frequent defaulters are factors that need to be tackled for rural women. Objectives: The Sarawak Travelling Women Health Project is aimed to improve pre-cancerous cervical
cancer detection in rural areas using the Visual Inspection of Acetic Acid (VIA) method. This project also helps to shorten the duration of follow up and treatment for patients with pre-cancerous lesion of cervix. Methods: Cervical screening campaigns outside Kuching areas were conducted from June until December 2018 by the Obstetrics and Gynaecology Department of Universiti Malaysia Sarawak (UNIMAS) in collaboration with Pink and Teal Empower, a Non-Government Organization. VIA
was performed for all women below 50 years old. Patients with positive VIA were a colposcopy appointment and cervical biopsies are taken at the clinic. Results: During the campaign period, 83 out of 333 women were found to be VIA positive, but only 47 women turned up for the colposcopy. This high number of defaulters is mostly due to logistic reasons. Two cervical biopsies were confirmed as Cervical Intraepithelial Neoplasia (CIN) 2, 15 cases with CIN 1, one case of microglandular
hyperplasia while 19 biopsies turned out to be cervicitis. The pickup rate for CIN during the outreach was about 20.4%. Conclusion: VIA is useful in low resource area with difficult access to tertiary centres as it enables faster diagnosis for CIN. However, proper training is needed to avoid false positive results and unnecessary intervention. To reduce the rate of defaulters, cervical biopsy for VIA positive women should be done in the field during the same setting
An experimental investigation into the dimensional error of powder-binder three-dimensional printing
This paper is an experimental investigation into the dimensional error of the rapid prototyping additive process of powder-binder three-dimensional printing. Ten replicates of a purpose-designed part were produced using a three-dimensional printer, and measurements of the internal and external features of all surfaces were made using a general purpose coordinate measuring machine. The results reveal that the bases of all replicates (nominally flat) have a concave curvature, producing a flatness error of the primary datum. This is in contrast to findings regarding other three-dimensional printing processes, widely reported in the literature, where a convex curvature was observed. All external surfaces investigated in this study showed positive deviation from nominal values, especially in the z-axis. The z-axis error consisted of a consistent positive cumulative error and a different constant error in different replicates. By compensating for datum surface error, the average total height error of the test parts can be reduced by 25.52 %. All the dimensional errors are hypothesised to be explained by expansion and the subsequent distortion caused by layer interaction during and after the printing process
Graft-vs-tumor effect in patients with advanced nasopharyngeal cancer treated with nonmyeloablative allogeneic PBSC transplantation
While nonmyeloablative peripheral blood stem cell transplantation (NST) has shown efficacy against several solid tumors, it is untested in nasopharyngeal cancer (NPC). In a phase II clinical trial, 21 patients with pretreated metastatic NPC underwent NST with sibling PBSC allografts, using CY conditioning, thymic irradiation and in vivo T-cell depletion with thymoglobulin. Stable lymphohematopoietic chimerism was achieved in most patients and prophylactic CYA was tapered at a median of day +30. Seven patients (33%) showed partial response and three (14%) achieved stable disease. Four patients were alive at 2 years and three showed prolonged disease control of 344, 525 and 550 days. With a median follow-up of 209 (4–1147) days, the median PFS was 100 days (95% confidence interval (CI), 66–128 days), and median OS was 209 days (95% CI, 128–236 days). Patients with chronic GVHD had better survival—median OS 426 days (95% CI, 194–NE days) vs 143 days (95% CI, 114–226 days) (P=0.010). Thus, NST may induce meaningful clinical responses in patients with advanced NPC
Phase 1 Safety and Immunogenicity Evaluation of ADVAX, a Multigenic, DNA-Based Clade C/B' HIV-1 Candidate Vaccine
BACKGROUND: We conducted a Phase I dose escalation trial of ADVAX, a DNA-based candidate HIV-1 vaccine expressing Clade C/B' env, gag, pol, nef, and tat genes. Sequences were derived from a prevalent circulating recombinant form in Yunnan, China, an area of high HIV-1 incidence. The objective was to evaluate the safety and immunogenicity of ADVAX in human volunteers. METHODOLOGY/PRINCIPAL FINDINGS: ADVAX or placebo was administered intramuscularly at months 0, 1 and 3 to 45 healthy volunteers not at high risk for HIV-1. Three dosage levels [0.2 mg (low), 1.0 mg (mid), and 4.0 mg (high)] were tested. Twelve volunteers in each dosage group were assigned to receive ADVAX and three to receive placebo in a double-blind design. Subjects were followed for local and systemic reactogenicity, adverse events, and clinical laboratory parameters. Study follow up was 18 months. Humoral immunogenicity was evaluated by anti-gp120 binding ELISA. Cellular immunogenicity was assessed by a validated IFNgamma ELISpot assay and intracellular cytokine staining. ADVAX was safe and well-tolerated, with no vaccine-related serious adverse events. Local and systemic reactogenicity events were reported by 64% and 42% of vaccine recipients, respectively. The majority of events were mild. The IFNgamma ELISpot response rates to any HIV antigen were 0/9 (0%) in the placebo group, 3/12 (25%) in the low-dosage group, 4/12 (33%) in the mid-dosage group, and 2/12 (17%) in the high-dosage group. Overall, responses were generally transient and occurred to each gene product, although volunteers responded to single antigens only. Binding antibodies to gp120 were not detected in any volunteers, and HIV seroconversion did not occur. CONCLUSIONS/SIGNIFICANCE: ADVAX delivered intramuscularly is safe, well-tolerated, and elicits modest but transient cellular immune responses. TRIAL REGISTRATION: Clinicaltrials.gov NCT00249106.published_or_final_versio
Prevalence of high-risk human papillomavirus types in Mexican women with cervical intraepithelial neoplasia and invasive carcinoma
<p>Abstract</p> <p>Background</p> <p>Prevalence of high risk (HR) human papillomavirus (HPV) types in the states of San Luis Potosí (SLP) and Guanajuato (Gto), Mexico, was determined by restriction fragment length-polymorphism (RFLP) analysis on the E6 ~250 bp (E6-250) HR-HPV products amplified from cervical scrapings of 442 women with cervical intraepithelial neoplasia and invasive carcinoma (280 from SLP and 192 from Gto). Fresh cervical scrapings for HPV detection and typing were obtained from all of them and cytological and/or histological diagnoses were performed on 383.</p> <p>Results</p> <p>Low grade intraepithelial squamous lesions (LSIL) were diagnosed in 280 cases (73.1%), high grade intraepithelial squamous lesions (HSIL) in 64 cases (16.7%) and invasive carcinoma in 39 cases (10.2%). In the 437 cervical scrapings containing amplifiable DNA, only four (0.9%) were not infected by HPV, whereas 402 (92.0%) were infected HR-HPV and 31 (7.1%) by low-risk HPV. RFLP analysis of the amplifiable samples identified infections by one HR-HPV type in 71.4%, by two types in 25.9% and by three types in 2.7%. The overall prevalence of HR-HPV types was, in descending order: 16 (53.4%) > 31 (15.6%) > 18 (8.9%) > 35 (5.6) > 52 (5.4%) > 33 (1.2%) > 58 (0.7%) = unidentified types (0.7%); in double infections (type 58 absent in Gto) it was 16 (88.5%) > 31 (57.7%) > 35 (19.2%) > 18 (16.3%) = 52 (16.3%) > 33 (2.8%) = 58 (2.8%) > unidentified types (1.0%); in triple infections (types 33 and 58 absent in both states) it was 16 (100.0%) > 35 (54.5%) > 31 (45.5%) = 52 (45.5%) > 18 (27.3%). Overall frequency of cervical lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%). The ratio of single to multiple infections was inversely proportional to the severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types in HSIL and invasive cancer lesions was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%).</p> <p>Conclusion</p> <p>Ninety percent of the women included in this study were infected by HR-HPV, with a prevalence 1.14 higher in Gto. All seven HR-HPV types identifiable with the PCR-RFLP method used circulate in SLP and Gto, and were diagnosed in 99.3% of the cases. Seventy-one percent of HR-HPV infections were due to a single type, 25.9% were double and 2.7% were triple. Overall frequency of lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%), and the ratio of single to multiple infections was inversely proportional to severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types found in HSIL and invasive cancer was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%). Since the three predominant types (16, 31 and 18) cause 77.9% of the HR-HPV infections and immunization against type 16 prevents type 31 infections, in this region the efficacy of the prophylactic vaccine against types 16 and 18 would be close to 80%.</p
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