380 results on '"Baker, Stephen"'
Search Results
52. The Role of Prophage-like Elements in the Diversity of Salmonella enterica Serovars
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Thomson, Nicholas, Baker, Stephen, Pickard, Derek, Fookes, Maria, Anjum, Muna, Hamlin, Nancy, Wain, John, House, Deborah, Bhutta, Zulfiqar, Chan, Kaman, Falkow, Stanley, Parkhill, Julian, Woodward, Martin, Ivens, Al, and Dougan, Gordon
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SALMONELLA , *AMINO acids , *GENOMICS , *MOLECULAR genetics - Abstract
The Salmonella enterica serovar Typhi CT18 (S. Typhi) chromosome harbours seven distinct prophage-like elements, some of which may encode functional bacteriophages. In silico analyses were used to investigate these regions in S. Typhi CT18, and ultimately compare these integrated bacteriophages against 40 other Salmonella isolates using DNA microarray technology. S. Typhi CT18 contains prophages that show similarity to the lambda, Mu, P2 and P4 bacteriophage families. When compared to other S. Typhi isolates, these elements were generally conserved, supporting a clonal origin of this serovar. However, distinct variation was detected within a broad range of Salmonella serovars; many of the prophage regions are predicted to be specific to S. Typhi. Some of the P2 family prophage analysed have the potential to carry non-essential “cargo” genes within the hyper-variable tail region, an observation that suggests that these bacteriophage may confer a level of specialisation on their host. Lysogenic bacteriophages therefore play a crucial role in the generation of genetic diversity within S. enterica. [Copyright &y& Elsevier]
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- 2004
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53. Genomic Comparison of Salmonella enterica Serovars and Salmonella bongori by Use of an S. enterica Serovar Typhimurium DNA Microarray.
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Chan, Kaman, Baker, Stephen, Kim, Charles C., Detweiler, Corrella S., Dougan, Gordon, and Falkow, Stanley
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SALMONELLA enteritidis , *DNA microarrays - Abstract
The genus Salmonella consists of over 2,200 serovars that differ in their host range and ability to cause disease despite their close genetic relatedness. The genetic factors that influence each serovar's level of host adaptation, how they evolved or were acquired, their influence on the evolution of each serovar, and the phylogenic relationships between the serovars are of great interest as they provide insight into the mechanisms behind these differences in host range and disease progression. We have used an Salmonella enterica serovar Typhimurium spotted DNA microarray to perform genomic hybridizations of various serovars and strains of both S. enterica (subspecies I and IIIa) and Salmonella bongori to gain insight into the genetic organization of the serovars. Our results are generally consistent with previously published DNA association and multilocus enzyme electrophoresis data. Our findings also reveal novel information. We observe a more distant relationship of serovar Arizona (subspecies IIIa) from the subspecies I serovars than previously measured. We also observe variability in the Arizona SPI-2 pathogenicity island, indicating that it has evolved in a manner distinct from the other serovars. In addition, we identify shared genetic features of S. enterica serovars Typhi, Paratyphi A, and Sendal that parallel their unique ability to cause enteric fever in humans. Therefore, whereas the taxonomic organization of Salmonella into serogroups provides a good first approximation of genetic relatedness, we show that it does not account for genomic changes that contribute to a serovar's degree of host adaptation. [ABSTRACT FROM AUTHOR]
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- 2003
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54. New irreversible adenosine A1 antagonists based on FSCPX
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Beauglehole, Anthony R., Baker, Stephen P., and Scammells, Peter J.
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ADENOSINES , *CHEMICAL inhibitors , *XANTHINE - Abstract
FSCPX (1) and its amide analogue (2) have been reported to exhibit potent and selective irreversible antagonism of the A1 adenosine receptor (A1AR) when used in in vitro biological preparations. In order to obtain an irreversible A1AR antagonist with improved stability, analogues of FSCPX incorporating the chemoreactive 4-(fluorosulfonyl)phenyl moiety separated from the xanthine pharmacophore by a ketone linkage were explored. Compounds 4a–c exhibited improved affinity for the A1AR and concentration-dependent irreversible binding to the A1AR. [Copyright &y& Elsevier]
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- 2002
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55. New 2,N6-Disubstituted adenosines: potent and selective A1 adenosine receptor agonists
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Hutchinson, Sally A., Baker, Stephen P., and Scammells, Peter J.
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ADENOSINES , *EPOXY compounds , *CELL receptors - Abstract
A number of adenosine analogues substituted in the 2- and N6-positions were synthesized and evaluated for affinity, functional potency and intrinsic activity at the A1 and A2A adenosine receptors (AR). Three classes of N6-substituents were tested; norbornen-2-yl (series 1), norborn-2-yl (series 2) and 5,6-epoxynorborn-2-yl (series 3). The halogens; fluoro, bromo, and iodo were evaluated as C-2 substituents. All compounds showed relatively high affinity (nanomolar) for the A1AR and high potency for inhibiting (−)isoproterenol-stimulated cAMP accumulation in hamster smooth muscle DDT1 MF-2 cells with the 2-fluoro derivatives from each series having the highest affinity. All of the derivatives showed the same intrinsic activity as CPA. At the A2AAR, all of the derivatives showed relatively low affinity and potency (micromolar) for stimulating cAMP accumulation in rat pheochromocytoma PC-12 cells. The intrinsic activity of the derivatives compared to CGS 21680 was dependent upon the halogen substituent in the C-2 position with most showing partial agonist activity. Of particular interest is 2-iodo-N6-(2S-endo-norborn-2-yl)adenosine (5e), which is over 100-fold selective for the A1AR, is a full agonist at this receptor subtype and has no detectable agonist activity at the A2AAR. [Copyright &y& Elsevier]
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- 2002
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56. `You Must Remember This': Salman Rushdie's The Moor's Last Sigh.
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Baker, Stephen
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STRUCTURALISM (Literary analysis) - Abstract
Presents a structural analysis of the novel `The Moor's Last Sigh,' by Salman Rushdie. Coherence of the novel with the book `Midnight's Children, The Satanic Verses'; Dramatization of the destruction of art in the novel; Integration of the history of exploitation in the story; Parallelism of the novel with the `Invisible Man,' by Ralph Ellison.
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- 2000
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57. The origins of haplotype 58 (H58) Salmonella enterica serovar Typhi.
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Carey, Megan E., Thi Nguyen, To Nguyen, Tran, Do Hoang Nhu, Dyson, Zoe A., Keane, Jacqueline A., Pham Thanh, Duy, Mylona, Elli, Nair, Satheesh, Chattaway, Marie, and Baker, Stephen
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HAPLOTYPES , *THIRD generation cephalosporins , *TYPHOID fever , *SALMONELLA enterica serovar Typhi , *SALMONELLA typhi - Abstract
Antimicrobial resistance (AMR) poses a serious threat to the clinical management of typhoid fever. AMR in Salmonella Typhi (S. Typhi) is commonly associated with the H58 lineage, a lineage that arose comparatively recently before becoming globally disseminated. To better understand when and how H58 emerged and became dominant, we performed detailed phylogenetic analyses on contemporary genome sequences from S. Typhi isolated in the period spanning the emergence. Our dataset, which contains the earliest described H58 S. Typhi organism, indicates that ancestral H58 organisms were already multi-drug resistant (MDR). These organisms emerged spontaneously in India in 1987 and became radially distributed throughout South Asia and then globally in the ensuing years. These early organisms were associated with a single long branch, possessing mutations associated with increased bile tolerance, suggesting that the first H58 organism was generated during chronic carriage. The subsequent use of fluoroquinolones led to several independent mutations in gyrA. The ability of H58 to acquire and maintain AMR genes continues to pose a threat, as extensively drug-resistant (XDR; MDR plus resistance to ciprofloxacin and third generation cephalosporins) variants, have emerged recently in this lineage. Understanding where and how H58 S. Typhi originated and became successful is key to understand how AMR drives successful lineages of bacterial pathogens. Additionally, these data can inform optimal targeting of typhoid conjugate vaccines (TCVs) for reducing the potential for emergence and the impact of new drug-resistant variants. Emphasis should also be placed upon the prospective identification and treatment of chronic carriers to prevent the emergence of new drug resistant variants with the ability to spread efficiently. A phylogenetic analysis of Salmonella Typhi isolated from returning travelers to the United Kingdom between 1980 and 1995 suggests that H58 emerged from a chronic carrier in India in 1987 before spreading globally and was already multidrug resistant. [ABSTRACT FROM AUTHOR]
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- 2024
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58. A retrospective investigation of the population structure and geospatial distribution of Salmonella Paratyphi A in Kathmandu, Nepal.
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Mylona, Elli, Pham Thanh, Duy, Keane, Jacqueline A., Dongol, Sabina, Basnyat, Buddha, Dolecek, Christiane, Voong Vinh, Phat, Tran Vu Thieu, Nga, Nguyen Thi Nguyen, To, Karkey, Abhilasha, and Baker, Stephen
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SALMONELLA enterica serovar Typhi , *TYPHOID fever , *LOCATION data , *SALMONELLA typhi , *WHOLE genome sequencing , *SALMONELLA - Abstract
Salmonella Paratyphi A, one of the major etiologic agents of enteric fever, has increased in prevalence in recent decades in certain endemic regions in comparison to S. Typhi, the most prevalent cause of enteric fever. Despite this increase, data on the prevalence and molecular epidemiology of S. Paratyphi A remain generally scarce. Here, we analysed the whole genome sequences of 216 S. Paratyphi A isolates originating from Kathmandu, Nepal between 2005 and 2014, of which 200 were from patients with acute enteric fever and 16 from the gallbladder of people with suspected chronic carriage. By exploiting the recently developed genotyping framework for S. Paratyphi A (Paratype), we identified several genotypes circulating in Kathmandu. Notably, we observed an unusual clonal expansion of genotype 2.4.3 over a four-year period that spread geographically and systematically replaced other genotypes. This rapid genotype replacement is hypothesised to have been driven by both reduced susceptibility to fluoroquinolones and genetic changes to virulence factors, such as functional and structural genes encoding the type 3 secretion systems. Finally, we show that person-to-person is likely the most common mode of transmission and chronic carriers seem to play a limited role in maintaining disease circulation. Author summary: Enteric (typhoid) fever is caused by bacteria of Salmonella enterica species, specifically Salmonella Typhi and Salmonella Paratyphi A. While the former is most commonly identified as the causative agent of enteric fever, S. Paratyphi A is increasing in prevalence in many endemic areas like Nepal. However, the understanding of the phylogenetic structure and population dynamics of this organism, as well as transmission patterns, remains incomplete. Here, we provide a detailed phylogenetic analysis of S. Paratyphi A isolated from enteric fever patients in Nepal through whole genome sequence analysis, combined with epidemiological observations, such as water source use, and chronological and location data. We observed an unusual expansion of a genotype (genetic ID) that replaced other genotypes in the area, indicative of changes in circulating population composition. This expansion is hypothesised to have been driven by reduction in antibiotic susceptibility and changes on bacterial structures that are important for pathogenicity. Our data also suggest person-to-person as the most likely mode of transmission for this pathogen. Understanding of S. Paratyphi A population structure, sources of infection, and transmission will help develop policies for enteric fever management, particularly prior to vaccine introduction, as changes in population composition may affect vaccine efficacy. [ABSTRACT FROM AUTHOR]
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- 2024
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59. The frequency and associated factors of typhoid carriage in patients undergoing cholecystectomy for gallbladder disease in Pakistan: A cross-sectional study.
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Qureshi, Sonia, Maria, Noshi, Chawla, Tabish, Iqbal, Junaid, Kazi, Abdul Momin, Adnan, Mehreen, Hotwani, Aneeta, Rahman, Najeeb, Sadiq, Muhammed Wahhaab, Charles, Richelle, Baker, Stephen, and Qamar, Farah Naz
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TYPHOID fever , *SALMONELLA enterica serovar Typhi , *GALLBLADDER , *CHOLECYSTECTOMY , *SALMONELLA typhi , *BACTERIOPHAGE typing , *CROSS-sectional method , *SALMONELLA detection - Abstract
Background: Enteric fever is caused by Salmonella enterica serovars Typhi (S. Typhi) and Paratyphi A, B, and C. It continues to be a significant cause of morbidity and mortality worldwide. In highly endemic areas, children are disproportionately affected, and antimicrobial resistance reduces therapeutic options. It is estimated that 2–5% of enteric fever patients develop chronic asymptomatic infection. These carriers may act as reservoirs of infection; therefore, the prospective identification and treatment of carriers are critical for long-term disease control. We aimed to find the frequency of Salmonella Typhi carriers in patients undergoing cholecystectomy. We also compared the detection limit of culturing versus qPCR in detecting S. Typhi, performed a geospatial analysis of the carriers identified using this study, and evaluated the accuracy of anti-Vi and anti-YncE in identifying chronic typhoid carriage. Methods: We performed a cross-sectional study in two centers in Pakistan. Gallbladder specimens were subjected to quantitative PCR (qPCR) and serum samples were analyzed for IgG against YncE and Vi by ELISA. We also mapped the residential location of those with a positive qPCR result. Findings: Out of 988 participants, 3.4% had qPCR-positive gallbladder samples (23 S. Typhi and 11 S. Paratyphi). Gallstones were more likely to be qPCR positive than bile and gallbladder tissue. Anti-Vi and YncE were significantly correlated (r = 0.78 p<0.0001) and elevated among carriers as compared to qPCR negative controls, except for anti-Vi response in Paratyphi A. But the discriminatory values of these antigens in identifying carriers from qPCR negative controls were low. Conclusion: The high prevalence of typhoid carriers observed in this study suggests that further studies are required to gain information that will help in controlling future typhoid outbreaks in a superior manner than they are currently being managed. Author summary: Enteric fever, caused by bacteria Salmonella Typhi or Paratyphi, is a serious global illness particularly affecting children in areas with inadequate hygiene and sanitation facilities. It is transmitted through the oral-fecal route. In Pakistan, prevalence of extensively drug resistant S. Typhi resistant strain further complicates its treatment. Some infected individuals develop chronic infections and become carriers of these pathogens. These asymptomatic carriers may potentially spread the disease by shedding the bacteria in urine or stool. To assess the frequency of the carrier state, we examined gallbladder specimens (bile, stones, and tissue) from patients who underwent gallbladder removal surgeries at Aga Khan University and Jinnah Post-graduate Medical Centre. We demonstrated that PCR had a higher sensitivity in detecting Salmonella carriage with a detection limit of 102 CFU/ml and identified 3.4% of typhoid carriers. Additionally, we investigated whether specific antibodies could identify these carriers using various serological tests. The results underscore the need for further research to promptly detect and appropriately treat this disease, thereby enhancing control and preventing future outbreaks. [ABSTRACT FROM AUTHOR]
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- 2024
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60. A return to the pre-antimicrobial era?
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Baker, Stephen
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DRUG resistance in bacteria , *ANTIBIOTICS , *DRUG resistance in microorganisms , *ANTIBIOTICS in animal nutrition , *DIAGNOSIS of bacterial diseases , *MICROBIAL genetics ,PUBLIC health in developing countries - Abstract
The author looks at antimicrobial resistance (AMR) in bacteria, saying that the problem is particularly serious in poorer countries and may lead to a return of higher mortality rates from diseases such as typhoid fever. He emphasizes the need for changes in areas including diagnostic testing of infections and veterinary use of human antibiotics. Genetic aspects of AMR are discussed.
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- 2015
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61. `Disorder of the lights perhaps an illusion'.
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Baker, Stephen
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DRAMA - Abstract
Presents an inquiry into Paramodern stage performance. relationship between perception, conception and the codes by which they are defined; Image at play; Uselessness of ration action; Intertextual and grammatological techniques.
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- 1991
62. Health belief model variables as predictors of screening mammography utilization.
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Hyman, Ruth Bernstein and Baker, Stephen
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MAMMOGRAMS , *DISEASES in women - Abstract
Discusses the use of Health Belief Model (HBM) as predictors of screening for the utilization of mammography. Factors affecting the utilization of mammography; Psychometrically validated measure of variables affecting the utilization of mammography; Avoidant behavior among women with history of breast cancer; Recommendations for increasing the use of mammography.
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- 1994
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63. Effect of Phospholipid Depletion by Phospholipases on the Properties and Formation of the Multiple Monoamine Oxidase Forms in the Rat Liver.
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Baker, Stephen P. and Hemsworth, Brian A.
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PHOSPHOLIPIDS , *PHOSPHOLIPASES , *MONOAMINE oxidase , *LIVER cells , *LABORATORY rats , *GEL permeation chromatography , *ENZYMES - Abstract
The effect of phospholipid depletion by phospholipases on the properties and formation of monoamine oxidase A and B been investigated. The enzyme was solubilized, partially purified, treated with phospholipases and subjected to gel filtration to reduce the amount of enzyme-associated phospholipids. Phospholipase A treatment of the purified monoamine oxidase fraction had no effect on the deprenil inhibition pattern or the observed transition temperatures in the Arrhenius plots. However, the rate of enzyme inactivation by heat and trypsin were greatly increased but differences in rates of inactivation of monoamine oxidase A and B were still observed. Phospholipase C treatment of the enzyme fraction had no effect on the deprenil inhibition pattern, Arrhenius plots, heat stability or trypsin digestibility. The inhibition pattern of membrane-bound monoamine oxidase and the phospholipase-treated fractions by propargylamine showed a reduced substrate specificity compared to deprenil suggesting a hydrophobic region in the enzyme is a factor involved in the structural differences of monoamine oxidase A and B. [ABSTRACT FROM AUTHOR]
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- 1978
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64. A method of detecting the muscle pain threshold using an objective software-mediated technique.
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Edwards, Thomas and Baker, Stephen
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MYALGIA , *THRESHOLD (Perception) - Abstract
Examines the reliability of an objective software-mediated technique for measuring muscle pain threshold. Study of 24 female subjects who were tested on three occasions at four muscle sites repeated daily over four days; Main effect for trials and discomfort-pain threshold at different muscle sites.
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- 1996
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65. The dictated report and the radiologist's ethos. An inextricable relationship: Pitfalls to avoid.
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Baker, Stephen R.
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RADIOLOGISTS , *IMAGE analysis , *TRANSLATORS , *QUESTIONNAIRES , *STATISTICAL correlation , *RESPECT - Abstract
Abstract: Radiologists’ reputation as expert image interpreters are in large measured defined by the content of their written reports. Habitually use of terms that reveal a lack of decisiveness will serve to diminish their esteem in the minds of their referrers. Recurrent resort expression to such as questionable, suspicious, cannot rule out, and clinical correlation requested when frequently deployed are examples of phrases that can have a negative effect on the radiologist's ethos. [Copyright &y& Elsevier]
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- 2014
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66. An initiative to implement a triage and referral system to make exercise and rehabilitation referrals standard of care in oncology.
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Schmitz, Kathryn H., Chongaway, Andrew, Saeed, Anwaar, Fontana, Toni, Wood, Kelley, Gibson, Susan, Trilk, Jennifer, Adsul, Prajakta, and Baker, Stephen
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Background: Clinical guidelines suggest that patients should be referred to exercise while undergoing cancer treatment. Oncology clinicians report being supportive of exercise referrals but not having the time to make referrals. Toward the goal of making exercise referrals standard of care, we implemented and evaluated a novel clinical workflow. Methods: For this QI project, a rehabilitation navigator was inserted in chemotherapy infusion clinics. Patients were offered a validated electronic triage survey. Exercise or rehabilitation recommendations were communicated to patients during a brief counseling visit by the rehabilitation navigator. The implementation approach was guided by the EPIS framework. Acceptability and feasibility were assessed. Results: Initial meetings with nursing and cancer center leadership ensured buy-in (exploration). The education of medical assistants contributed to the adoption of the triage process (preparation). Audit and feedback ensured leadership was aware of medical assistants’ performance (implementation). 100% of medical assistants participated in implementing the triage tool. A total of 587 patients visited the infusion clinics during the 6-month period when this QI project was conducted. Of these, 501 (85.3%) were offered the triage survey and 391 (78%) completed the survey (acceptability). A total of 176 (45%) of triaged patients accepted a referral to exercise or rehabilitation interventions (feasibility). Conclusions: Implementation of a validated triage tool by medical assistants and brief counseling by a rehabilitation navigator resulted in 45% of infusion patients accepting a referral to exercise or rehabilitation. The triage process showed promise for making exercise referrals standard of care for patients undergoing cancer treatment. [ABSTRACT FROM AUTHOR]
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- 2024
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67. The Identification of Enteric Fever-Specific Antigens for Population-Based Serosurveillance.
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Mylona, Elli, Hefele, Lisa, Thieu, Nga Tran Vu, Van, Tan Trinh, Minh, Chau Nguyen Ngoc, Tuan, Anh Tran, Karkey, Abhilasha, Dongol, Sabina, Basnyat, Buddha, Vinh, Phat Voong, Dan, Thanh Ho Ngoc, Russell, Paula, Charles, Richelle C, Parry, Christopher M, and Baker, Stephen
- Abstract
Background Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A, is a major public health problem in low- and middle-income countries. Moderate sensitivity and scalability of current methods likely underestimate enteric fever burden. Determining the serological responses to organism-specific antigens may improve incidence measures. Methods Plasma samples were collected from blood culture-confirmed enteric fever patients, blood culture-negative febrile patients over the course of 3 months, and afebrile community controls. A panel of 17 Salmonella Typhi and Paratyphi A antigens was purified and used to determine antigen-specific antibody responses by indirect ELISAs. Results The antigen-specific longitudinal antibody responses were comparable between enteric fever patients, patients with blood culture-negative febrile controls, and afebrile community controls for most antigens. However, we found that IgG responses against STY1479 (YncE), STY1886 (CdtB), STY1498 (HlyE), and the serovar-specific O2 and O9 antigens were greatly elevated over a 3-month follow up period in S. Typhi/ S. Paratyphi A patients compared to controls, suggesting seroconversion. Conclusions We identified a set of antigens as good candidates to demonstrate enteric fever exposure. These targets can be used in combination to develop more sensitive and scalable approaches to enteric fever surveillance and generate invaluable epidemiological data for informing vaccine policies. Clinical Trial Registration ISRCTN63006567. [ABSTRACT FROM AUTHOR]
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- 2024
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68. Clinical and Laboratory Findings In Individuals With Acute Norovirus Disease.
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Yu, Catherine, Baker, Stephen, Morse, Leonard J., Gardiner, James, Meehan, Marcia, Esposito, Anthony, Roberto, Regina, and Ellison III, Richard T.
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GASTROINTESTINAL diseases , *LEUCOCYTOSIS , *LEUCOCYTES , *NEUTROPHILS , *NAUSEA , *VOMITING , *DIARRHEA , *ABDOMINAL pain - Abstract
The article reports on the clinical and laboratory results of patients with acute norovirus disease. The illness, caused by noroviruses, manifested on the students of Worcester Polytechnic Institute in Massachusetts in 2005 following the symptoms of nausea, vomiting, diarrhea, and abdominal pain occurred. The researchers disclose the presence of high frequency leukocytes and fecal leukocytes and reveal that clinical findings prove leukocytosis with a neutrophil predominance. They also highlight the significance of increased neutrophil counts and fecal leukocytes in understanding norovirus disease and its outbreak.
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- 2007
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69. Risk factors for polymyxin-resistant carbapenemase-producing Enterobacteriaceae in critically ill patients: An epidemiological and clinical study.
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da Silva, Kesia Esther, Baker, Stephen, Croda, Julio, Nguyen, To Nguyen Thi, Boinett, Christine J., Barbosa, Leticia Spanivello, Tetila, Andyane, and Simionatto, Simone
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CRITICALLY ill , *CENTRAL venous catheters , *ENTEROBACTERIACEAE , *INTENSIVE care units , *URINARY catheters - Abstract
• Several risk factors were associated with polymyxin-resistant strains. • The mortality rate was significantly higher in patients with polymyxin-resistant strains. • Carbapenem exposure was strongly associated with mortality. • Aminoglycoside use was a protection factor against mortality from polymyxin-resistant strains. • Polymyxin resistance occurred through mutational changes in mgrB, phoPQ and soxS genes. This study aimed to assess the clinical impact and potential risk factors associated with polymyxin-resistant Enterobacteriaceae strains isolated from patients hospitalized in adult and neonatal intensive care units. A case–control study was conducted from September 2015 to January 2017. Antimicrobial susceptibility of polymyxin-resistant Enterobacteriaceae strains was determined by broth microdilution. The presence of resistance genes was evaluated by polymerase chain reaction and DNA sequencing. Renal failure [ P =0.02, odds ratio (OR) 11.37, 95% confidence interval (CI) 1.0–128.63], use of a urinary catheter (P <0.01, OR 4.16, 95% CI 38.82–366.07), transfer between hospital units (P =0.03, OR 9.98, 95% CI 1.01–98.42), carbapenem use (P <0.01, OR 45.49, 95% CI 6.93–298.62) and surgical procedure (P <0.01, OR 16.52, 95% CI 2.83–96.32) were found to be risk factors for the acquisition of polymyxin-resistant strains in adult patients. For neonatal patients, use of a central venous catheter (P <0.01, OR 69.59, 95% CI 7.33–660.30) was the only risk factor associated with the acquisition of polymyxin-resistant strains. Analysis of the outcomes revealed that the mortality rate was significantly higher in adult (66.6%) and neonatal (23.5%) patients with polymyxin-resistant strains than in those with polymyxin-susceptible strains. In addition, carbapenem exposure (P <0.01, OR 50.93, 95% CI 2.26–>999.999) was strongly associated with mortality. On the other hand, aminoglycoside use (P <0.03, OR 0.06, 95% CI 0.004–0.97) was a protective factor against mortality from polymyxin-resistant strains. Several risk factors were associated with polymyxin-resistant strains. The high mortality rates showed that acquisition of these strains is a predictor for unfavourable outcomes. Combination treatment with an aminoglycoside and polymyxin might be a better combination to improve patient outcomes. [ABSTRACT FROM AUTHOR]
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- 2020
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70. The thyroid cancer epidemic: Is it the dark side of the CT revolution?
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Baker, Stephen R. and Bhatti, Waseem A.
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THYROID cancer , *CANCER in women , *TOMOGRAPHY , *MEDICAL radiology - Abstract
Abstract: The rapid increase in CT use since 1990 and especially in the past 10 years has been accompanied by a coterminous worldwide increase in incidence of thyroid cancer especially in women. Are the two trends independent or related? Specific information from many countries and seven American states suggest that the relationship is real as no other cause can account fully for the temporal change in the frequency of this malignancy. Moreover, newer techniques of CT performance with or without the administration of iodinated contrast material favor the likelihood of a contingent association of image test utilization and thyroid cancer induction. [Copyright &y& Elsevier]
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- 2006
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71. The Proteasome: Not Just Degrading Anymore
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Baker, Stephen P. and Grant, Patrick A.
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PROTEINS , *BIOMOLECULES , *MOLECULAR biology , *ORGANIC compounds - Abstract
The proteasome is a large multiprotein complex that has a critical role in the degradation of ubiquitylated proteins. A fascinating paper in this issue of Cell () now reveals that the proteasome recruits the SAGA histone acetyltransferase complex to a target promoter during gene activation. This finding adds to the growing body of evidence indicating that the proteasome has nonproteolytic functions. [Copyright &y& Elsevier]
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- 2005
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72. Natural inflation, strong dynamics, and the role of generalized anomalies.
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Anber, Mohamed M. and Baker, Stephen
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INFLATIONARY universe , *PRICE inflation , *DISCRETE symmetries , *BARYON number , *PLANCK scale , *OSCILLATOR strengths , *COSMIC background radiation - Abstract
We revisit models of natural inflation and show that the single-field effective theory described by the potential V(a)∼cosa/f breaks down as the inflaton a makes large-field excursions, even for values of f smaller than the Planck scale. To remedy the problem, we modify the potential in order to account for the heavy degrees of freedom (hadrons) that become intertwined with the light inflaton as the latter rolls down its potential. By embedding the low-energy degrees of freedom into an ultraviolet-complete gauge theory, we argue that the intertwining between the two scales can be explained as the result of a generalized mixed 't Hooft anomaly between the discrete chiral symmetry and background fractional fluxes in the baryon number, color, and flavor directions. Further, we study the multifield inflation and show that it entertains rich dynamics. Inflating near the hilltop excites the hadrons and spoils the slow-roll parameters, in contradistinction with the expectations in the single-field inflation. Nevertheless, we identify a safe zone where inflation can proceed successfully. We determine the conditions under which the Universe inflates by at least 60 e-foldings and inflation leads to a power spectrum and tensor to scalar ratio that are consistent with the cosmic microwave background data. [ABSTRACT FROM AUTHOR]
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- 2020
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73. Fibrinogen αC-subregions critically contribute blood clot fibre growth, mechanical stability, and resistance to fibrinolysis.
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McPherson, Helen R., Duval, Cedric, Baker, Stephen R., Hindle, Matthew S., Lih T. Cheah, Asquith, Nathan L., Domingues, Marco M., Ridger, Victoria C., Connell, Simon D. A., Naseem, Khalid M., Philippou, Helen, Ajjan, Ramzi A., and Ariëns, Robert A. S.
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FIBRINOGEN , *BLOOD coagulation , *FIBRINOLYSIS , *FIBERS , *STRUCTURAL stability - Abstract
Fibrinogen is essential for blood coagulation. The C-terminus of the fibrinogen α-chain (αC-region) is composed of an αC-domain and αC-connector. Two recombinant fibrinogen variants (α390 and α220) were produced to investigate the role of subregions in modulating clot stability and resistance to lysis. The α390 variant, truncated before the αC-domain, produced clots with a denser structure and thinner fibres. In contrast, the α220 variant, truncated at the start of the αC-connector, produced clots that were porous with short, stunted fibres and visible fibre ends. These clots were mechanically weak and susceptible to lysis. Our data demonstrate differential effects for the αC-sub-regions in fibrin polymerisation, clot mechanical strength, and fibrinolytic susceptibility. Furthermore, we demonstrate that the αC-subregions are key for promoting longitudinal fibre growth. Together, these findings highlight critical functions of the αC-subregions in relation to clot structure and stability, with future implications for development of novel therapeutics for thrombosis. [ABSTRACT FROM AUTHOR]
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- 2021
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74. Determining the burden of fungal infections in Zimbabwe.
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Pfavayi, Lorraine T., Denning, David W., Baker, Stephen, Sibanda, Elopy N., and Mutapi, Francisca
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MYCOSES , *TUBERCULOSIS , *HIV infections , *COVID-19 , *MALARIA - Abstract
Zimbabwe currently faces several healthcare challenges, most notably HIV and associated infections including tuberculosis (TB), malaria and recently outbreaks of cholera, typhoid fever and COVID-19. Fungal infections, which are also a major public health threat, receive considerably less attention. Consequently, there is dearth of data regarding the burden of fungal diseases in the country. We estimated the burden of fungal diseases in Zimbabwe based on published literature and 'at-risk' populations (HIV/AIDS patients, survivors of pulmonary TB, cancer, chronic obstructive pulmonary disease, asthma and patients receiving critical care) using previously described methods. Where there was no data for Zimbabwe, regional, or international data was used. Our study revealed that approximately 14.9% of Zimbabweans suffer from fungal infections annually, with 80% having tinea capitis. The annual incidence of cryptococcal meningitis and Pneumocystis jirovecii pneumonia in HIV/AIDS were estimated at 41/100,000 and 63/100,000, respectively. The estimated prevalence of recurrent vulvovaginal candidiasis (RVVC) was 2,739/100,000. The estimated burden of fungal diseases in Zimbabwe is high in comparison to other African countries, highlighting the urgent need for increased awareness and surveillance to improve diagnosis and management. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
75. IRAQ: Washington Prepares for Another War.
- Author
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Baker, Stephen H. and Donovan, Michael
- Subjects
IRAQ-United States military relations - Abstract
Reports on the U.S. preparations for war against Iraq. Concerns of U.S. government on the provision of weapons of mass destruction to terrorists; Claims of chemical and biological weapons; Insistence of weapons inspections by the U.S.
- Published
- 2002
76. Vaccine value profile for Salmonella enterica serovar Paratyphi A.
- Author
-
Martin, Laura B., Khanam, Farhana, Qadri, Firdausi, Khalil, Ibrahim, Sikorski, Michael J., and Baker, Stephen
- Subjects
- *
SALMONELLA enterica serovar Typhi , *SALMONELLA enterica , *SALMONELLA diseases , *TYPHOID fever , *COMBINED vaccines , *EVIDENCE gaps - Abstract
In Asia, there are an estimated 12 million annual cases of enteric fever, a potentially fatal systemic bacterial infection caused by Salmonella enterica serovars Typhi (STy) and Paratyphi A (SPA). The recent availability of typhoid conjugate vaccines (TCV), an increasing incidence of disease caused by SPA and growing antimicrobial resistance (AMR) across the genus Salmonella makes a bivalent STy/SPA vaccine a useful public health proposition. The uptake of a stand-alone paratyphoid vaccine is likely low thus, there is a pipeline of bivalent STy/SPA candidate vaccines. Several candidates are close to entering clinical trials, which if successful should facilitate a more comprehensive approach for enteric fever control. Additionally, the World Health Organization (WHO) has made advancing the development of vaccines that protect young children and working aged adults against both agents of enteric fever a priority objective. This "Vaccine Value Profile" (VVP) addresses information related predominantly to invasive disease caused by SPA prevalent in Asia. Information is included on stand-alone SPA candidate vaccines and candidate vaccines targeting SPA combined with STy. Out of scope for the first version of this VVP is a wider discussion on the development of a universal Salmonella combination candidate vaccine, addressing both enteric fever and invasive non-typhoidal Salmonella disease, for use globally. This VVP is a detailed, high-level assessment of existing, publicly available information to inform and contextualize the public health, economic, and societal potential of pipeline vaccines and vaccine-like products for SPA. Future versions of this VVP will be updated to reflect ongoing activities such as vaccine development strategies and "Full Vaccine Value Assessment" that will inform the value proposition of an SPA vaccine. This VVP was developed by an expert working group from academia, non-profit organizations, public–private partnerships, and multi-lateral organizations as well as in collaboration with stakeholders from the WHO South-East Asian Region. All contributors have extensive expertise on various elements of the VVP for SPA and collectively aimed to identify current research and knowledge gaps. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
77. Quo vadis?
- Author
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Baker, Stephen R. and Suberlak, Matthew N.
- Subjects
- *
CARCINOEMBRYONIC antigen , *MAGNETIC resonance imaging of cancer , *CANCER tomography , *CANCER radiotherapy , *MEDICAL specialties & specialists , *MEDICAL radiology - Published
- 2016
- Full Text
- View/download PDF
78. The seroincidence of childhood Shigella sonnei infection in Ho Chi Minh City, Vietnam.
- Author
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Jones, Nick K., Thu, Trang Nguyen Hoang, de Alwis, Ruklanthi, Thompson, Corinne, Tuyen, Ha Thanh, Nhu, Tran Do Hoang, Phat, Voong Vinh, Trung, Pham Duc, Lam, Phung Khanh, Tien, Bui Thi Thuy, Tuyet, Hoang Thi Diem, Vi, Lu Lan, Van Vinh Chau, Nguyen, Le Thi Quynh, Nhi, and Baker, Stephen
- Subjects
- *
SHIGELLOSIS , *ENZYME-linked immunosorbent assay , *VACCINE development , *SHIGELLA , *SEROCONVERSION - Abstract
Background: Shigella sonnei is a pathogen of growing global importance as a cause of diarrhoeal illness in childhood, particularly in transitional low-middle income countries (LMICs). Here, we sought to determine the incidence of childhood exposure to S. sonnei infection in a contemporary transitional LMIC population, where it represents the dominant Shigella species. Methods: Participants were enrolled between the age of 12–36 months between June and December 2014. Baseline characteristics were obtained through standardized electronic questionnaires, and serum samples were collected at 6-month intervals over two years of follow-up. IgG antibody against S. sonnei O-antigen (anti-O) was measured using an enzyme-linked immunosorbent assay (ELISA). A four-fold increase in ELISA units (EU) with convalescent IgG titre >10.3 EU was taken as evidence of seroconversion between timepoints. Results: A total of 3,498 serum samples were collected from 748 participants; 3,170 from the 634 participants that completed follow-up. Measures of anti-O IgG varied significantly by calendar month (p = 0.03). Estimated S. sonnei seroincidence was 21,451 infections per 100,000 population per year (95% CI 19,307–23,834), with peak incidence occurring at 12–18 months of age. Three baseline factors were independently associated with the likelihood of seroconversion; ever having breastfed (aOR 2.54, CI 1.22–5.26), history of prior hospital admission (aOR 0.57, CI 0.34–0.95), and use of a toilet spray-wash in the household (aOR 0.42, CI 0.20–0.89). Conclusions: Incidence of S. sonnei exposure in Ho Chi Minh City is substantial, with significant reduction in the likelihood of exposure as age increases beyond 2 years. Author summary: Bacteria belonging to the genus Shigella are a leading cause of childhood diarrhea globally. In Vietnam and other transitional low-middle income countries (LMIC), S. sonnei has recently emerged as the dominant Shigella species, displacing S. flexneri, which usually predominates in industrializing regions. Little is known about the epidemiology of S. sonnei and how common infection is amongst children in such settings. In this study, we used regular blood sampling from a large cohort of children in Ho Chi Minh City over a two year period to examine changes in antibody concentrations against S. sonnei, using this to detect evidence of exposure to the bacteria. Importantly, this approach allowed us to identify exposures irrespective of whether the children had experienced symptoms or not. Our findings showed that exposure to S. sonnei was common in this cohort, with the highest incidence of exposure occurring in children observed between the ages of 12 months and 18 months. This is the first study of its kind to describe the epidemiology of S. sonnei infection in a LMIC setting and will be useful in informing future vaccine development and deployment strategies against this important pathogen. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
79. Shigella Serotypes Associated With Carriage in Humans Establish Persistent Infection in Zebrafish.
- Author
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Torraca, Vincenzo, Brokatzky, Dominik, Miles, Sydney L, Chong, Charlotte E, Silva, P Malaka De, Baker, Stephen, Jenkins, Claire, Holt, Kathryn E, Baker, Kate S, and Mostowy, Serge
- Subjects
- *
SHIGELLA , *SHIGELLA flexneri , *SEROTYPES , *BRACHYDANIO , *SHIGELLOSIS - Abstract
Shigella represents a paraphyletic group of enteroinvasive Escherichia coli. More than 40 Shigella serotypes have been reported. However, most cases within the men who have sex with men (MSM) community are attributed to 3 serotypes: Shigella sonnei unique serotype and Shigella flexneri 2a and 3a serotypes. Using the zebrafish model, we demonstrate that Shigella can establish persistent infection in vivo. Bacteria are not cleared by the immune system and become antibiotic tolerant. Establishment of persistent infection depends on the O-antigen, a key constituent of the bacterial surface and a serotype determinant. Representative isolates associated with MSM transmission persist in zebrafish, while representative isolates of a serotype not associated with MSM transmission do not. Isolates of a Shigella serotype establishing persistent infections elicited significantly less macrophage death in vivo than isolates of a serotype unable to persist. We conclude that zebrafish are a valuable platform to illuminate factors underlying establishment of Shigella persistent infection in humans. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
80. Multidrug resistance plasmids underlie clonal expansions and international spread of Salmonella enterica serotype 1,4,[5],12:i:- ST34 in Southeast Asia.
- Author
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Chung The, Hao, Pham, Phuong, Ha Thanh, Tuyen, Phuong, Linh Vo Kim, Yen, Nguyen Phuong, Le, Son-Nam H., Vu Thuy, Duong, Chau, Tran Thi Hong, Le Phuc, Hoang, Ngoc, Nguyen Minh, Vi, Lu Lan, Mather, Alison E., Thwaites, Guy E., Thomson, Nicholas R., Baker, Stephen, and Pham, Duy Thanh
- Subjects
- *
MULTIDRUG resistance , *SALMONELLA typhimurium , *PLASMIDS , *DRUG resistance in microorganisms , *GENOMES , *SALMONELLA enterica , *SALMONELLA enterica serovar typhimurium - Abstract
Salmonella enterica serotype 1,4,[5],12:i:- (Typhimurium monophasic variant) of sequence type (ST) 34 has emerged as the predominant pandemic genotype in recent decades. Despite increasing reports of resistance to antimicrobials in Southeast Asia, Salmonella ST34 population structure and evolution remained understudied in the region. Here we performed detailed genomic investigations on 454 ST34 genomes collected from Vietnam and diverse geographical sources to elucidate the pathogen's epidemiology, evolution and antimicrobial resistance. We showed that ST34 has been introduced into Vietnam in at least nine occasions since 2000, forming five co-circulating major clones responsible for paediatric diarrhoea and bloodstream infection. Most expansion events were associated with acquisitions of large multidrug resistance plasmids of IncHI2 or IncA/C2. Particularly, the self-conjugative IncA/C2 pST34VN2 (co-transferring blaCTX-M-55, mcr-3.1, and qnrS1) underlies local expansion and intercontinental spread in two separate ST34 clones. At the global scale, Southeast Asia was identified as a potential hub for the emergence and dissemination of multidrug resistant Salmonella ST34, and mutation analysis suggests of selection in antimicrobial responses and key virulence factors. A genomic epidemiology approach describes the population structure of Salmonella monophasic Typhimurium ST34 from Vietnam, and identifies Southeast Asia as a potential hub for the emergence and international spread of multidrug resistant Salm. ST34. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
81. The Next Time You Trade in Your Car, It Could Be for a Phone: To widen commuting options, new efforts aim to tie together all forms of transit within one mobile app.
- Author
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Rossant, John and Baker, Stephen
- Subjects
- *
INFORMATION technology , *HOUSEHOLD electronics , *APPLICATION software , *MOBILE apps , *TRANSPORTATION - Published
- 2019
82. The Relationship Between Blood Sample Volume and Diagnostic Sensitivity of Blood Culture for Typhoid and Paratyphoid Fever: A Systematic Review and Meta-Analysis.
- Author
-
Antillon, Marina, Saad, Neil J, Baker, Stephen, Pollard, Andrew J, and Pitzer, Virginia E
- Subjects
- *
BLOOD sampling , *BLOOD testing , *TYPHOID fever , *PARATYPHOID fever , *META-analysis - Abstract
Background: Blood culture is the standard diagnostic method for typhoid and paratyphoid (enteric) fever in surveillance studies and clinical trials, but sensitivity is widely acknowledged to be suboptimal. We conducted a systematic review and meta-analysis to examine sources of heterogeneity across studies and quantified the effect of blood volume.Methods: We searched the literature to identify all studies that performed blood culture alongside bone marrow culture (a gold standard) to detect cases of enteric fever. We performed a meta-regression analysis to quantify the relationship between blood sample volume and diagnostic sensitivity. Furthermore, we evaluated the impact of patient age, antimicrobial use, and symptom duration on sensitivity.Results: We estimated blood culture diagnostic sensitivity was 0.59 (95% confidence interval [CI], 0.54-0.64) with significant between-study heterogeneity (I2, 76% [95% CI, 68%-82%]; P < .01). Sensitivity ranged from 0.51 (95% CI, 0.44-0.57) for a 2-mL blood specimen to 0.65 (95% CI, 0.58-0.70) for a 10-mL blood specimen, indicative of a relationship between specimen volume and sensitivity. Subgroup analysis showed significant heterogeneity by patient age and a weak trend towards higher sensitivity among more recent studies. Sensitivity was 34% lower (95% CI, 4%-54%) among patients with prior antimicrobial use and 31% lower after the first week of symptoms (95% CI, 19%-41%). There was no evidence of confounding by patient age, antimicrobial use, symptom duration, or study date on the relationship between specimen volume and sensitivity.Conclusions: The relationship between the blood sample volume and culture sensitivity should be accounted for in incidence and next-generation diagnostic studies. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
83. Bacterial shedding and serologic responses following an outbreak of Salmonella Typhi in an endemic cohort.
- Author
-
Johnston, Peter I., Bogue, Patrick, Chirambo, Angeziwa Chunga, Mbewe, Maurice, Prakash, Reenesh, Kandoole-Kabwere, Vanessa, Lester, Rebecca, Darton, Thomas, Baker, Stephen, Gordon, Melita A., and Meiring, James E.
- Subjects
- *
SALMONELLA typhi , *SALMONELLA enterica serovar Typhi , *HEALTH facilities , *TYPHOID fever , *THIRST , *ANTIBODY titer - Abstract
Background: Salmonella enterica serovar Typhi (Salmonella Typhi) is the cause of typhoid fever. Salmonella Typhi may be transmitted through shedding in the stool, which can continue after recovery from acute illness. Shedding is detected by culturing stool, which is challenging to co-ordinate at scale. We hypothesised that sero-surveillance would direct us to those shedding Salmonella Typhi in stool following a typhoid outbreak. Methods: In 2016 a typhoid outbreak affected one in four residents of a Nursing School in Malosa, Malawi. The Department of Health asked for assistance to identify nursing students that might spread the outbreak to other health facilities. We measured IgG antibody titres against Vi capsular polysaccharide (anti-Vi IgG) and IgM / IgG antibodies against H:d flagellin (anti-H:d) three and six months after the outbreak. We selected participants in the highest and lowest deciles for anti-Vi IgG titre (measured at visit one) and obtained stool for Salmonella culture and PCR. All participants reported whether they had experienced fever persisting for three days or more during the outbreak (in keeping with the WHO definitions of 'suspected typhoid'). We tested for salmonellae in the Nursing School environment. Results: We obtained 320 paired serum samples from 407 residents. We cultured stool from 25 residents with high anti-Vi IgG titres and 24 residents with low titres. We did not recover Salmonella Typhi from stool; four stool samples yielded non-typhoidal salmonellae; one sample produced a positive PCR amplification for a Salmonella Typhi target. Median anti-Vi and anti-H:d IgG titres fell among participants who reported persistent fever. There was a smaller fall in anti-H:d IgG titres among participants who did not report persistent fever. Non-typhoidal salmonellae were identified in water sampled at source and from a kitchen tap. Conclusion: High titres of anti-Vi IgG did not identify culture-confirmed shedding of Salmonella Typhi. There was a clear serologic signal of recent typhoid exposure in the cohort, represented by waning IgG antibody titres over time. The presence of non-typhoidal salmonellae in drinking water indicates sub-optimal sanitation. Developing methods to detect and treat shedding remains an important priority to complement typhoid conjugate vaccination in efforts to achieve typhoid elimination. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
84. Perspectives of pharmacy employees on an inappropriate use of antimicrobials in Kathmandu, Nepal.
- Author
-
Shrestha, Nistha, Manandhar, Sulochana, Maharjan, Nhukesh, Twati, Devina, Dongol, Sabina, Basnyat, Buddha, Baker, Stephen, and Karkey, Abhilasha
- Subjects
- *
EMPLOYEE attitudes , *ANTI-infective agents , *RESPIRATORY infections , *MIDDLE-income countries , *DRUGSTORES , *AZITHROMYCIN - Abstract
Background: Unregulated antimicrobial use is common in both hospital and community settings of low- and middle-income countries (LMICs). However, discrete data regarding the use/misuse of antimicrobials at pharmacies in LMICs are limited. This study was conducted to understand knowledge, attitude, and practice of pharmacy employees on antimicrobial dispensing in Nepal. Methods: We conducted a cross-sectional survey using a structured questionnaire on 801 pharmacy employees working in community and hospital pharmacies located in Lalitpur metropolitan city (LMC) of Kathmandu, Nepal between April 2017 and March 2019. Results: A majority (92%) of respondents agreed that demand for non-prescription antimicrobials was common. Asking for prescription before dispensing was ranked as the first preference by majority (69%) of participants. Suspected respiratory tract infection was the most common reason demanding for non-prescription antimicrobials with the highest mean rank of 1.5. Azithromycin was the most commonly prescribed and sold antimicrobial, as reported by 46% and 48% of participants respectively. A majority (87%) of respondents agreed on antimicrobial resistance (AMR) to be a global public health threat; and misuse/overuse of antimicrobials was perceived as the most common cause of AMR with a mean rank of 1.93. Conclusion: Our study revealed that unfounded dispensing and use of antimicrobials is prevalent among pharmacies in Kathmandu, Nepal. This over reliance on antimicrobials, notably azithromycin, may escalate burden of AMR. We identified several drivers of inappropriate antimicrobial dispensing practice in pharmacies, which will aid public health authorities in addressing these issues. Further studies considering role of other stakeholders, such as doctors, veterinarians, general public, and policy makers are required to obtain a more holistic perspectives on practices of antimicrobial use so to curb the extant AMR crisis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
85. What Should We Be Recommending for the Treatment of Enteric Fever?
- Author
-
Parry, Christopher M, Qamar, Farah N, Rijal, Samita, McCann, Naina, Baker, Stephen, and Basnyat, Buddha
- Subjects
- *
TYPHOID fever , *SYMPTOMS , *DRUG resistance in microorganisms , *RANDOMIZED controlled trials , *MEROPENEM , *AZITHROMYCIN - Abstract
Patients with suspected enteric (typhoid and paratyphoid) fever are predominantly managed as outpatients in endemic regions. Nonspecific clinical presentation, lack of accurate diagnostic tools, and widespread antimicrobial resistance makes management challenging. Resistance has been described for all antimicrobials including chloramphenicol, amoxycillin, trimethoprim-sulfamethoxazole, ciprofloxacin, ceftriaxone, and azithromycin. No significant differences have been demonstrated between these antimicrobials in their ability to treat enteric fever in systematic reviews of randomized controlled trials (RCTs). Antimicrobial choice should be guided by local resistance patterns and national guidance. Extensively drug-resistant typhoid isolates require treatment with azithromycin and/or meropenem. Combining antimicrobials that target intracellular and extracellular typhoid bacteria is a strategy being explored in the Azithromycin and Cefixime in Typhoid Fever (ACT-SA) RCT, in progress in South Asia. Alternative antimicrobials, such as the oral carbapenem, tebipenem, need clinical evaluation. There is a paucity of evidence to guide the antimicrobial management of chronic fecal carriers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
86. Diagnostics for Typhoid Fever: Current Perspectives and Future Outlooks for Product Development and Access.
- Author
-
Sapkota, Jyotshna, Roberts, Tamalee, Basnyat, Buddha, Baker, Stephen, Hampton, Lee M, and Dittrich, Sabine
- Subjects
- *
TYPHOID fever , *SALMONELLA diseases , *NEW product development , *SALMONELLA typhi , *RAPID diagnostic tests , *MIDDLE-income countries - Abstract
Typhoid is an enteric disease caused by Salmonella Typhi. Like many febrile illnesses, typhoid presents with nonspecific symptoms. In routine healthcare settings in low- and middle-income countries, typhoid fever is suspected and treated empirically. Though many diagnostic tests are available for typhoid diagnosis, there are currently no diagnostic tests that meet ideal requirements for sensitivity, specificity, speed, and cost-effectiveness. With introduction of typhoid conjugate vaccine, it is essential to explore the current and future typhoid approach in the context of use case and access to ensure their utilization for disease control. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
87. Unlocking the Potential of Genomic Data to Inform Typhoid Fever Control Policy: Supportive Resources for Genomic Data Generation, Analysis, and Visualization.
- Author
-
Carey, Megan E, Dyson, Zoe A, Argimón, Silvia, Cerdeira, Louise, Yeats, Corin, Aanensen, David, Mboowa, Gerald, Baker, Stephen, Tessema, Sofonias K, Smith, Anthony M, Okeke, Iruka N, and Holt, Kathryn E
- Subjects
- *
SARS-CoV-2 , *TYPHOID fever , *SALMONELLA typhi - Abstract
The global response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic demonstrated the value of timely and open sharing of genomic data with standardized metadata to facilitate monitoring of the emergence and spread of new variants. Here, we make the case for the value of Salmonella Typhi (S. Typhi) genomic data and demonstrate the utility of freely available platforms and services that support the generation, analysis, and visualization of S. Typhi genomic data on the African continent and more broadly by introducing the Africa Centres for Disease Control and Prevention's Pathogen Genomics Initiative, SEQAFRICA, Typhi Pathogenwatch, TyphiNET, and the Global Typhoid Genomics Consortium. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
88. Pneumoperitoneum--the radiographic and clinical virtues of the supine abdominal film.
- Author
-
Baker SR and Baker, Stephen R
- Published
- 2012
- Full Text
- View/download PDF
89. Executive Insight: The Computer Is Personal Again.
- Author
-
Baker, Stephen
- Subjects
- *
PERSONAL computers , *INSIGHT - Published
- 2020
90. Trauma computed tomography and radiation dose: A matter of concern.
- Author
-
Baker, Stephen
- Subjects
- *
TOMOGRAPHY , *RADIATION doses , *MEDICAL radiography , *TRAUMATISM , *CANCER patients , *THERAPEUTICS - Abstract
In this article, the author focuses on the use of computed tomography (CT) and the efficacy of radiation dose on patients suffering from trauma. He ponders on the overuse of CT scanning in medical diagnosis and the adverse effect it cause on patients, such as radiation-induced cancer. He thus gives account on the effectiveness of the administration of dose radiation to patients with trauma for the prevention of the radiation-induced disease.
- Published
- 2009
- Full Text
- View/download PDF
91. Typhoid carriage in the gallbladder.
- Author
-
Basnyat, Buddha and Baker, Stephen
- Subjects
- *
SALMONELLA enterica serovar Typhi , *SYMPTOMS , *DIAGNOSIS , *GALLBLADDER , *IMMUNOFLUORESCENCE , *CARRIER state (Communicable diseases) , *CHOLECYSTECTOMY , *CHOLECYSTITIS , *SALMONELLA ,TYPHOID fever diagnosis - Abstract
The article describes the case of a male patient with Salmonella enterica serovar S Typhi. It discusses the symptoms shown by the patient upon admission to Patan Hospital in Kathmandu, Nepal, the patient's diagnosis, and examination of the patient's gallbladder with the use of immunofluorescent labelling.
- Published
- 2015
- Full Text
- View/download PDF
92. Trichomonal Infection and Associated Squamous Cell Abnormalities.
- Author
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Ray, Nancy J., Baker, Stephen, Procop, Gary W., and Brainard, Jennifer A.
- Subjects
- *
TRICHOMONAS vaginalis - Abstract
An abstract of the article "Trichomonal Infection and Associated Squamous Cell Abnormalities," by Nancy J. Ray, Stephen Baker, Gary W. Procop, and Jennifer A. Brainard is presented.
- Published
- 2008
93. The Role of Fine Needle Aspiration in the Evaluation of Uveal Tumors: A Clinicopathologic Analysis of 26 Consecutive Cases.
- Author
-
Baker, Stephen E., Singh, Arun D., Fu, Evelyn, Weber, Dana, and Biscotti, Charles V.
- Subjects
- *
UVEA , *TUMORS - Abstract
An abstract of the article "The Role of Fine Needle Aspiration in the Evaluation of Uveal Tumors: A Clinicopathologic Analysis of 26 Consecutive Cases," by Stephen E. Baker, Arun D. Singh, Evelyn Fu, Dana Weber and Charles V. Biscotti is presented.
- Published
- 2008
94. First-year radiology residents not taking call.
- Author
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Baker SR and Baker, Stephen R
- Published
- 2008
95. Response to editorial by Dr. Dawson
- Author
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Baker, Stephen R. and Bhatti, Waseem
- Published
- 2008
- Full Text
- View/download PDF
96. Bush and congress near a showdown on fetal-tissue use.
- Author
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Baker, Stephen
- Subjects
- NATIONAL Institutes of Health (U.S.)
- Abstract
Outlines legislation nearing a vote in the House of Representatives and in the Senate on reauthorization of the National Institutes of Health which would lift the ban on federal support of research involving the transplantation of fetal tissue. Top goal of biomedical researchers; Establishment of a fetal-tissue bank for tissue from ectopic pregnancies and spontaneous abortions; Anti-abortion lawmakers who criticize the president's stance; Threatened veto by President Bush.
- Published
- 1992
97. Erratum to: Radiology medical malpractice suits in gastrointestinal radiology: prevalence, causes, and outcomes.
- Author
-
Baker, Stephen, Shah, Shivam, Ghosh, Shanchita, and Castro, Alejandro
- Subjects
- *
RADIOLOGY , *MEDICAL malpractice - Abstract
A correction to the article "Radiology medical malpractice suits in gastrointestinal radiology: prevalence, causes, and outcomes," that was published in the 3 October 2014 issue is presented.
- Published
- 2015
- Full Text
- View/download PDF
98. ChemInform Abstract: Synthesis of Homochiral Tetrahydropteridines.
- Author
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Baker, Stephen J., Beresford, Kenneth J. M., and Young, Douglas W.
- Subjects
- *
ORGANONITROGEN compounds , *STEREOCHEMISTRY - Abstract
The synthesis of protected homochiral tetrahydropteridines with stereochemistry of natural coenzymes at C-6 from (S)-malic acid is reported. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
99. Human-relevant potency threshold (HRPT) for ERα agonism.
- Author
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Borgert, Christopher J., Matthews, John C., and Baker, Stephen P.
- Subjects
- *
ENDOCRINE disruptors , *HAZARDOUS substances , *PHYSIOLOGICAL effects of estrogen , *PHYSIOLOGICAL effects of chemicals - Abstract
The European Commission has recently proposed draft criteria for the identification of endocrine disrupting chemicals (EDCs) that pose a significant hazard to humans or the environment. Identifying and characterizing toxic hazards based on the manner by which adverse effects are produced rather than on the nature of those adverse effects departs from traditional practice and requires a proper interpretation of the evidence regarding the chemical’s ability to produce physiological effect(s) via a specific mode of action (MoA). The ability of any chemical to produce a physiological effect depends on its pharmacokinetics and the potency by which it acts via the various MoAs that can lead to the particular effect. A chemical’s potency for a specific MoA—its mechanistic potency—is determined by two properties: (1) its affinity for the functional components that comprise the MoA, i.e., its specific receptors, enzymes, transporters, transcriptional elements, etc., and (2) its ability to alter the functional state of those components (activity). Using the agonist MoA via estrogen receptor alpha, we illustrate an empirical method for determining a human-relevant potency threshold (HRPT), defined as the minimum level of mechanistic potency necessary for a chemical to be able to act via a particular MoA in humans. One important use for an HRPT is to distinguish between chemicals that may be capable of, versus those likely to be incapable of, producing adverse effects in humans via the specified MoA. The method involves comparing chemicals that have different ERα agonist potencies with the ability of those chemicals to produce ERα-mediated agonist responses in human clinical trials. Based on this approach, we propose an HRPT for ERα agonism of 1E-04 relative to the potency of the endogenous estrogenic hormone 17β-estradiol or the pharmaceutical estrogen, 17α-ethinylestradiol. This approach provides a practical way to address Hazard Identification according to the draft criteria for identification of EDCs recently proposed by the European Commission. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
100. Nonuniform Internal Structure of Fibrin Fibers: Protein Density and Bond Density Strongly Decrease with Increasing Diameter.
- Author
-
Li, Wei, Sigley, Justin, Baker, Stephen R., Helms, Christine C., Kinney, Mary T., Pieters, Marlien, Brubaker, Peter H., Cubcciotti, Roger, and Guthold, Martin
- Subjects
- *
BLOOD , *BLOOD plasma , *FIBRIN , *FIBRINOGEN , *PROTEINS - Abstract
The major structural component of a blood clot is a meshwork of fibrin fibers. It has long been thought that the internal structure of fibrin fibers is homogeneous; that is, the protein density and the bond density between protofibrils are uniform and do not depend on fiber diameter. We performed experiments to investigate the internal structure of fibrin fibers. We formed fibrin fibers with fluorescently labeled fibrinogen and determined the light intensity of a fiber, I, as a function of fiber diameter, D. The intensity and, thus, the total number of fibrin molecules in a cross-section scaled as D1.4. This means that the protein density (fibrin per cross-sectional area), ρp, is not homogeneous but instead strongly decreases with fiber diameter as D-0.6. Thinner fibers are denser than thicker fibers. We also determined Young’s modulus, Y, as a function of fiber diameter. Y decreased strongly with increasing D; Y scaled as D-1.5. This implies that the bond density, ρb, also scales as D-1.5. Thinner fibers are stiffer than thicker fibers. Our data suggest that fibrin fibers have a dense, well-connected core and a sparse, loosely connected periphery. In contrast, electrospun fibrinogen fibers, used as a control, have a homogeneous cross-section. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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