Mycobacterium tuberculosis (M.tb) is the second leading infectious cause of death worldwide and the primary cause of death in people living with HIV/AIDS. There are several excellent animal models ...employed to study tuberculosis (TB), but many have limitations for reproducing human pathology and none are amenable to the direct study of HIV/M.tb co-infection. The humanized mouse has been increasingly employed to explore HIV infection and other pathogens where animal models are limiting. Our goal was to develop a small animal model of M.tb infection using the bone marrow, liver, thymus (BLT) humanized mouse. NOD-SCID/γc(null) mice were engrafted with human fetal liver and thymus tissue, and supplemented with CD34(+) fetal liver cells. Excellent reconstitution, as measured by expression of the human CD45 pan leukocyte marker by peripheral blood populations, was observed at 12 weeks after engraftment. Human T cells (CD3, CD4, CD8), as well as natural killer cells and monocyte/macrophages were all observed within the human leukocyte (CD45(+)) population. Importantly, human T cells were functionally competent as determined by proliferative capacity and effector molecule (e.g. IFN-γ, granulysin, perforin) expression in response to positive stimuli. Animals infected intranasally with M.tb had progressive bacterial infection in the lung and dissemination to spleen and liver from 2-8 weeks post infection. Sites of infection in the lung were characterized by the formation of organized granulomatous lesions, caseous necrosis, bronchial obstruction, and crystallization of cholesterol deposits. Human T cells were distributed throughout the lung, liver, and spleen at sites of inflammation and bacterial growth and were organized to the periphery of granulomas. These preliminary results demonstrate the potential to use the humanized mouse as a model of experimental TB.
To explore local induction of labour pathways in the UK National Health Service to provide insight into current practice.
National survey.
Hospital maternity services in all four nations of the UK.
...Convenience sample of 71 UK maternity units.
An online cross-sectional survey was disseminated and completed via a national network of obstetrics and gynaecology specialist trainees (October 2021-March 2022). Results were analysed descriptively, with associations explored using Fisher's Exact and ANOVA.
Induction rates, criteria, processes, delays, incidents, safety concerns.
54/71 units responded (76%, 35% of UK units). Induction rate range 19.2%-53.4%, median 36.3%. 72% (39/54) had agreed induction criteria: these varied widely and were not all in national guidance. Multidisciplinary booking decision-making was not reported by 38/54 (70%). Delays reported 'often/always' in hospital admission for induction (19%, 10/54) and Delivery Suite transfer once induction in progress (63%, 34/54). Staffing was frequently reported cause of delay (76%, 41/54 'often/always'). Delays triggered incident reports in 36/54 (67%) and resulted in harm in 3/54 (6%). Induction was an area of concern (44%, 24/54); 61% (33/54) reported induction-focused quality improvement work.
There is substantial variation in induction rates, processes and policies across UK maternity services. Delays appear to be common and are a cause of safety concerns. With induction rates likely to increase, improved guidance and pathways are critically needed to improve safety and experience of care.
Prophylactic administration of CpG oligodeoxynucleotides (CpG ODNs) is known to confer protection against lethal sepsis caused by Burkholderia pseudomallei in the mouse model. The mechanisms whereby ...CpG regulates the innate immune response to provide protection against B. pseudomallei, however, are poorly characterized. In the present study, we demonstrate that intranasal treatment of mice with Class C CpG, results in recruitment of inflammatory monocytes and neutrophils to the lung at 48 h post-treatment. Mice infected with B. pseudomallei 48 h post-CpG treatment had reduced organ bacterial load and significantly altered cytokine and chemokine profiles concomitant with protection as compared to control animals. CpG administration reduced the robust production of chemokines and pro-inflammatory cytokines in blood, lung and spleen, observed following infection of non-treated animals. Death of control animals coincided with the time of peak cytokine production (day 1-3), while a moderate; sustained cytokine production in CpG-treated animals was associated with survival. In general, CpG treatment resulted in diminished expression of cytokines and chemokines post-infection, though IL-12p40 was released in larger quantities in CpG treated animals. In contrast to CpG-treated animals, the lungs of infected control animals were infiltrated with leukocytes, especially neutrophils, and large numbers of necrotic lesions were observed in lung sections. Therapeutic treatment of B. pseudomallei-infected animals with CpG at 24 h post-infection did not impact survival compared to control animals. In summary, protection of CpG-treated animals was associated with recruitment of inflammatory monocytes and neutrophils into the lungs prior to infection. These responses correspond with early control of bacterial growth, a dampened inflammatory cytokine/chemokine response, reduced lung pathology, and greatly increased survival. In contrast, a delay in recruitment of inflammatory cell populations, despite a robust production of pro-inflammatory cytokines, was associated with poorly controlled bacterial growth, severe lung pathology, and death of control animals.
Abstract Validation studies support the use of self-administered computerized methods for reporting energy intake; however, the degree of interpretation bias with these methods is unknown. This ...research compared nutrient intake for food records that were both participant coded (using the National Cancer Institute's Automated Self-Administered 24-hour recall ASA24 online program) and investigator-coded (a single investigator coded all food records using the ESHA Food Processor diet analysis program). Participants (n=28; mean age=41±11 years; mean body mass index=31±6) were participants in an 8-week trial (conducted between March 2011 and June 2011 in Phoenix, AZ) investigating the impact of meal preloads on satiety. Food records were collected on four occasions during the trial and, of the food records available for this investigation (n=161), 88% were completed on a weekday. Intra-class correlation coefficients were computed for selected nutrients and ranged from 0.65 to 0.81 for the macronutrients and from 0.50 to 0.66 for the micronutrients (overall mean=0.67). Overall mean coefficient improved to 0.77 when the data from three or more food records per participant were averaged, as is commonly done in nutrition research. All intra-class correlation coefficients were significant ( P <0.020) and were not impacted by the day of week that food was recorded. For energy, macronutrients, and minerals, the percent median differences between coders were <±17%; however, percent median differences were large for vitamin C (+27%) and beta carotene (+294%). Findings from this study suggest that self-administered dietary assessment has merit as a research tool. Pretrial training for research participants is suggested to reduce interpretation bias.
Peanut consumption favorably influences satiety. This study examined the acute effect of peanut versus grain bar preloads on postmeal satiety and glycemia in healthy adults and the long-term effect ...of these meal preloads on body mass in healthy overweight adults.
In the acute crossover trial (n = 15; 28.4 ± 2.9 y; 23.1 ± 0.9 kg/m2), the preload (isoenergetic peanut or grain bar with water, or water alone) was followed after 60 min with ingestion of a standardized glycemic test meal. Satiety and blood glucose were assessed immediately prior to the preload and to the test meal, and for two hours postmeal at 30-min intervals. In the parallel-arm, randomized trial (n = 44; 40.5 ± 1.6 y, 31.8 ± 0.9 kg/m2), the peanut or grain bar preload was consumed one hour prior to the evening meal for eight weeks. Body mass was measured at 2-week intervals, and secondary endpoints included blood hemoglobin A1c and energy intake as assessed by 3-d diet records collected at pre-trial and trial weeks 1 and 8.
Satiety was elevated in the postprandial period following grain bar ingestion in comparison to peanut or water ingestion (p = 0.001, repeated-measures ANOVA). Blood glucose was elevated one hour after ingestion of the grain bar as compared to the peanut or water treatments; yet, total glycemia did not vary between treatments in the two hour postprandial period. In the 8-week trial, body mass was reduced for the grain bar versus peanut groups after eight weeks (-1.3 ± 0.4 kg versus -0.2 ± 0.3 kg, p = 0.033, analysis of covariance). Energy intake was reduced by 458 kcal/d in the first week of the trial for the grain bar group as compared to the peanut group (p = 0.118). Hemoglobin A1c changed significantly between groups during the trial (-0.25 ± 0.07% and -0.18 ± 0.12% for the grain bar and peanut groups respectively, p = 0.001).
Compared to an isoenergetic peanut preload, consumption of a grain bar preload one hour prior to a standardized meal significantly raised postmeal satiety. Moreover, consumption of the grain bar prior to the evening meal was associated with significant weight loss over time suggesting that glycemic carbohydrate ingestion prior to meals may be a weight management strategy.
A major outbreak of bloody diarrhea associated with Shiga toxin-producing Escherichia coli O104:H4 occurred early in 2011, to which an unusual number of hemolytic uremic syndrome cases were linked. ...Due to limited information regarding pathogenesis and/or virulence properties of this particular serotype, we investigated the contribution of the aerobactin iron transport system during in vitro and in vivo conditions.
A bioluminescent reporter construct was used to perform real-time monitoring of E. coli O104:H4 in a mouse model of infection. We verified that our reporter strain maintained characteristics and growth kinetics that were similar to those of the wild-type E. coli strain. We found that the intestinal cecum of ICR (CD-1) mice was colonized by O104:H4, with bacteria persisting for up to 7 days after intragastric inoculation. MALDI-TOF analysis of heat-extracted proteins was performed to identify putative surface-exposed virulence determinants. A protein with a high similarity to the aerobactin iron receptor was identified and further demonstrated to be up-regulated in E. coli O104:H4 when grown on MacConkey agar or during iron-depleted conditions. Because the aerobactin iron acquisition system is a key virulence factor in Enterobacteriaceae, an isogenic aerobactin receptor (iutA) mutant was created and its intestinal fitness assessed in the murine model. We demonstrated that the aerobactin mutant was out-competed by the wild-type E. coli O104:H4 during in vivo competition experiments, and the mutant was unable to persist in the cecum.
Our findings demonstrate that bioluminescent imaging is a useful tool to monitor E. coli O104:H4 colonization properties, and the murine model can become a rapid way to evaluate bacterial factors associated with fitness and/or colonization during E. coli O104:H4 infections.
, the etiologic agent of glanders, are Category B select agents with biothreat potential, and yet effective therapeutic treatments are lacking. In this study, we showed that CpG administration ...increased survival, demonstrating protection in the murine glanders model. Bacterial recovery from infected lungs, liver and spleen was significantly reduced in CpG-treated animals as compared with non-treated mice. Reciprocally, lungs of CpG-treated infected animals were infiltrated with higher levels of neutrophils and inflammatory monocytes, as compared to control animals. Employing the
bioluminescent strain CSM001 and the Neutrophil-Specific Fluorescent Imaging Agent, bacterial dissemination and neutrophil trafficking were monitored in real-time using multimodal
whole body imaging techniques. CpG-treatment increased recruitment of neutrophils to the lungs and reduced bioluminescent bacteria, correlating with decreased bacterial burden and increased protection against acute murine glanders. Our results indicate that protection of CpG-treated animals was associated with recruitment of neutrophils prior to infection and demonstrated, for the first time, simultaneous real time
imaging of neutrophils and bacteria. This study provides experimental evidence supporting the importance of incorporating optimized
imaging methods to monitor disease progression and to evaluate the efficacy of therapeutic treatment during bacterial infections.
Background Health care-associated infections (HAIs) cause considerable morbidity and mortality to hospitalized patients. The objective of this point prevalence study was to assess the burden of HAIs ...in the Canadian pediatric population, updating results reported from a similar study conducted in 2002. Methods A point prevalence survey of pediatric inpatients was conducted in February 2009 in 30 pediatric or combined adult/pediatric hospitals. Data pertaining to one 24-hour period were collected, including information on HAIs, microorganisms isolated, antimicrobials prescribed, and use of additional (transmission based) precautions. The following prevalent infections were included: pneumonia, urinary tract infection, bloodstream infection, surgical site infection, viral respiratory infection, Clostridium difficile infection, viral gastroenteritis, and necrotizing enterocolitis. Results One hundred eighteen patients had 1 or more HAI, corresponding to a prevalence of 8.7% (n = 118 of 1353, 95% confidence interval: 7.2-10.2). Six patients had 2 infections. Bloodstream infections were the most frequent infection in neonates (3.0%), infants (3.1%), and children (3.5%). Among all patients surveyed, 16.3% were on additional precautions, and 40.1% were on antimicrobial agents, whereas 40.7% of patients with a HAI were on additional precautions, and 89.0% were on antimicrobial agents. Conclusion Overall prevalence of HAI in 2009 has remained similar to the prevalence reported from 2002. The unchanged prevalence of these infections nonetheless warrants continued vigilance on their prevention and control.
An EMS mutagenesis screen was conducted in
Drosophila melanogaster
to identify growth control mutants. The multi-institution Fly-CURE consortium phenotypically characterized the
O.2.2
mutant using ...the
FLP/FRT
system which displayed a mutant lethal phenotype with reduced head development, and darkened ocular tissue. Complementation mapping was conducted to identify the affected gene. A failure to complement was identified in
Uba3
, resulting in the identification of the novel allele,
Uba3
O.2.2
.
Uba3
is a known disruptor of the cell cycle and our data are consistent with early larval/embryonic lethality displayed in numerous species.
Mycobacterium tuberculosis (M.tb) is the second leading infectious cause of death worldwide and the primary cause of death in people living with HIV/AIDS. There are several excellent animal models ...employed to study tuberculosis (TB), but many have limitations for reproducing human pathology and none are amenable to the direct study of HIV/M.tb co-infection. The humanized mouse has been increasingly employed to explore HIV infection and other pathogens where animal models are limiting. Our goal was to develop a small animal model of M.tb infection using the bone marrow, liver, thymus (BLT) humanized mouse. NOD-SCID/ gamma cnull mice were engrafted with human fetal liver and thymus tissue, and supplemented with CD34+ fetal liver cells. Excellent reconstitution, as measured by expression of the human CD45 pan leukocyte marker by peripheral blood populations, was observed at 12 weeks after engraftment. Human T cells (CD3, CD4, CD8), as well as natural killer cells and monocyte/macrophages were all observed within the human leukocyte (CD45+) population. Importantly, human T cells were functionally competent as determined by proliferative capacity and effector molecule (e.g. IFN- gamma , granulysin, perforin) expression in response to positive stimuli. Animals infected intranasally with M.tb had progressive bacterial infection in the lung and dissemination to spleen and liver from 2-8 weeks post infection. Sites of infection in the lung were characterized by the formation of organized granulomatous lesions, caseous necrosis, bronchial obstruction, and crystallization of cholesterol deposits. Human T cells were distributed throughout the lung, liver, and spleen at sites of inflammation and bacterial growth and were organized to the periphery of granulomas. These preliminary results demonstrate the potential to use the humanized mouse as a model of experimental TB.
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