The Dangers of Acetaminophen for Neurodevelopment Outweigh Scant Evidence for Long-Term Benefits

Based on available data that include approximately 20 lines of evidence from studies in laboratory animal models, observations in humans, correlations in time, and pharmacological/toxicological considerations, it has been concluded without reasonable doubt and with no evidence to the contrary that exposure of susceptible babies and children to acetaminophen (paracetamol) induces many, if not most, cases of autism spectrum disorder (ASD). However, the relative number of cases of ASD that might be induced by acetaminophen has not yet been estimated. Here, we examine a variety of evidence, including the acetaminophen-induced reduction of social awareness in adults, the prevalence of ASD through time, and crude estimates of the relative number of ASD cases induced by acetaminophen during various periods of neurodevelopment. We conclude that the very early postpartum period poses the greatest risk for acetaminophen-induced ASD, and that nearly ubiquitous use of acetaminophen during early development could conceivably be responsible for the induction in the vast majority, perhaps 90% or more, of all cases of ASD. Despite over a decade of accumulating evidence that acetaminophen is harmful for neurodevelopment, numerous studies demonstrate that acetaminophen is frequently administered to children in excess of currently approved amounts and under conditions in which it provides no benefit. Further, studies have failed to demonstrate long-term benefits of acetaminophen for the pediatric population, leaving no valid rationale for continued use of the drug in that population given its risks to neurodevelopment.

Obesity Alters cytokine signaling and gut microbiome in septic mice

Sepsis is a leading cause of mortality. Plasma cytokine levels may identify those at increased risk of mortality from sepsis. Our aim was to understand how obesity alters cytokine levels during early sepsis and its correlation with survival. Six-week-old C57BL/6 male mice were randomized to control (non-obese) or high fat diet (obese) for 5-7 weeks. Sepsis was induced by cecal ligation and perforation (CLP). Cytokine levels were measured from cheek bleeds 8 h after CLP, and mice were monitored for survival. Other cohorts were sacrificed 1 h after CLP for plasma and tissue. Septic obese mice had higher survival. At 8 h after sepsis, obese mice had higher adiponectin, leptin, and resistin but lower TNFα and IL-6 compared to non-obese mice. When stratified by 24-h survival, adipokines were not significantly different in obese and non-obese mice. TNFα and IL-6 were higher in non-obese, compared to obese, mice that died within 24 h of sepsis. Diet and to sepsis significantly impacted the cecal microbiome. IL-6 is a prognostic biomarker during early sepsis in non-obese and obese mice. A plausible mechanism for the survival difference in non-obese and obese mice may be the difference in gut microbiome and its evolution during sepsis.

SEX-DEPENDENT EFFECTS OF ADIPOCYTE STAT3 INHIBITION ON THE INFLAMMATORY RESPONSE DURING SEVERE SEPSIS

ABSTRACT

Introduction: Sepsis is a dysregulated host response to infection that can lead to life-threatening organ dysfunction. Clinical and animal studies consistently demonstrate that female subjects are less susceptible to the adverse effects of sepsis, demonstrating the importance of understanding how sex influences sepsis outcomes. The signal transducer and activator of transcription 3 (STAT3) pathway are a major signaling pathway that facilitates inflammation during sepsis. STAT3 is abundantly expressed in white adipose tissue; however, little is known about the contribution of white adipose tissue STAT3 activation during sepsis. We hypothesize that adipocyte STAT3 inhibition during severe sepsis will exaggerate the inflammatory response and impact organ injury, in a sex-dependent manner. Methods: We generated STAT3 flox/flox (wild-type [WT]) and adipocyte STAT3 knock out (A-STAT3 KO) mice using Cre-lox technology. Studies were done in 12- to 16-week-old male and female mice. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Control nonseptic mice did not undergo CLP (0 h CLP). Tissues were harvested 18 h after CLP. Body composition was determined by echo magnetic resonance imaging. Energy metabolism was determined by indirect calorimetry. White adipose tissue morphology was determined by hematoxylin and eosin staining, while STAT3 activation in the white adipose tissue was determined by western blot analysis and immunohistochemistry staining of STAT3 activation/phosphorylation at tyrosine 705. Plasma cytokines (TNF-α, IL-6, and leptin) were determined by luminex assay. Neutrophil infiltration of the lung and liver was assessed by myeloperoxidase activity assay. Histological signs of organ injury on lung and liver tissue were assessed by hematoxylin and eosin staining. Liver injury was further assessed by measuring plasma alanine and aspartate aminotransferase. In a separate cohort of mice, sepsis was induced by CLP and mice were monitored every 6-12 h over a 7-day period to assess survival rate. Results: We demonstrate that neither body composition nor energy metabolism is altered with adipocyte STAT3 inhibition in male or female mice, under nonseptic conditions. Sepsis was associated with reduced adipocyte size in female WT and A-STAT3 KO mice, suggesting that this event is STAT3 independent. Sepsis did not alter adipocyte size in male WT and A-STAT3 KO mice, suggesting that this event is also sex dependent. Although STAT3 phosphorylation at tyrosine 705 expression is negligible in male and female A-STAT3 KO mice, septic female WT and A-STAT3 KO mice have higher white adipose tissue STAT3 activation than male WT and A-STAT3 KO mice. Adipocyte STAT3 inhibition did not alter the proinflammatory cytokine response during sepsis in male or female mice, as measured by plasma TNF-α, IL-6, and leptin levels. Adipocyte STAT3 inhibition reduced lung neutrophil infiltration and histological signs of lung injury during sepsis in male mice. On the contrary, adipocyte STAT3 inhibition had no effect on lung neutrophil infiltration or lung injury in female mice. We further demonstrate that neither liver neutrophil infiltration nor histological signs of liver injury are altered by adipocyte STAT3 inhibition during sepsis, in male or female mice. Lastly, adipocyte STAT3 inhibition did not affect survival rate of male or female mice during sepsis. Conclusions: Our study demonstrates that sex influences white adipose tissue STAT3 activation and morphology during sepsis, which is not dependent on the presence of functional STAT3 in mature adipocytes. Furthermore, genetic inhibition of adipocyte STAT3 activation in male, but not female mice, results in reduced lung neutrophil infiltration and lung injury during sepsis. The results from our study demonstrate the importance of considering biological sex and the white adipose tissue as potential sources and targets of inflammation during sepsis.

OBESE MICE WITH PNEUMONIA HAVE HYPERLEPTINEMIA AND INCREASED PULMONARY SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 ACTIVATION

ABSTRACT

Obesity is an ongoing epidemic that influences pathobiology in numerous disease states. Obesity is associated with increased plasma leptin levels, a hormone that activates the signal transducer and activator of transcription 3 (STAT3) pathway. Pneumonia is a significant cause of morbidity and mortality. During pneumonia, inflammatory pathways including STAT3 are activated. Outcomes in obese patients with pneumonia are mixed, with some studies showing obesity increases harm and others showing benefit. It is unclear whether obesity alters STAT3 activation during bacterial pneumonia and how this might impact outcomes from pneumonia. We used a murine model of obesity and pneumonia challenge with Pseudomonas aeruginosa in obese and nonobese mice to investigate the effect of obesity on STAT3 activation. We found obese mice with bacterial pneumonia had increased mortality compared with nonobese mice. Inflammatory markers, IL-6 and TNF-α, and lung neutrophil infiltration were elevated at 6 h after pneumonia in both nonobese and obese mice. Obese mice had greater lung injury compared with nonobese mice at 6 h after pneumonia. Leptin and insulin levels were higher in obese mice compared with nonobese mice, and obese mice with pneumonia had higher pulmonary STAT3 activation compared with nonobese mice.

Youth organizations, social mobility and health in middle age: evidence from a Scottish 1950s prospective cohort study

BACKGROUND

Informal educational programmes focused on youth development appear to improve health and well-being at time of involvement. Less is known about long-term effects. We investigate their impact on self-reported general health in mid-life using the Aberdeen Children of the 1950s (ACONF) cohort.

METHODS

We use a subset (n = 1333) of the ACONF cohort, born 1950-56, in Aberdeen Scotland, who took part in Family and Reading Surveys in 1964 and a follow-up questionnaire in 2001. We explore exposure to youth development focused clubs in childhood on self-reported general health around age 50 mediated by adult socioeconomic position. Logistic regression and mediation analysis were used to report odds ratios and natural direct and indirect effects, respectively, on multiply imputed data.

RESULTS

Being a member of the Scouts/Guides (G&S) was associated with a 53% (95% confidence interval 1.03-2.27) higher odds of 'excellent' general health in adulthood compared to children attending 'other clubs'. Indirect effects of G&S and Boys'/Girls' Brigade (B&GB) on general health acting via higher socioeconomic position show positive associations; 12% and 6% higher odds of 'excellent' general health in adulthood compared to children attending 'other clubs', respectively. Comparison of indirect with direct effects suggests 27% of this association is mediated through a higher adult socioeconomic position in adulthood.

CONCLUSIONS

These results suggest a beneficial association between attending G&S and B&GB clubs in childhood and adult general health. As these organizations are volunteer-led, this may represent a cost-effective method for improving population health.

Social determinants of health screening and intervention: A cystic fibrosis quality improvement process

INTRODUCTION

Lower socioeconomic status is associated with significantly poorer outcomes in weight, lung function, and pulmonary exacerbation rates in people with cystic fibrosis (PwCF).

GLOBAL AIM

We aim to reduce health disparities and inequities faced by PwCF by screening for and addressing unmet social needs.

SPECIFIC AIMS

We aimed to increase routine social determinants of health (SDoH) screening of eligible PwCF from 0% to 95% and follow-up within 2 weeks for those PwCF who screened positive and requested assistance from 0% to 95% by December 31, 2021.

METHODS

The Model for Improvement methodology was used. A process map and a simplified failure mode effects analysis chart were created for the screening and SDoH follow-up process. For those who screened positive for SDoH and requested assistance, follow-up contact was made to offer intervention.

INTERVENTION

Adult PwCF who had at least one UVA Clinic encounter in 2021 were screened for SDoH. The SDoH screening tool included eight domains: housing, food, transportation, utilities, health-care access, medication access, income/employment, and education. Follow-up was completed with all PwCF who screened positive for SDoH.

RESULTS

A total of 132 of 142 (93.0%) PwCF eligible for screening completed the SDoH screening. Of the PwCF who completed screening, 56 (42.4%) screened positive for SDoH. A follow-up rate of 100% was achieved in June 2021 and maintained through December 2021.

CONCLUSION

Implementing screening for SDOH and follow-up to mitigate social difficulties in adult PwCF at UVA was successful and could be reproduced at other CF care centers.

Evaluation of the DAISY (Diseases Attacking the Immune SYstem) Award for recognising excellence in nursing

BACKGROUND

With increasing demand for nursing services worldwide, the onus is on healthcare systems to implement measures to improve retention. The DAISY Award was designed to celebrate nursing with the suggestion that it may improve staff retention.

AIM

To describe the experience and impact of winning the DAISY Award.

METHOD

Data were collected through virtual semistructured interviews from award winners (n=4), nominees (n=4) and nominators (n=4). An analytical framework was developed to allow the responses of the three groups to be compared.

FINDINGS

Four major themes emerged from the responses: awareness of the DAISY Award; the nomination process, the impact on retention and winner benefits.

CONCLUSION

Being nominated or winning a DAISY Award had a positive impact on nurses' feelings towards their role. This was a small evaluation in a single organisation, so the value of adopting the DAISY Award for recognising nurses' contributions to patient care merits further investigation, especially with regards to its effects on retention.

A scoping review of strategies used to recruit and retain nurses in the healthcare workforce

AIMS

This article reports the results of a scoping review to identify initiatives for improving recruitment and retention of nurses in healthcare and ascertain their effectiveness.

BACKGROUND

The global shortage of nurses has results in greater competition for vacant posts and an increased need to retain existing post holders. While there are a large number of publications discussing ways to improve recruitment and retention, the effectiveness of these need to be established.

EVALUATION

Thirteen papers met the inclusion criteria. There was no literature identified focusing on recruitment and only one paper reported a formal evaluation of a retention initiative.

KEY ISSUES

Five themes summarised the initiatives for retaining nurses: leadership and support; ongoing professional development; recognition; work environment; and flexible scheduling.

CONCLUSION

While strategies have been proposed to retain nurses, there is a dearth of evidence supporting the effectiveness of these.

IMPLICATIONS FOR NURSING MANAGEMENT

Although there is a lack of evaluations of retention strategies, the review identified a number of initiatives that warrant consideration. With the launch of the National Health Service People Plan in England in 2021, which is recommending initiatives identified in this review without robust evidence, an integrated programme of research evaluating this is recommended.

Obesity protects against sepsis-induced and norepinephrine-induced white adipose tissue browning

Sepsis is a dysregulated systemic response to infection and can lead to organ damage and death. Obesity is a significant problem worldwide and affects outcomes from sepsis. Our laboratory demonstrated that white adipose tissue (WAT) undergoes browning during sepsis, a process whereby WAT adopts a brown adipose tissue phenotype. However, this browning process was not observed in obese mice during sepsis. White adipose tissue browning is detrimental in patients with burn injury and cancer. We hypothesize that norepinephrine (NE) induces WAT browning in nonobese mice but not in obese mice similarly to sepsis-induced WAT browning. Six-week-old C57BL/6 male mice were randomized to a high-fat diet or normal diet. After 6-7 wk of feeding, polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Norepinephrine was administered intraperitoneally via osmotic minipumps for 18 h or 72 h (no CLP) at which time tissue and plasma were harvested. Controls were mice that underwent CLP (no NE) with 18-h harvest. A separate group of mice underwent pretreatment with NE or vehicle infusion for 72 h, CLP was performed, and at 18 h had tissue and plasma harvested. Sepsis resulted in significant weight loss in both nonobese and obese mice. NE treatment alone caused weight loss in obese mice. Septic nonobese mice had higher uncoupling protein-1 (UCP1) expression compared with control and obese septic mice. NE treatment increased UCP1 expression in nonobese, but not obese mice. NE-treated obese septic mice had lower lung myeloperoxidase (MPO) activity, alanine aminotransferase (ALT), aspartate aminotransferase (AST), TNFα, and IL-6 levels compared with NE-treated nonobese septic mice. Obesity protects mice from septic-induced and NE-induced WAT browning.NEW & NOTEWORTHY White adipose tissue browning is detrimental in patients with burn injury and cancer. WAT browning occurs in nonobese mice and can be induced by β receptor norepinephrine infusion, but obese mice are resistant to sepsis-induced and norepinephrine-induced WAT browning. We propose that the lack of WAT browning and unchanged inflammatory cytokine response may contribute to the protection of obese mice from sepsis.

Home spirometry utilisation in telemedicine clinic for cystic fibrosis care during COVID-19 pandemic: a quality improvement process

The Cystic Fibrosis (CF) Foundation chronic care guidelines recommend monitoring spirometry during quarterly multidisciplinary visits to identify early lung function decline. During the COVID-19 pandemic, the CF adult clinic at University of Virginia (UVA) transitioned from the classic CF care model to a model that included quarterly multidisciplinary telemedicine visits. While using telemedicine, CF care needed to include spirometry monitoring. Only a fraction of adult CF patients at UVA owned and used home spirometers (HS) in March 2020.

2593. Human Monoclonal Antibodies Potently Neutralize Enterovirus D68 in both a Clade-Specific and -Independent Manner

Background

Enterovirus D68 (EV-D68) causes worldwide outbreaks of human respiratory illness with spacio-temporally related outbreaks of acute flaccid myelitis (AFM), a polio-like illness. Numerous seroepidemiology studies show that nearly all humans older than 2 years have EV-D68-neutralizing antibodies in their serum, even in serum collected prior to large outbreaks. However, little else is known about the human antibody response to this virus. We sought to isolate human monoclonal antibodies (mAbs) from B cells in peripheral blood mononuclear cells (PBMCs) of immune subjects, induced by natural infection, to understand human humoral immunity to EV-D68.

Methods

We obtained PBMCs from donors with known infection during the largest ever recorded outbreak, which occurred in the United States in 2014. We used EV-D68 virus isolates from this outbreak in an indirect ELISA to screen immortalized PBMCs for antigen-specificity, then fused them with myeloma cells to create hybridomas.

Results

To date, we have isolated > 60 naturally occurring anti-EV-D68 human mAbs from the B cells of subjects with documented infection. These mAbs exhibit diverse binding affinities when compared across different clades of recent EV-D68 isolates. Many mAbs neutralize EV-D68 quite potently in vitro, with [ng/mL] half maximal effective concentrations. Some mAbs neutralize diverse clades of EV-D68, whereas others are highly clade-specific. Binding of antibodies to at least three, but likely more, major antigenic sites on the virus leads to neutralization.

Conclusion

We observed a qualitative difference among antibodies isolated from patients who had natural infection. These differences could contribute to certain individuals being susceptible to respiratory disease and AFM. Our studies of humoral immunity are especially important for a disease with nearly universal apparent seroprotection, in which the virus somehow persistently causes outbreaks across the world. Furthermore, no licensed vaccines or treatments exist for EV-D68. Given the ability of human intravenous immune globulin to protect mice from AFM, these mAbs are being tested for therapeutic benefit in vivo, and may have promise in the prevention and/or treatment of EV-D68-related diseases.

Disclosures

All authors: No reported disclosures.

Hepatic STAT3 inhibition amplifies the inflammatory response in obese mice during sepsis

The purpose of this study was to better understand the role obesity plays in the inflammatory response during sepsis, specifically regarding the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway in the liver. We hypothesized that inhibiting STAT3 would lead to an increase in the inflammatory response and that obesity would amplify this effect. To investigate this, we inhibited STAT3 in two ways: pharmacological systemic inhibition and genetic hepatic-specific inhibition. In pharmacological inhibition studies, male C57BL/6 mice were randomized to a high-fat (60% kcal fat) or normal (16% kcal fat) diet for 6-7 wk and pretreated with Stattic before inducing sepsis by cecal ligation and puncture. In genetic inhibition studies, mice were randomized by genotype before induction of sepsis. To investigate obesity in mice with hepatic-specific STAT3 inhibition, we randomized mice to a high-fat or normal diet as described above for 6 mo before induction of sepsis. Body composition was analyzed using EchoMRI. We found that systemic STAT3 inhibition by Stattic resulted in an increased inflammatory response and that obesity amplified this effect. We also found that genetically inhibiting STAT3 in the liver resulted in higher mortality, increased inflammation, and liver injury. High-fat-fed mice with hepatic STAT3 inhibition gained more weight and had more fat than control mice on the same diet, and obesity increased neutrophil infiltration to the liver of these mice during sepsis. In conclusion, STAT3 plays an important regulatory role in the inflammatory response during sepsis, and obesity contributes to the dysregulated response observed when STAT3 is inhibited.

Hay Fever Treatment in General Practice: A Randomised Controlled Trial Comparing Standardised Western Acupuncture with Sham Acupuncture

The effect of standardised, Western acupuncture on hay fever symptoms was investigated in a randomised, controlled, single-blind trial in comparison with “sham” acupuncture. Three general practices, in Oxfordshire (rural), Lincolnshire (semi-rural), and Peterborough (urban), recruited 102 patients aged 16 or over with long-standing, moderate or severe hay fever symptoms that had required continuous therapy for at least one month of the year for three or more consecutive years.

The patients were asked to keep a diary to record: the amount of medication used daily; a daily symptom score (using a ten-point scale), from which was derived a weekly remission of symptoms score; and their assessment of the effect of acupuncture on the hay fever symptoms. Symptom scores and use of medication were similar in the two groups. In the four-week period following each patient's first treatment, remission of symptoms was reported by 39.0% in the active treatment group and 45.2% in the sham group; mean weekly symptom scores were 18.4 and 17.6 respectively; and mean units of medication used were 4.1 and 5.0 respectively. Sixteen out of 43 patients in the active treatment group and 14 out of 43 in the sham group felt that the acupuncture had had an excellent or very good effect on their hay fever. The treatments were simple, safe, reproducible and perceived as equally effective. Whether this represented an acupuncture effect, a placebo effect, or natural variation in a fluctuating condition, is not clear.

The dangers of sublethal carvacrol exposure: increases in virulence of Bacillus cereus during endophthalmitis

Bacillus cereus can cause endophthalmitis through secretion of virulence factors, including hemolysin BL (Hbl) and nonhemolytic entertoxin (Nhe). Carvacrol is an extract from oregano oil, with potential for curtailing B. cereus endophthalmitis, due to antimicrobial and anti-inflammatory qualities. However, sublethal levels of carvacrol increases B. cereus virulence. The goal of this study was to investigate the increase in B. cereus virulence potential in response stress induced by a subinhibitory concentration (SIC) of carvacrol. Enterotoxin production and tissue damage were examined during ocular infections in vitro and in vivo. We hypothesized that the SIC of carvacrol would significantly increase toxin production in B. cereus without progressing systemically. RT-PCR determined SIC carvacrol-treated B. cereus had significantly higher hblC and nheA mRNA expression levels than controls in vitro. ELISA and RPLA analysis revealed a 46.8% and 50% increase in NheA and HblC toxin levels, respectively, in SIC-treated cultures. Caenorhabditis elegans-fed SIC carvacrol-treated B. cereus had a significantly higher mean mortality rate than nematodes fed untreated B. cereus. Significantly higher TNF-α levels were observed in SIC carvacrol-treated B. cereus mice compared to other treatment groups except for mice infected with B. cereus alone. Significantly higher IL-6 levels were also found in SIC-B. cereus mice. Histological analysis using Rose-Bengal and DAPI determined that the eyes of mice infected with SIC carvacrol-treated B. cereus had significantly more damage than eyes treated with B. cereus alone. The SIC of carvacrol increased B. cereus virulence in vitro and in vivo, with a mild systemic infection noted.

Prognostic factors of functional outcome after hip fracture surgery: a systematic review

Objective

this systematic review aimed to identify immutable and modifiable prognostic factors of functional outcomes and their proposed mechanism after hip fracture surgery.

Design

systematic search of MEDLINE, Embase, CINAHL, PEDRO, OpenGrey and ClinicalTrials.gov for observational studies of prognostic factors of functional outcome after hip fracture among surgically treated adults with mean age of 65 years and older. Study selection, quality assessment, and data extraction were completed independently by two reviewers. The Quality in Prognosis Studies Tool was used for quality assessment and assigning a level of evidence to factors. Proposed mechanisms for reported associations were extracted from discussion sections.

Results

from 33 studies of 9,552 patients, we identified 25 prognostic factors of functional outcome after hip fracture surgery. We organised factors into groups: demographics, injury and comorbidities, body composition, complications, and acute care. We assigned two factors a weak evidence level-anaemia and cognition. We assigned Parkinson's disease an inconclusive evidence level. We could not assign an evidence level to the remaining 22 factors due to the high risk of bias across studies. Frailty was the proposed mechanism for the association between anaemia and functional outcome. Medication management, perceived potential, complications and time to mobility were proposed as mechanisms for the association between cognition and functional outcome.

Conclusion

we identified one modifiable and one immutable prognostic factor for functional outcomes after hip fracture surgery. Future research may target patients with anaemia or cognitive impairment by intervening on the prognostic factor or the underlying mechanisms.

Role of Non-local Interactions between CDR Loops in Binding Affinity of MR78 Antibody to Marburg Virus Glycoprotein

An atomic-detail model of the Marburg virus glycoprotein in complex with a neutralizing human monoclonal antibody designated MR78 was constructed using Phenix.Rosetta starting from a 3.6Å crystallographic density map. The Asp at T6 in the HCDR3's bulged torso cannot form the canonical salt bridge as position T2 lacks an Arg or Lys residue. It instead engages in a hydrogen bond interaction with a Tyr contributed by the HCDR1 loop. This inter-CDR loop interaction stabilizes the bulged conformation needed for binding to the viral glycoprotein: a Tyr to Phe mutant displays a binding affinity reduced by a factor of at least 10. We found that 5% of a database of 465 million human antibody sequences has the same residues at T2 and T6 positions in HCDR3 and Tyr in HCDR1 that could potentially form this Asp-Tyr interaction, and that this interaction might contribute to a non-canonical bulged torso conformation.

Alteration of the rat cecal microbiome during colonization with the helminth Hymenolepis diminuta

The microbiome is now widely recognized as being important in health and disease, and makes up a substantial subset of the biome within the ecosystem of the vertebrate body. At the same time, multicellular, eukaryotic organisms such as helminths are being recognized as an important component of the biome that shaped the evolution of our genes. The absence of these macroscopic organisms during the early development and life of humans in Western culture probably leads to a wide range of human immunological diseases. However, the interaction between the microbiome and macroscopic components of the biome remains poorly characterized. In this study, the microbiome of the cecum in rats colonized for 2 generations with the small intestinal helminth Hymenolepis diminuta was evaluated. The introduction of this benign helminth, which is of considerable therapeutic interest, led to several changes in the cecal microbiome. Most of the changes were within the Firmicutes phylum, involved about 20% of the total bacteria, and generally entailed a shift from Bacilli to Clostridia species in the presence of the helminth. The results point toward ecological relationships between various components of the biome, with the observed shifts in the microbiome suggesting potential mechanisms by which this helminth might exert therapeutic effects.

Modulation of immune cell function by an early life experience (167.11)

Pro-inflammatory IL-1 beta cytokine production within the hippocampus (HP) is required for normal learning. However, excessive IL-1 beta levels in the brain can interfere with memory consolidation, resulting in cognitive deficits and neurodegeneration. We have identified the cellular source of IL-1 beta during learning as microglia, a CNS-resident macrophage cell type. Intriguingly, microglia from adult rats that suffered an immune challenge early in life are “primed” for exaggerated IL-1 beta responses, which is maladaptive because it can interfere with normal learning and memory. Similar to control cells, primed microglia do not produce cytokines constitutively. Rather, exaggerated cytokine responses in primed microglia likely result from an altered pattern of transcriptional regulation that was initiated during an early life infection and is propagated into adulthood via specific epigenetic markings. We have found that HP microglia from neonatally infected rats have a global reduction in dimethylated histone H3K9 compared to control (mock-infected) rats. The specific gene loci involved in the regulation of microglial cytokine expression from primed and control rats are now under investigation. Thus, our model of early life infection demonstrates a role for brain-resident immune cells in mediating the “programming” of a later cognitive dysfunction via intrinsic differences in their epigenetic status.