ABSTRACT
Proposals for SARS-CoV-2 virus vaccination priorities in the UK and in many other countries are heavily influenced by epidemiological models, which use outcome measures such as deaths or hospitalisation. Limiting the values under consideration to those attributable to the direct effects of infection has the advantage of simplifying the models and the process of decision-making. However, the consequences of the pandemic extend beyond outcomes directly attributable to SARS-CoV-2 infection, and include restrictions on educational and work opportunities, access to services, recreational activities, affiliations and relationships with others, freedom of movement (including escaping abusive relationships), and other determinants of human experience. Capability theory gives emphasis to the freedoms that individuals have to express themselves (in doings and beings). Restrictions on freedoms restrict our capabilities. Capability theory has been used to provide a framework for the evaluation and comparison of international development approaches and in the evaluation of public health policy. There is a clustering of disadvantages associated with this pandemic that adds to pre-existing inequalities. Much of the disadvantage engendered in the SARS-CoV-2 pandemic is left out when public health policy is based on a limited range of metrics. Acknowledging the impact of policy across the range of human freedoms at both a national and international level has the potential to improve policy, facilitate the mitigation of direct and indirect adverse consequences, and improve public confidence and the effectiveness of vaccine deployment strategies.
Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19 Vaccines , Epidemiological Models , Humans , VaccinationABSTRACT
BACKGROUND: Uncertainty remains about the role of probiotics to prevent necrotising enterocolitis (NEC) some of which arises from the variety of probiotic interventions used in different trials, many with no prior evidence of potential efficacy. Mechanistic studies of intestinal barrier function embedded in a large probiotic trial could provide evidence about which properties of probiotics might be important for NEC prevention thus facilitating identification of strains with therapeutic potential. METHODS: Intestinal permeability, stool microbiota, SCFAs and mucosal inflammation were assessed from the second postnatal week in babies enrolled to a randomised controlled trial of B. breve BBG-001 (the PiPS trial). Results were compared by allocation and by stool colonisation with the probiotic. RESULTS: Ninety-four preterm babies were recruited across six nested studies. B. breve BBG-001 content was higher by allocation and colonisation; Enterobacteriaceae and acetic acid levels were higher by colonisation. No measure of intestinal barrier function showed differences. The PiPS trial found no evidence of efficacy to reduce NEC. CONCLUSIONS: That the negative results of the PiPS trial were associated with failure of this probiotic to modify intestinal barrier function supports the possibility that the tests described here have the potential to identify strains to progress to large clinical trials. IMPACT: Uncertainty about the therapeutic role of probiotics to prevent necrotising enterocolitis is in part due to the wide range of bacterial strains with no previous evidence of efficacy used in clinical trials. We hypothesised that mechanistic studies embedded in a probiotic trial would provide evidence about which properties of probiotics might be important for NEC prevention. The finding that the probiotic strain tested, Bifidobacterium breve BBG-001, showed neither effects on intestinal barrier function nor clinical efficacy supports the possibility that these tests have the potential to identify strains to progress to large clinical trials.
Subject(s)
Bifidobacterium breve/physiology , Infant, Premature , Intestinal Mucosa/physiology , Probiotics/therapeutic use , Female , Humans , Infant, Newborn , Male , PermeabilityABSTRACT
BACKGROUND: Probiotics may reduce necrotising enterocolitis and late-onset sepsis after preterm birth. However, there has been concern about the rigour and generalisability of some trials and there is no agreement about whether or not they should be used routinely. We aimed to test the effectiveness of the probiotic Bifidobacterium breve BBG-001 to reduce necrotising enterocolitis, late-onset sepsis, and death in preterm infants. METHODS: In this multicentre, randomised controlled phase 3 study (the PiPS trial), we recruited infants born between 23 and 30 weeks' gestational age within 48 h of birth from 24 hospitals in southeast England. Infants were randomly assigned (1:1) to probiotic or placebo via a minimisation algorithm randomisation programme. The probiotic intervention was B breve BBG-001 suspended in dilute elemental infant formula given enterally in a daily dose of 8·2 to 9·2 log10 CFU; the placebo was dilute infant formula alone. Clinicians and families were masked to allocation. The primary outcomes were necrotising enterocolitis (Bell stage 2 or 3), blood culture positive sepsis more than 72 h after birth; and death before discharge from hospital. All primary analyses were by intention to treat. This trial is registered with ISRCTN, number 05511098 and EudraCT, number 2006-003445-17. FINDINGS: Between July 1, 2010, and July 31, 2013, 1315 infants were recruited; of whom 654 were allocated to probiotic and 661 to placebo. Five infants had consent withdrawn after randomisation, thus 650 were analysed in the probiotic group and 660 in the placebo group. Rates of the primary outcomes did not differ significantly between the probiotic and placebo groups. 61 infants (9%) in the probiotic group had necrotising enterocolitis compared with 66 (10%) in the placebo group (adjusted risk ratio 0·93 (95% CI 0·68-1·27); 73 (11%) infants in the probiotics group had sepsis compared with 77 (12%) in the placebo group (0·97 (0·73-1·29); and 54 (8%) deaths occurred before discharge home in the probiotic group compared with 56 (9%) in the placebo group (0·93 [0·67-1·30]). No probiotic-associated adverse events were reported. INTERPRETATION: There is no evidence of benefit for this intervention in this population; this result does not support the routine use of B breve BBG-001 for prevention of necrotising enterocolitis and late-onset sepis in very preterm infants. FUNDING: UK National Institute for Health Research Health Technology Assessment programme.
Subject(s)
Bifidobacterium , Enterocolitis, Necrotizing/prevention & control , Infant, Premature, Diseases/prevention & control , Probiotics/administration & dosage , Sepsis/prevention & control , Adult , Birth Weight , Double-Blind Method , Drug Administration Schedule , Female , Gestational Age , Gram-Positive Bacterial Infections/prevention & control , Humans , Infant, Newborn , Infant, Premature , Male , Maternal Age , Treatment OutcomeABSTRACT
OBJECTIVES: The objectives of this study were to characterize ESBL-producing Enterobacteriaceae present in 24 neonatal units (NNUs) in eight networks participating in a multicentre probiotic study and to test the hypothesis that specific strains would cluster within individual units and networks. METHODS: We performed analysis of stool samples for the presence of ESBL-producing Enterobacteriaceae at 2 weeks post-natal age and 36 weeks post-menstrual age. ESBL-producing Enterobacteriaceae were characterized and typed using molecular methods. RESULTS: ESBL-producing Enterobacteriaceae (nâ=â71) were isolated from 67/1229 (5.5%) infants from whom we received a sample at either sampling time or both sampling times, and from infants in 18 (75%) of the 24 recruiting NNUs. Thirty-three Escherichia coli, 23 Klebsiella spp. and 6 Enterobacter spp. strains were characterized. ESBL-producing E. coli were all distinguishable within individual NNUs by antibiotic resistance genotype, serogroup (O25b), phenotype, phylotype or ST. Ten of the 33 were ST131 and 9 of the 10 ST131 isolates were ciprofloxacin resistant. Seven of the 10 ST131 isolates carried genes encoding CTX-M group 1 enzymes. ST131 isolates were isolated from centres within five of the eight NNU networks. There were clusters of indistinguishable ESBL-producing Klebsiella and Enterobacter isolates associated with specific NNUs. CONCLUSIONS: Strains of E. coli ST131 were distributed across neonatal networks in the south of England. There was no evidence of clustering of clonally related ESBL-producing E. coli strains, by contrast with Klebsiella spp. and Enterobacter spp., which did cluster within units. The possibility that ESBL-producing E. coli strains are spread by vertical transmission requires further investigation.
Subject(s)
Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/classification , Enterobacteriaceae/enzymology , Genetic Variation , beta-Lactamases/metabolism , Cluster Analysis , England/epidemiology , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Feces/microbiology , Genotype , Humans , Infant , Infant, Newborn , Molecular Epidemiology , Molecular TypingABSTRACT
Hereditary hypouricemia may result from mutations in the renal tubular uric acid transporter URAT1. Whether mutation of other uric acid transporters produces a similar phenotype is unknown. We studied two families who had severe hereditary hypouricemia and did not have a URAT1 defect. We performed a genome-wide homozygosity screen and linkage analysis and identified the candidate gene SLC2A9, which encodes the glucose transporter 9 (GLUT9). Both families had homozygous SLC2A9 mutations: A missense mutation (L75R) in six affected members of one family and a 36-kb deletion, resulting in a truncated protein, in the other. In vitro, the L75R mutation dramatically impaired transport of uric acid. The mean concentration of serum uric acid of seven homozygous individuals was 0.17 +/- 0.2 mg/dl, and all had a fractional excretion of uric acid >150%. Three individuals had nephrolithiasis, and three had a history of exercise-induced acute renal failure. In conclusion, homozygous loss-of-function mutations of GLUT9 cause a total defect of uric acid absorption, leading to severe renal hypouricemia complicated by nephrolithiasis and exercise-induced acute renal failure. In addition to clarifying renal handling of uric acid, our findings may provide a better understanding of the pathophysiology of acute renal failure, nephrolithiasis, hyperuricemia, and gout.
Subject(s)
Acute Kidney Injury/genetics , Glucose Transport Proteins, Facilitative/genetics , Homozygote , Mutation, Missense/genetics , Nephrolithiasis/genetics , Uric Acid/blood , Acute Kidney Injury/blood , Acute Kidney Injury/etiology , Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Chromosome Mapping , Exercise , Female , Genotype , Glucose Transport Proteins, Facilitative/metabolism , Humans , Male , Middle Aged , Nephrolithiasis/blood , Oocytes/metabolism , Pedigree , Phenotype , Xenopus , Young AdultABSTRACT
The roles of tumor-associated macrophages (TAMs) and circulating monocytes in human cancer are poorly understood. Here, we show that monocyte subpopulation distribution and transcriptomes are significantly altered by the presence of endometrial and breast cancer. Furthermore, TAMs from endometrial and breast cancers are transcriptionally distinct from monocytes and their respective tissue-resident macrophages. We identified a breast TAM signature that is highly enriched in aggressive breast cancer subtypes and associated with shorter disease-specific survival. We also identified an auto-regulatory loop between TAMs and cancer cells driven by tumor necrosis factor alpha involving SIGLEC1 and CCL8, which is self-reinforcing through the production of CSF1. Together these data provide direct evidence that monocyte and macrophage transcriptional landscapes are perturbed by cancer, reflecting patient outcomes.
Subject(s)
Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Cellular Reprogramming , Macrophages/metabolism , Monocytes/metabolism , Paracrine Communication , Transcription, Genetic , Antineoplastic Agents/pharmacology , Biomarkers, Tumor/genetics , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Chemokine CCL8/genetics , Chemokine CCL8/metabolism , Endometrial Neoplasms/genetics , Endometrial Neoplasms/metabolism , Endometrial Neoplasms/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Induced Pluripotent Stem Cells/metabolism , Macrophage Colony-Stimulating Factor/genetics , Macrophages/pathology , Molecular Targeted Therapy , Monocytes/pathology , Sialic Acid Binding Ig-like Lectin 1/genetics , Sialic Acid Binding Ig-like Lectin 1/metabolism , Signal Transduction , THP-1 Cells , Tumor MicroenvironmentABSTRACT
The asynchronous secretion of gonadotrope LH and FSH under the control of GnRH is crucial for ovarian cyclicity but the underlying mechanism is not fully resolved. Because prostaglandins (PG) are autocrine regulators in many tissues, we determined whether they have this role in gonadotropes. We first demonstrated that GnRH stimulates PG synthesis by induction of cyclooxygenase-2, via the protein kinase C/c-Src/phosphatidylinositol 3'-kinase/MAPK pathway in the LbetaT2 gonadotrope cell line. We then demonstrated that PGF(2alpha) and PGI2, but not PGE2 inhibited GnRH receptor expression by inhibition of phosphoinositide turnover. PGF(2alpha), but not PGI2 or PGE2, reduced GnRH-induction of LHbeta gene expression, but not the alpha-gonadotropin subunit or the FSHbeta subunit genes. The prostanoid receptors EP1, EP2, FP, and IP were expressed in rat gonadotropes. Incubations of rat pituitaries with PGF(2alpha), but not PGI2 or PGE2, inhibited GnRH-induced LH secretion, whereas the cyclooxygenase inhibitor, indomethacin, stimulated GnRH-induced LH secretion. None of these treatments had any effect on GnRH-induced FSH secretion. The findings have thus elaborated a novel GnRH signaling pathway mediated by PGF(2alpha)-FP and PGI2-IP, which acts through an autocrine/paracrine modality to limit autoregulation of the GnRH receptor and differentially inhibit LH and FSH release. These findings provide a mechanism for asynchronous LH and FSH secretions and suggest the use of combination therapies of GnRH and prostanoid analogs to treat infertility, diseases with unbalanced LH and FSH secretion and in hormone-dependent diseases such as prostatic cancer.
Subject(s)
Follicle Stimulating Hormone/metabolism , Gonadotropin-Releasing Hormone/physiology , Luteinizing Hormone/metabolism , Receptors, LHRH/biosynthesis , Receptors, Prostaglandin/physiology , Animals , CSK Tyrosine-Protein Kinase , Cell Line , Cyclooxygenase 2/biosynthesis , Cyclooxygenase Inhibitors/pharmacology , Enzyme Induction , Follicle Stimulating Hormone, beta Subunit/metabolism , Gene Expression Regulation , In Vitro Techniques , Indomethacin/pharmacology , MAP Kinase Signaling System/physiology , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositols/metabolism , Pituitary Gland/metabolism , Prostaglandins/biosynthesis , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , Rats , Signal Transduction , src-Family KinasesABSTRACT
BACKGROUND: Necrotising enterocolitis (NEC) is a significant cause of infant morbidity and mortality, disproportionately affecting those of extreme prematurity and/or very low birth weight. A number of risk factors have been identified, including an association between the use of antibiotics, and the subsequent development of NEC. AIM: This review sought to address whether the choice of antibiotic(s) used to treat infants with suspected late-onset sepsis (LOS) influences the risk of developing NEC. METHODS: A systematic review was performed across Web of Knowledge, Cochrane Library, Ovid Medline, EMBASE and CINAHL databases, up to February 2018, assessing the primary outcome of NEC occurrence, as extracted directly from the published articles. Studies were included if they were randomised control trials (or featured adequate adjustment for confounders); included clear criteria for defining LOS/NEC; and assessed occurrence of NEC in premature infants treated for LOS with intravenous antibiotics. Studies were excluded if non-original, not exclusively featuring premature infants, or where treatment was given for early-onset sepsis only. FINDINGS: 2291 titles and abstracts were identified, of which one study (81 subjects) was suitable for analysis, following screening against eligibility criteria. This suggested a decreased risk of developing definite NEC following treatment with a vancomycin/aztreonam combination, versus a vancomycin/gentamicin regimen (ORâ¯=â¯0·08, 95%CIâ¯=â¯0·00-1·45). CONCLUSION: This systematic review identified one study where the occurrence of NEC was reported in the context of comparing different antibiotic regimens for late onset sepsis and highlights that the type of antibiotic used to treat LOS in preterm infants might be a determinant of the risk of developing NEC. Although it is known that different antibiotic combinations impact the enteric microbiome and that antibiotic exposure is a risk factor for NEC, there is a paucity of well-designed studies that look at the relationship between NEC risk and specific antibiotic exposures.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Enterocolitis, Necrotizing/etiology , Sepsis/drug therapy , Anti-Bacterial Agents/adverse effects , Enterocolitis, Necrotizing/epidemiology , Humans , Infant, Newborn , Infant, PrematureABSTRACT
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The need for accurate and rapid screening methods to detect MRSA carriers has been clearly established. The performance of a novel assay, BacLite Rapid MRSA (Acolyte Biomedica, UK) for the rapid detection (5 h) and identification of hospital associated ciprofloxacin resistant strains of MRSA directly from nasal swab specimens was compared to that obtained by culture on Mannitol salt agar containing Oxacillin (MSAO) after 48 h incubation. RESULTS: A total of 1382 nasal screening swabs were tested by multiple operators. The BacLite Rapid MRSA test detected 142 out of the 157 confirmed MRSA that were detected on MSAO giving a diagnostic sensitivity of 90.4, diagnostic specificity of 95.7% and a negative predictive value of 98.7%. Of the 15 false negatives obtained by the BacLite Rapid MRSA test, seven grew small amounts (< 10 colonies of MRSA) on the MSAO culture plate and five isolates were ciprofloxacin sensitive. However there were 13 confirmed BacLite MRSA positive samples, which were negative by the direct culture method, probably due to overgrowth on the MSAO plate. There were 53 false positive results obtained by the BacLite Rapid MRSA test at 5 h and 115 cases where MRSA colonies were tentatively identified on the MSAO plate when read at 48 h, and which subsequently proved not to be MRSA. CONCLUSION: The BacLite MRSA test is easy to use and provides a similar level of sensitivity to conventional culture for the detection of nasal carriage of MRSA with the advantage that the results are obtained much more rapidly.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteriological Techniques/methods , Ciprofloxacin/pharmacology , Methicillin Resistance , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Bacteriological Techniques/economics , Carrier State , False Negative Reactions , False Positive Reactions , Humans , Microbial Sensitivity Tests , Predictive Value of Tests , Sensitivity and Specificity , Staphylococcal Infections/microbiology , Staphylococcus aureus/physiology , Time FactorsABSTRACT
OBJECTIVE: To describe the control of multidrug-resistant Acinetobacter baumannii-calcoaceticus (MDRABC) colonization and infection in an intensive care unit (ICU). SETTING: An 18-bed ICU in a large tertiary care teaching hospital in London. INTERVENTIONS: After recognition of the outbreak, a range of infection control measures were introduced over several months that were primarily aimed at reducing environmental contamination with the outbreak strain. Strategies included use of a closed tracheal suction system for all patients receiving mechanical ventilation, use of nebulized colistin for patients with evidence of mild to moderate ventilator-associated pneumonia, improved availability of alcohol for hand decontamination, and clearer designation of responsibilities and strategies for cleaning equipment and the environment in the proximity of patients colonized or infected with MDRABC. RESULTS: The outbreak lasted from June 2001 through November 2002 and involved 136 new cases of MDRABC infection or colonization. The number of newly diagnosed cases per month reached a maximum of 15 in February 2002, and the number of new cases slowly decreased over the next 9 months. CONCLUSION: This outbreak was controlled by emphasizing the control of environmental reservoirs and did not require recourse to ward closure or placement of affected patients in isolation.
Subject(s)
Acinetobacter Infections/epidemiology , Acinetobacter baumannii/isolation & purification , Disease Outbreaks/prevention & control , Drug Resistance, Microbial , Drug Resistance, Multiple , Intensive Care Units , Patient Isolation , Acinetobacter Infections/microbiology , Humans , London/epidemiologyABSTRACT
Newer methods such as PCR are being investigated in order to improve the diagnosis of invasive aspergillosis. One of the major obstacles to using PCR to diagnose aspergillosis is a reliable, simple method for extraction of the fungal DNA. The presence of a complex, sturdy cell wall that is resistant to lysis impairs extraction of the DNA by conventional methods employed for bacteria. Numerous fungal DNA extraction protocols have been described in the literature. However, these methods are time-consuming, require a high level of skill and may not be suitable for use as a routine diagnostic technique. Here, a number of extraction methods were compared: a freeze-thaw method, a freeze-boil method, enzyme extraction and a bead-beating method using Mini-BeadBeater-8. The quality and quantity of the DNA extracted was compared using real-time PCR. It was found that the use of a bead-beating method followed by extraction with AL buffer (Qiagen) was the most successful extraction technique, giving the greatest yield of DNA, and was also the least time-consuming method assessed.
Subject(s)
Aspergillus fumigatus/genetics , DNA, Fungal/analysis , DNA, Fungal/isolation & purification , Mycology/methods , Polymerase Chain Reaction , HumansABSTRACT
Problems with antibiotic resistant bacteria are increasing in the hospital and particularly in the intensive care unit. Methicillin-resistant Staphylococcus aureus, Acinetobacter baumanii and extended spectrum beta-lactamase producing gram-negative bacilli constitute a therapeutic and infection control challenge. Early enteral feeding improves survival in patients in the intensive care unit. Prokinetic agents are routinely used in patients with inappropriate gastrointestinal motility. The use of erythromycin at sub-therapeutic doses as a prokinetic agent is a cause of concern for the following reasons: it can increase the emergence and spread of antibiotic resistance and the likelihood of Clostridium difficile disease. The use of an antibiotic as a prokinetic agent does not constitute prudent antimicrobial prescribing and should be avoided. Alternative agents, whenever possible, should be used.
Subject(s)
Bacterial Infections/therapy , Drug Resistance , Enteral Nutrition , Erythromycin/adverse effects , Erythromycin/therapeutic use , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Critical Care , Gastrointestinal Diseases/therapy , Gastrointestinal Motility , Humans , Methicillin ResistanceABSTRACT
BACKGROUND: Necrotising enterocolitis (NEC) and late-onset sepsis remain important causes of death and morbidity in preterm babies. Probiotic administration might strengthen intestinal barrier function and provide protection; this is supported by published meta-analyses, but there is a lack of large well-designed trials. OBJECTIVE: To test the use of the probiotic Bifidobacterium breve strain BBG-001 to prevent NEC, late-onset sepsis and death in preterm babies while monitoring probiotic colonisation of participants. DESIGN: Double-blind, randomised, placebo-controlled trial. SETTING: Recruitment was carried out in 24 hospitals, and the randomisation programme used a minimisation algorithm. Parents, clinicians and outcome assessors were blinded to the allocation. PARTICIPANTS: Babies born between 23 and 30 weeks' gestation and randomised within 48 hours of birth. Exclusions included life-threatening or any gastrointestinal malformation detected within 48 hours of birth and no realistic chance of survival. INTERVENTIONS: Active intervention: 1 ml of B. breve BBG-001 in one-eighth-strength infant formula Neocate(®) (Nutricia Ltd, Trowbridge, UK), (6.7 × 10(7) to 6.7 × 10(9) colony-forming units) per dose administered enterally. Placebo: 1 ml of one-eighth-strength infant formula Neocate. Started as soon as practicable and continued daily until 36 weeks' postmenstrual age. MAIN OUTCOME MEASURES: Primary outcomes were an episode of bloodstream infection, with any organism other than a skin commensal, in any baby between 72 hours and 46 weeks' postmenstrual age; an episode of NEC Bell stage ≥ 2 in any baby; and death before discharge from hospital. Secondary outcomes included stool colonisation with B. breve. RESULTS: In total, 654 babies were allocated to receive probiotic and 661 to receive placebo over 37 months from July 2010. Five babies were withdrawn; 650 babies from the probiotic group and 660 from the placebo group were included in the primary analysis. Baseline characteristics were well balanced. There was no evidence of benefit for the primary outcomes {sepsis: 11.2% vs. 11.7% [adjusted relative risk (RR) 0.97, 95% confidence interval (CI) 0.73 to 1.29]; NEC Bell stage ≥ 2: 9.4% vs. 10.0% [adjusted RR 0.93, 95% CI 0.68 to 1.27]; and death: 8.3% vs. 8.5% [adjusted RR 0.93, 95% CI 0.67 to 1.30]}. B. breve colonisation status was available for 1186 (94%) survivors at 2 weeks' postnatal age, of whom 724 (61%) were positive: 85% of the probiotic group and 37% of the placebo group. There were no differences for subgroup analyses by minimisation criteria and by stool colonisation with B. breve at 2 weeks. No harms associated with the interventions were reported. LIMITATIONS: Cross-colonisation of the placebo arm could have reduced statistical power and confounded results; analyses suggest that this did not happen. CONCLUSIONS: This is the largest trial to date of a probiotic intervention. It shows no evidence of benefit and does not support routine use of probiotics for preterm infants. FUTURE WORK RECOMMENDATIONS: The increasing understanding of the pathogenesis of NEC and sepsis will inform the choice of probiotics for testing and better define the target population. Future Phase III trials should incorporate monitoring of the quality and viability of the intervention and colonisation rates of participants; cluster design should be considered. TRIAL REGISTRATION: Current Controlled Trials ISRCTN05511098 and EudraCT 2006-003445-17. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 66. See the NIHR Journals Library website for further project information.
Subject(s)
Bifidobacterium breve , Enterocolitis, Necrotizing/prevention & control , Infant, Premature , Probiotics/administration & dosage , Sepsis/prevention & control , Double-Blind Method , Enterocolitis, Necrotizing/mortality , Gestational Age , Humans , Infant, Newborn , Intensive Care Units, Neonatal , Sepsis/mortalityABSTRACT
Levels of estrogen within the male reproductive tract are higher than in the general circulation and the aromatase enzyme is expressed in the adult testis. Estrogens such as estradiol (E2) modify cell function by binding to high-affinity estrogen receptors (ER). Two subtypes (ERalpha and ERbeta) have been identified. Studies in animals have shown that over- or underexposure to estrogens can have an impact on testis function. For example, mice with targeted disruption of the aromatase cyp19 gene become infertile because round spermatids fail to differentiate normally. In rodents, ERalpha is expressed in Leydig cells; ERalpha mRNA and protein are not detectable in testes from humans or primates. High levels of expression of ERalpha occur in the efferent ductules in rodents, primates, and the human. ERbeta protein has been immunolocalized to all somatic cells and to some germ cells in these same species. Messenger RNAs for splice variant isoforms of human ERbeta are expressed in human testes. Homologues of the ERbeta2 variant have been cloned from primates; this isoform does not exist in rodents and does not bind E2. Full-length ERbeta protein (ERbeta1) and ERbeta2 have differential patterns of expression in human testes. In conclusion, although estrogens are synthesized in the testis and it has been suggested that E2 may function as a germ cell survival factor, the mechanisms by which estrogens influence male fertility remain uncertain and rodents may be poor models in which to examine this.
Subject(s)
Estrogens/metabolism , Receptors, Estrogen/metabolism , Testis/metabolism , Animals , Fertility , Humans , Male , Mice , Models, Animal , Primates , Rats , Receptors, Estrogen/chemistry , Testis/cytology , Tissue DistributionABSTRACT
Estrogens can regulate germ cell function. Estrogen action is mediated via high affinity ERs; two subtypes (ERalpha and ERbeta) have been identified. We have shown previously that ERbeta is expressed in nuclei of multiple human testicular cells. A variant isoform of human (h) ERbeta (hERbetacx/2), formed by alternative splicing, has been identified in testicular cDNA libraries by two laboratories. The present study examined the expression of wild-type (ERbeta1) and variant (ERbeta2) beta receptors in human testes by 1) RT-PCR with isoform specific primers, and 2) single and double immunohistochemistry using monoclonal antibodies raised against peptides unique to the C termini of hERbeta1 and hERbeta2. PCR products specific for ERbeta1 and ERbeta2 were amplified from cDNA pools prepared from human testes and granulosa cells. On Western blots, the anti-ERbeta1 monoclonal antibody bound to recombinant ERbeta1 and the anti-ERbeta2 monoclonal to recombinant hERbeta2. Neither bound to the other ERbeta isoform nor to recombinant ERalpha. ERbeta1 and ERbeta2 proteins were both detected in human testis. Immunoexpression of ERbeta1 was most intense in pachytene spermatocytes and round spermatids, whereas low levels of expression were detected in Sertoli cells, spermatogonia, preleptotene, leptotene, zygotene, and diplotene spermatocytes. Highest levels of expression of ERbeta2 protein were detected in Sertoli cells and spermatogonia with low/variable expression in preleptotene, pachytene, and diplotene spermatocytes. No immunostaining was detected in elongating spermatids. Most interstitial cells expressed more ERbeta2 than ERbeta1. It is speculated that the cells most susceptible to modulation by estrogenic ligands are round spermatids in which levels of expression of ERbeta1 are high. In contrast, expression of ERbeta2, an isoform that may act as a dominant negative inhibitor of ER action, in Sertoli cells and spermatogonia, could protect these cells from adverse effects of estrogens.
Subject(s)
DNA, Recombinant , Receptors, Estrogen/genetics , Receptors, Estrogen/metabolism , Testis/metabolism , Adult , Antibodies, Monoclonal , Estrogen Receptor beta , Fluorescent Antibody Technique , Genetic Variation , Humans , Immunohistochemistry , Male , Protein Isoforms/metabolism , Testis/cytology , Tissue DistributionABSTRACT
Two structurally related subtypes of oestrogen receptor (ER), known as alpha (ER alpha, NR3A1) and beta (ER beta, NR3A2) have been identified. ER beta mRNA and protein have been detected in a wide range of tissues including the vasculature, bone, and gonads in both males and females, as well as in cancers of the breast and prostate. In many tissues the pattern of expression of ER beta is distinct from that of ER alpha. A number of variant isoforms of the wild type beta receptor (ER beta 1), have been identified. In the human these include: (1). use of alternative start sites within the mRNA leading to translation of either a long (530 amino acids, hER beta 1L) or a truncated form (487aa hER beta 1s); (2). deletion of exons by alternative splicing; (3). formation of several isoforms (ER beta 2-beta 5) due to alternative splicing of exons encoding the carboxy terminus (F domain). We have raised monoclonal antibodies specific for hER beta1 as well as to three of the C terminal isoforms (beta2, beta 4 and beta 5). Using these antibodies we have found that ER beta 2, beta 4 and beta 5 proteins are expressed in nuclei of human tissues including the ovary, placenta, testis and vas deferens. In conclusion, in addition to the differential expression of full length ER alpha and ER beta a number of ER variant isoforms have been identified. The impact of the expression of these isoforms on cell responsiveness to oestrogens may add additional complexity to the ways in which oestrogenic ligands influence cell function.
Subject(s)
Receptors, Estrogen/biosynthesis , Alternative Splicing , Animals , Estrogen Receptor alpha , Estrogen Receptor beta , Female , Humans , Male , Mice , Placenta/metabolism , Protein Isoforms/genetics , RNA, Messenger/metabolism , Receptors, Estrogen/genetics , Uterus/metabolism , Vas Deferens/metabolismABSTRACT
BACKGROUND: Sometimes decisions have to be made even when we do not have all of the information that we would like to have. It is not uncommon for infection control professionals to be faced with an outbreak of colonization or infection while there is uncertainty about the impact of the outbreak on patient outcomes. How do we decide a proportional response when we do not know the seriousness of the outbreak? AIM: The precautionary approach has become established in the European Union (EU) as a way of structuring responses to potentially serious threats (such as novel pandemic influenza viruses) when there are substantial uncertainties about the true impact of the threat. The potential of this approach to help with structuring responses to outbreaks involving substantial uncertainties is considered in this article. METHODS: The EU approach requires that actions should be proportional, non-discriminatory, consistent, take account of costs and benefits, be subject to review, and that the responsibility for producing the scientific evidence to fill critical information gaps is assigned. The example of management of outbreaks with multidrug-resistant Acinetobacter baumannii is used here to illustrate how the precautionary approach might be used in infection prevention and control. FINDINGS AND CONCLUSION: The precautionary approach has potential to provide a structured response to outbreaks of hospital infection when there is uncertainty about the impact of the outbreak on outcomes. Most importantly there is a requirement that we specify which risks we are prioritizing for control, the information that is uncertain but critical to informing decisions, and the responsibilities for gathering that information.