Toward Comprehensive Analysis of the 3D Chemistry of Pseudomonas aeruginosa Biofilms

Bacterial biofilms are structured communities consisting of cells enmeshed in a self-generated extracellular matrix usually attached to a surface. They contain diverse classes of molecules including polysaccharides, lipids, proteins, nucleic acids, and diverse small organic molecules (primary and secondary metabolites) which are organized to optimize survival and facilitate dispersal to new colonization sites. In situ characterization of the chemical composition and structure of bacterial biofilms is necessary to fully understand their development on surfaces relevant to biofouling in health, industry, and the environment. Biofilm development has been extensively studied using confocal microscopy using targeted fluorescent labels providing important insights into the architecture of biofilms. Recently, cryopreparation has been used to undertake targeted in situ chemical characterization using Orbitrap secondary ion mass spectrometry (OrbiSIMS), providing a label-free method for imaging biofilms in their native state. Although the high mass resolution of OrbiSIMS enables more confident peak assignments, it is still very challenging to assign most of the peaks in the spectra due to complexity of SIMS spectra and lack of automatic peak assignment methods. Here, we analyze the same OrbiSIMS depth profile data generated from the frozen-hydrated biofilm, but employ a new untargeted chemical filtering process utilizing mass spectral databases to assign secondary ions to decipher the large number of fragments present in the SIMS spectra. To move towards comprehensive analysis of different chemistries in the sample, we apply a molecular formula prediction approach which putatively assigns 81% of peaks in the 3D OrbiSIMS depth profile analysis. This enables us to catalog over 1000 lipids and their fragments, 3500 protein fragments, 71 quorum sensing-related molecules (2-alkyl-4-quinolones and N-acylhomoserine lactones), 150 polysaccharide fragments, and glycolipids simultaneously from one data set and map these separated molecular classes spatially through a Pseudomonas aeruginosa biofilm. Assignment of different chemistries in this sample facilitates identification of differences between biofilms grown on biofilm-promoting and biofilm-resistant polymers.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Development and validation of an algorithm to assist in the interpretation of the electrocardiogram

Funding Acknowledgements

Type of funding sources: None.

Background and Purpose

Interpretation of the electrocardiogram (ECG) is often poorly performed, affecting time critical patient care. There are no reliable methods that consistently bridge the gap between novices and competency. However, the development of a framework allowing a step-wise approach to interpret the ECG based on relevant signals might help. Indeed, in addition to expert teaching, a pilot study of this algorithm significantly improves sustained ECG interpretation in medical students. This study aimed to validate the ECG algorithm tool by confirming the appropriateness of its step-wise components through expert cardiologists.

Methods

A Modified Delphi Exercise protocol was used. Cardiologists were invited to participate in a questionnaire through an online survey tool. Expert participants evaluated each stage of the ECG algorithm through multiple levels of agreement and explained their decision making with the option of free-text comments. These were collated and analysed by the four authors and changes subsequently made. The process was repeated, with evaluation of the changes from each round until a predetermined level of agreement was achieved.

Results

This Modified Delphi Exercise produced two rounds. Overall, 55 responses from experts was achieved (first round = 33, round two = 22). The average agreement in round one was 85.8%  with 25 changes from 124 comments. Round two achieved 93.4% agreement with 12 changes from 57 comments. After discussion by four authors, a consensus was reached and a final algorithm was achieved. Figure 1 shows the bradycardia section of the final algorithm (tachycardia and ST/T-wave/ischaemia sections not shown).

Conclusions

We have validated an ECG algorithm through a rigorous development and review process in a multi-institutional and multi-national Modified Delphi study. The completed expert reviewed algorithm may be a safe, informative tool for novice users to improve ECG interpretation. However, further validation in user groups is now mandated to refine the tool. Abstract Figure 1- Algorithm one of three

First Precision Measurement of the Parity Violating Asymmetry in Cold Neutron Capture on ^{3}He

We report the first precision measurement of the parity-violating asymmetry in the direction of proton momentum with respect to the neutron spin, in the reaction ^{3}He(n,p)^{3}H, using the capture of polarized cold neutrons in an unpolarized active ^{3}He target. The asymmetry is a result of the weak interaction between nucleons, which remains one of the least well-understood aspects of electroweak theory. The measurement provides an important benchmark for modern effective field theory and potential model calculations. Measurements like this are necessary to determine the spin-isospin structure of the hadronic weak interaction. Our asymmetry result is A_{PV}=[1.55±0.97(stat)±0.24(sys)]×10^{-8}, which has the smallest uncertainty of any hadronic parity-violating asymmetry measurement so far.

Future challenges of coastal landfills exacerbated by sea level rise

In England and Wales, there are at least 1700 coastal landfills in the coastal flood plain and at least 60 threatened by erosion, illustrating a global problem. These landfills are a major issue in shoreline management planning (SMP) which aims to manage the risks associated with flooding and coastal erosion. Where landfills exist, "hold the line" (requiring the building or upgrading of artificial defences to maintain the current shoreline) is often selected as the preferred SMP option, although government funding is not available at present. To investigate these issues in detail, three case-study landfills are used to examine the risks of future flooding and erosion together with potential mitigation options. These cases represent a contrasting range of coastal landfill settings. The study includes consideration of sea-level rise and climate change which exacerbates risks of erosion and flooding of landfills. It is fundamental to recognise that the release of solid waste in coastal zones is a problem with a geological timescale and these problems will not go away if ignored. Future erosion and release of solid waste is found to be more of a threat than flooding and leachate release from landfills. However, while leachate release can be assessed, there is presently a lack of methods to assess the risks from the release of solid waste. Hence, a lack of science constrains the design of remediation options.

The use of bipolar electrosurgical forceps for haemostasis in open surgical ovariectomy of bitches and queens and castration of dogs

OBJECTIVES

To describe a technique using bipolar electrosurgical forceps for haemostasis during open ovariectomy of bitches and queens and for castration of dogs and to determine whether these forceps reduced surgical time compared to ligation with suture.

MATERIALS AND METHODS

Bipolar electrosurgical forceps were used for haemostasis in 3744 open surgeries including ovariectomies in bitches (n=1406) and queens (n=859) and castrations in dogs (n=1335). The forceps were also used to assist with ovariohysterectomy in bitches (n=89) and queens (n=55). The effect of bipolar electrocoagulation and other likely factors influencing surgical time was examined using linear regression analysis of 367 surgeries.

RESULTS

The use of the forceps reduced surgical time by 9·7 ±2·8 minutes in bitches and by 3·0 ±1·5 minutes in queens. The complications encountered initially were small superficial skin burns requiring topical treatment and one case of haemorrhage associated with surgical technique.

CLINICAL SIGNIFICANCE

Bipolar electrosurgical forceps reduce surgical time in ovariectomies, and complications are rare. This technique has promise for widespread application in veterinary practice to assist with haemostasis in ovariectomy of bitches and queens.

Effectiveness of a multidisciplinary team approach to the prevention of readmission for acute glycaemic events

AIMS

To describe the effect of a combined diabetes specialist/mental health team approach to prevent readmissions for acute glycaemic events among patients with diabetes.

METHODS

Consecutive patients with diabetes, readmitted to a single hospital for an acute glycaemic condition, were offered one or more diabetes (including assessment, education, medication, technology use and intensive support) and mental health (including assessment, training and therapies) interventions. The pilot service took place over 11 months, with the preceding 24 months and subsequent 8 months serving as control periods.

RESULTS

Of the 58 patients admitted, 50 had Type 1 diabetes and were from within the hospital catchment area, and were discharged home. Of these, 32 (64%) had a pre-existing mental health issue and 14 (28%) had a complex social situation. In all, 96% of patients were met as an inpatient by a team member, and 94% accepted at least one intervention. The mean ±sd number of admissions per patient/month dropped from 0.12 ± 0.10 to 0.05 ± 0.10 (P < 0.001) during the intervention, increasing, once the intervention ended, to 0.16 ± 0.36 (P = 0.002). The mean ± sd length of stay similarly decreased and increased (0.6 ± 0.9 to 0.2 ± 0.7 days; P < 0.001 to 0.006) to 0.6 ± 1.4 days (P = 0.003) per patient/month) across the three periods, as did the mean ±sd tariff paid per patient/month (₤258.0 ± 374.0 vs ₤92.1 ± 245.0 vs ₤287.3 ± 563.8; P < 0.001 and P = 0.018, respectively). The mean ± sd HbA1c level dropped from 99 ± 22 to 92 ± 24 mmol/mol (11.2 ± 4.2% vs 10.6 ± 4.3%; P = 0.014) but did not increase after the intervention [89 ± 26 mmol/mol (10.4 ± 4.5%)].

CONCLUSIONS

The cost and long-term risks of hospitalization among patients with Type 1 diabetes and recurrent admissions can be reduced by a combined specialist diabetes/mental health team approach.

Evaluation of two commercial, rapid, ELISA kits testing for scrapie in retro-pharyngeal lymph nodes in sheep

AIMS

To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN) from non-infected and infected sheep of different PrP genotypes.

METHODS

Using published data on the distribution of PrP genotypes within the New Zealand sheep flock and the prevalence of cases of scrapie in these genotypes in the United Kingdom, the annual expected number of cases of scrapie per genotype was estimated, should scrapie become established in New Zealand, assuming a total population of 28 million sheep. A non-infected panel of RLN was collected from 737 sheep from New Zealand that had been culled, found in extremis or died. Brain stem samples were also collected from 131 of these sheep. A second panel of infected samples comprised 218 and 117 RLN from confirmed scrapie cases that had originated in Europe and the United States of America, respectively. All samples were screened using two commercial, rapid, transmissible spongiform encephalopathy ELISA kits: Bio-Rad TeSeE ELISA (ELISA-BR), and IDEXX HerdChek BSE-Scrapie AG Test (ELISA-ID).

RESULTS

If scrapie became established in New Zealand, an estimated 596 cases would occur per year; of these 234 (39%) and 271 (46%) would be in sheep carrying ARQ/ARQ and ARQ/VRQ PrP genotypes, respectively. For the non-infected samples from New Zealand the diagnostic specificity of both ELISA kits was 100%. When considering all infected samples, the diagnostic sensitivity was 70.4 (95% CI=65.3-75.3)% for ELISA-BR and 91.6 (95% CI=88.2-94.4)% for ELISA-ID. For the ARQ/ARQ genotype (n=195), sensitivity was 66.2% for ELISA-BR and 90.8% for ELISA-ID, and for the ARQ/VRQ genotype (n=107), sensitivity was 81.3% for ELISA-BR and 98.1% for ELISA-ID.

CONCLUSIONS

In this study, the ELISA-ID kit demonstrated a higher diagnostic sensitivity for detecting scrapie in samples of RLN from sheep carrying scrapie-susceptible PrP genotypes than the ELISA-BR kit at comparable diagnostic specificity.

CLINICAL RELEVANCE

The diagnostic performance of the ELISA-ID kit using ovine RLN merits the consideration of including this assay in the national scrapie surveillance programme in New Zealand.

Inhibition of follicle-stimulating hormone-induced preovulatory follicles in rats treated with a nonsteroidal negative allosteric modulator of follicle-stimulating hormone receptor

We previously described a negative allosteric modulator (NAM) of FSHR (ADX61623) that blocked FSH-induced cAMP and progesterone production but did not block estradiol production. That FSHR NAM did not affect FSH-induced preovulatory follicle development as evidenced by the lack of an effect on the number of FSH-dependent oocytes found in the ampullae following ovulation with hCG. A goal is the development of a nonsteroidal contraceptive. Toward this end, a high-throughput screen using human FSHR identified an additional nonsteroidal small molecule (ADX68692). Although ADX68692 behaved like ADX61623 in inhibiting production of cAMP and progesterone, it also inhibited FSH-induced estradiol in an in vitro rat granulosa primary cell culture bioassay. When immature, noncycling female rats were injected subcutaneously or by oral dosing prior to exogenous FSH administration, it was found that ADX68692 decreased the number of oocytes recovered from the ampullae. The estrous cycles of mature female rats were disrupted by administration by oral gavage of 25 mg/kg and 10 mg/kg ADX68692. In the highest dose tested (25 mg/kg), 55% of animals cohabited with mature males had implantation sites compared to 33% in the 10 mg/kg group and 77% in the control group. A surprising finding was that a structural analog ADX68693, while effectively blocking progesterone production with similar efficacy as ADX68692, did not block estrogen production and despite better oral availability did not decrease the number of oocytes found in the ampullae even when used at 100 mg/kg. These data demonstrate that because of biased antagonism of the FSHR, nonsteroidal contraception requires that both arms of the FSHR steroidogenic pathway must be effectively blocked, particularly estrogen biosynthesis. Thus, a corollary to these findings is that it seems reasonable to propose that the estrogen-dependent diseases such as endometriosis may benefit from inhibition of FSH action at the ovary using the FSHR NAM approach.

Females without reflux symptoms or gastroesophageal reflux disease have less distal esophageal acid exposure than males without reflux symptoms or gastroesophageal reflux disease

Ambulatory 24-hour esophageal pH monitoring is the gold standard examination to assess esophageal acid exposure. Gender-related variation is a well-recognized physiologic phenomenon in health and disease. To date, limited gender-specific 24-hour esophageal pH monitoring data are available. The aim of this study was to obtain values of esophageal pH monitoring in males and females without reflux symptoms or gastroesophageal reflux disease (GERD) to determine if gender variation exists in esophageal acid exposure among individuals without these factors. Twenty-four-hour dual esophageal pH monitoring was performed in male and female volunteers without reflux symptoms or GERD. Values for total number of reflux episodes, episodes longer than 5 minutes, total reflux time in minutes, % time with pH below 4, and longest reflux episode in the proximal/distal esophagus were obtained and recorded for both groups. The distal channel was placed 5 cm and proximal channel 15 cm above the manometrically determined lower esophageal sphincter. Means were compared using an independent sample t-test. Sixty-seven males and 69 females were enrolled. All subjects completed esophageal 24-hour pH monitoring without difficulty. There was no age or body mass difference between groups. Females had significantly fewer reflux episodes at both esophageal measuring sites and, significantly less total reflux time and % time with pH below 4 in the distal esophagus than males. All other parameters were similar. Significant gender-related differences exist in esophageal acid exposure, especially in the distal esophagus in individuals without reflux symptoms or GERD. These differences underscore the need for gender-specific reference values for 24-hour pH monitoring, allowing for an accurate evaluation of esophageal acid exposure in symptomatic patients.

Cross-cultural evaluation of the French version of the LEIPAD, a health-related quality of life instrument for use in the elderly living at home

PURPOSE

To cross-culturally adapt a French version of the LEIPAD, a self-administered questionnaire assessing the health-related quality of life (HRQoL) in adults aged 65 years and over living at home, and to evaluate its psychometric properties.

METHODS

After having translated LEIPAD in accordance with guidelines, we studied psychometric properties: reliability and construct validity-factor analysis, relationships between items and scales, internal consistency, concurrent validity with the Medical Outcome Study Short-Form 36 and known-groups validity.

RESULTS

The results obtained in a sample of 195 elderly from the general population showed very good acceptability, with response rates superior to 93 %. Exploratory factor analysis extracted eight factors providing a multidimensionality structure with five misclassifications of items in the seven theoretical scales. Good internal consistency (Cronbach's alpha ranging from 0.73 and 0.86) and strong test-retest reliability (ICCs higher than 0.80 for six scales and 0.70 for one) were demonstrated. Concurrent validity with the SF-36 showed small to strong expected correlations.

CONCLUSION

This first evaluation of the French version of LEIPAD's psychometric properties provides evidence in construct validity and reliability. It would allow HRQoL assessment in clinical and common practice, and investigators would be able to take part in national and international research projects.

Developing best practice for fungal specimen management: audit of UK microbiology laboratories

This study represents an audit of microbiology laboratories in the UK to ascertain whether they are aware of, or follow, the Health Protection Agency (HPA) National Standard Methods Standard Operating Procedure (NSM SOP) for the investigation of dermatological specimens for superficial mycoses, or use a locally adapted version. A questionnaire audit was distributed to 179 NHS microbiology laboratories throughout England, Wales, Scotland and Northern Ireland. The NSM SOP was followed by 92% of laboratories for the microscopy of dermatological samples; light microscopy/ KOH digestion was used by 63% and fluorescence microscopy/KOH digestion by 29% of laboratories. Preliminary reports post-microscopy were issued by 98% of laboratories, with 93% issuing reports within 48 hours. Adherence to the NSM SOP guidelines for culture was low; only 34% of laboratories incubated microscopy-negative specimens for the recommended 14 days, while approximately 60% incubated microscopy-positive specimens for 21 days. The culture medium recommended by the NSM SOP was used in 82% of laboratories. Comments were added to culture reports by 51% of laboratories; most were added manually and comments varied between laboratories. Nail samples were the most common sample received from primary care, followed by skin and hair. These results show no significant difference in the rate of microscopy positives versus culture positives. Microscopy and culture are the easiest and cheapest methods available to UK laboratories for the investigation of suspected superficial fungal infections. Although most laboratories included in this audit claimed to follow the NSM SOP for microscopy and culture, these results show that the techniques used vary throughout the UK. To maximise the service provided to primary care, UK laboratories should use standardise methods based on the NSM SOP.

Host-response patterns of intramammary infections in dairy cows

Many different bacterial species have the ability to cause an infection of the bovine mammary gland and the host response to these infections is what we recognize as mastitis. In this review we evaluate the pathogen specific response to the three main bacterial species causing bovine mastitis: Escherichia coli, Streptococcus uberis and Staphylococcus aureus. In this paper we will review the bacterial growth patterns, host immune response and clinical response that results from the intramammary infections. Clear differences in bacterial growth pattern are shown between bacterial species. The dominant pattern in E. coli infections is a short duration high bacteria count infection, in S. aureus this is more commonly a persistent infection with relative low bacteria counts and in S. uberis a long duration high bacteria count infection is often observed. The host immune response differs significantly depending on the invading bacterial species. The underlying reasons for the differences and the resulting host response are described. Finally we discuss the clinical response pattern for each of the three bacterial species. The largest contrast is between E. coli and S. aureus where a larger proportion of E. coli infections cause potentially severe clinical symptoms, whereas the majority of S. aureus infections go clinically unnoticed. The relevance of fully understanding the bovine host response to intramammary infection is discussed, some major gaps in our knowledge are highlighted and directions for future research are indicated.

A negative allosteric modulator demonstrates biased antagonism of the follicle stimulating hormone receptor

High quality gamete production in males and females requires the pituitary gonadotropin follicle stimulating hormone (FSH). In this report a novel chemical class of small molecule inhibitors of FSH receptor (FSHR) is described. ADX61623, a negative allosteric modulator (NAM), increased the affinity of interaction between (125)I-hFSH and human FSHR (hFSHR) five fold. This form of FSHR occupied simultaneously by FSH and ADX61623 was inactive for cAMP and progesterone production in primary cultures of rat granulosa cells. In contrast, ADX61623 did not block estrogen production. This demonstrates for the first time, biased antagonism at the FSHR. To determine if ADX61623 blocked FSH induction of follicle development in vivo, a bioassay to measure follicular development and oocyte production in immature female rats was validated. ADX61623 was not completely effective in blocking FSH induced follicular development in vivo at doses up to 100mg/kg as oocyte production and ovarian weight gain were only moderately reduced. These data illustrate that FSHR couples to multiple signaling pathways in vivo. Suppression of one pool of FSHR uncouples Gαs and cAMP production, and decreases progesterone production. Occupancy of another pool of FSHR sensitizes granulosa cells to FSH induced estradiol production. Therefore, ADX61623 is a useful tool to investigate further the mechanism of the FSHR signaling dichotomy. This may lead to a greater understanding of the signaling infrastructure which enables estrogen biosynthesis and may prove useful in treating estrogen dependent disease.

Reflux episodes are similar in healthy African Americans and non-Hispanic whites

Ambulatory esophageal pH monitoring is the current gold standard diagnostic exam for gastroesphageal reflux disease. Presently, no data are available for normal 24-hour esophageal pH monitoring among any US ethnic group. The aim of the present study was to obtain normal values of 24-hour esophageal pH monitoring in healthy adult African American (AA) volunteers and compare these with values obtained in healthy non-Hispanic white (nHw) volunteers to determine if ethnic variation exists in 24-hour esophageal pH testing. Twenty-four-hour dual esophageal pH monitoring was performed in healthy AA and nHw. Values for total number of reflux episodes, episodes longer than 5 min, total reflux time in minutes, and longest reflux episode in the proximal and distal esophagus were obtained for both ethnic groups. Differences between groups were considered significant if P < 0.05. Eighty subjects volunteered for the study and completed 24-hour pH testing. Forty-one were AAs and 39 were nHws, with males making up 49% of each group. The AAs were older and had higher body mass index than the nHws. No difference was observed between the AA and the nHw subjects for any measured pH parameter in either the proximal or distal esophagus. There is no difference in values obtained during esophageal pH monitoring in healthy African Americans and non-Hispanic whites. This indicates that the currently accepted normal values of ambulatory esophageal pH monitoring are readily applicable to African Americans and can be used without compromising diagnostic accuracy in this ethnic group.

Identification of Porphyromonas levii isolated from clinical cases of bovine interdigital necrobacillosis by 16S rRNA sequencing

Laboratories use pigmentation, antibiotic susceptibility, and biochemical tests to identify anaerobic organisms that play a role in bovine interdigital necrobacillosis (bovine foot rot). In this study, 16S rRNA gene sequencing was used to identify strains to the species level that were originally classified as Prevotella or Porphyromonas spp by conventional phenotype assessment methods. Of 264 qualified strains from ceftiofur clinical trials, 241 isolates were definitively identified by 16S rRNA sequencing as Porphyromonas levii. Similarly, of 275 qualified strains from tulathromycin clinical trials, 156 isolates were definitively identified by 16S rRNA sequencing as P. levii. The predominance of P. levii in this study supports the role of this organism as an associative agent of bovine foot rot and may have implications for routine laboratory diagnosis.

Pioneer factors, genetic competence, and inductive signaling: programming liver and pancreas progenitors from the endoderm

The endoderm is a multipotent progenitor cell population in the embryo that gives rise to the liver, pancreas, and other cell types and provides paradigms for understanding cell-type specification. Studies of isolated embryo tissue cells and genetic approaches in vivo have defined fibroblast growth factor/mitogen-activated protein kinase (FGF/MAPK) and bone morphogenetic protein (BMP) signaling pathways that induce liver and pancreatic fates in the endoderm. In undifferentiated endoderm cells, the FoxA and GATA transcription factors are among the first to engage silent genes, helping to endow competence for cell-type specification. FoxA proteins can bind their target sites in highly compacted chromatin and open up the local region for other factors to bind; hence, they have been termed "pioneer factors." We recently found that FoxA proteins remain bound to chromatin in mitosis, as an epigenetic mark. In embryonic stem cells, which lack FoxA, FoxA target sites can be occupied by FoxD3, which in turn helps to maintain a local demethylation of chromatin. By these means, a cascade of Fox factors helps to endow progenitor cells with the competence to activate genes in response to tissue-inductive signals. Understanding such epigenetic mechanisms for transcriptional competence coupled with knowledge of the relevant signals for cell-type specification should greatly facilitate efforts to predictably differentiate stem cells to liver and pancreatic fates.

Western analyses of pregnancy-associated glycoprotein family (PAG) in placental extracts of various mammals

The present study was conducted in order to analyze the immunoreactivity of placental extracts of several animal species and humans against the following three groups of PAG antisera: anti-boPAG-I (R#497), -boPAG-II (R#435), and -caPAG (R#706). Placental proteins were obtained after extraction at neutral pH, followed by ammonium sulfate (A.S.) precipitation, dialysis, and lyophilization. The immunoreactivity of different placental extracts was revealed by the use of monodimensional SDS-PAGE, followed by blotting on nitrocellulose membrane and the identification of immunoreactive proteins after incubation with PAG antisera (Western blot technique). A strong immunoreactivity of proteins from synepitheliochorial placenta (cattle, sheep, goat, bison, buffalo, and deer) was demonstrated in both 20-50% and 50-80% A.S. fractions using the three antisera. Proteins from species with epitheliochorial placenta presented variable profiles of detected PAG-like proteins: in the sow, many immunoreactive forms were revealed by antisera boPAG-I and boPAG-II, whereas in the dromedary, only two forms were revealed by anti-boPAG-II. Concerning other species, our protocols showed for the first time a cross-reaction between PAG antisera with proteins extracted from dog, alpaca, dromedary, sea lion, and human placenta.

Influence of progesterone concentrations on secretory functions of trophoblast and pituitary during the first trimester of pregnancy in dairy cattle

The essential role played by progesterone in the maintenance of pregnancy is unequivocal; however, the effects of progesterone on the secretory patterns of placental and pituitary molecules during the gestation period are not well defined. The objective of this study was to describe pregnancy-associated glycoprotein (PAG) concentrations (measured by RIA-497 and RIA-Pool) in pregnant females with progesterone concentrations lower (low-P4 group, n=20) or higher (high-P4 group, n=17) than the mean of 8.74 ng/mL on Day 21 (AI=Day 0). Luteinizing hormone (LH) and prolactin concentrations were also measured in both groups. Throughout the study period, blood samples were collected on Days 0, 21, 45, 60, and 80 from 37 females that were confirmed to be pregnant. PAG concentrations measured by both RIA-497 and RIA-Pool tended to be higher in high-P4 group than in low-P4 group from Day 30 until Day 80. On Day 80, plasma PAG concentrations that were measured using RIA-497 were observed to be higher (P<0.05) in the high-P4 group than in the low-P4 group (10.2+/-8.7 ng/mL versus 6.9+/-3.8 ng/mL). Concentrations of LH on Day 60 and prolactin on Day 80 were observed to be significantly lower (P<0.05) in the high-P4 group. There was a tendency for the concentrations of LH (Days 45 and 80) and prolactin (Days 30, 45, and 60) to be lower in cows in the high-P4 group than in the low-P4 group. Our results suggest the existence of a relationship among the concentration levels of progesterone, PAG, LH, and prolactin during early pregnancy.

A randomized, double-blind, placebo-controlled trial of donepezil hydrochloride (Aricept) for reducing the incidence of postoperative delirium after elective total hip replacement

OBJECTIVES

This was a pilot, phase 2a study to assess methodological feasibility and the safety and efficacy of donepezil in preventing postoperative delirium after elective total hip replacement surgery in older people without pre-existing dementia. The hypothesis was that donepezil would reduce the incidence of postoperative delirium.

METHODS

A double blind, placebo controlled, parallel group randomized trial was undertaken. Patients were block randomized pre-operatively to receive placebo or donepezil 5 mg immediately following surgery and every 24 h thereafter for a further three days. The main outcome was the incidence of delirium (using the Delirium Symptom Interview). The secondary outcome was length of hospital stay.

RESULTS

Thirty-three patients (mean age 67 years; 17 males, 16 females) completed the study (19 donepezil, 14 placebo). Donepezil was well tolerated with no serious adverse events. Postoperative delirium occurred in 21.2% of subjects. Donepezil did not significantly reduce the incidence of delirium. The unadjusted risk ratio (donepezil vs placebo) for delirium was 0.29 (95% CI = 0.06,1.30) (chi(2) ([1]) = 3.06; p = 0.08). Mean length of hospital stay was 9.9 days for the donepezil group vs 12.1 days in the placebo group; difference in means = -2.2 days (95% CI = -0.39,4.78) (t([31]) = 1.73: p = 0.09).

CONCLUSIONS

The experimental paradigm was feasible and acceptable. Donepezil did not significantly reduce the incidence of delirium or length of hospital stay, however for both outcomes there was a consistent trend suggesting possible benefit. The sample size required for a definitive trial (99% power, alpha 0.05) would be 95 subjects per arm.

Effect of glutathione S-transferase polymorphisms and proximity to hazardous waste sites on time to systemic lupus erythematosus diagnosis: results from the Roxbury lupus project

OBJECTIVE

The high prevalence of systemic lupus erythematosus (SLE) among African American women may be due to environmental exposures, genetic factors, or a combination of factors. Our goal was to assess association of residential proximity to hazardous waste sites and genetic variation in 3 glutathione Stransferase (GST) genes (GSTM1, GSTT1, and GSTP1) with age at diagnosis of SLE.

METHODS

Residential histories were obtained by interviewing 93 SLE patients from 3 predominantly African American neighborhoods in Boston. Residential addresses and locations of 416 hazardous waste sites in the study area were geocoded using ArcView software. Time-varying Cox models were used to study the effect of residential proximity to hazardous sites, GST genotype, and interaction between genotype and exposure in determining age at diagnosis.

RESULTS

The prevalence of SLE among African American women in these neighborhoods was 3.56 SLE cases per 1,000. Homozygosity for GSTM1-null and GSTP1 Ile105Val in combination was associated with earlier SLE diagnosis (P = 0.03), but there was no association with proximity to 416 hazardous sites. Available data on specific site contaminants suggested that, at a subset of 67 sites, there was higher potential risk for exposure to volatile organic compounds (P < 0.05 with Bonferroni correction). GST genotypes had a significant interaction with proximity (P = 0.03) in analyses limited to these sites.

CONCLUSION

There was no independent association between residential proximity to hazardous waste sites and the risk of earlier SLE diagnosis in this urban population. However, analysis of a limited number of sites indicated that the risk of earlier SLE associated with proximity to hazardous sites might be modulated by GST polymorphisms.

Occupational silica and solvent exposures and risk of systemic lupus erythematosus in urban women

OBJECTIVE

To assess the risk of systemic lupus erythematosus (SLE) associated with occupational exposure to silica dust and organic solvents in an urban population.

METHODS

Women with SLE were identified through both community screening and hospital databases in 4 predominantly African American neighborhoods in Boston. Female control patients were volunteers from the same communities and were screened for the absence of connective tissue disease. Demographic factors, smoking history, and a detailed occupational history, including exposures to specific chemicals, were obtained by in-person interviews. The exposure assessment was based on independent evaluation of the occupational history by 2 reviewers who were blinded to each subject's disease status. The risks associated with exposure to silica and solvents were analyzed using multivariate conditional logistic regression models, adjusted for potential confounders.

RESULTS

Ninety-five patients and 191 age- and race-matched controls were included in this analysis. Exposure to silica for longer than 1 year was associated with SLE (odds ratio [OR] 4.3, 95% confidence interval [95% CI] 1.7-11.2). An exposure-response effect was seen for longer duration of exposures to silica (P for trend = 0.01). The association between occupational exposure to organic solvents and SLE was not statistically significant (OR 1.04, 95% CI 0.34-3.2).

CONCLUSION

Silica exposure from a variety of industrial occupations in urban areas is associated with an increased risk of SLE. A longer duration of exposure to silica dust is associated with greater risks. This study provides further impetus for additional research into the influence of modifiable exposures on the pathogenesis of SLE.