Robust deep learning-based protein sequence design using ProteinMPNN

Although deep learning has revolutionized protein structure prediction, almost all experimentally characterized de novo protein designs have been generated using physically based approaches such as Rosetta. Here, we describe a deep learning-based protein sequence design method, ProteinMPNN, that has outstanding performance in both in silico and experimental tests. On native protein backbones, ProteinMPNN has a sequence recovery of 52.4% compared with 32.9% for Rosetta. The amino acid sequence at different positions can be coupled between single or multiple chains, enabling application to a wide range of current protein design challenges. We demonstrate the broad utility and high accuracy of ProteinMPNN using x-ray crystallography, cryo-electron microscopy, and functional studies by rescuing previously failed designs, which were made using Rosetta or AlphaFold, of protein monomers, cyclic homo-oligomers, tetrahedral nanoparticles, and target-binding proteins.

Real-world assessment of anti-platelet therapies for recurrent stroke prevention in non-atrial fibrillation Japanese patients after recent ischemic stroke or transient ischemic attack

Background

Stroke is one of the leading causes of cardiovascular-related deaths and disability for adults in Japan and is more commonly seen among the elderly. The risks of developing a secondary stroke resulting in permanent damage after the incident ischemic stroke (IS)/transient ischemic stroke (TIA) are very high. It is critical to understand the treatment landscape for the secondary stroke prevention (SSP) and unmet needs of patients with prior IS/ TIA events.

Purpose

To evaluate the antiplatelet therapy (APT) treatment patterns for SSP after first hospitalization for IS/TIA events among the Japanese population.

Methods

Japan's Medical Data Vision (MDV) from Q12011 to Q22021 was used for this study. MDV is a hospital-based claims database covering approximately 35.5 million individuals in the inpatient and outpatient settings among 438 hospitals. Adult patients with an inpatient primary diagnosis of IS/TIA during the index period were identified. Patients require at least one medical claim each quarter within the 1 year before and after index date to ensure longitudinal analysis. Atrial fibrillation patients or patients on oral anticoagulant use were excluded. Patients' characteristics, treatment pattern and duration were evaluated.

Results

Of 18,948 patients in this study, the mean age was 75 years and 36.7% were female; 91.5% were treated with APT and 8.5% were untreated within 90 days of hospital discharge. Among 17,332 APT treated patients, 76.9% were initiated on single APT (SAPT), 22.7% were initiated on dual APT (DAPT), and <1% were initiated on multiple APT (MAPT). The most used SAPT were aspirin (ASA; 33.2%), clopidogrel (28.7%) or cilostazol (14.8%) and the most used DAPT were ASA+clopidogrel (15.1%), ASA+cilostazol (4.2%) or cilostazol+clopidogrel (2.7%). The median duration of APT was 320, 414 and 411 days for patients who initiated ASA, clopidogrel and cilostazol, respectively. The median duration of APT for patients who initiated ASA+clopidogrel, ASA+cilostazol and cilostazol+clopidogrel was 298, 359 and 473 days respectively. Of patients initiated on ASA+clopidogrel, 52.4% were de-escalated to SAPT (71% clopidogrel, 29% ASA; median duration of 20 days); 36.2% of patients initiated on ASA+cilostazol were de-escalated to SAPT within a median of 19 days (84% cilostazol, 16% ASA); lastly, 54.4% of patients initiated on cilostazol+clopidogrel de-escalated to SAPT within a median of 35 days (76% cilostazol, 24% clopidogrel). Two years after initial hospitalization of IS/TIA, 52%-56% discontinued APT treatments among those previously receiving SAPT while 46%-57% of patients receiving DAPT discontinued treatment.

Conclusion

Majority of patients at risk of secondary stroke received APT. Further analyses are needed to explore reasons for early APT discontinuation, for no APT use, and to evaluate outcomes of patients in this study.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This study was sponsored by Bristol Myers Squibb and Janssen Research & Development, LLC. – Anonymised and used for statistical purposes only

Heart failure across the range of preserved ejection fraction in United States clinical practice

Introduction

Recent clinical trials of heart failure with preserved ejection fraction (HFpEF) have observed varying patient profiles by ejection fraction (EF), with attenuation of treatment benefits as EF increases. In routine clinical practice, the degree to which patients hospitalized for HF with EF≥60% may differ from those with lower EF is unknown.

Purpose

To compare patient characteristics, treatment patterns, and clinical outcomes across the range of EF among patients hospitalized for HFpEF.

Methods

Using the Humedica electronic medical records database between Jan 2010 and Dec 2020, patients hospitalized for a primary diagnosis of HF with EF>40% and who were haemodynamically stable at admission, without concurrent acute coronary syndrome or end-stage renal disease, and treated with intravenous (IV) diuretic agents within 48 h of admission were identified. Patient characteristics, treatment patterns, and clinical outcomes were compared by EF ranges of 41–49%, 50–59%, and ≥60%.

Results

Of 47,026 patients hospitalized with HFpEF, 6,335 (13%) had EF 41–49%, 18,603 (40%) had EF 50–59%, and 22,088 (47%) had EF≥60%. Across all 3 groups, patients were similar with respect to age (median 77 years for each group), race (83–84% White, 12–13% Black), systolic blood pressure (137–138 mmHg at admission), and eGFR (63–64 mL/min/1.73 m2 at admission). With progressively higher EF group, the proportion of women increased (45% vs 54% vs 65%) and median NT-proBNP decreased (4,221 vs 2,945 vs 2,234 pg/mL). Patients with EF ≥60% had the lowest rates of coronary artery disease and atrial fibrillation, and the highest rates of chronic pulmonary disease (Figure 1, Panel A). Discharge medications were generally similar, with exception of less beta-blocker use and more calcium channel blocker use among those with EF ≥60% (Figure 1, Panel B). Discharge use of angiotensin receptor-neprilysin inhibitor and sodium glucose cotransporter-2 inhibitor therapies were each <1% in all groups. Hospital length of stay (median 4 days for each group) and in-hospital mortality (1.1–1.3%) were similar across groups, but rates of in-hospital acute respiratory failure were higher among patients with EF ≥60% (27% vs 230-25% for lower EF groups). Rates of 30-day and 12-month post-discharge clinical events were high irrespective of EF, without meaningful differences between groups (Figure 2).

Conclusion

In a contemporary real-world population of US patients hospitalized for HF with EF >40%, nearly half had an EF≥60%. While clinical profiles and discharge medications varied, post-discharge outcomes were similarly poor irrespective of EF. There remain important opportunities to improve the care and outcomes for patients with HF across the range of preserved ejection fraction.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): MyoKardia, Inc., a wholly owned subsidiary of Bristol Myers Squibb

Hallucinating symmetric protein assemblies

Deep learning generative approaches provide an opportunity to broadly explore protein structure space beyond the sequences and structures of natural proteins. Here we use deep network hallucination to generate a wide range of symmetric protein homo-oligomers given only a specification of the number of protomers and the protomer length. Crystal structures of 7 designs are very close to the computational models (median RMSD: 0.6 Å), as are 3 cryoEM structures of giant 10 nanometer rings with up to 1550 residues and C33 symmetry; all differ considerably from previously solved structures. Our results highlight the rich diversity of new protein structures that can be generated using deep learning, and pave the way for the design of increasingly complex components for nanomachines and biomaterials.

Four Dietary Patterns Observed Within an Elderly Asian Cohort

Objectives

Dietary indices are largely established in American and European populations to measure diet quality based on the predominant food type and quantity consumed in those countries. However, applying these dietary indices to Asian or South Asian populations is complicated by diverse region-specific eating patterns, cultures and food availability. A challenge exists to identify a more relevant dietary index that agrees with distinct dietary patterns within the multi-ethnic Singapore context and what measures of dietary quality are appropriate for the unique food availability. This study aimed to characterise dietary patterns and quality in older Singapore individuals.

Methods

Daily energy, food and nutrient intakes were estimated from 2 sets of 3-day food records (IRB-2018–01-011)using an in-house and public databases (Singapore Food and Nutrient Composition database, and Phenol-Explorer). Diet composition was categorised into 33 food groups and hierarchical clustering (Ward's method) was performed to characterise habitual dietary patterns based on energy intake. Adherence to Healthy Eating Index (HEI) and MEDI-LITE score were assessed. Differences in energy, food groups and nutrients were analysed using Kruskal-Wallis test and permutational multivariate analysis of variance.

Results

We observed four distinct dietary patterns- i) noodle/rice-based diet, ii) highly refined diet, iii) energy-dense diet and iv) high-fibre diet consumed by 21%, 27%, 36% and 16% of the cohort, respectively (66 ± 5 years old, 1640–1874 kcal/day). Two patterns comprised high intakes of refined foods (i.e., white rice, bread, noodles), differed substantially from Western or Mediterranean diets and were characterised by higher visceral trunk fat. In contrast, the high-fibre pattern had favourable cardiometabolic risk markers and reduced body fat. These dietary patterns did not fit with HEI and MEDI-LITE score, considering the preference for rice, noodles and spices in Asian diets, and reduced preference for cereals, olive oil and red wine (emphasised in MEDI-LITE score).

Conclusions

Studying populations exposed to regionally diverse food components challenge the relevance of applying previously established diet indices.

Funding Sources

This project was funded by LKC, CONIC and ARISE, NTU, and NTU-CSIRO Precision Health and Technologies Seed Fund.

Diet-Associated Variability in the Elderly Gut Microbiome

Objectives

The gut microbiome adapts to diet variations, which contribute to interindividual variability in human host metabolism and environmental factors. Microbe-diet studies have largely focused on specific diets (e.g., high-fat Western, Mediterranean-style) in American and European populations, with limited studies on compositionally-different diets in Asian populations. This study aimed to understand how diet composition modulates the gut microbiome in a Singapore multi-ethnic population.

Methods

We performed metagenomic sequencing of faecal samples from 118 healthy individuals (66 ± 5 years old), and estimated their food and nutrient intakes from 3-day food records (IRB-2018–01-011). Multivariate associations between microbial composition (species) and functional potentials (pathways, enzymes) with diet variables were analysed using linear mixed models with Benjamin-Hochberg correction, and adjusted for age, sex, BMI, physical activity, energy intake and medications. Permutational multivariate analysis of variance, based on Bray-Curtis dissimilarity metric, was applied to quantify variance within the microbiome that is explained by diet variables.

Results

We found gut microbes (5 phyla, >100 species) significantly associated with one of four observed dietary patterns (P < 0.05), various food groups and nutrients (q < 0.1). The microbiome was driven by intake and diversity of plant-based foods. Parabacteroides and Blautia species, and microbial metabolism of energy, carbohydrate and glycan were associated with increased intakes of white rice and noodles. Prevotella species were associated with increased intakes of legumes, wholegrains and plant protein. Lachnospira, Clostridiumand Fournierella species, and microbial lipid metabolism were associated with energy-dense diet. Lastly, Firmicutes, Eubacterium, Ruminococcus and Roseburia species as well as microbial regulation of amino acid metabolism were associated with high-fibre diet.

Conclusions

This study provides new insights into gut microbial variations by distinct Asian dietary composition, supporting the feasibility of intervening habitual diets to reshape the gut microbiome for better health.

Funding Sources

This project was funded by LKC, CONIC and ARISE, NTU, and NTU-CSIRO Precision Health and Technologies Seed Fund.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulants versus warfarin among nonvalvular atrial fibrillation patients with prior bleeding events

Background

Patients with non-valvular atrial fibrillation (NVAF) use oral anticoagulants such as warfarin or non-vitamin K antagonist oral anticoagulants (NOACs) for the prevention of stroke. However, the effectiveness and safety of warfarin and NOACs can be influenced by pre-existing patient comorbidities, such as a history of bleeding, and limited evidence are available to inform the choice of the most appropriate anticoagulant treatment for NVAF patients with bleeding history.

Purpose

This study used five United States insurance claims databases to evaluate the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) among NVAF patients with prior bleeding events who were prescribed NOACs versus warfarin.

Methods

This retrospective observational study used data from 5 databases (CMS Medicare and four commercial databases, covering &gt;180 million beneficiaries) to select adult NVAF patients who were treated with apixaban, dabigatran, rivaroxaban, or warfarin (01JAN2013–30JUN2019). Patients were required to have a prior bleeding event, defined as a hospitalization with a diagnosis for intracranial hemorrhage (ICH), gastrointestinal (GI) bleeding or bleeding at other key sites prior to or during the index treatment episode. In each database, three 1:1 NOAC-warfarin propensity-score-matched (PSM) cohorts were created before pooling the results. Outcome measures were time to first stroke/SE, (ischemic stroke, hemorrhagic stroke, and SE), and time to first MB (gastrointestinal bleeding, intracranial hemorrhage, and MB at other key sites), and were measured from the index treatment episode to treatment discontinuation or switch, death, health plan disenrollment, or end of study period. Hazard ratios of S/SE and MB were calculated using Cox proportional hazards models.

Results

Among the eligible NVAF population, 8.2% of patients had a prior bleeding event (ICH: 12.3%; GI: 60.7%; Other: 27.0%). After PSM, a total of 43,092 apixaban-warfarin, 11,295 dabigatran-warfarin, and 32,723 rivaroxaban-warfarin patient pairs with prior bleeding were selected with a mean follow-up of 8–9 months. Apixaban and rivaroxaban were associated with a lower risk of S/SE, and dabigatran was associated with a similar risk of S/SE when compared to warfarin. Apixaban and dabigatran were associated with a lower risk of MB, and rivaroxaban was associated with a similar risk of MB, compared to warfarin (Figure).

Conclusion

Among NVAF patients with prior bleeding events, NOACs were associated with varying risks of S/SE and MB compared to warfarin. These results can help inform healthcare providers concerning the impact of OAC treatment in NVAF patients with history of bleeding.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer, Inc.

Time at home among nonvalvular atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants: an ARISTOPHANES analysis

Background

Patient-centered outcomes, such as home time, are becoming increasingly important quality-of-life measures. There are limited data on the impact of oral anticoagulants (OACs) on home time among patients with non-valvular atrial fibrillation.

Purpose

This analysis, based on the previously published ARISTOPHANES study, used five US insurance claims databases (CMS Medicare and four commercial databases) to compare home time among NVAF patients who were prescribed non-vitamin K antagonist OACs (NOACs).

Methods

Adult NVAF patients who were newly prescribed apixaban, dabigatran, or rivaroxaban (01JAN2013–30SEP2015) were selected. Time at home was calculated as the number of days from the index date (NOAC prescription) without any of the following: an inpatient, skilled nursing facility (SNF) or nursing facility, hospice, or inpatient rehabilitation facility admission. Time at home and without external AF-related care was defined as days from index date without any events from the home time endpoint or any days with a claim for bleeding, stroke/systemic embolism (S/SE), AF, or an INR test. Time at home and without external AF-related care were measured during the 180 days of follow-up; patients were required to have been alive and have 180 days of follow-up post index. In each database, three 1:1 NOAC-NOAC propensity-score-matched (PSM) cohorts were created before combining the databases. For each NOAC-NOAC matched cohort, Poisson regression was conducted to compare time at home and time at home without external AF-related care.

Results

After PSM, 37,314 apixaban-dabigatran, 107,236 apixaban-rivaroxaban, and 37,693 rivaroxaban-dabigatran patient pairs were created of which 37–44% had 180 days of follow-up available. Across the NOAC cohorts, approximately 21–25% of patients had an admission to a hospital, SNF, nursing facility, rehabilitation center, or hospice during the 180-day follow-up. The time at home was generally consistent between the NOAC cohorts (177 days); however, apixaban patients had 0.5 more days at home compared to rivaroxaban patients. Across all NOAC cohorts, 7–8% had a claim for a S/SE, 11–15% had a claim for bleeding, and 15–22% had an INR test, while 87–89% of all patients had an AF-claim during the 180-day follow-up. Patients prescribed apixaban had 1 more day at home without external AF-related care compared to dabigatran, and 1.5 more days at home without external AF-related care compared to rivaroxaban. Dabigatran had &lt;1 more day at home without external AF-related care compared to rivaroxaban.

Conclusion

Among NVAF patients treated with NOACs, there were small differences in the time at home and time at home without external AF-related care during the first 6 months of NOAC treatment. As NVAF is a chronic condition, it is important to understand the impact of NOAC treatment on these patient-centered outcomes.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer Inc.

Time at home among nonvalvular atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants versus warfarin

Background

Clinical trials and real-world database studies have shown the benefits of non-vitamin K antagonist oral anticoagulants (NOACs) compared to warfarin; however, measures of functional outcomes are critical in evaluating a patient's quality of life. Previous measures of time spent out of hospital in a home setting and time spent receiving disease-related care among non-valvular atrial fibrillation (NVAF) patients are lacking in the current literature.

Purpose

This analysis was based on the previously published ARISTOPHANES study, and used multiple data sources to evaluate the amount of time spent at a patient's home among NVAF patients who were prescribed NOACs versus warfarin.

Methods

This retrospective observational study used US data from CMS Medicare and four commercial databases to select adult NVAF patients who initiated apixaban, dabigatran, rivaroxaban, or warfarin (01JAN2013–30SEP2015). Time at home and time at home without external AF-related care were measured during the 180 days after the index date (OAC prescription). Time at home was defined as days from index date without any of the following: an inpatient, skilled nursing facility or nursing facility, hospice, or inpatient rehabilitation facility admission. Time at home and without external AF-related care was defined as days away from home and days with a claim for bleeding, stroke/systemic embolism, AF, or an INR test. Each day a claim was observed was counted as one day. In each database, three 1:1 NOAC-warfarin propensity-score-matched (PSM) cohorts were created before pooling the results. After PSM, a subgroup of patients who were alive and had ≥180 days of follow-up was created. Poisson regression was conducted in each NOAC-warfarin matched cohort to compare time at home and time at home without external AF-related care.

Results

After matching, a total of 100,977 apixaban-warfarin, 36,990 dabigatran-warfarin, and 125,068 rivaroxaban-warfarin patient pairs were selected. Of those patients, 38–46% had 180 days of follow-up available. Across treatment cohorts, approximately 75% of patients were at home for the 180-day follow-up. Apixaban, dabigatran, and rivaroxaban patients had 1.3, 0.9, and 0.8 more days at home, respectively, compared to warfarin patients. Patients treated with apixaban had 13.4 more days at home without AF-related care compared to warfarin, while dabigatran and rivaroxaban had 11.6 and 11.7 more days at home without AF-related care compared to warfarin. A greater proportion of warfarin patients than NOAC patients had an INR test (81–82% vs 14–21%), and days with INR testing were the main driver for external AF-related care for warfarin patients.

Conclusion

Among NVAF patients treated with OACs, NOACs were associated with a longer time at home and time at home without external AF-related care compared to warfarin. These results can help inform healthcare providers and patients regarding the impact of NOAC treatment in NVAF patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer Inc.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulants among nonvalvular atrial fibrillation patients with prior bleeding events

Background

Among non-valvular atrial fibrillation (NVAF) patients with a history of bleeding, there is a reluctance to use oral anticoagulants (OACs) due to concerns about the risk of bleeding associated with OACs. However, lack of OAC treatments for NVAF patients is associated with a higher risk of stroke and mortality. Non-vitamin K antagonist OAC (NOACs) have been approved for the prevention of stroke in NVAF patients. There are limited data comparing the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) between patients prescribed NOACs and with a history of bleeding.

Purpose

This study used multiple United States data sources to evaluate the risk of S/SE and MB among NVAF patients with prior bleeding events who were prescribed NOACs.

Methods

This retrospective observational study used data from CMS Medicare and four commercial databases–covering &gt;180 million beneficiaries. The study selected adult NVAF patients who were prescribed apixaban, dabigatran, or rivaroxaban (01JAN2013–30JUN2019) and had a prior bleeding event which was defined as a hospitalization with a bleeding diagnosis (intracranial hemorrhage [ICH], gastrointestinal [GI] bleeding, or other bleeding sites) prior to or during the index treatment episode. After 1:1 propensity-score-matched (PSM) in each database between NOACs (apixaban-dabigatran, apixaban-rivaroxaban, and dabigatran-rivaroxaban), the resulting patient records were pooled. S/SE and MB (identified by inpatient claims) were captured during the follow-up period, which was defined as the time between the day after the index treatment date and treatment discontinuation or switch, death, end of study period, or end of medical and pharmacy enrollment. Hazard ratios of S/SE and MB were calculated using Cox proportional hazards models.

Results

Of the overall NVAF population treated with NOACs, 6.2% had a prior bleeding event (ICH: 13.5%; GI: 61.8%; Other: 24.6%). After PSM, a total of 11,106 apixaban-dabigatran, 30,665 apixaban-rivaroxaban, and 11,148 dabigatran-rivaroxaban pairs were matched. Apixaban was associated with a lower risk of S/SE compared to dabigatran and rivaroxaban, and dabigatran was associated with a similar risk of S/SE compared to rivaroxaban. Apixaban was associated with a lower risk of MB compared to dabigatran and rivaroxaban, and dabigatran was associated with a lower risk of MB compared to rivaroxaban (Figure).

Conclusions

In this subgroup of NVAF patients with a history of bleeding, apixaban was associated with a lower risk of S/SE and MB compared to dabigatran and rivaroxaban. Dabigatran was associated with a lower risk of MB compared to rivaroxaban. These results are informative for understanding the impact of NOAC treatment in NVAF patients with prior bleeding events.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer, Inc.

Encapsulation of bacterial cells in cytoprotective ZIF-90 crystals as living composites

Exploiting metal-organic frameworks (MOFs) as selectively permeable shelters for encapsulating engineered cells to form hybrid living materials has attracted increasing attention in recent years. Optimizing the synthesis process to improve encapsulation efficiency (EE) is critical for further technological development and applications. Here, using ZIF-90 and genetically engineered Escherichia coli (E. coli) as a demo, we fabricated E. coli@ZIF-90 living composites in which E. coli cells were encapsulated in ZIF-90 crystals. We illustrated that ZIF-90 could serve as a protective porous cage for cells to shield against toxic bactericides including benzaldehyde, cinnamaldehyde, and kanamycin. Notably, the E. coli cells remained alive and could self-reproduce after removing the ZIF-90 crystal cages in ethylenediaminetetraacetic acid, suggesting a feasible route for protecting and prolonging the lifespan of bacterial cells. Moreover, an aqueous multiple-step deposition approach was developed to improve EE of the E. coli@ZIF-90 composites: the EE increased to 61.9 ± 5.2%, in contrast with the efficiency of the traditional method (21.3 ± 4.4%) prepared with PBS buffer. In short, we develop a simple yet viable strategy to manufacture MOF-based living hybrid materials that promise new applications across diverse fields.

P4794Comparative effectiveness and safety of non-VKA oral anticoagulants versus warfarin in non-valvular atrial fibrillation patients with differential treatment duration: an ARISTOPHANES study analysis

Background

The ARISTOPHANES (Anticoagulants for Reduction In STroke: Observational Pooled analysis on Health outcomes ANd Experience of patientS) study showed that non-vitamin K antagonist oral anticoagulants (NOACs) were associated with lower risks of stroke/systemic embolism (S/SE) and variable comparative risks of major bleeding (MB) versus warfarin.

Purpose

To assess long-term use of non-VKA oral anticoagulants (NOACs) vs. warfarin in

ARISTOPHANES by evaluating the risk of S/SE and MB among non-valvular atrial fibrillation (NVAF) patients by duration of treatment (<1 and ≥1 year).

Methods

In the ARISTOPHANES study, NVAF patients initiating apixaban, dabigatran, rivaroxaban, or warfarin from 01/01/2013–09/30/2015 were identified from the CMS Medicare data and four US commercial claims databases, covering >180 million beneficiaries annually (∼56% of US population). After 1:1 propensity score matching (PSM) in each database between NOACs and warfarin (apixaban-warfarin, dabigatran-warfarin, and rivaroxaban-warfarin), the resulting patient records were pooled. Treatment duration was defined as time between the day after the treatment index date and discontinuation (30 days after a 30-day gap in the prescription), treatment switch, death, end of study period, or end of continuous medical and pharmacy enrollment, whichever occurred first. Matched patients with observed treatment duration <1 or ≥1 year were separately examined. Cox models were used to estimate hazard ratios of S/SE and MB (identified by inpatient claims) during observed treatment duration.

Results

The mean treatment duration for patients with shorter (<1 year) vs longer (≥1 year) duration was 4–5 months vs 18–21 months across the three matched cohorts. All the matched baseline variables remained balanced. The incidence rates of S/SE and MB and the proportion of patients with treatment discontinuation were higher in patients with shorter treatment duration. Regardless of treatment duration, apixaban patients had a lower risk of S/SE and MB versus warfarin; dabigatran patients had a lower risk of MB versus warfarin; and rivaroxaban patients had a lower risk of S/SE versus warfarin. Compared to warfarin patients, dabigatran patients with treatment duration <1 year had a similar risk of S/SE, while those with treatment duration ≥1 year had lower S/SE risk; rivaroxaban patients with treatment duration <1 year had a higher risk of MB, while those with treatment duration ≥1 year had similar MB risk.

Conclusions

Among NVAF patients with duration of treatment <1 and ≥1 year in the ARISTOPHANES study, apixaban and rivaroxaban were associated with lower risk of S/SE, while apixaban and dabigatran were associated with lower risk of MB, compared to warfarin. These findings indicate varying long-term effectiveness and safety outcomes between NOACs and warfarin.

Acknowledgement/Funding

This study was funded by Bristol-Myers Squibb and Pfizer Inc.

P4768Comparative effectiveness and safety between non-VKA oral anticoagulants in non-valvular atrial fibrillation patients with differential duration of treatment: an analysis of the ARISTOPHANES study

Background

The ARISTOPHANES (Anticoagulants for Reduction In STroke: Observational Pooled analysis on Health outcomes ANd Experience of patientS) study showed that apixaban was associated with lower risks of stroke/systemic embolism (S/SE) and major bleeding (MB) versus dabigatran and rivaroxaban; dabigatran was associated with similar risk of S/SE and lower risk of MB compared to rivaroxaban.

Purpose

To assess long-term use of non-VKA oral anticoagulants (NOACs) in ARISTOPHANES by evaluating the risk of S/SE and MB among non-valvular atrial fibrillation (NVAF) patients receiving different NOACs by duration of treatment (<1 and ≥1 year).

Methods

In the ARISTOPHANES study, NVAF patients initiating apixaban, dabigatran, and rivaroxaban from 01/01/2013–09/30/2015 were identified from the CMS Medicare data and four US commercial claims databases, covering >180 million beneficiaries annually (∼56% of US population). After 1:1 propensity score matching (PSM) in each database between NOACs (apixaban-dabigatran, apixaban-dabigatran, and dabigatran-rivaroxaban), the resulting patient records were pooled. Treatment duration was defined as time between the day after the index treatment date and discontinuation (defined using a 30-day gap in the prescription), treatment switch, death, end of study period, or end of continuous medical and pharmacy enrollment, whichever occurred first. Matched patients with observed treatment duration <1 or ≥1 year were separately examined. Cox models were used to estimate hazard ratios of S/SE and MB (identified by inpatient claims) during observed treatment duration. S/SE included ischemic stroke, hemorrhagic stroke, and SE; MB included gastrointestinal (GI) bleeding, intracranial hemorrhage (ICH), and other MB.

Results

The mean treatment duration for patients with shorter (<1 year) vs longer (≥1 year) duration was ∼4 months vs 18–21 months across the three matched cohorts. All the matched baseline variables remained balanced. The incidence rates of S/SE and MB and the proportion of patients with treatment discontinuation were higher in patients with shorter treatment duration. Regardless of treatment duration, apixaban and dabigatran had a lower risk of MB versus rivaroxaban; and dabigatran had a similar risk of S/SE versus rivaroxaban. Compared to dabigatran patients, apixaban patients with treatment duration <1 year had a lower risk of S/SE and MB, while those with treatment duration ≥1 year had similar S/SE and MB risk. Compared to rivaroxaban patients, apixaban patients with treatment duration <1 year had a lower risk of S/SE, while those with treatment duration ≥1 year had similar S/SE risk.

Conclusions

Across NVAF patients with duration of treatment <1 and ≥1 year in the ARISTOPHANES study, both apixaban and dabigatran were associated with a lower risk of MB compared to rivaroxaban. These findings indicate varying long-term safety outcomes among different NOACs.

Acknowledgement/Funding

This study was funded by Bristol-Myers Squibb and Pfizer Inc.

P3346Validation of obesity coding among newly-treated nonvalvular atrial fibrillation patients using an integrated electronic medical record and claims database

Background

Obesity is prevalent among patients with non-valvular atrial fibrillation (NVAF). Administrative claims databases offer the opportunity to evaluate obesity and morbid obesity in this patient population. However, there is limited information about the use and accuracy of diagnosis codes in claims data to identify obesity and morbid obesity among patients with NVAF.

Purpose

To evaluate the use and accuracy of diagnosis codes in claims data for identifying obesity and morbid obesity among newly-treated NVAF patients using a large geographically-diverse US database.

Methods

This retrospective study used Optum's de-identified integrated electronic medical record (EMR) and claims database (1/1/2013–3/31/2018). Adult (≥18 years) patients with ≥1 claim for an oral anticoagulant (OAC) from 1/1/2014–9/30/2017 were identified (treatment date as index date). Patients were required to have ≥1 atrial fibrillation diagnosis prior to the index date and were excluded if they had evidence of OAC use or valvular disease during the 12 months prior to the index date. Patients were required to have ≥12 months of continuous enrollment prior to and ≥6 months after the index date as well as ≥1 BMI measurement in the EMR data during the 6 months before or after the index date. Based on the World Health Organization's definition, patients were classified as obese if their BMI was ≥30 kg/m2 and morbidly obese if their BMI was ≥40 kg/m2. Sensitivity, specificity, and positive predictive value (PPV) were calculated to assess the accuracy of diagnosis codes for obesity (ICD-9 diagnosis codes: 278.00, 278.01, 278.03, V85.30-V85.39, V85.41-V85.45; ICD-10 diagnosis codes: E66.01, E66.09, E66.2, E66.8, E66.9, Z68.30-Z68.39, Z68.41-Z68.45) and morbid obesity (ICD-9 diagnosis codes: 278.01, V85.41-V85.45; ICD-10 diagnosis codes: E66.01, E66.2, Z68.41-Z68.45) commonly used in claims database research.

Results

There were 7,501 patients included in the newly-treated NVAF cohort (mean [±SD] age=72.4 [±10.7] years, 55% male, 90% white, and mean [±SD] Quan-Charlson Comorbidity Index =2.10 [±2.08]). Forty-six percent of these patients had BMI≥30 kg/m2, of whom about one-quarter (11% of the overall sample) had a BMI≥40 kg/m2. In contrast, 25% and 10% of patients had a diagnosis code for obesity or morbid obesity, respectively. For obesity diagnosis codes, sensitivity, specificity, and PPV were 49% (95% CI: 47%-50%), 95% (95%-96%), and 90% (88%-91%), respectively. For morbid obesity diagnosis codes, sensitivity, specificity, and PPV were 63% (59%-63%), 96% (96%-97%) and 68% (64%-71%), respectively.

Conclusion

Among newly-treated NVAF patients, obesity diagnosis codes in the claims database had high PPV, high specificity, and modest sensitivity. Morbid obesity diagnosis codes also had high specificity but modest PPV and sensitivity. These findings have implications for both case selection and control for obesity as a confounder in observational studies using a claims database.

Acknowledgement/Funding

The funding for the research project was provided by Pfizer Inc.

The current role for clinical and renal histological findings as predictor for outcome in Australian patients with lupus nephritis

Objectives To investigate the current demographic, clinical and histological characteristics of patients with lupus nephritis (LN) in Western Australia (WA) with regards to their predictive value for patient and renal outcome. Methods Retrospective study of adult systemic lupus erythematosus (SLE) patients with a first renal biopsy demonstrating LN between 1997 and 2017 at a metropolitan tertiary hospital in WA. Clinical data were collected at baseline and last follow-up with renal biopsy findings classified by International Society of Nephrology (ISN) criteria. Annual incidence rates (AIRs)/100,000, Kaplan-Meyer curves and Cox regression hazard ratio for independent predictors for patient and renal survival were applied. Results The AIR was 3.3, 3.1 and 0.4 for Asian ( n = 29), Indigenous Australian (IA) ( n = 11) and Caucasian ( n = 43) patients, respectively ( p < 0.01). There was no significant subgroup difference regarding ISN class (proliferative 66%, membranous 19%, mesangial 15%), levels of proteinuria (median PCR 300 mg/mmol) or frequency of raised creatinine (31%), anti-dsDNA antibody (89%) or hypocomplementaemia (88%). Treatment included corticosteroids (91%), cyclophosphamide (30%), mycophenolate (67%) and antihypertensive drugs (67%). Five- (81%) and 10-year (70%) survival was lower for IAs than for Caucasians and Asians (95% each at both time points) ( p = 0.016). Five- and 10-year renal survival (endpoint renal replacement therapy (RRT)) was 86% and 64% for IA vs 100% for Asian, 100% and 96% for Caucasian patients ( p = 0.02). IA background was the only independent predictor for poor patient survival and together with male gender also for renal survival. Only 25% of all patients remained free of any organ damage with non-renal damage observed in 53% of survivors. Conclusions LN incidence in WA was 0.75/100,000 with the lowest rate observed in Caucasians. While Asian patients have the same favourable outlook as Caucasians, the outcome is much bleaker for IA patients. Other clinical and histological findings did not predict outcomes, and importantly more than half of all surviving patients accrued non-renal damage.

Assessment of Tocilizumab (Anti-Interleukin-6 Receptor Monoclonal) as a Potential Treatment for Chronic Antibody-Mediated Rejection and Transplant Glomerulopathy in HLA-Sensitized Renal Allograft Recipients

Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.

Risk factors associated with in-hospital mortality in elderly patients admitted to a regional trauma center after sustaining a fall

BACKGROUND AND AIMS

Falls are a significant cause of mortality in the elderly patients. Despite this, the literature on in-hospital mortality related to elderly falls remains sparse. Our study aims to determine the risk factors associated with in-hospital mortality in elderly patients admitted to a regional trauma center after sustaining a fall.

METHODS

All elderly case records with fall-related injuries between 2003 and 2013 were retrospectively analyzed for demographic characteristics, injury severities, comorbidity factors and clinical outcomes. Logistic regression analysis was used to examine the risk factors associated with in-hospital mortality.

RESULTS

In total, 1026 elderly patients with fall-related injuries were included in the study. The average age of patients was 80.94 ± 8.16 years. Seventy seven percent of the patients had at least one comorbid condition. Majority of the falls occurred at home. More than half of the patients fell from ground level. Overall, the in-hospital mortality rate was 16 %. Head injury constituted the most common injury sustained in patients who died (77 %). In addition to age, ISS, GCS, ICU admission and anemia were significantly (P < 0.05) associated with in-hospital deaths in elderly fall patients.

CONCLUSION

Ground-level falls in the elderly can be devastating and carry a significant mortality rate. Elderly patients with anemia were two times more likely to die in the hospital after sustaining a fall in our study population. Increased focus on anemia which is often underappreciated in elderly fall patients can be beneficial in improving outcomes and reducing in-hospital mortality.

High Fat Diets Induce Colonic Epithelial Cell Stress and Inflammation that is Reversed by IL-22

Prolonged high fat diets (HFD) induce low-grade chronic intestinal inflammation in mice, and diets high in saturated fat are a risk factor for the development of human inflammatory bowel diseases. We hypothesized that HFD-induced endoplasmic reticulum (ER)/oxidative stress occur in intestinal secretory goblet cells, triggering inflammatory signaling and reducing synthesis/secretion of proteins that form the protective mucus barrier. In cultured intestinal cells non-esterified long-chain saturated fatty acids directly increased oxidative/ER stress leading to protein misfolding. A prolonged HFD elevated the intestinal inflammatory cytokine signature, alongside compromised mucosal barrier integrity with a decrease in goblet cell differentiation and Muc2, a loss in the tight junction protein, claudin-1 and increased serum endotoxin levels. In Winnie mice, that develop spontaneous colitis, HFD-feeding increased ER stress, further compromised the mucosal barrier and increased the severity of colitis. In obese mice IL-22 reduced ER/oxidative stress and improved the integrity of the mucosal barrier, and reversed microbial changes associated with obesity with an increase in Akkermansia muciniphila. Consistent with epidemiological studies, our experiments suggest that HFDs are likely to impair intestinal barrier function, particularly in early life, which partially involves direct effects of free-fatty acids on intestinal cells, and this can be reversed by IL-22 therapy.

Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing

Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach.

Peripheral immunomodulation with ginsenoside Rg1 ameliorates neuroinflammation-induced behavioral deficits in rats

Neuroinflammatory disturbances have been closely associated with depression and many other neuropsychiatric diseases. Although targeting neuroinflammatory mediators with centrally acting drugs has shown certain promise, its translation is faced with several challenges especially drug delivery and safety concerns. Here, we report that neuroinflammation-induced behavioral abnormality could be effectively attenuated with immunomodulatory agents that need not to gain brain penetration. In a rat model with intracerebral lipopolysaccharide (LPS) challenge, we validated that ginsenoside Rg1 (Rg1), a well-established anti-inflammatory agent, was unable to produce a direct action in the brain. Interestingly, peripherally restricted Rg1 could effectively attenuate the weight loss, anorexic- and depressive-like behavior as well as neurochemical disturbances associated with central LPS challenge. Biochemical assay of neuroimmune mediators in the periphery revealed that Rg1 could mitigate the deregulation of the hypothalamic-pituitary-adrenal axis and selectively blunt the increase in circulating interleukin-6 levels. Furthermore, these peripheral regulatory effects were accompanied by dampened microglial activation, mitigated expression of pro-inflammatory mediators and neurotoxic species in the central compartment. Taken together, our work suggested that targeting the peripheral immune system may serve as a novel therapeutic approach to neuroinflammation-induced neuropsychiatric disorders. Moreover, our findings provided the rationale for employing peripherally active agents like Rg1 to combat mental disturbances.

Simple prescribing errors and allergy documentation in medical hospital admissions in Australia and New Zealand

This study aimed to quantify and compare the prevalence of simple prescribing errors made by clinicians in the first 24 hours of a general medical patient's hospital admission. Four public or private acute care hospitals across Australia and New Zealand each audited 200 patients' drug charts. Patient demographics, pharmacist review and pre-defined prescribing errors were recorded. At least one simple error was present on the medication charts of 672/715 patients, with a linear relationship between the number of medications prescribed and the number of errors (r = 0.571, p < 0.001). The four sites differed significantly in the prevalence of different types of simple prescribing errors. Pharmacists were more likely to review patients aged > or = 75 years (39.9% vs 26.0%; p < 0.001) and those with more than 10 drug prescriptions (39.4% vs 25.7%; p < 0.001). Patients reviewed by a pharmacist were less likely to have inadequate documentation of allergies (13.5% vs 29.4%, p < 0.001). Simple prescribing errors are common, although their nature differs from site to site. Clinical pharmacists target patients with the most complex health situations, and their involvement leads to improved documentation.

Is a routine ultrasound in the third trimester justified? Additional fetal anomalies diagnosed after two previous unremarkable ultrasound examinations

PURPOSE

The detection of fetal structural abnormalities is a routine part of antenatal care. Ultrasound examination policies vary among European countries. An additional ultrasound for fetal structural anomalies in the 3 rd trimester seems important for many reasons. Some abnormalities develop or first become apparent later in pregnancy. The aim of the study was to analyze the rate of previously undetected structural abnormalities in the 3 rd trimester.

MATERIALS AND METHODS

8074 fetuses were examined in this prospective study between 1998 and 2008. All received an examination at 11 - 14 weeks and 79 % (6378 / 8074) of these fetuses also received an ultrasound at 20 - 24 weeks. If both of the examinations did not detect structural abnormalities, the fetuses were included in the study group and received an ultrasound at 28 - 32 weeks (n = 5044). New structural abnormalities in the 3 rd trimester were analyzed. The outcome was available in 96 % of the cases.

RESULTS

The overall incidence of fetal malformations was 3.6 % (n = 289), of which 40 % (116 / 289) were diagnosed at 11 - 14 weeks. The following 2nd trimester scan revealed 102 (35 %) new fetal malformations. An additional 44 (15 %) structural abnormalities were found in the 3 rd trimester. These were mainly abnormalities of the urogenital system (n = 18). There were also anomalies of the cardiovascular system (n = 9), the gastrointestinal system (n = 6) and the central nervous system (n = 4). One of the cases had a previously undiagnosed abnormal karyotype.

CONCLUSION

The ultrasound examination in the 3 rd trimester is of additional benefit and can detect previously unknown structural abnormalities. These findings are relevant for perinatal management and postnatal follow-up.

Collagen-induced arthritis

Collagen-induced arthritis (CIA) is an experimental autoimmune disease that can be elicited in susceptible strains of rodents (rat and mouse) and nonhuman primates by immunization with type II collagen (CII), the major constituent protein of articular cartilage. Because of the important similarities between CIA and rheumatoid arthritis, this experimental model of autoimmune arthritis has been the subject of extensive investigation in several laboratories. Protocols for CIA are described in this unit for both the mouse model and the rat model. In addition, protocols are included for the purification of CII from bovine articular joints and chicken sternums, for the purification of collagen a1(II) chains, and for the purification of fragments of these chains following cyanogen bromide (CNBr) digestion. The preparation of CII is a time-consuming procedure but is usually required because of the scarcity and expense of commercial sources of purified native CII. In addition, support protocols are provided for assessing the severity of inflammation following CIA and for measuring B and T cell responses to CII.

[Prenatal diagnosis of diastematomyelia and tethered cord - a case report and review of the literature]

Diastematomyelia is a rare form of occult spinal dysraphism. It is characterized by longitudinal clefting and separating of the spinal cord by a bony or fibrous spur. Diastematomyelia is associated with other anomalies, i. e. spina bifida, scoliosis, visceral malformations or anomalies of the overlying skin. Prenatal diagnosis is based on fetal ultrasound supplemented by fetal MRI. We present a case of diastematomyelia and prenatal diagnosis in the 23rd gestational week using routine ultrasound scanning and confirmation by fetal MRI. After vaginal delivery at term, the child's development is normal. Prenatal diagnosis of isolated diastematomyelia is challenging. Management and prognosis are still controversial as only few cases have been reported. Affected fetuses might benefit from early diagnosis enabling surgical intervention before the development of neurological sequelae.

Haploinsufficiency of CDK4 prevents hepatocarcinogenesis in mice deficient in ELF, a mediator of TGF-beta signaling

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Background: The transforming growth factor-β (TGF-β) has a dual role in cancer, but in the prevention of tumorigenesis, TGF-β signaling inhibits cell cycle progression through an increase in cell cycle inhibitors and decrease in cell cycle activators. The adaptor protein embryonic liver fodrin (ELF) is crucial for normal TGF-β signaling. ELF facilitates the association and nuclear translocation of the TGF-β signaling proteins, Smad3 and Smad4. We have demonstrated that elf± mice develop hepatocellular cancers (HCC) spontaneously within 12 months. We have also shown that most human HCCs demonstrate a decreased expression of ELF. Our goal was to assess the interaction between ELF and cyclin dependent kinase 4 (CDK4), which is overexpressed in most human cancers. Methods: We compared the expression of CDK4 and ELF by immunohistochemistry and analyzed the interaction between CDK4 and ELF, in vitro by immunoprecitpitation and western blot. Finally, we assessed the development of HCC in intercrossed elf± and CDK4+/neo mice. Results: CDK4 and ELF expression are inversely correlated in HCCs from elf± mice. Furthermore, ELF interacts with CDK4 by forming a complex that includes Smad3 in COS-7 and HepG2 cells. ELF is phosphorylated upon overexpression of CDK4, revealing a possible mechanism by which CDK4 may inhibit ELF-dependent TGF-β signaling. To further assess whether the development of HCC in elf± mice is dependent upon CDK4 expression, we have intercrossed elf± and CDK4+/neo mice. At 12 months, only 17% of the elf±/CDK4+/neo mice developed HCC, compared to 40% of our historical control elf± mice. This initial data strongly suggests that haploinsufficiency of CDK4 can prevent the HCCs seen in elf± mice, and provides the genetic foundation for further exploring the benefits of specific inhibitors of CDK4 in the treatment of HCC. Conclusions: These results demonstrate the molecular interactions between ELF and CDK4, and suggest a mechanism by which CDK4 may render cells unresponsive to the growth inhibitory effects of TGF-β signaling. Furthermore, haploinsufficiency of CDK4 prevents the formation of HCC, and thus targeted-inhibition of CDK4 activity may be a logical treatment for HCC in humans.

No significant financial relationships to disclose.

Complete genome sequence of the genetically tractable hydrogenotrophic methanogen Methanococcus maripaludis

The genome sequence of the genetically tractable, mesophilic, hydrogenotrophic methanogen Methanococcus maripaludis contains 1,722 protein-coding genes in a single circular chromosome of 1,661,137 bp. Of the protein-coding genes (open reading frames [ORFs]), 44% were assigned a function, 48% were conserved but had unknown or uncertain functions, and 7.5% (129 ORFs) were unique to M. maripaludis. Of the unique ORFs, 27 were confirmed to encode proteins by the mass spectrometric identification of unique peptides. Genes for most known functions and pathways were identified. For example, a full complement of hydrogenases and methanogenesis enzymes was identified, including eight selenocysteine-containing proteins, with each being paralogous to a cysteine-containing counterpart. At least 59 proteins were predicted to contain iron-sulfur centers, including ferredoxins, polyferredoxins, and subunits of enzymes with various redox functions. Unusual features included the absence of a Cdc6 homolog, implying a variation in replication initiation, and the presence of a bacterial-like RNase HI as well as an RNase HII typical of the Archaea. The presence of alanine dehydrogenase and alanine racemase, which are uniquely present among the Archaea, explained the ability of the organism to use L- and D-alanine as nitrogen sources. Features that contrasted with the related organism Methanocaldococcus jannaschii included the absence of inteins, even though close homologs of most intein-containing proteins were encoded. Although two-thirds of the ORFs had their highest Blastp hits in Methanocaldococcus jannaschii, lateral gene transfer or gene loss has apparently resulted in genes, which are often clustered, with top Blastp hits in more distantly related groups.

Celiac sprue and ulcerative colitis in three South Asian women

The association of celiac disease and inflammatory bowel disease has not been described in females of South Asian descent. We report three women, aged 33, 43 and 46 years, of South Asian origin, with both ulcerative colitis and celiac disease.

Both maternal and fetal cell-free DNA in plasma fluctuate

Elevations in the concentration of cell-free fetal DNA in maternal plasma have recently been determined in various pregnancy-related disorders, including preeclampsia, preterm labor, and polyhydramnios. In addition, almost 2-fold increments in cell-free fetal DNA levels have been recorded in pregnancies with certain aneuploid fetuses, in particular trisomy 21. These findings have led to the speculation that quantitative assessment of circulatory fetal DNA may be useful in the noninvasive prenatal diagnosis of certain fetal genetic constellations or pregnancy-related disorders. A premise for any quantitative analysis is that the quantity of the analyte being assayed does not vary greatly over time. As this aspect has not been examined for circulatory DNA levels, we examined these in normal healthy individuals as well as in pregnant women. Our data indicate that severalfold alterations in circulatory DNA amounts do occur over short periods of time. Of particular note is that we observed almost 2-fold variations in free fetal DNA levels over a period of 3 days, which are in a similar range to the elevations noted in aneuploid pregnancies. Our results, therefore, imply that caution should be used when using small increments in circulatory fetal DNA concentrations for potential diagnostic applications.

Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice

Gastrointestinal (GI) tract damage by chemotherapy or radiation limits their efficacy in cancer treatment. Radiation has been postulated to target epithelial stem cells within the crypts of Lieberkühn to initiate the lethal GI syndrome. Here, we show in mouse models that microvascular endothelial apoptosis is the primary lesion leading to stem cell dysfunction. Radiation-induced crypt damage, organ failure, and death from the GI syndrome were prevented when endothelial apoptosis was inhibited pharmacologically by intravenous basic fibroblast growth factor (bFGF) or genetically by deletion of the acid sphingomyelinase gene. Endothelial, but not crypt, cells express FGF receptor transcripts, suggesting that the endothelial lesion occurs before crypt stem cell damage in the evolution of the GI syndrome. This study provides a basis for new approaches to prevent radiation damage to the bowel.