Sodium-glucose cotransporter 2 inhibitors influence skeletal muscle pathology in patients with heart failure and reduced ejection fraction

AIMS

Patients with heart failure and reduced ejection fraction (HFrEF) exhibit skeletal muscle pathology, which contributes to symptoms and decreased quality of life. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve clinical outcomes in HFrEF but their mechanism of action remains poorly understood. We aimed, therefore, to determine whether SGLT2i influence skeletal muscle pathology in patients with HFrEF.

METHODS AND RESULTS

Muscle biopsies from 28 male patients with HFrEF (New York Heart association class I-III) treated with SGLT2i (>12 months) or without SGLT2i were compared. Comprehensive analyses of muscle structure (immunohistochemistry), transcriptome (RNA sequencing), and metabolome (liquid chromatography-mass spectrometry) were performed, and serum inflammatory profiling (ELISA). Experiments in mice (n = 16) treated with SGLT2i were also performed. Myofiber atrophy was ~20% less in patients taking SGLT2i (p = 0.07). Transcriptomics and follow-up measures identified a unique signature in patients taking SGLT2i related to beneficial effects on atrophy, metabolism, and inflammation. Metabolomics identified influenced tryptophan metabolism in patients taking SGLT2i: kynurenic acid was 24% higher and kynurenine was 32% lower (p < 0.001). Serum profiling identified that SGLT2i treatment was associated with lower (p < 0.05) pro-inflammatory cytokines by 26-64% alongside downstream muscle interleukin (IL)-6-JAK/STAT3 signalling (p = 008 and 0.09). Serum IL-6 and muscle kynurenine were correlated (R = 0.65; p < 0.05). Muscle pathology was lower in mice treated with SGLT2i indicative of a conserved mammalian response to treatment.

CONCLUSIONS

Treatment with SGLT2i influenced skeletal muscle pathology in patients with HFrEF and was associated with anti-atrophic, anti-inflammatory, and pro-metabolic effects. These changes may be regulated via IL-6-kynurenine signalling. Together, clinical improvements following SGLT2i treatment in patients with HFrEF may be partly explained by their positive effects on skeletal muscle pathology.

Caloric Restriction Rejuvenates Skeletal Muscle Growth in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a major clinical problem, with limited treatments. HFpEF is characterized by a distinct, but poorly understood, skeletal muscle pathology, which could offer an alternative therapeutic target. In a rat model, we identified impaired myonuclear accretion as a mechanism for low myofiber growth in HFpEF following resistance exercise. Acute caloric restriction rescued skeletal muscle pathology in HFpEF, whereas cardiac therapies had no effect. Mechanisms regulating myonuclear accretion were dysregulated in patients with HFpEF. Overall, these findings may have widespread implications in HFpEF, indicating combined dietary with exercise interventions as a beneficial approach to overcome skeletal muscle pathology.

Skeletal muscle atrophy, regeneration, and dysfunction in heart failure: Impact of exercise training

This review highlights some established and some more contemporary mechanisms responsible for heart failure (HF)-induced skeletal muscle wasting and weakness. We first describe the effects of HF on the relationship between protein synthesis and degradation rates, which determine muscle mass, the involvement of the satellite cells for continual muscle regeneration, and changes in myofiber calcium homeostasis linked to contractile dysfunction. We then highlight key mechanistic effects of both aerobic and resistance exercise training on skeletal muscle in HF and outline its application as a beneficial treatment. Overall, HF causes multiple impairments related to autophagy, anabolic-catabolic signaling, satellite cell proliferation, and calcium homeostasis, which together promote fiber atrophy, contractile dysfunction, and impaired regeneration. Although both wasting and weakness are partly rescued by aerobic and resistance exercise training in HF, the effects of satellite cell dynamics remain poorly explored.

Neutrino-Induced Coherent π^{+} Production in C, CH, Fe, and Pb at ⟨E_{ν}⟩∼6 GeV

MINERvA has measured the ν_{μ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{μ} energies and at produced π^{+} energies and angles, E_{π}>1  GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10  GeV.

Simultaneous Measurement of Muon Neutrino ν_{μ} Charged-Current Single π^{+} Production in CH, C, H_{2}O, Fe, and Pb Targets in MINERvA

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{μ}A→μ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{μ} beam with ⟨E_{ν}⟩≈6  GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

Simultaneous Measurement of ν_{μ} Quasielasticlike Cross Sections on CH, C, H_{2}O, Fe, and Pb as a Function of Muon Kinematics at MINERvA

This Letter presents the first simultaneous measurement of the quasielasticlike neutrino-nucleus cross sections on C, water, Fe, Pb, and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5  GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielasticlike interactions, which are major contributors to long-baseline neutrino oscillation data samples.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Simultaneous Measurement of Proton and Lepton Kinematics in Quasielasticlike ν_{μ}-Hydrocarbon Interactions from 2 to 20 GeV

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{μ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20  GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Publisher's Note: Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer [Phys. Rev. Lett. 116, 071802 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.116.071802.

Measurement of Final-State Correlations in Neutrino Muon-Proton Mesonless Production on Hydrocarbon at ⟨E_{ν}⟩=3 GeV

Final-state kinematic imbalances are measured in mesonless production of ν_{μ}+A→μ^{-}+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ^{-}-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

We report on multinucleon effects in low momentum transfer (<0.8  GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

Charged-current ν_{μ} interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q^{2}, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q^{2} and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

Measurement of Neutral-Current K^{+} Production by Neutrinos using MINERvA

Neutral-current production of K^{+} by atmospheric neutrinos is a background in searches for the proton decay p→K^{+}ν[over ¯]. Reactions such as νp→νK^{+}Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K^{+} are identified in MINERvA by reconstructing the timing signature of a K^{+} decay at rest. A sample of 201 neutrino-induced neutral-current K^{+} events is used to measure differential cross sections with respect to the K^{+} kinetic energy, and the non-K^{+} hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π^{0} decay, which would veto a neutral-current K^{+} event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.

Evidence for Neutral-Current Diffractive π^{0} Production from Hydrogen in Neutrino Interactions on Hydrocarbon

The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π^{0} production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26±0.02(stat.)±0.08(sys.)×10^{-39}  cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π^{0} production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ν_{μ} to ν_{e} oscillations.

Evidence of Coherent K^{+} Meson Production in Neutrino-Nucleus Scattering

Neutrino-induced charged-current coherent kaon production ν_{μ}A→μ^{-}K^{+}A is a rare, inelastic electroweak process that brings a K^{+} on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than the neutrino-induced charged-current coherent pion production because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K^{+}, μ^{-}, and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3σ significance.

Diabetic nephropathy: where are we on the journey from pathophysiology to treatment?

Diabetic nephropathy affects 30-40% of people with diabetes, and is the leading cause of end-stage kidney disease. The current treatment paradigm relies on early detection, glycaemic control and tight blood pressure management with preferential use of renin-angiotensin system blockade. This strategy has transformed outcomes in diabetic kidney disease over the last 20 years. Over the last two decades we have also witnessed significant advances in the understanding of the pathophysiology of diabetic nephropathy; however, despite this new knowledge, we have yet to develop new treatments of proven efficacy. Whilst a continued emphasis on preclinical and clinical research is clearly needed, clinicians treating people with diabetes should not forget that, in the short term, the greatest gains are likely to be realised by more consistent deployment of existing therapies.

Measurement of Electron Neutrino Quasielastic and Quasielasticlike Scattering on Hydrocarbon at ⟨E_{ν}⟩=3.6 GeV

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{μ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ν_{μ} interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

Measurement of coherent production of π(±) in neutrino and antineutrino beams on carbon from Eν of 1.5 to 20 GeV

Neutrino-induced coherent charged pion production on nuclei νμA→μ(±)π(∓)A is a rare, inelastic interaction in which a small squared four-momentum |t| is transferred to the recoil nucleus, leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct |t| from the final-state pion and muon. We select low |t| events to isolate a sample rich in coherent candidates. By selecting low |t| events, we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and antineutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

Measurement of ratios of νμ charged-current cross sections on C, Fe, and Pb to CH at neutrino energies 2-20 GeV

We present measurements of ν(μ) charged-current cross section ratios on carbon, iron, and lead relative to a scintillator (CH) using the fine-grained MINERvA detector exposed to the NuMI neutrino beam at Fermilab. The measurements utilize events of energies 2<E(ν)<20 GeV, with ⟨E(ν)⟩ = 8 GeV, which have a reconstructed μ(-) scattering angle less than 17° to extract ratios of inclusive total cross sections as a function of neutrino energy E(ν) and flux-integrated differential cross sections with respect to the Bjorken scaling variable x. These results provide the first high-statistics direct measurements of nuclear effects in neutrino scattering using different targets in the same neutrino beam. Measured cross section ratios exhibit a relative depletion at low x and enhancement at large x. Both become more pronounced as the nucleon number of the target nucleus increases. The data are not reproduced by GENIE, a conventional neutrino-nucleus scattering simulation, or by the alternative models for the nuclear dependence of inelastic scattering that are considered.

Kidneys at higher risk of discard: expanding the role of dual kidney transplantation

Half of the recovered expanded criteria donor (ECD) kidneys are discarded in the United States. A new kidney allocation system offers kidneys at higher risk of discard, Kidney Donor Profile Index (KDPI)>85%, to a wider geographic area to promote broader sharing and expedite utilization. Dual kidney transplantation (DKT) based on the KDPI is a potential option to streamline allocation of kidneys which otherwise would have been discarded. To assess the clinical utility of the KDPI in kidneys at higher risk of discard, we analyzed the OPTN/UNOS Registry that included the deceased donor kidneys recovered between 2002 and 2012. The primary outcomes were allograft survival, patient survival and discard rate based on different KDPI categories (<80%, 80-90% and >90%). Kidneys with KDPI>90% were associated with increased odds of discard (OR=1.99, 95% CI 1.74-2.29) compared to ones with KDPI<80%. DKTs of KDPI>90% were associated with lower overall allograft failure (HR=0.74, 95% CI 0.62-0.89) and better patient survival (HR=0.79, 95% CI 0.64-0.98) compared to single ECD kidneys with KDPI>90%. Kidneys at higher risk of discard may be offered in the up-front allocation system as a DKT. Further modeling and simulation studies are required to determine a reasonable KDPI cutoff percentile.

Measurement of muon neutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

Measurement of muon antineutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

Trends and transient change in end-digit preference in blood pressure recording: studies of sequential and longitudinal collected primary care data

BACKGROUND

End-digit preference (EDP) is a known cause of inaccurate BP recording. Distortion has been reported around pay-for-performance (P4P) indicators.

METHODS

We studied sequential datasets (n = 148,000 to n = 900,000) and performed a longitudinal analysis of CONDUIT data (n = 250,000) over a 10-year period. We examined general trends in EDP and investigated the impact of diabetes and chronic kidney disease (CKD) P4P targets.

RESULTS

EDP reduces over time in both datasets; the percentage of patients with a zero EDP declined from 70% to 27% and 68% to 26% for SBP and DBP respectively. There is more zero EDP at the extremes of BP, but in people with chronic disease, the use of zero EDP was mainly seen at higher BP levels. P4P targets are associated with increased preference for the even end-digit just below target: in diabetes odds ratio (OR) is 1.47 (p = 0.003) for SBP, 1.19 (p = 0.09) for DBP and in CKD OR 1.65 (p < 0.001) for SBP and 1.48 (p = 0.0001) for DBP. Trends observed in pilot data were validated with a longitudinal set.

CONCLUSIONS

The decline in EDP is levelling off and P4P targets are associated with sub-target-EDP. Primary care should automate BP measurement and recording.

A method of identifying and correcting miscoding, misclassification and misdiagnosis in diabetes: a pilot and validation study of routinely collected data

AIMS

Incorrect classification, diagnosis and coding of the type of diabetes may have implications for patient management and limit our ability to measure quality. The aim of the study was to measure the accuracy of diabetes diagnostic data and explore the scope for identifying errors.

METHOD

We used two sets of anonymized routinely collected computer data: the pilot used Cutting out Needless Deaths Using Information Technology (CONDUIT) study data (n = 221 958), which we then validated using 100 practices from the Quality Improvement in Chronic Kidney Disease (QICKD) study (n = 760,588). We searched for contradictory diagnostic codes and also compatibility with prescription, demographic and laboratory test data. We classified errors as: misclassified-incorrect type of diabetes; misdiagnosed-where there was no evidence of diabetes; or miscoded-cases where it was difficult to infer the type of diabetes.

RESULTS

The standardized prevalence of diabetes was 5.0 and 4.0% in the CONDUIT and the QICKD data, respectively: 13.1% (n = 930) of CONDUIT and 14.8% (n = 4363) QICKD are incorrectly coded; 10.3% (n = 96) in CONDUIT and 26.2% (n = 1143) in QICKD are misclassified; nearly all of these cases are people classified with Type 1 diabetes who should be classified as Type 2. Approximately 5% of T2DM in both samples have no objective evidence to support a diagnosis of diabetes. Miscoding was present in approximately 7.8% of the CONDUIT and 6.1% of QICKD diabetes records.

CONCLUSIONS

The prevalence of miscoding, misclassification and misdiagnosis of diabetes is high and there is substantial scope for further improvement in diagnosis and data quality. Algorithms which identify likely misdiagnosis, misclassification and miscoding could be used to flag cases for review.

The effects of vinblastine on endothelial cells

The development of drug-eluting stents to combat the problem of in-stent restenosis has revolutionized interventional cardiology. However, concerns have emerged about the risk of late angiographic stent thromboses associated with drug-eluting stents. It has been shown that noncytotoxic concentrations of paclitaxel exert an antiangiogenic effect, suggesting that paclitaxel and similar agents may inhibit key cellular functions in a threshold-independent manner. In this study, the effect of vinblastine, an antimitotic drug, on endothelial cells is analyzed. It is investigated whether noncytotoxic concentrations of the drug could exert an antirestenotic effect. The change in levels of cell proliferation, activity, and viability in human umbilical vein endothelial cells was measured at a range of concentrations and over a number of time points. Also, the level of apoptotic activity in response to vinblastine was analyzed. This study shows that the concentration of vinblastine most appropriate in restenosis treatment would be between 0.1 and 1 nM. At this concentration, vinblastine exerts a distinct biological effect without causing an increase in apoptotic activity. These results emphasize the importance of finding an appropriate concentration window in order to minimize the risk of delayed endothelialization and thrombosis.

Global gene expression analysis of the effects of vinblastine on endothelial cells, when eluted from a thermo-responsive polymer

In-stent restenosis remains a significant problem associated with bare metal stents. This drawback has prompted research into improving stent design and the development of novel coatings, including drug-eluting stents. A number of drug-eluting stents are currently on the market; however, the success rate of these stents in complex situations has been found to be quite low. Thus, there remains potential for the development of more suitable drug-eluting stents. The aims of this study were to use a thermoresponsive polymer to develop a system to locally deliver vinblastine, an antimitotic agent currently used as an anticancer drug, and in addition, assess the effects of this drug at the gene expression level in vitro. An N-isopropylacrylamide/N-tert-butylacrylamide (NiPAAm/NtBAAm) copolymer solution in the ratio 65:35 was prepared and appropriate volumes of vinblastine were added to generate two final drug concentrations of 22 nanomoles/film or 0.022 nanomoles/film. Stainless steel discs (316) were coated with the copolymer solution or this solution containing drug. Human endothelial cells were cultured on collagen type 1 gels and then incubated with the coated discs for 24 h. Gene expression studies using oligonucleotide microarray analysis and quantitative RT-PCR were then performed. Microarray analysis revealed that vinblastine causes the differential expression of a range of genes involved in a variety of different functions, including cell cycle and apoptosis. The changes in expression of some of these genes culminate in cell cycle arrest and apoptotic pathways.

Cytomegalovirus Infection and Abdominal Pain with Mycophenolate Mofetil

Mycophenolate mofetil (MMF) is an immunosuppressive agent that exerts relatively selective antiproliferative effects on T and B lymphocytes. Efficacy has been demonstrated in large-scale randomised studies, but the use of MMF is complicated by gastrointestinal upset and is associated with an increased incidence of tissue-invasive cytomegalovirus (CMV) disease. The gastrointestinal tract is a well recognised site for invasive CMV disease, and it has therefore been hypothesised that the abdominal pain commonly seen with MMF is related to CMV infection. This has only been tested in a single small uncontrolled study, where abdominal pain was associated with the presence of CMV on endoscopic biopsy. In contrast, the toxicity profile in 85 patients with psoriasis who had received relatively high dosages of mycophenolic acid, the active moiety of MMF, for up to 13 years showed that the incidence of gastrointestinal upset fell dramatically over time. We can find little evidence that CMV disease explains the gastrointestinal adverse event profile associated with MMF, and instead support the contention that high local concentrations of MMF have a direct toxic effect on cells of the small intestine. We do not recommend any changes to current policy on CMV prophylaxis in patients receiving MMF, although we recognise that some severe gastrointestinal adverse effects may be CMV-associated. The use of trough plasma concentration monitoring, divided doses and a gradually increasing dosage schedule may be of value in limiting toxicity.

Progressive renal disease: does the quality of the proteinuria matter or only the quantity?

Proteinuria is now accepted to be not just a sign of renal disease but also a contributory factor to the development of progressive tubulointerstitial fibrosis. Excellent correlations between the degree of proteinuria and rate of decline of glomerular filtration rate have been demonstrated. What has been investigated less is whether the type of protein found in the urine is important. Using transformed and primary human proximal tubular epithelial cells, we have investigated the binding of albumin and retinol binding protein to plasma membrane preparations and studied the response of the intact cells to increasing concentrations of these same proteins. We have preliminary evidence for differences in the pattern of binding of these two proteins to the plasma membrane receptors and also for differential release of pro-inflammatory cytokines from intact cells. These in vitro results, along with those of other groups, and some recent clinical findings suggest that the quality of proteinuria may play a role in the early development of interstitial fibrosis. Furthermore, the use of such in vitro model systems based on human proximal epithelial cell culture can provide a means of evaluating the potential significance of different markers of tubular damage.

Prospective assessment of the hepatic perfusion index in patients with colorectal cancer

BACKGROUND

This prospective study was designed to test the hypothesis that abnormal liver blood flow is related to poor prognosis in patients with colorectal cancer.

METHODS

The hepatic perfusion index (HPI), measured by dynamic hepatic scintigraphy, was assessed in 202 patients with colorectal cancer. Assessment for overt hepatic metastasis included liver palpation at laparotomy and perioperative computed tomography (CT). Follow-up at a dedicated clinic included regular abdominal ultrasonography and CT.

RESULTS

The HPI was abnormal (greater than 0.37) in 92 (88 per cent) of 105 patients with overt liver metastases. Of 89 patients with no evidence of overt metastases or residual tumour after primary resection, 52 had an abnormal and 37 a normal HPI. At a median follow-up of 39 (range 13-76) months, 25 of 38 patients with recurrence had an abnormal HPI. Some 31 of 45 patients who died had an abnormal HPI. The HPI predicted overall recurrence (P=0.04, log rank test). Multivariate analysis showed the HPI was independent of Dukes stage for predicting disease-free survival (P=0.04, relative risk 1.94 (95 per cent confidence interval (c.i.) 1.03-3.67)) but this just failed to attain significance for overall survival (P=0.055, relative hazard 1.88 (95 per cent c.i. 1.00-3.58)).

CONCLUSION

The HPI predicts a poor outcome in patients with colorectal cancer and may be useful in patient selection for adjuvant chemotherapy.

Precision and reliability for measurement of change in MRI lesion volume in multiple sclerosis: a comparison of two computer assisted techniques

OBJECTIVE

The serial quantification of MRI lesion load in multiple sclerosis provides an effective tool for monitoring disease progression and this has led to its increasing use as an outcome measure in treatment trials. Segmentation techniques must display a high degree of precision and reliability if they are to be responsive to small changes over time. This study has evaluated the performance of two such techniques, the manual outlining and contour methods, in serial lesion load quantification.

METHODS

Sixteen patients with clinically definite multiple sclerosis were scanned at baseline and after two years. Scan analysis was performed twice, independently by three observers using each technique.

RESULTS

For the absolute lesion volumes the median intrarater coefficient of variation (CV) was 3.2% for the contour technique and 7.6% for the manual outlining method (p < 0.005), the interrater CVs were 3.8% and 6.1% respectively (p < 0.01) and the reliability of both techniques was very high. For the change in lesion volume the intrarater and interrater repeatability coefficients were respectively 2.6 cm3 and 2.8 cm3 for the contour technique, and 3.3 cm3 and 3.7 cm3 for the manual outlining method (lower values reflect higher precision). The values for intrarater and interrater reliability for measuring change in lesion volume were respectively, 0.945 and 0.944 for the contour technique, and 0.939 and 0.921 for the manual outline method (perfect reliability = 1.0).

CONCLUSIONS

With such high values for reliability, the impact of measurement error in lesion segmentation on sample size requirements in multiple sclerosis treatment trials is minor. This study shows that a change in lesion volume can be measured with a higher level of precision and reliability with the contour technique and this supports its further application in serial studies.

The role of orchiectomy in the management of postpubertal cryptorchidism

PURPOSE

Owing to the risk of future malignancy, many postpubertal male subjects presenting with unilateral cryptorchidism undergo orchiectomy rather than orchiopexy. We examined the incidence of spermatogenesis and carcinogenesis in whole orchiectomy specimens removed from postpubertal cryptorchid male subjects. We review the concept that orchiectomy is justifiable in these patients.

MATERIALS AND METHODS

A total of 52 patients with postpubertal cryptorchidism (unilateral in 48, bilateral in 4) were retrospectively analyzed from 1984. Patient age ranged from 15 to 66 years (mean 26). Six patients presented with primary infertility (unilateral in 3, bilateral in 3). The undescended testicles were palpable in 32 cases (62%). All patients underwent unilateral orchiectomy and whole specimens were examined histologically.

RESULTS

Histology showed normal spermatogenesis in only 1 orchiectomy specimen, while 15 had maturation arrest, 6 testicular agenesis and 30 seminiferous tubular atrophy and/or Sertoli-cell-only syndrome with no spermatogenesis. The location of the undescended testis was the superficial inguinal pouch in 32 cases, inguinal canal in 6 and inside the deep ring in 8. Absent spermatogenesis was significantly associated with a high level of maldescent and with increasing age. Two patients (4%) had carcinoma in situ of the testicle. Torsion of an undescended testicle occurred in 1 patient (2%).

CONCLUSIONS

This analysis of cryptorchid testes in postpubertal male subjects confirms that the majority cannot contribute to fertility, have significant malignant potential and may undergo torsion. Therefore, orchiectomy remains the treatment of choice for the majority of postpubertal male subjects presenting with unilateral cryptorchidism.

Infusion pumps for systemic and intra-arterial chemotherapy of colorectal liver metastases

Over a 12 month period, we prospectively evaluated the use of an ambulatory infusion pump for intra-arterial and intravenous chemotherapy in patients with colorectal liver metastases. In all, 274 separate infusions were given with minor complications occurring on six occasions. Administering treatment on an outpatient basis rather than as an inpatient has resulted in savings of over Pounds 17000 in the first year.

A low dielectric constant customized phantom design to measure RF coil nonuniformity

The selection of a suitable low dielectric constant liquid for radiofrequency coil nonuniformity measurements is described. Measurements of dielectric constant (relative permittivity) were made on a range of candidate liquids. After excluding liquids that were too inflammable or too viscous, Esso Bayol 82 oil (dielectric constant epsilon' = 2.37) was chosen. At 1.5 T, a 27 cm diameter cylindrical phantom (test object) filled with Bayol 82 has a maximum nonuniformity of 1.9% arising from radiofrequency standing waves. The maximum diameter cylinder that can be used without the nonuniformity exceeding 2% is given for a range of liquids and field strengths. The construction of customized containers that fit closely inside a radiofrequency head coil from glass fiber reinforced resin ("fiberglass") is described. Thermal expansion of the liquid takes place without a rise in the internal pressure in the container.