Lipoprotein(a), cardiovascular events, and benefit of P2Y12 inhibition: insights from the PEGASUS-TIMI 54 trial

Background

Lp(a) plays a causal role in atherogenesis and may exert pro-thrombotic effects by inhibiting fibrinolysis owing to its structural homology with plasminogen. Patients with higher Lp(a) concentrations may derive greater benefit from anti-thrombotic therapy.

Purpose

We assessed whether patients with higher Lp(a) derive greater risk reduction from P2Y12 inhibition with ticagrelor vs. placebo on a background of aspirin therapy.

Methods

Lp(a) concentration was measured (Randox) in a prospective nested cohort of 8,967 pts enrolled in PEGASUS-TIMI 54, a randomized trial of ticagrelor vs. placebo in patients 1–3 years post MI (median follow-up: 2.7 y). Lp(a) was dichotomized at 200 nmol/L as an established threshold of risk. The prespecified MACE endpoint was CV death, MI or stroke, with KM rates reported at 3y. Cox proportional hazards were used to assess the relationship between Lp(a), MACE and treatment benefit. Models were adjusted for relevant baseline characteristics including apolipoprotein B.

Results

The median Lp(a) was 29 (25th-75th percentile: 12–137) nmol/L. A total of 1,053 pts (11.7%) had a high Lp(a) (≥200 nmol/L). In the pooled trial population, high Lp(a) concentration was associated with a 29% higher risk of MACE (9.1% vs 7.6%; adjusted hazard ratio [adj HR] 1.29, 95% confidence interval [CI] 1.02–1.62; p=0.03), including a 37% higher risk of MI (6.9% vs. 5.3%; adj HR 1.37, 95% CI 1.05–1.79; p=0.02). The hazard ratios for MACE with ticagrelor vs. placebo were 0.73 (95% CI 0.48–1.11) for patients with higher Lp(a) and 0.88 (95% CI 0.74–1.05) for patients with lower Lp(a) (p-interaction=0.41; Figure 1). The absolute risk reductions were 2.4% and 1.2%, respectively.

Conclusion

Lp(a) above 200 nmol/L identifies patients with prior MI at increased risk of MACE who may derive greater absolute risk reduction from treatment with ticagrelor. These exploratory observations provide insights for therapeutics that are evaluating the clinical benefit of Lp(a) reduction.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The PEGASUS-TIMI 54 trial was funded by AstraZeneca

Serial measurement of biomarkers and the risk of stroke or systemic embolism and bleeding in patients with atrial fibrillation in ENGAGE AF-TIMI 48

Background

Patients with atrial fibrillation (AF) have progressive cardiac structural changes that may be manifest by biomarkers of myocardial injury and hemodynamic stress. Baseline values of hsTnT (high-sensitivity troponin T), and NT-proBNP (N-terminal pro-brain natriuretic peptide) are associated with stroke risk and GDF-15 (growth differentiation factor-15) is associated with bleeding risk in patients with AF. However, the variability of these biomarkers over time and their associations with stroke or systemic embolism events (S/SEE) and bleeding in patients with AF remain unclear.

Purpose

We examined whether patients with AF demonstrate detectable changes in these biomarkers over 12 months and whether such changes from baseline to 12 months are associated with the subsequent risk of S/SEE (hsTnT, NT-proBNP) and bleeding (GDF-15).

Methods

ENGAGE AF-TIMI 48 was a multinational randomized trial of the oral factor Xa inhibitor edoxaban in patients with atrial fibrillation and a CHADS2 score ≥2. We performed a nested prospective biomarker study in 6062 patients, analyzing hsTnT, NT-proBNP, and GDF-15 at baseline and 12 months. Event rates were estimated and displayed with annualized event rates after 12 months.

Results

Of 6062 patients, hsTnT was dynamic in 46.9% (≥2 ng/L change), NT-proBNP in 51.9% (≥200 pg/L change), GDF-15 in 45.6% (≥300 pg/L change) between baseline and 12 months. In addition, 7.7% in hsTnT shifted from low->high categories, 9.4% in NT-proBNP from low->high, 10.6% in GDF-15 from low->high over 12 months (Figure). Elevated hsTnT (≥14 ng/L) and NT-proBNP (≥900 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent S/SEE, and elevated GDF-15 (≥1800 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent bleeding (P<0.001 for each). In a Cox regression model, the absolute changes in log2-transformed hsTnT and NT-proBNP were associated with increased risk of S/SEE (adj-HR, 1.75; 95% CI, 1.38–2.23; p<0.001, and adj-HR, 1.31; 95% CI, 1.11–1.55; p=0.002, respectively) and log2-transformed GDF-15 with bleeding (adj-HR, 1.42; 95% CI, 1.04–1.92; p=0.025). Analyzed in a categorical manner (Figure), patients who increased hsTnT or NT-proBNP between baseline and 12 months or had high hsTnT or NT-proBNP at both timepoints were at higher risk for S/SEE (adj-HR 1.87 and 1.50 for hsTnT; adj-HR 1.80 and 2.59 for NT-proBNP, respectively). Patients with persistently elevated GDF-15 appeared to be at higher risk for bleeding (adj-HR,1.35) (Figure).

Conclusions

Serial assessment of hsTnT, NT-proBNP, and GDF-15 revealed a substantial proportion of patients with AF had dynamic values. Patients with either persistently elevated or dynamic values were at higher risk of adverse clinical outcomes. Those biomarkers may play a role in personalizing preventive strategies in patients with AF based on risk.

Change in biomarkers and event rate

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Daiichi Sankyo Pharma Development

FRI0235 PHASE 1 CLINICAL STUDY OF MGTA-145 IN COMBINATION WITH PLERIXAFOR SHOWS RAPID SINGLE-DAY MOBILISATION AND COLLECTION OF CD34+ HAEMATOPOIETIC STEM CELLS WITHOUT G-CSF

Background:

Autologous haematopoietic stem cell (HSC) transplantation is a recommended therapeutic option for selected patients with autoimmune diseases. G-CSF mobilisation of HSCs requires 4-7 days of injections that are associated with significant side effects and potential for severe complications including disease flares (e.g., scleroderma and multiple sclerosis). MGTA-145 is a biologic that activates CXCR2 on neutrophils, and with plerixafor rapidly mobilises HSCs in mice and non-human primates. The combination promises to be a same-day, G-CSF-free mobilisation regimen.

Objectives:

To evaluate the safety, tolerability, and mobilisation efficacy of MGTA-145 monotherapy and combination therapy with plerixafor in healthy volunteers.

Methods:

This healthy volunteer phase 1 study consisted of 4 parts- Part A: single-agent MGTA-145 or placebo; Part B: MGTA-145 or placebo given immediately or 2 hours after plerixafor; Part C: MGTA-145 or placebo given 2 hours after plerixafor on 2 consecutive days; Part D: MGTA-145 given 2 hours after plerixafor, just prior to apheresis cell collection.

Results:

Monotherapy of MGTA-145 mobilised CD34+ cells within minutes and peaked within 1 hour post MGTA-145 (median 11 CD34+ cells/µL, a 7-fold increase vs baseline). White blood cells and neutrophils followed a similar pattern. Importantly, markers of neutrophil activation were relatively unchanged (≤2-fold vs baseline).

MGTA-145 combined with plerixafor increased CD34+ cell mobilisation, whether given simultaneously or 2h after plerixafor (Fig. 1A). Mobilisation was highly enriched for CD34+CD90+CD45RA- HSCs, which tracked closely with the total CD34 count. At the 0.03 mg/kg dose with 2h stagger, median peak CD34+ peripheral blood mobilisation was ≥40 cells/µL in Part B. On a second consecutive day of dosing, MGTA-145 + plerixafor mobilises HSCs to levels comparable to day 1. Initial data from the ongoing Part D show that sufficient numbers of cells (median 4.3 x 10^6 CD34+ cells/kg) for transplant were collected in a single day.. Preliminary data from NSG mouse transplant studies of those mobilised HSCs in part D show higher engraftment rates of MGTA-145 + plerixafor mobilised HSCs, compared to G-CSF-mobilised HSCs.

Figure.

Peripheral blood mobilisation after plerixafor + 0.03 mg/kg MGTA-145 in healthy subjects with simultaneous and 2h stagger dosing after plerixafor. Dotted line: previously reported CD34+ counts with plerixafor alone mobilisation (Chenet al,Blood Advances. 2018).

MGTA-145 monotherapy was well tolerated with no significant adverse events (AEs). Grade 1, transient lower back pain that dissipated within minutes was reported. The combination of MGTA-145 with plerixafor was well tolerated, with some subjects experiencing grade 1/2 gastrointestinal AEs commonly observed with plerixafor and one grade 2 back pain with MGTA-145 at 0.075 mg/kg that resolved within minutes.

Conclusion:

MGTA-145 monotherapy was well-tolerated and induced rapid mobilisation of significant numbers of HSCs. CD34+ cell mobilisation with MGTA-145 + plerixafor was immediate and superior to plerixafor alone. These data suggest that the combination can enable the collection of sufficient HSCs for transplant in one day without the need for G-CSF. Further development as a first line mobilisation product is warranted in autoimmune diseases, gene therapy and haematologic malignancies.

Table.

Single-day Mobilisation and Apheresis Cell Yields in Part D

SubjectTotal CD34+ Yield (x106 cells)CD34+/kg (x106 cells)CD90+ (%)8013194.139%8073224.441%8175005.326%821 (*completed only 13L of planned 20L collection)2392.719%Median3214.333%

Disclosure of Interests:

John Dipersio Shareholder of: Magenta, Consultant of: Cellworks, Tioma, Rivervest, Bioline, Asterias, Amphivena and Bluebird, Celgene, Incyte, NeoImuneTech, Macrogenics, Steven Devine: None declared, Jonathan Hoggatt Shareholder of: Magenta, Grant/research support from: Magenta, Consultant of: Magenta, David Scadden Shareholder of: Magenta, Consultant of: Magenta, Haley Howell Shareholder of: Magenta, Employee of: Magenta, Veit Schmelmer Shareholder of: Magenta, Employee of: Magenta, Jason Neale Shareholder of: Magenta, Employee of: Magenta, Tony Boitano Shareholder of: Magenta, Employee of: Magenta, Michael Cooke Shareholder of: Magenta, Employee of: Magenta, Dwight Morrow Shareholder of: Magenta, Employee of: Magenta, Glen Raffel Shareholder of: Magenta, Employee of: Magenta, Will Savage Shareholder of: Magenta, Employee of: Magenta, Kevin Goncalves Shareholder of: Magenta, Employee of: Magenta, Pat Falahee Shareholder of: Magenta, Employee of: Magenta, John Davis Shareholder of: Magenta, Employee of: Magenta

P5738Multicenter analysis of left ventricular unloading on top of VA-ECMO for treatment of cardiogenic shock

Background

Veno-arterial extracorporeal membrane oxygenation therapy (VA-ECMO) is increasingly used for treatment of severe cardiogenic shock, although it causes an increase in left ventricular (LV) afterload and might therefore hamper myocardial recovery. Recently, the addition of catheter-based left ventricular assist device (cLVAD) on top of VA-ECMO has been used to unload the LV and to improve outcome measures. However, there is limited data on predictors of outcome in this high-risk population.

Aim

The aim of this study was to evaluate predictors of 30-day survival in a multicentre cohort of severe cardiogenic shock patients treated with cLVADon top of VA-ECMO.

Material and methods

We report on consecutive patients from six tertiary care centers being treated with cLVAD in addition to VA-ECMO for treatment of cardiogenic shock. The primary endpoint is 30-day all-cause mortality. To identify predictors of the primary endpoint, multivariate analysis using an “elastic net” variable selection algorithm was done after imputation of missing variables.

Results

A total of 220 patients treated with cLVAD on top of VA-ECMO were included in the analysis. Of these, 79.1% were male with a median age of 55.5 (25thpercentile 48.0, 75thpercentile 65.6) years. In 60.5% of the patients, acute myocardial infarction was the underlying cause of cardiogenic shock and in 44.6% VA-ECMO was used for refractory cardiac arrest (eCPR). In the multivariable analysis, the following baseline parameters were significantly associated with the primary endpoint: Age (odds ratio of 1.68 per standard deviation), duration of cardiopulmonary resuscitation (OR 2.08 per SD), lactate (OR 1.04 per SD) and time from onset of shock to VA-ECMO (OR 1.30 per SD).

Conclusion and outlook

In this large-scale multicentre analysis of severe cardiogenic shock patients treated with VA-ECMO plus additional cLVAD unloading, age, duration of cardiopulmonary resuscitation, lactate and time from onset of shock to VA-ECMO were significantly associated with 30-day all-cause mortality.

To further investigate this topic, we will evaluate predictors of outcome in distinct patient populations such as acute myocardial infarction vs. acute heart failure and patients without vs. patients with prior cardiopulmonary association.

1135Angiotensin receptor-neprilysin inhibition in patients with de novo acute decompensated heart failure: a prespecified subgroup analysis of the PIONEER-HF trial

Background

The efficacy, safety, and tolerability of an angiotensin receptor-neprilysin inhibitor (ARNi) in patients presenting with de novo heart failure (HF) has not been previously well-defined.

Methods

The PIONEER-HF trial was a prospective, multicenter, double-blind, active-controlled, randomized clinical trial which enrolled 887 patients (pts) at 129 sites in the United States. Pts with or without a history of prior HF and an ejection fraction (EF) <40% and a NT-proBNP >1600 pg/mL or BNP >400 pg/mL were eligible for participation no earlier than 24 hours while still hospitalized for acute decompensated HF (ADHF). Pts were randomly assigned 1:1 to in-hospital initiation of sacubitril/valsartan (S/V) titrated to 97/103 mg vs. enalapril titrated to 10 mg both by mouth twice daily for 8 weeks. We performed a pre-specified analysis in pts with de novo HF (i.e., defined as pts without a history of HF prior to the qualifying ADHF event).

Results

At the time of enrollment, 34% (N=303) had de novo HF. These pts experienced a similar improvement in NT-proBNP with S/V vs. enalapril (Ratio of geometric means 0.65, 95% Confidence Interval [CI] 0.53–0.81; p-value = 0.0002) compared to pts with worsening chronic HF (ratio 0.72 (0.63–0.83, p-value <0.0001) (Figure). In addition, the incidence of worsening renal function, hyperkalemia, and hypotension was comparable with S/V vs. enalapril regardless of whether they were hospitalized for de novo or worsening chronic HF. Finally, there was no interaction (p-value = 0.350) between previous HF status and the effect of S/V on the composite of cardiovascular death or rehospitalization for HF (de novo HF: Hazard Ratio [HR] 0.34, 95% CI 0.11–1.05 vs. worsening chronic HF: HR 0.60, 95% CI 0.39–0.93).

Conclusion

Among patients admitted for ADHF, irrespective of prior HF history, in-hospital initiation of an ARNi led to a greater reduction in natriuretic peptide levels, a comparable safety profile, and a significant improvement in clinical outcomes.

Acknowledgement/Funding

Novartis

Novel KV7 ion channel openers for the treatment of epilepsy and implications for detrusor tissue contraction

Neuronal voltage-gated potassium channels, K_V7s, are the molecular mediators of the M current and regulate membrane excitability in the central and peripheral neuronal systems. Herein, we report novel small molecule K_V7 openers that demonstrate anti-seizure activities in electroshock and pentylenetetrazol-induced seizure models without influencing Rotarod readouts in mice. The anti-seizure activity was determined to be proportional to the unbound concentration in the brain. K_V7 channels are also expressed in the bladder smooth muscle (detrusor) and activation of these channels may cause localized undesired effects. Therefore, the impact of individual K_V7 isoforms was investigated in human detrusor tissue using a panel of K_V7 openers with distinct activity profiles among K_V7 isoforms. KCNQ4 and KCNQ5 mRNA were highly expressed in detrusor tissue, yet a compound that has significantly reduced activity on homomeric K_V7.4 did not reduce detrusor contraction. This may suggest that the homomeric K_V7.4 channel plays a less significant role in bladder contraction and further investigation is needed.

A Novel Neuroprotective Small Molecule for Glial Cell Derived Neurotrophic Factor Induction and Photoreceptor Rescue

PURPOSE

Degenerative diseases of the retina, such as retinitis pigmentosa and age-related macular degeneration, are characterized by the irreversible loss of photoreceptors. Several growth factors, including glial cell derived neurotrophic factor (GDNF), have been shown to rescue retinal neurons. An alternative strategy to direct GDNF administration is its induction in host retina by small molecules. Here we studied the ability of a novel small molecule GSK812 to induce GDNF in vitro/in vivo and rescue photoreceptors.

METHODS

GDNF induction in vitro was assessed in human ARPE-19, human retinal progenitor cells (RPCs) and mouse pluripotent cell-derived eyecups. For time course pharmacokinetic and GDNF induction studies in C57Bl/6 mice, GSK812 sustained release formulation was injected intravitreally. The same delivery approach was used in the rhodopsin knockout mice and Royal College of Surgeon (RCS) rats to assess long-term GDNF induction and photoreceptor rescue.

RESULTS

The suspension provided sustained GSK812 delivery with 28 μg of drug remaining in the eye 2 weeks after a single injection. GSK812 suspension injection in C57Bl/6 mice resulted in significant upregulation of GDNF mRNA (>1.8-fold) and protein levels (>2.8-fold). Importantly, GSK812 treatment resulted in outer nuclear layer preservation in rho-/- mice with a 2-fold difference in photoreceptor number. In the RCS rat, the GSK812 injection provided long-term rescue of photoreceptors and outer segments, accompanied by function preservation as well.

CONCLUSIONS

GSK812 is a potent neuroprotectant that can induce GDNF in normal and diseased retina. This induction results in photoreceptor rescue in 2 models of retinal degeneration.

A High-Content Imaging Screen for Cellular Regulators of β-Catenin Protein Abundance

Abnormal accumulation of β-catenin protein, a key transcriptional activator required for Wnt signaling, is the hallmark of many tumor types, including colon cancer. In normal cells, β-catenin protein level is tightly controlled by a multiprotein complex through the proteosome pathway. Mutations in the components of the β-catenin degradation complex, such as adenomatous polyposis coli (APC) and Axin, lead to β-catenin stabilization and the constitutive activation of target genes. Since the signal transduction of Wnt/β-catenin is mainly mediated by protein-protein interactions, this pathway has been particularly refractory to conventional target-based small-molecule screening. Here we designed a cellular high-content imaging assay to detect β-catenin protein through immunofluorescent staining in the SW480 colon cancer cell line, which has elevated β-catenin endogenously. We demonstrate that the assay is robust and specific to screen a focused biologically diverse chemical library set against known targets that play diverse cellular functions. We identified a number of hits that reduce β-catenin levels without causing cell death. These hits may serve as tools to understand the dynamics of β-catenin degradation. This study demonstrates that detecting cell-based β-catenin protein stability is a viable approach to identifying novel mechanisms of β-catenin regulation as well as small molecules of therapeutic potential.

An antibiotic formulary for a tertiary care foot clinic: admission avoidance using intramuscular antibiotics for borderline foot infections in people with diabetes

AIMS

To develop an antibiotic foot formulary for the empirical treatment of diabetes-related foot infections presenting to our service. Subsequently, to asses costs associated with the introduction of our protocol, in particular to assess the effect on admissions avoidance and any cost savings achieved.

METHODS

We reviewed several existing antibiotic protocols. We analysed data on costs related to treatment and admission rates prior to and after the introduction of the protocol.

RESULTS

We rationalized our antibiotic protocol and adapted the Infectious Disease Society of America guideline by introducing a category of 'moderate infection-borderline admission' to our classification. This enabled the administration of outpatient intramuscular antibiotics. After introducing the rationalized protocol, our average antibiotic prescribing costs for a 3-week course of treatment fell from £17.12 to £16.42. Over 22 months of follow-up, 26 episodes were eligible for treatment with intramuscular antibiotics. Over the same time period, 121 people were admitted directly from the foot clinic. The costs saved as a result of avoided or delayed admission for those 26 episodes was over £76 000. For 12 people who required subsequent admission, their length of hospital stay was significantly shorter than those admitted directly [9.25 days (range 2-25) vs. 16.11 (2-64), P = 0.045].

CONCLUSIONS

By modifying the Infectious Disease Society of America classification and adopting a protocol to administer outpatient oral and intramuscular antibiotics, we have led to substantial cost savings, shorter hospital admissions and also have developed a successful admissions avoidance strategy.

Structure-activity relationship studies of novel 3-oxazolidinedione-6-naphthyl-2-pyridinones as potent and orally bioavailable EP3 receptor antagonists

Multiple regions of the 3-oxazolidinedione-6-naphthyl-pyridinone series identified via high throughput screening were explored. SAR studies of these regions including the left-hand side oxazolidinedione moiety, α-substituent on the oxazolidinedione ring, central pyridinone core, and substituents on the central pyridinone core led to the discovery of potent EP(3) receptor antagonists such as compound 29 which possesses outstanding rat pharmacokinetic properties. Synthesis and SAR of these novel compounds and DMPK properties of representative compounds are discussed.

Clinical experience of a new NPWT system in diabetic foot ulcers and post-amputation wounds

OBJECTIVE

The primary aim of this pilot observational study was to assess the reduction in wound depth and area achieved with a new negative pressure wound therapy (NPWT) system in diabetic patients with foot ulcers and post-amputation wounds. Secondary aims were to assess pain levels, extent of exudate removal, and ease of use of the system for both the patient and care giver.

METHOD

Patients in both acute and home care settings were enrolled into this 4-week study. Dressings were changed three times per week. Wound area and depth, exudate removal and pain severity were evaluated at each dressing change. At the final visit, the investigators and patients were surveyed with respect to equipment and dressings used in the study.

RESULTS

Sixteen patients were enrolled into the study. Data relating to 14 patients with a variety of post-amputation wounds were included in the intention-to-treat (ITT) analysis. The post-amputation wounds showed a general trend for a reduction in the median wound surface area between baseline (22.9cm2; range 0.5-55) and the final visit (15.3cm2; range 2.4-63.5). This equates to a median change (calculated from the percentage change in wound area for each patient individually) of -41% (range -82% to +15%). There was also a general trend in reduction in the median depth between baseline (17mm; range 0-35) to final visit (5mm; range 0-35). One patient presented with a foot ulcer that demonstrated a 50% reduction in depth from baseline to the final assessment. The device effectively managed wound exudate and most patients reported low pain levels during therapy. Ease of use of the system was rated very highly by investigators and patients.

CONCLUSION

This pilot study indicates that the use of the new NPWT system can be expected to have a positive effect on the healing of post-amputation wounds and foot ulcers in patients with diabetes. The findings demonstrate that the system is easy to use, effectively controls exudate and minimises pain and inconvenience for patients being treated with NPWT.

DECLARATION OF INTEREST

This study was sponsored by Mölnlycke Heath Care (Gothenburg, Sweden) and Medela AG (Baar, Switzerland). The authors have no other conflicts of interest that are directly relevant to the content of this manuscript.

Novel 3-Oxazolidinedione-6-aryl-pyridinones as Potent, Selective, and Orally Active EP3 Receptor Antagonists

High-throughput screening and subsequent optimization led to the discovery of novel 3-oxazolidinedione-6-aryl-pyridinones exemplified by compound 2 as potent and selective EP3 antagonists with excellent pharmacokinetic properties. Compound 2 was orally active and showed robust in vivo activities in overactive bladder models. To address potential bioactivation liabilities of compound 2, further optimization resulted in compounds 9 and 10, which maintained excellent potency, selectivity, and pharmacokinetic properties and showed no bioactivation liability in glutathione trapping studies. These highly potent, selective, and orally active EP3 antagonists are excellent tool compounds for investigating and validating potential therapeutic benefits from selectively inhibiting the EP3 receptor.

An Ultraminiature MEMS Pressure Sensor With High Sensitivity for Measurement of Intramuscular Pressure (IMP) in Patients With Neuromuscular Diseases

An ultraminiature micropressure sensor to accurately measure intramuscular pressure has been developed. The MEMS sensor is fabricated through surface micromachining and consists of a capacitive array of eight 150 μm diameter sensing membranes connected in parallel. The membranes have been vacuum-sealed via a subsequent deposition and patterning batch microfabrication step. A deep reactive ion etcher (DRIE) based postfabrication self-release has been utilized to fabricate individual devices. Each device has an outline that incorporates specially designed “anchor” structures that are utilized to attach on the muscle tissue during measurements to minimize the effect of muscle contractions on sensor readings. Electrical isolation of the wire bonds and bonding pads has been accomplished by utilizing glob-topping technique. The fabricated sensor performance has been experimentally validated inside a pressure chamber. The current sensors have 0.2 mm Hg pressure resolution in the ±19 mm Hg dynamic range with negligible hysteresis and show a flat frequency response in the 0–5.5 Hz experimental test range.

Factors associated with exacerbation of heart failure include treatment adherence and health literacy skills

We determined the factors associated with exacerbation of heart failure, using a cohort (n = 192) nested within a randomized trial at a university-affiliated ambulatory practice. Factors associated with emergency or hospital care included left ventricular ejection fraction, hematocrit and serum sodium levels, refill adherence, and the ability to read a prescription label. Refill adherence of <40% was associated with a threefold higher incidence of hospitalization for heart failure than a refill adherence of >or=80% (P = 0.002). In multivariable analysis, prescription label reading skills were associated with a lower incidence of heart failure-specific emergency care (incidence rate ratio, 0.76; 95% confidence interval (CI), 0.19-0.69), and participants with adequate health literacy had a lower risk of hospitalization for heart failure (incidence rate ratio, 0.34; 95% CI, 0.15-0.76). We conclude that inadequate treatment adherence and health literacy skills are key factors in the exacerbation of heart failure. These findings emphasize the need for careful instruction of patients about their medications.

Paralogues of porcine aromatase cytochrome P450: a novel hydroxylase activity is associated with the survival of a duplicated gene

The gonadal and placental paralogues of porcine aromatase cytochrome P450 (P450arom) were examined for novel catalytic properties to shed light on the evolutionary survival of duplicated copies of an enzyme critical to reproduction. Recombinant gonadal P450arom catalyzed the formation of a novel metabolite from testosterone, identified by gas chromatography/mass spectrometry and biochemical analyses as 1 beta-hydroxytestosterone (1 beta OH-T), in almost equal proportion to 17beta-estradiol (E(2)). This activity was absent in reactions with the porcine placental paralogue (or other orthologues) of P450arom and was minimal with androstenedione. Incubations with both porcine enzymes and with bovine and human P450arom demonstrated that 1 beta OH-T was not aromatizable, and 1 beta OH-T activated the androgen receptor of prostate cancer cells in vitro. Porcine testicular and follicular granulosa tissues synthesized 1 beta OH-T, which was also detected in testicular venous plasma. These results constitute the first of identification of a novel, perhaps potent, nonaromatizable metabolite of testosterone, whose synthesis (paradoxically) can be definitively ascribed to the activity of the gonadal paralogue of porcine P450arom. It probably represents an evolutionary gain of function associated with fixation and the survival of the genes after CYP19 duplication. Novel activities and adaptive functions may exist among other duplicated vertebrate aromatases.

GPCR drug discovery through the exploitation of allosteric drug binding sites

G-protein-coupled receptors (GPCRs) represent the most important class of drug targets both in terms of therapeutic benefit and pharmaceutical sales. The majority of current GPCR drugs have been identified in ligand binding assays and interact with the receptor in a competitive manner with the natural ligand. There is increasing evidence that it is possible to identify GPCR agonist and antagonist ligands that do not interact at the natural ligand binding site, rather such compounds interact elsewhere on the receptor to modulate receptor activity. This finding allows the possibility that there may be many as yet uncharacterized drug binding sites within the GPCR that could be exploited for therapeutic intervention. The characterization of such "allosteric" ligand interaction sites, following the identification of molecules capable of interacting at these sites, would be expected to lead to the identification of drug molecules with improved selectivity and efficacy. Such activities may enable the identification of selective ligands at GPCRs for which competitive natural ligand binding screens have been unsuccessful. In this manuscript we review known examples of GPCR allosteric ligands, the functional assay technologies that are being employed to identify further ligands of this type, and the potential benefit that may result from the identification of such ligands.

Development of a bioassay for phytochemicals using Daphnia pulex

The freshwater cladoceran Daphnia pulex was explored as an alternative to Artemia salina for the biological screening of phytochemicals. This paper reports on the results of screening 27 compounds, and comparisons are made with screens using Artemia salina. The effect of miniaturisation of the assay system was investigated. Petri-dish based tests were performed for the 27 compounds using 10 daphnids at each of 5 concentrations (1 - 1000 mg l(-1)). Potassium dichromate was used as a control and the number immobile after 24 hours were counted. Results were expressed as EC(50) values. The active compounds (EC(50) < 25 mg l(-1)) comprised mainly adrenoceptor agonist alkaloids, while the cytotoxins vincristine and colchicine, and several antibiotics were relatively non-toxic towards Daphnia. The method was validated by comparative bioassay of A. belladonna fractions. Overall, this screen compared favourably with those based on Artemia. Daphnia were sensitive to a wide range of biologically active molecules including CNS-stimulants, anti-malarials, narcotics and anti-spasmodics, and the sensitivity was broader than previously seen with Artemia. The screen is perhaps limited by the lack of sensitivity to cytotoxins, but this might be overcome by altering the test criteria.

Surgical therapy for tremor in multiple sclerosis: an evaluation of outcome measures

OBJECTIVE

To assess the reliability, validity, and sensitivity of outcome measures that might be used in a clinical trial of surgery for the treatment of severe tremor associated with MS (MS tremor).

METHODS

Nine patients with MS tremor were evaluated before and 3 and 12 months after thalamic surgery (six thalamotomy, three deep brain stimulation). A clinical tremor rating scale (CTRS), a novel quantitative movement analysis technique (QMA), and a variety of measures of disability, neurologic impairment, and quality of life was utilized.

RESULTS

Both the CTRS and QMA were reliable measures of tremor and both were sensitive to the improvement in tremor following surgery. However, QMA correlated with disability measures and corresponded better to patient and examiner assessment of surgical results. The disability scales used were insensitive to functional improvements that may follow surgery. The box and blocks test clearly separated three patients who had excellent results from three who had poor results. Baseline QMA values predicted improvement on the box and blocks test.

CONCLUSIONS

1) QMA is a reliable, objective and valid measure of MS tremor that could be used in a clinical trial. 2) The box and blocks test can detect the improvement in prehensile function that follows surgery, but standard disability scales are poorly responsive to this change. 3) Preoperative QMA values may predict which patients are most amenable to functional improvement after surgery.

Methyl-substituted diindolylmethanes as inhibitors of estrogen-induced growth of T47D cells and mammary tumors in rats

Diindolylmethane (DIM) is formed by acid catalyzed dimerization of the phytochemical indole-3-carbinol, and both compounds inhibit formation and/or growth of mammary tumors in rodents. In this study, we have investigated the aryl hydrocarbon receptor (AhR) agonist activity and inhibitory AhR-estrogen receptor crosstalk induced by the following methyl-substituted DIMs: 1,1'-dimethyl-, 2,2'-dimethyl-, 5,5'-dimethyl-, 6,6'-dimethyl-, and 7,7'-dimethylDIM and 1,1',2,2'-tetramethylDIM. The six compounds bound to the rat cytosolic AhR in a transformation assay but, at concentrations < or = 10 microM, exhibited minimal to non-detectable AhR agonist or antagonist activities associated with CYP1A1 induction. In contrast, the methyl-substituted DIMs inhibited estrogen-induced T47D human breast cancer cell growth and the four most active compounds (1,1'-, 2,2'-, 5,5'-dimethylDIM and 1,1',2,2'-tetramethylDIM) inhibited one or more estrogen-induced responses in the 21-day-old female B6C3F1 mice at a dose of 100 mg/kg/day (X3). Induction of hepatic CYP1A1-dependent activity was not observed at this high dose. The antitumorigenic activity of these compounds was examined in 7,12-dimethylbenz[a]anthracene-induced rat mammary tumor model in which the DIM analogs were orally administered (by gavage in corn oil) at a dose of 1 mg/kg/day (X10). 1,1'-DimethylDIM, 5,5'-dimethylDIM and 1,1',2,2'-tetramethylDIM significantly inhibited mammary tumor growth, and this was not accompanied by changes in organ/body weights or histopathology. These studies demonstrate that methyl-substituted DIMs are selective AhR modulators (SAhRMs) with potential for clinical treatment of breast cancer.

Asymptomatic occlusion of the left main coronary artery by an aortic pseudoaneurysm

Extrinsic compression of the left main coronary artery is a rare cause of coronary ischemia. We describe a 35-year-old Asian woman with complete asymptomatic occlusion of the left main coronary artery by a large aortic pseudoaneurysm. She underwent repair of the pseudoaneurysm and coronary artery bypass grafting at the Mayo Clinic in Rochester, Minn. The differential diagnosis is discussed. Based on this patient's age and associated vascular lesions, we conclude that Takayasu arteritis was the most likely cause of her condition.

Medication schemas and memory for automated telephone messages

The present study investigated whether older and younger adults use a schema to organize and remember spoken reminder messages for taking medication. Previous research has shown that older and younger adults share preferences for organizing printed instructions for taking medication, suggesting a shared schema. Older and younger participants in Experiment 1 of the present study used a similar schema to organize medication reminder messages. This finding suggests that the medication schema generalizes across communication purpose (to remind or to instruct) as well as across patient age. Medication reminder messages were better understood and remembered when organized to match this schema, whether the reminders were presented as automated telephone messages (Experiment 2) or in printed form (Experiment 3). Schema-compatible organization especially helped people draw inferences from the messages, suggesting that organization helps older and younger adults construct a situation model of the medication-taking task from the messages. Potential applications of organized messages include increasing the impact of automated systems for delivering health services.

Repetition improves older and younger adult memory for automated appointment messages

Automated telephone messaging systems have dramatically expanded communication about health service appointments, but few studies have directly investigated these messages. The present study investigated whether message repetition (1, 2, or 3 presentations) and listener age (mean age = 71 or 19 years) improved memory for automated appointment messages. Repetition improved older and younger adult memory for appointment information. Moreover, 2 presentations reduced age differences in accuracy of answering questions about the messages. This was not the case for free recall, suggesting that older adults differentially benefited from repetition only when provided with additional retrieval support. These findings show that older as well as younger adults benefit from at least 1 repetition of appointment messages. Actual or potential applications of this research include the use of repetition to improve comprehension of automated telephone messages.

High-resolution comparative physical mapping of mouse chromosome 10 in the region of homology with human chromosome 21

Comparative mapping of human and mouse chromosomes can be used to predict locations of homologous loci between the species, provides the substrate to examine the process of chromosomal evolution, and facilitates the continuing development of mouse genetic models for human disorders. A YAC contig of the region of mouse Chromosome (Chr) 10 (MMU10) that demonstrates conserved linkage with the distal portion of human Chr 21 (HSA21) has been constructed. The contig contains all known genes mapped in both species, defines the proximal region of homology between MMU10 and HSA22, and contains the evolutionary junction between HSA21 and HSA22 on MMU10. It consists of 23 YACs and 2 PACs, and covers 3.2 Mb of MMU10. The average marker density for this region is 1 marker/69 kb. Nine of 22 expressed sequences are mapped here for the first time in mouse, and two are newly characterized expressed sequences. The contig also contains 12 simple sequence repeats (SSRs) and 16 YAC and PAC endclone markers. YAC fragmentation analysis was used to create a physical map for the proximal 2.2 Mb of the contig. Cloning of the corresponding region of HSA21 has proven difficult, and the mouse contig includes segments absent from previously described sequence ready maps of HSA21.

Dentistry at the top of the world

This report provides a brief description of the Khumbu region of Nepal, its people, and the availability of dental treatment in this remote area. It also highlights Canadian involvement in the training of dental staff who provide treatment in a new clinic in the region.

The endoscopic forehead lift

Endoscopic techniques are being successfully applied to address eyebrow and forehead ptosis. The methods rely on extensive subperiosteal and subgaleal release of the forehead and scalp flap, allowing the elevation of soft tissues. Ablation of the depressor supercilli and procerus can be performed to address skin folding in the glabellar region. The mobilized frontotemporal flap is then elevated to the desired level and fixated with microscrews to the outer table of the skull. Laterally, the flap is fixed to the deep temporalis fascia. The technique relies upon a solid knowledge of the regional anatomy and the use of specialized instruments now available for dissecting under the flap. The endoscopic forehead lift can achieve results comparable to those obtained by the open coronal forehead lift while minimizing the incidence and extent of postoperative cutaneous anesthesia and telogenic hair loss, which frequently follows open coronal forehead surgery. In addition, the endoscopic technique is able to address eyebrow ptosis in the balding male without causing disfiguring scarring.

Improving consultations between health-care professionals and older clients: implications for pharmacists

Consultations between pharmacists and many clients are now federally mandated in the United States, but guidelines have not been developed for communication in this context. This article reviews research on communication between clients and health-care professionals in order to help develop recommendations for consultations between pharmacists and older clients. The review is organized around a collaborative approach to health communication, which identifies strategies by which speakers and listeners work together to achieve mutually defined goals. This approach is used to analyze cognitive processes underlying communication during pharmacist consultations. This review suggests that miscommunication often reflects a break-down in collaboration between health-care professional and clients. Recommendations are developed to improve collaboration, including suggestions for initiating consultations, presenting easy to understand messages, and monitoring to ensure that the messages are mutually understood. Most important, successful collaboration requires tailoring strategies to individual clients rather than basing communication on general assumptions about clients.

Career pathways and current practice patterns of clinical and counseling psychologists: a follow-up study of former interns

The present study examined career pathways and current work patterns for 110 graduates of an internship program. Results show that the group trained after 1980 went into private practice more rapidly than those trained prior to 1980. Both groups do extensive psychological testing. Implications are discussed.

Acute and 8-hour effects of alcohol (0.08% BAC) on younger and older pilots' simulator performance

This preliminary study examined the acute and 8-hour effects of alcohol at a target peak BAC of 0.08% on pilot performance. Fourteen younger (mean age 27.6 years) and fourteen older (mean age 60.3 years) pilots flew a Frasca 141 simulator in a scenario that included ATC communications and emergencies. Plots were tested during an alcohol and placebo condition at three timepoints: predrink, acute intoxication, and 8 h postdrink. Of eight performance measures, two showed statistically significant effects related to alcohol. First, cockpit monitoring was poorer when pilots were intoxicated, with recovery at 8 h. Second, younger pilots made more communication errors under the influence and there was no significant recovery at 8 h. Older pilots made more communication errors than younger pilots, but possibly because of methodological problems, older pilots' communication performance was not significantly impaired by alcohol. These results provide direction for future research.

Intrathecal cholinergic agonists lessen bupivacaine spinal-block-induced hypotension in rats

Hypotension is an important side effect of spinal anesthesia. Intrathecal (IT) cholinergic agonists, including neostigmine (NEO), increase arterial blood pressure by stimulating spinal sympathetic neurons. Therefore, we tested the ability of IT cholinergic agonists to prevent the hypotensive effect of IT bupivacaine (BUP) (430 nmol) in rats instrumented with IT and arterial catheters. The mean arterial pressure (MAP) decreased 35 +/- 4 mm Hg (n = 10) after IT-BUP alone. In contrast, MAP did not significantly change after IT-BUP + IT-NEO (12.5 and 25 nmol; n = 5 for each dose). Intramuscular (IM) NEO was not effective, and MAP decreased 38 +/- 4 mm Hg after IT-BUP + IM-NEO (25 nmol; n = 5). Three additional cholinesterase inhibitors, physostigmine, edrophonium, and ambenonium, as well as the direct-acting cholinergic agonists carbachol, oxotremorine, and arecoline, each lessened the hypotension seen after IT-BUP. Furthermore, the nonselective muscarinic antagonist, atropine, as well as the M2 receptor selective antagonist, methoctramine, prevented the vasopressor effect of IT-NEO in our model. Finally, the nicotinic antagonist, mecamylamine, and the M1 selective antagonist, pirenzepine, did not affect the pressor effects of NEO in our model. In conclusion, IT cholinergic agonists lessen BUP spinal-block-induced hypotension in rats by a muscarinic dependent pathway.