Positive allosteric modulators of the α7 nicotinic acetylcholine receptor: SAR investigation around PNU-120596.

The α7 nicotinic acetylcholine receptor is a calcium permeable, ligand-gated ion channel that modulates synaptic transmission in the hippocampus, thalamus, and cerebral cortex. Previously disclosed work described PNU-120596 that acts as a powerful positive allosteric modulator of the α7 nicotinic acetylcholine receptor. The initial structure-activity relationships around PNU-120596 were gleaned from screening a large thiazole library. Independent systematic examination of the aryl and heteroaryl groups resulted in compounds with enhanced potency and improved physico-chemical properties culminating in the identification of 16 (PHA-758454). In the presence of acetylcholine, 16 enhanced evoked currents in rat hippocampal neurons. In a rat model of impaired sensory gating, treatment with 16 led to a reversal of the gating deficit in a dose-dependent manner. These results demonstrate that aryl heteroaryl ureas, like compound 16, may be useful tools for continued exploration of the unique biology of the α7 nicotinic acetylcholine receptor.

Cost-effectiveness of bariatric surgery and non-surgical weight management programmes for adults with severe obesity: a decision analysis model.

OBJECTIVES: To determine the most cost-effective weight management programmes (WMPs) for adults, in England with severe obesity (BMI ≥ 35 kg/m2), who are more at risk of obesity related diseases. METHODS: An economic evaluation of five different WMPs: 1) low intensity (WMP1); 2) very low calorie diets (VLCD) added to WMP1; 3) moderate intensity (WMP2); 4) high intensity (Look AHEAD); and 5) Roux-en-Y gastric bypass (RYGB) surgery, all compared to a baseline scenario representing no WMP. We also compare a VLCD added to WMP1 vs. WMP1 alone. A microsimulation decision analysis model was used to extrapolate the impact of changes in BMI, obtained from a systematic review and meta-analysis of randomised controlled trials (RCTs) of WMPs and bariatric surgery, on long-term risks of obesity related disease, costs, quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) measured as incremental cost per QALY gained over a 30-year time horizon from a UK National Health Service (NHS) perspective. Sensitivity analyses explored the impact of long-term weight regain assumptions on results. RESULTS: RYGB was the most costly intervention but also generated the lowest incidence of obesity related disease and hence the highest QALY gains. Base case ICERs for WMP1, a VLCD added to WMP1, WMP2, Look AHEAD, and RYGB compared to no WMP were £557, £6628, £1540, £23,725 and £10,126 per QALY gained respectively. Adding a VLCD to WMP1 generated an ICER of over £121,000 per QALY compared to WMP1 alone. Sensitivity analysis found that all ICERs were sensitive to the modelled base case, five year post intervention cessation, weight regain assumption. CONCLUSIONS: RYGB surgery was the most effective and cost-effective use of scarce NHS funding resources. However, where fixed healthcare budgets or patient preferences exclude surgery as an option, a standard 12 week behavioural WMP (WMP1) was the next most cost-effective intervention.

Family recurrence risk of alopecia areata in the Faroe Islands.

BACKGROUND: Reports of a positive family history of alopecia areata (AA) have led to the assumption of a genetic component. The Faroe Islands population is small, has been isolated until the 20th century, and is served by only one dermatology clinic, making it highly suitable for genealogical studies. AIM: To determine the incidence of AA and to estimate the recurrence risk ratio (RRR) in five generations and in a nationwide dermatologist-based AA cohort using the Faroese genealogy database. METHODS: All registered cases of AA during the period 1973-2011 were identified from the Faroese national dermatology clinics. The AA cases were linked with the genealogy database covering the entire Faroese population, and the probability of AA among first-, second- and third-degree relatives was calculated. RESULTS: In total, 178 cases of AA were identified, giving a crude incidence of 10.1 per 100 000 person-years (10.9 for women and 9.4 for men). The cumulative incidence proportion over life was 0.8%. There was no apparent trend in the probabilities for AA in first-degree family members compared with second- and third-degree relatives. RRR was > 1 in second-degree family members only. CONCLUSION: A lower prevalence rate of AA was found than previously published. The genealogical study failed to identify any apparent trend in the RRR estimates, questioning the role of genetic factors in AA in the Faroe Islands. However, it is possible that the trend is masked by bias and low power; larger studies are therefore warranted to estimate the heritability of AA.

Healthcare utilisation, induced labour and caesarean section in the pregnancy after stillbirth: a prospective study.

OBJECTIVE: To investigate healthcare utilisation, induced labour and caesarean section (CS) in the pregnancy after stillbirth and assess anxiety and dread of childbirth as mediators for these outcomes. DESIGN: Population-based pregnancy cohort study. SETTING: The Norwegian Mother and Child Cohort Study. SAMPLE: A total of 901 pregnant women; 174 pregnant after stillbirth, 362 pregnant after live birth and 365 previously nulliparous. METHODS: Data from questionnaires answered in the second and third trimesters of pregnancy and information from the Medical Birth Registry of Norway. MAIN OUTCOME MEASURES: Self-reported assessment of antenatal care, register-based assessment of onset and mode of delivery. RESULTS: Women with a previous stillbirth had more frequent antenatal visits (mean 10.0; 95% CI 9.4-10.7) compared with women with a previous live birth (mean 6.0; 95% CI 5.8-6.2) and previously nulliparous women (mean 6.3; 95% CI 6.1-6.6). Induced labour and CS, elective and emergency, were also more prevalent in the stillbirth group. The adjusted odds ratio for elective CS was 2.5 (95% CI 1.3-5.0) compared with women with previous live birth and 3.7 (1.8-7.6) compared with previously nulliparous women. Anxiety was a minor mediator for the association between stillbirth and frequency of antenatal visits, whereas dread of childbirth was not a significant mediator for elective CS. CONCLUSIONS: Women pregnant after stillbirth were more ample users of healthcare services and more often had induced labour and CS. The higher frequency of antenatal visits and elective CS could not be accounted for by anxiety or dread of childbirth. TWEETABLE ABSTRACT: Women pregnant after stillbirth are ample users of healthcare services and interventions during childbirth.

Normalized serum eosinophil peroxidase levels are inversely correlated with esophageal eosinophilia in eosinophilic esophagitis.

Eosinophil peroxidase is an eosinophil-specific, cytoplasmic protein stored in the secondary granules of eosinophils. While eosinophil peroxidase deposition is increased in the esophagus in eosinophilic esophagitis (EOE), its potential role as a peripheral marker is unknown. This study aims to examine the relationship between serum eosinophil peroxidase and esophageal eosinophilia in eosinophilic esophagitis. Prospectively collected serum from 19 subjects with incident EoE prior to treatment and 20 non-EoE controls were tested for serum eosinophil peroxidase, eosinophilic cationic protein, and eosinophil derived neurotoxin using ELISA. Matching esophageal tissue sections were stained and assessed for eosinophil peroxidase deposition using a histopathologic scoring algorithm. Mean peripheral blood absolute eosinophil counts in eosinophilic esophagitis subjects were significantly elevated compared to controls (363 vs. 195 cells/µL, P = 0.008). Absolute median serum eosinophil peroxidase, eosinophil cationic protein, and eosinophil derived neurotoxin did not differ between groups; however, when normalized for absolute eosinophil counts, eosinophilic esophagitis subjects had significantly lower median eosinophil peroxidase levels (2.56 vs. 6.96 ng/mL per eos/µL, P = 0.002, AUC 0.79 (0.64, 0.94 95% CI)). Multivariate analysis demonstrated this relationship persisted after controlling for atopy. Esophageal biopsies from eosinophilic esophagitis subjects demonstrated marked eosinophil peroxidase deposition (median score 46 vs. 0, P < 0.0001). Normalized eosinophil peroxidase levels inversely correlated with esophageal eosinophil density (r = -0.41, P = 0.009). In contrast to marked tissue eosinophil degranulation, circulating eosinophils appear to retain their granule proteins in EoE. Investigations of normalized serum eosinophil peroxidase levels as a biomarker of EoE are ongoing.

Antiphospholipid Antibodies are Associated with Low Levels of Complement C3 and C4 in Patients with Systemic Lupus Erythematosus.

Complement activation and low complement levels are common in systemic lupus erythematosus (SLE). Antiphospholipid antibodies (aPL) are found in about 30-40% of patients with SLE. This study aimed to investigate the association between aPL and complement levels in patients with SLE. Serum samples were collected from 269 patients with SLE enrolled in the Norwegian Systemic Connective Tissue and Vasculitis Registry (NOSVAR) during 2003-2009, and from 353 controls. All samples were analysed for anti-ß2 glycoprotein 1 (anti-ß2GP1) and anticardiolipin antibodies (aCL), C-reactive protein (CRP) and complement components C3 and C4. Median CRP level was significantly higher in cases than in controls (2.06 versus 0.90 mg/l; P < 0.0001). No significant difference in CRP was found between SLE patients with or without aPL (2.09 versus 1.89; P = 0.665). Median C3 levels were similar in cases (1.03 g/l) and controls (1.00 g/l), whereas median C4 levels were 0.16 g/l in cases versus. 0.19 in controls (P < 0.0001). However, aPL-positive SLE patients had significantly lower median C3 levels (0.92 versus. 1.07 g/l; P = 0.001) and C4 levels (0.11 versus 0.16 g/l; P < 0.0001) compared to aPL-negative patients. Lower C3 and C4 values in aPL-positive SLE patients may reflect a higher consumption of C3 and C4 due to more pronounced complement activation in aPL-positive SLE patients compared to SLE patients without aPL.

The hepatitis B virus ribonuclease H is sensitive to inhibitors of the human immunodeficiency virus ribonuclease H and integrase enzymes.

Nucleos(t)ide analog therapy blocks DNA synthesis by the hepatitis B virus (HBV) reverse transcriptase and can control the infection, but treatment is life-long and has high costs and unpredictable long-term side effects. The profound suppression of HBV by the nucleos(t)ide analogs and their ability to cure some patients indicates that they can push HBV to the brink of extinction. Consequently, more patients could be cured by suppressing HBV replication further using a new drug in combination with the nucleos(t)ide analogs. The HBV ribonuclease H (RNAseH) is a logical drug target because it is the second of only two viral enzymes that are essential for viral replication, but it has not been exploited, primarily because it is very difficult to produce active enzyme. To address this difficulty, we expressed HBV genotype D and H RNAseHs in E. coli and enriched the enzymes by nickel-affinity chromatography. HBV RNAseH activity in the enriched lysates was characterized in preparation for drug screening. Twenty-one candidate HBV RNAseH inhibitors were identified using chemical structure-activity analyses based on inhibitors of the HIV RNAseH and integrase. Twelve anti-RNAseH and anti-integrase compounds inhibited the HBV RNAseH at 10 µM, the best compounds had low micromolar IC(50) values against the RNAseH, and one compound inhibited HBV replication in tissue culture at 10 µM. Recombinant HBV genotype D RNAseH was more sensitive to inhibition than genotype H. This study demonstrates that recombinant HBV RNAseH suitable for low-throughput antiviral drug screening has been produced. The high percentage of compounds developed against the HIV RNAseH and integrase that were active against the HBV RNAseH indicates that the extensive drug design efforts against these HIV enzymes can guide anti-HBV RNAseH drug discovery. Finally, differential inhibition of HBV genotype D and H RNAseHs indicates that viral genetic variability will be a factor during drug development.

Differential activation of airway eosinophils induces IL-13-mediated allergic Th2 pulmonary responses in mice.

BACKGROUND: Eosinophils are hallmark cells of allergic Th2 respiratory inflammation. However, the relative importance of eosinophil activation and the induction of effector functions such as the expression of IL-13 to allergic Th2 pulmonary disease remain to be defined. METHODS: Wild-type or cytokine-deficient (IL-13(-/-) or IL-4(-/-) ) eosinophils treated with cytokines (GM-CSF, IL-4, IL-33) were adoptively transferred into eosinophil-deficient recipient mice subjected to allergen provocation using established models of respiratory inflammation. Allergen-induced pulmonary changes were assessed. RESULTS: In contrast to the transfer of untreated blood eosinophils to the lungs of recipient eosinophil deficient mice, which induced no immune/inflammatory changes either in the lung or in the lung draining lymph nodes (LDLN), pretreatment of blood eosinophils with GM-CSF prior to transfer elicited trafficking of these eosinophils to LDLN. In turn, these LDLN eosinophils elicited the accumulation of dendritic cells and CD4(+) T cells to these same LDLNs without inducing pulmonary inflammation. However, exposure of eosinophils to GM-CSF, IL-4, and IL-33 prior to transfer induced not only immune events in the LDLN, but also allergen-mediated increases in airway Th2 cytokine/chemokine levels, the subsequent accumulation of CD4(+) T cells as well as alternatively activated (M2) macrophages, and the induction of pulmonary histopathologies. Significantly, this allergic respiratory inflammation was dependent on eosinophil-derived IL-13, whereas IL-4 expression by eosinophils had no significant role. CONCLUSION: The data demonstrate the differential activation of eosinophils as a function of cytokine exposure and suggest that eosinophil-specific IL-13 expression by activated cells is a necessary component of the subsequent allergic Th2 pulmonary pathologies.

Re-defining the unique roles for eosinophils in allergic respiratory inflammation.

The role of eosinophils in the progression and resolution of allergic respiratory inflammation is poorly defined despite the commonality of their presence and in some cases their use as a biomarker for disease severity and/or symptom control. However, this ambiguity belies the wealth of insights that have recently been gained through the use of eosinophil-deficient/attenuated strains of mice that have demonstrated novel immunoregulatory and remodelling/repair functions for these cells in the lung following allergen provocation. Specifically, studies of eosinophil-deficient mice suggest that eosinophils contribute to events occurring in the lungs following allergen provocation at several key moments: (i) the initiating phase of events leading to Th2-polarized pulmonary inflammation, (ii) the suppression Th1/Th17 pathways in lung-draining lymph nodes, (iii) the recruitment of effector Th2 T cells to the lung, and finally, (iv) mechanisms of inflammatory resolution that re-establish pulmonary homoeostasis. These suggested functions have recently been confirmed and expanded upon using allergen provocation of an inducible eosinophil-deficient strain of mice (iPHIL) that demonstrated an eosinophil-dependent mechanism(s) leading to Th2 dominated immune responses in the presence of eosinophils in contrast to neutrophilic as well as mixed Th1/Th17/Th2 variant phenotypes in the absence of eosinophils. These findings highlighted that eosinophils are not exclusively downstream mediators controlled by T cells, dendritic cells (DC) and/or innate lymphocytic cells (ILC2). Instead, eosinophils appear to be more aptly described as significant contributors in complex interrelated pathways that lead to pulmonary inflammation and subsequently promote resolution and the re-establishment of homoeostatic baseline. In this review, we summarize and put into the context the evolving hypotheses that are now expanding our understanding of the roles eosinophils likely have in the lung following allergen provocation.

Eosinophil activities modulate the immune/inflammatory character of allergic respiratory responses in mice.

BACKGROUND: The importance and specific role(s) of eosinophils in modulating the immune/inflammatory phenotype of allergic pulmonary disease remain to be defined. Established animal models assessing the role(s) of eosinophils as contributors and/or causative agents of disease have relied on congenitally deficient mice where the developmental consequences of eosinophil depletion are unknown. METHODS: We developed a novel conditional eosinophil-deficient strain of mice (iPHIL) through a gene knock-in strategy inserting the human diphtheria toxin (DT) receptor (DTR) into the endogenous eosinophil peroxidase genomic locus. RESULTS: Expression of DTR rendered resistant mouse eosinophil progenitors sensitive to DT without affecting any other cell types. The presence of eosinophils was shown to be unnecessary during the sensitization phase of either ovalbumin (OVA) or house dust mite (HDM) acute asthma models. However, eosinophil ablation during airway challenge led to a predominantly neutrophilic phenotype (>15% neutrophils) accompanied by allergen-induced histopathologies and airway hyper-responsiveness in response to methacholine indistinguishable from eosinophilic wild-type mice. Moreover, the iPHIL neutrophilic airway phenotype was shown to be a steroid-resistant allergic respiratory variant that was reversible upon the restoration of peripheral eosinophils. CONCLUSIONS: Eosinophil contributions to allergic immune/inflammatory responses appear to be limited to the airway challenge and not to the sensitization phase of allergen provocation models. The reversible steroid-resistant character of the iPHIL neutrophilic airway variant suggests underappreciated mechanisms by which eosinophils shape the character of allergic respiratory responses.

Successful haploidentical hematopoietic stem cell transplantation in a patient with SCID due to CD3ε deficiency: need for IgG-substitution 6 years later.

BACKGROUND: The CD3 co-receptor complex is essential for signal transduction after specific binding of the T-cell receptor (TCR). CD3E encodes the CD3ε chain, one of the protein components (γ-, δ-, ε- and ζ-chain) of the CD3 co-receptor. As previously reported in one family CD3ε deficiency causes SCID. PATIENT: We report on a patient with SCID due to CD3ε deficiency treated by HLA-haploidentical stem cell transplantation (SCT) (donor: mother) 15 years ago which resulted in development of normal T- and B-cell immunity. Despite conditioning donor cell engraftment was confined to T cells, while all other blood cell lineages remained of patient origin (split chimerism). In spite of normal functions, T-cell numbers never reached normal levels and naïve CD45+RA+ T-cells remained low. At 6 years after SCT the patient developed signs of humoral immunodeficiency, requiring regular substitution of IgG. RESULTS: In a retrospective genetic work up 11 years after SCT, a homozygous splice site mutation in CD3E was identified resulting in the loss of CD3ε protein. The loss of B-cell function as observed in the patient was reflected by a lack of switched memory B cells. To rule out a primary role of CD3ε in B-cell function we studied expression of CD3E in B-cells which was found not to be expressed. DISCUSSION: The clinical presentation of a secondary loss of specific humoral immunity in this constellation of split chimerism after allogeneic haploidentical SCT is unusual and unexpected in a patient with a primary T-cell defect. A most likely explanation is the gradual loss of T-helper-cell function.

Socioeconomic position, stage of lung cancer and time between referral and diagnosis in Denmark, 2001-2008.

INTRODUCTION: We investigated the association between socioeconomic position, stage at diagnosis, and length of period between referral and diagnosis in a nationwide cohort of lung cancer patients. METHODS: Through the Danish Lung Cancer Register, we identified 18,103 persons diagnosed with lung cancer (small cell and non-small cell) in Denmark, 2001-2008, and obtained information on socioeconomic position and comorbidity from nationwide administrative registries. The odds ratio (OR) for a diagnosis of advanced-stage lung cancer (stages IIIB-IV) and for a diagnosis >28 days after referral were analysed by multivariate logistic regression models. RESULTS: The adjusted OR for advanced-stage lung cancer was reduced among persons with higher education (OR, 0.92; 95% confidence interval (CI), 0.84-0.99), was increased in persons living alone (OR, 1.06; 95% CI, 1.01-1.13) and decreased stepwise with increasing comorbidity. Higher education was associated with a reduced OR for >28 days between referral and diagnosis as was high income in early-stage patients. Male gender, age and severe comorbidity were associated with increased ORs in advanced-stage patients. INTERPRETATION: Differences by socioeconomic position in stage at diagnosis and in the period between referral and diagnosis indicate that vulnerable patients presenting with lung cancer symptoms require special attention.

A large single-center experience with allogeneic stem-cell transplantation for peripheral T-cell non-Hodgkin lymphoma and advanced mycosis fungoides/Sezary syndrome.

BACKGROUND: The prognosis for patients with most forms of T-cell lymphoma is poor. Allogeneic hematopoietic stem-cell transplantation (HSCT) may improve the outcome. PATIENTS AND METHODS: This study examines the outcome of 52 patients who underwent ablative or nonablative allogeneic HSCT for peripheral T-cell lymphoma (PTCL) or advanced mycosis fungoides/Sezary syndrome over a 12-year period at a single institution. We divided the patients into those with predominantly nodal histologies: peripheral T-cell not otherwise specified (PTCL NOS), angioimmunoblastic (AITL), or anaplastic large cell lymphoma, T/null type (systemic) (ALCL), and predominantly extranodal histologies: natural killer (NK)/T cell, enteropathy type, hepatosplenic, subcutaneous panniculitic, mycosis fungoides, or T cell or NK cell other. RESULTS: Median follow-up of survivors is 49 months. Non-relapse mortality and relapse at 3 years was 27% and 43%, respectively. The incidence of grade II-IV acute graft-versus-host disease (GVHD) was 21%. The incidence of extensive chronic GVHD at 2 years was 27%. The 3-year progression-free survival was 30%: 45% in patients with predominantly nodal histologies (PTCL NOS, AITL, and ALCL) and 6% in patients with predominantly extranodal histologies (P = 0.016). Overall survival at 3 years was 41% for all patients. CONCLUSION: Allogeneic HSCT can produce long-term remissions in relapsed/refractory T-cell lymphoma, especially those with nodal histologies.

Anthocyanin production as a potential visual selection marker during plant transformation.

A mutant allele of the transcription factor gene MYB10 from apple induces anthocyanin production throughout the plant. This gene, including its upstream promoter, gene coding region and terminator sequence, was introduced into apple, strawberry and potato plants to determine whether it could be used as a visible selectable marker for plant transformation as an alternative to chemically selectable markers, such as kanamycin resistance. After transformation, red coloured calli, red shoots and red well-growing plants were scored. Red and green shoots were harvested from apple explants and examined for the presence of the MYB10 gene by PCR analysis. Red shoots of apple explants always contained the MYB10 gene but not all MYB10 containing shoots were red. Strawberry plants transformed with the MYB10 gene showed anthocyanin accumulation in leaves and roots. No visible accumulation of anthocyanin could be observed in potato plants grown in vitro, even the ones carrying the MYB10 gene. However, acid methanol extracts of potato shoots or roots carrying the MYB10 gene contained up to four times higher anthocyanin content than control plants. Therefore anthocyanin production as result of the apple MYB10 gene can be used as a selectable marker for apple, strawberry and potato transformation, replacing kanamycin resistance.

Investigation of the pyrazinones as PDE5 inhibitors: evaluation of regioisomeric projections into the solvent region.

We describe the design, synthesis and profiling of a novel series of PDE5 inhibitors. We take advantage of an alternate projection into the solvent region to identify compounds with excellent potency, selectivity and pharmacokinetic profiles.

Eosinophils in health and disease: the LIAR hypothesis.

Discussions of eosinophils are often descriptions of end-stage effector cells with destructive capabilities mediated predominantly by released cytotoxic cationic granule proteins. Moreover, eosinophils in the medical literature are invariably associated with the pathologies linked with helminth infections or allergic diseases such as asthma. This has led to an almost fatalist view of eosinophil effector functions and associated therapeutic strategies targeting these cells that would make even William of Ockham proud - eosinophil effector functions have physiological consequences that increase patient morbidity/mortality and 'the only good eosinophils are dead eosinophils'. Unfortunately, the strengths of dogmas are also their greatest weaknesses. Namely, while the repetitive proclamation of dogmatic concepts by authoritative sources (i.e. reviews, meeting proceedings, textbooks, etc.) builds consensus within the medical community and lower the entropies surrounding difficult issues, they often ignore not easily explained details and place diminished importance on alternative hypotheses. The goal of this perspective is twofold: (i) we will review recent observations regarding eosinophils and their activities as well as reinterpret earlier data as part of the synthesis of a new paradigm. In this paradigm, we hypothesize that eosinophils accumulate at unique sites in response to cell turnover or in response to local stem cell activity(ies). We further suggest that this accumulation is part of one or more mechanisms regulating tissue homeostasis. Specifically, instead of immune cells exclusively mediating innate host defence, we suggest that accumulating tissue eosinophils are actually regulators of Local Immunity And/or Remodeling/Repair in both health and disease - the LIAR hypothesis; (ii) we want to be inflammatory (pun intended!) and challenge the currently common perspective of eosinophils as destructive end-stage effector cells. Our hope is to create more questions than we answer and provoke everyone to spend countless hours simply to prove us wrong!

1-(2-Ethoxyethyl)-1H-pyrazolo[4,3-d]pyrimidines as potent phosphodiesterase 5 (PDE5) inhibitors.

1H-Pyrazolo[4,3-d]pyrimidines are a class of potent and selective second generation phosphodiesterase 5 (PDE5) inhibitors. This work explores the potency, selectivity and efficacy of 1-(2-ethoxyethyl)-1H-pyrazolo[4,5-d]pyrimidines as PDE5 inhibitors resulting in the advancement of a clinical candidate.

1-(2-(2,2,2-trifluoroethoxy)ethyl-1H-pyrazolo[4,3-d]pyrimidines as potent phosphodiesterase 5 (PDE5) inhibitors.

1H-Pyrazolo[4,3-d]pyrimidines were previously disclosed as a potent second generation class of phosphodiesterase 5 (PDE5) inhibitors. This work explores the advancement of more selective and potent PDE5 inhibitors resulting from the substitution of 2-(2,2,2-trifluoroethoxy)ethyl at the 1 position in the so-called alkoxy pocket.

Generation and Detection of Coherent Elastic Waves at 114,000 Mc/sec.

Coherent elastic waves were generated and detected at 114,000 megacycles per second in quartz at liquid-helium temperatures. Effective input power was approximately 3 milliwatts. The results suggest that the piezoelectric method may be applicable to similar experiments at much higher frequencies.