Intrinsic and Extrinsic Factors Affecting Skin Surface pH.

The body skin pH can usually vary from 4.0 to 7.0 depending on location. The presence of natural acidic compounds on the skin surface helps maintain the skin's physicochemical properties as well as its protective functions. Since the slightly acidic pH of the skin is extremely important for the skin's protective function, the skin is widely known as "acid mantel." Factors such as age, race, gender, body sites, biochemical differences, and even washing affect the pH of the stratum corneum. Recent clinical studies using an emollient-base finish product using the traditional way of measuring skin pH produced results that indicated an apparent increase in skin pH. The apparent pH increase with these products is most probably an artifact of the skin pH measurement technique. Our findings show that certain petrolatum-based emollients and components could create a protective barrier and help maintain the healthy acidity of the skin. Our work provides new evidence of emollients helping to stabilize skin pH in its natural balanced state rather than affecting it. This new learning should be taken into consideration by other researchers in the area of skin pH as well as in clinical studies to avoid misleading results.

Selective inhibition of the p38α MAPK-MK2 axis inhibits inflammatory cues including inflammasome priming signals.

p38α activation of multiple effectors may underlie the failure of global p38α inhibitors in clinical trials. A unique inhibitor (CDD-450) was developed that selectively blocked p38α activation of the proinflammatory kinase MK2 while sparing p38α activation of PRAK and ATF2. Next, the hypothesis that the p38α-MK2 complex mediates inflammasome priming cues was tested. CDD-450 had no effect on NLRP3 expression, but it decreased IL-1ß expression by promoting IL-1ß mRNA degradation. Thus, IL-1ß is regulated not only transcriptionally by NF-κB and posttranslationally by the inflammasomes but also posttranscriptionally by p38α-MK2. CDD-450 also accelerated TNF-α and IL-6 mRNA decay, inhibited inflammation in mice with cryopyrinopathy, and was as efficacious as global p38α inhibitors in attenuating arthritis in rats and cytokine expression by cells from patients with cryopyrinopathy and rheumatoid arthritis. These findings have clinical translation implications as CDD-450 offers the potential to avoid tachyphylaxis associated with global p38α inhibitors that may result from their inhibition of non-MK2 substrates involved in antiinflammatory and housekeeping responses.

Mediated effects of perceived discrimination on adolescent academic achievement: A test of four models.

Many adolescents feel they are subjected to acts of discrimination. Research shows that discrimination is associated with adverse outcomes including poor psychological adjustment, school adjustment, and academic achievement. This study investigated alternative pathways through which discrimination affects adolescents' academic achievement. A sample of 244 Year 7-10 Australian secondary school students (65% male; Mage = 13.6 years; SD = 1.24) completed questionnaires measuring discrimination, psychological adjustment, and sense of school membership. Both at the time of questionnaire completion and one semester later, absenteeism data, teacher ratings of classroom behavior, and academic grades were retrieved from school records. The fit of four competing structural models were compared. In the best fitting model, the effects of prior discrimination on academic achievement one semester later were serially mediated, first through psychological adjustment, and then through school adjustment. By elucidating these mechanisms, the study informs theory and practice regarding the effects of discrimination on adolescents.

Tofacitinib for the treatment of tumor necrosis factor-α inhibitor refractory esophageal Crohn's disease: a case report.

BACKGROUND: Esophageal Crohn's disease is reported as a rare manifestation, although its prevalence may be underestimated because upper endoscopies are not routinely performed in asymptomatic adults. Tofacitinib, an oral janus kinase inhibitor, is a new biologic that has shown promise in the treatment of ulcerative colitis and may be effective in the treatment of Crohn's disease according to phase 2 trials. We report the first case of esophageal Crohn's disease successfully treated with tofacitinib in a patient with worsening symptoms despite maintenance therapy with a tumor necrosis factor-α inhibitor. CASE PRESENTATION: A 67-year-old Caucasian woman presented with new dysphagia and had findings of esophageal Crohn's disease on endoscopy. The dosage of her current biologic therapy-adalimumab-was increased in frequency, without improvement. Our patient was started on tofacitinib and demonstrated an improvement in symptoms, with a repeat endoscopy showing resolution of the previous lesions. CONCLUSION: Esophageal Crohn's disease is likely underdiagnosed but is an important consideration in a patient with new symptoms of dysphagia and known Crohn's disease. Tofacitinib, while a novel agent, could have a role in the treatment of esophageal Crohn's disease that does not improve with intensification of the current biologic therapy. It provides a different mechanism in patients who become refractory to maintenance therapy.

Digitalis for treatment of heart failure in patients in sinus rhythm.

BACKGROUND: Digitalis glycosides have been in clinical use for the treatment of heart failure (HF) for longer than 200 years. In recent years, several trials have been conducted to address concerns about their efficacy and toxicity. OBJECTIVES: To examine the effectiveness of digitalis glycosides in treating HF in patients with normal sinus rhythm. To examine the effects of digitalis in patients taking diuretics and angiotensin-converting enzyme inhibitors; in patients with varying severity and duration of disease; in patients with prior exposure to digitalis versus no prior exposure; and in patients with "HF due to systolic dysfunction" versus "HF with preserved ejection fraction." SEARCH METHODS: Searches on the following databases were updated in May 2013: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Dissertation Abstracts. Annual meeting abstracts of the American Heart Association, the American College of Cardiology, and the European Society of Cardiology were searched from 1996 to March 2013. In addition, reference lists provided by the pharmaceutical industry (GlaxoSmithKline and Covis Pharma) were searched. SELECTION CRITERIA: Included were randomized placebo-controlled trials of 20 or more adult participants of either sex with symptomatic HF who were studied for seven weeks or longer. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of HF such as acute ischemic heart disease or myocarditis was present. DATA COLLECTION AND ANALYSIS: Articles selected from the searches described above were evaluated in a joint effort of the review authors. The staff of the Cochrane Heart Group ran searches on the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE. MAIN RESULTS: No new studies were identified in the updated searches. Thirteen studies (7896 participants) are included, and major endpoints of mortality, hospitalization, and clinical status, based respectively on 8, 4, and 12 of these selected studies, were recorded and analyzed. The data show no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with lower rates of both hospitalization and clinical deterioration. The largest study, in which most participants were taking angiotensin-converting enzyme inhibitors, showed a significant rise in "other cardiac" deaths, possibly due to arrhythmias. However collectively, these findings were based on studies done before beta-blockers, as well as angiotensin receptor blockers and aldosterone antagonists, became widely used to treat HF. AUTHORS' CONCLUSIONS: The literature indicates that digitalis may have a useful role in the treatment of patients with HF who are in normal sinus rhythm. New trials are needed to elucidate the importance of the dosage of digitalis and its usefulness in the era of beta-blockers and other agents shown to be effective in treating HF.

Proton pump inhibitor prescribing and costs in a large outpatient clinic.

UNLABELLED: Concerns have been raised regarding potential adverse effects and high costs of proton pump inhibitors (PPIs). Our objective was to assess issues of PPI utilization and expense in a large outpatient clinic population. METHODS: Two hundred-fifty-nine outpatient records were reviewed regarding PPI prescribing and indications during 2009. A cost analysis was performed to project cost differences if histamine-2 receptor antagonists (H2RAs) were used as an alternative to PPIs in appropriate clinical situations. RESULTS: Eighty-three (32.0%) were taking PPIs. Problem-listed gastroesophageal reflux disease (GERD) was the primary diagnosis in 69 (83.1%) of patients on PPIs. GERD was not apparent by documented history and/or endoscopy in 46.3% of problem-listed GERD patients. Symptom severity had been documented in only 36.2%. Cost analysis projected substantial savings if H2RAs had been used initially for mild to moderate symptoms. CONCLUSIONS: Outpatient PPI prescribing indications are not well documented and PPI use is probably excessive. H2RA therapy is likely underutilized.

Niacin induced coagulopathy as a manifestation of occult liver injury.

Niacin is an effective lipid-lowering agent which occasionally may cause hepatic failure. Liver enzymes are periodically tested during niacin therapy to assess for hepatic injury. We report a case of suppressed synthesis of hepatically derived coagulation factors and other liver proteins in a patient on niacin with no elevation of hepatic aminotransferases. The protein abnormalities reversed rapidly on discontinuation of niacin. It appears that niacin can cause occult liver injury without frank aminotransferase elevations, and may portend severe hepatotoxicity. Periodic assessment of prothrombin time should be considered in addition to aminotransferase levels to screen for liver injury. We believe this is the first reported case of occult hepatic injury due to extended release niacin, presenting as coagulopathy.

Techniques used to characterize the binding of cyclooxygenase inhibitors to the cyclooxygenase active site.

Inhibitors of enzyme-catalyzed reactions are typically characterized by their ability to diminish product formation while altering the Michaelis Menten constants V(max) and K(m). Determination of an apparent inhibitor affinity (K(i)) for the enzyme is also possible using this approach. Unfortunately, analysis of product formation does not easily provide information regarding the kinetics of inhibitor binding and may not be possible depending upon the mechanism of action. Radiolabeling of the inhibitor allows one to do a direct binding assay and thereby more directly determine the kinetics of inhibitor binding. With this in mind, we developed a radioligand-based binding assay for inhibitors of cyclooxygenase.

A benzothiophene inhibitor of mitogen-activated protein kinase-activated protein kinase 2 inhibits tumor necrosis factor alpha production and has oral anti-inflammatory efficacy in acute and chronic models of inflammation.

Activation of the p38 kinase pathway in immune cells leads to the transcriptional and translational regulation of proinflammatory cytokines. Mitogen-activated protein kinase-activated protein kinase 2 (MK2), a direct downstream substrate of p38 kinase, regulates lipopolysaccharide (LPS)-stimulated tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) production through modulating the stability and translation of these mRNAs. Developing small-molecule inhibitors of MK2 may yield anti-inflammatory efficacy with a different safety profile relative to p38 kinase inhibitors. This article describes the pharmacologic properties of a benzothiophene MK2 inhibitor, PF-3644022 [(10R)-10-methyl-3-(6-methylpyridin-3-yl)-9,10,11,12-tetrahydro-8H-[1,4]diazepino[5',6':4,5]thieno[3,2-f]quinolin-8-one]. PF-3644022 is a potent freely reversible ATP-competitive compound that inhibits MK2 activity (K(i) = 3 nM) with good selectivity when profiled against 200 human kinases. In the human U937 monocytic cell line or peripheral blood mononuclear cells, PF-3644022 potently inhibits TNFalpha production with similar activity (IC(50) = 160 nM). PF-3644022 blocks TNFalpha and IL-6 production in LPS-stimulated human whole blood with IC(50) values of 1.6 and 10.3 microM, respectively. Inhibition of TNFalpha in U937 cells and blood correlates closely with inhibition of phospho-heat shock protein 27, a target biomarker of MK2 activity. PF-3644022 displays good pharmacokinetic parameters in rats and is orally efficacious in both the rat acute LPS-induced TNFalpha model and the chronic streptococcal cell wall-induced arthritis model. Dose-dependent inhibition of TNFalpha production in the acute model and inhibition of paw swelling in the chronic model is observed with ED(50) values of 6.9 and 20 mg/kg, respectively. PF-3644022 efficacy in the chronic inflammation model is strongly correlated with maintaining a C(min) higher than the EC(50) measured in the rat LPS-induced TNFalpha model.

Novel insights into the cellular mechanisms of the anti-inflammatory effects of NF-kappaB essential modulator binding domain peptides.

The classical nuclear factor kappaB (NF-kappaB) signaling pathway is under the control of the IkappaB kinase (IKK) complex, which consists of IKK-1, IKK-2, and NF-kappaB essential modulator (NEMO). This complex is responsible for the regulation of cell proliferation, survival, and differentiation. Dysregulation of this pathway is associated with several human diseases, and as such, its inhibition offers an exciting opportunity for therapeutic intervention. NEMO binding domain (NBD) peptides inhibit the binding of recombinant NEMO to IKK-2 in vitro. However, direct evidence of disruption of this binding by NBD peptides in biological systems has not been provided. Using a cell system, we expanded on previous observations to show that NBD peptides inhibit inflammation-induced but not basal cytokine production. We report that these peptides cause the release of IKK-2 from an IKK complex and disrupt NEMO-IKK-2 interactions in cells. We demonstrate that by interfering with NEMO-IKK-2 interactions, NBD peptides inhibit IKK-2 phosphorylation, without affecting signaling intermediates upstream of the IKK complex of the NF-kappaB pathway. Furthermore, in a cell-free system of IKK complex activation by TRAF6 (TNF receptor-associated factor 6), we show that these peptides inhibit the ability of this complex to phosphorylate downstream substrates, such as p65 and inhibitor of kappaB alpha (IkappaB alpha). Thus, consistent with the notion that NEMO regulates IKK-2 catalytic activity by serving as a scaffold, appropriately positioning IKK-2 for activation by upstream kinase(s), our findings provide novel insights into the molecular mechanisms by which NBD peptides exert their anti-inflammatory effects in cells.

A servo-controlled canine model of stable severe ischemic left ventricular failure.

Reversible left ventricular failure was produced in conscious dogs by compromise of the coronary circulation. In animals with prior left anterior descending coronary artery occlusion, mean left atrial pressure (LAP) was incorporated into an automatic feedback control system used to inflate a balloon cuff on the circumflex (Cfx) coronary artery. The system could produce stable increases in LAP to 15-20 mm Hg. The dominating system transfer function was the ratio of LAP to balloon volume (BV), which was characterized by a fixed delay (5 s), with LAP/BV = (8e(-jomegatau ))/(0.02 + jomega). The system was stabilized by a phase lead network to reduce oscillations of LAP. A total of seven experiments were conducted in three dogs, and testing of inotropic agents was possible in three experiments under stable conditions with the pump off after an hour or more of operation. Problems encountered were 0.003-0.008 Hz oscillations in LAP in three experiments, which could usually be controlled by reducing the system gain. Late stage ventricular fibrillation occurred in all three animals, but defibrillation was easily accomplished after deflating the Cfx balloon. This system produces reversible left ventricular failure solely due to ischemia, thus closely simulating clinical heart failure due to coronary insufficiency.

Valdecoxib: assessment of cyclooxygenase-2 potency and selectivity.

The discovery of a second isoform of cyclooxygenase (COX) led to the search for compounds that could selectively inhibit COX-2 in humans while sparing prostaglandin formation from COX-1. Celecoxib and rofecoxib were among the molecules developed from these efforts. We report here the pharmacological properties of a third selective COX-2 inhibitor, valdecoxib, which is the most potent and in vitro selective of the marketed COX-2 inhibitors that we have studied. Recombinant human COX-1 and COX-2 were used to screen for new highly potent and in vitro selective COX-2 inhibitors and compare kinetic mechanisms of binding and enzyme inhibition with other COX inhibitors. Valdecoxib potently inhibits recombinant COX-2, with an IC(50) of 0.005 microM; this compares with IC values of 0.05 microM for celecoxib, 0.5 microM for rofecoxib, and 5 microM for etoricoxib. Unique binding interactions of valdecoxib with COX-2 translate into a fast rate of inactivation of COX-2 (110,000 M/s compared with 7000 M/s for rofecoxib and 80 M/s for etoricoxib). The overall saturation binding affinity for COX-2 of valdecoxib is 2.6 nM (compared with 1.6 nM for celecoxib, 51 nM for rofecoxib, and 260 nM for etoricoxib), with a slow off-rate (t(1/2) approximately 98 min). Valdecoxib inhibits COX-1 in a competitive fashion only at very high concentrations (IC(50) = 150 microM). Collectively, these data provide a mechanistic basis for the potency and in vitro selectivity of valdecoxib for COX-2. Valdecoxib showed similar activity in the human whole-blood COX assay (COX-2 IC(50) = 0.24 microM; COX-1 IC(50) = 21.9 microM). We also determined whether this in vitro potency and selectivity translated to significant potency in vivo. In rats, valdecoxib demonstrated marked potency in acute and chronic models of inflammation (air pouch ED(50) = 0.06 mg/kg; paw edema ED(50) = 5.9 mg/kg; adjuvant arthritis ED(50) = 0.03 mg/kg). In these same animals, COX-1 was spared at doses greater than 200 mg/kg. These data provide a basis for the observed potent anti-inflammatory activity of valdecoxib in humans.

Digitalis for treatment of congestive heart failure in patients in sinus rhythm: a systematic review and meta-analysis.

BACKGROUND: This review summarizes the current status of randomized trials of digitalis in treating patients with congestive heart failure who are in sinus rhythm. Methods and results Randomized double-blind placebo-controlled trials of 20 or more adult patients followed for 7 weeks or more were selected. We identified 13 trials that met the inclusion criteria, comprising a total of 7896 patients. Of this number, 7755 patients contributed to information on mortality, 7262 to information on hospitalization for worsening heart failure, and 1096 to information on clinical status. Patients treated with digitalis compared with placebo had an odds ratio and confidence intervals for mortality of 0.98 (0.89, 1.09), for hospitalization of 0.68 (0.61, 0.75), and for a lesser degree of deterioration in clinical status of 0.31 (0.21, 0.43). CONCLUSIONS: The literature indicates that the drug has no effect on long-term mortality, but reduces the incidence of hospitalization, and has a positive effect on the clinical status of symptomatic patients. The drug has beneficial effects in patients who remain symptomatic despite being appropriately treated with diuretics and angiotensin-converting enzyme inhibitors. However the effects of coadministration with beta-blockers, spironolactone, and valsartan remain uncertain.

Characterization of celecoxib and valdecoxib binding to cyclooxygenase.

Two compounds (celecoxib and valdecoxib) from the diarylheterocycle class of cyclooxygenase inhibitors were radiolabeled and used to characterize their binding to cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), several single-point variants of COX-2 (Val523Ile, Tyr355Ala, Arg120Ala, Arg120Gln, Arg120Asn) and one triple-point variant of COX-2 [Val523Ile, Arg513His, Val434Ile (IHI)]. We demonstrate highly specific and saturable binding of these inhibitors to COX-2. Under the same assay conditions, little or no specific binding to COX-1 could be detected. The affinity of [(3)H]celecoxib for COX-2 (K(D) = 2.3 nM) was similar to the affinity of [(3)H]valdecoxib (K(D) = 3.2 nM). The binding to COX-2 seems to be both rapid and slowly reversible with association rates of 5.8 x 10(6)/M/min and 4.5 x 10(6)/M/min and dissociation rates of 14 x 10(-3)/min (t(1/2) = 50 min) and 7.0 x 10(-3)/min (t(1/2) = 98 min) for [(3)H]celecoxib and [(3)H]valdecoxib, respectively. These association rates increased (4- to 11-fold) when the charged arginine residue located at the entrance to the main hydrophobic channel was mutated to smaller uncharged amino acids (Arg120Ala, Arg120Gln, and Arg120Asn). Mutation of residues located within the active site of COX-2 that define a 'side pocket' (Tyr355Ala, Val523Ile, IHI) of the main channel had a greater effect on the dissociation rate than the association rate. These mutations, which modified the shape of and access to the 'side pocket', affected the binding affinity of [(3)H]valdecoxib more than that of [(3)H]celecoxib. These binding studies provide direct insight into the properties and binding constants of celecoxib and valdecoxib to COX-2.

Examination of the kinetic mechanism of mitogen-activated protein kinase activated protein kinase-2.

The kinetic mechanism of mitogen-activated protein kinase activated protein kinase-2 (MAPKAPK2) was investigated using a peptide (LKRSLSEM) based on the phosphorylation site found in serum response factor (SRF). Initial velocity studies yielded a family of double-reciprocal lines that appear parallel and indicative of a ping-pong mechanism. The use of dead-end inhibition studies did not provide a definitive assignment of a reaction mechanism. However, product inhibition studies suggested that MAPKAPK2 follows an ordered bi-bi kinetic mechanism, where ATP must bind to the enzyme prior to the SRF-peptide and the phosphorylated product is released first, followed by ADP. In agreement with these latter results, surface plasmon resonance measurements demonstrate that the binding of the inhibitor peptide to MAPKAPK2 requires the presence of ATP. Furthermore, competitive inhibitors of ATP, adenosine 5'-(beta,gamma-imino)triphosphate (AMPPNP) and a staurosporine analog (K252a), can inhibit this ATP-dependent binding providing further evidence that the peptide substrate binds preferably to the E:ATP complex.

Effect of enalapril on survival in patients with reduced left ventricular ejection fractions and congestive heart failure.

BACKGROUND: Patients with congestive heart failure have a high mortality rate and are also hospitalized frequently. We studied the effect of an angiotensin-converting-enzyme inhibitor, enalapril, on mortality and hospitalization in patients with chronic heart failure and ejection fractions less than or equal to 0.35. METHODS: Patients receiving conventional treatment for heart failure were randomly assigned to receive either placebo (n = 1284) or enalapril (n = 1285) at doses of 2.5 to 20 mg per day in a double-bind trial. Approximately 90 percent of the patients were in New York Heart Association functional classes II and III. The follow-up averaged 41.4 months. RESULTS: There were 510 deaths in the placebo group (39.7 percent), as compared with 452 in the enalapril group (35.2 percent) (reduction in risk, 16 percent; 95 percent confidence interval, 5 to 26 percent; P = 0.0036). Although reductions in mortality were observed in several categories of cardiac deaths, the largest reduction occurred among the deaths attributed to progressive heart failure (251 in the placebo group vs. 209 in the enalapril group; reduction in risk, 22 percent; 95 percent confidence interval, 6 to 35 percent). There was little apparent effect of treatment on deaths classified as due to arrhythmia without pump failure. Fewer patients died or were hospitalized for worsening heart failure (736 in the placebo group and 613 in the enalapril group; risk reduction, 26 percent; 95 percent confidence interval, 18 to 34 percent; P less than 0.0001). CONCLUSIONS: The addition of enalapril to conventional therapy significantly reduced mortality and hospitalizations for heart failure in patients with chronic congestive heart failure and reduced ejection fractions.