Preliminary clinical pharmacokinetic evaluation of bemotrizinol - A new sunscreen active ingredient being considered for inclusion under FDA's over-the-counter (OTC) sunscreen monograph

Protection against sunburn, skin damage and the carcinogenic effects of ultraviolet light are the primary health benefits associated with UV filters used in topical sunscreen drug products. Countries such as Europe have 30+ UV filters approved for sunscreen products while the US has about 10, greatly reducing the options to provide diverse, effective sun protection products. Bemotrizinol (BEMT) is the first new sunscreen active ingredient to be evaluated for inclusion in the Over-The-Counter (OTC) sunscreen monograph using FDA's new Generally Recognized as Safe and Effective (GRASE) testing guidelines. An in vitro skin permeation test (IVPT) and clinical pilot pharmacokinetic Maximum Usage Trial (MUsT) were completed to support the GRASE determination for 6% BEMT. IVPT results indicated an oil +10% ethanol as the model sunscreen intervention for the pilot MUsT. The open-label trial revealed: BEMT concentrations rarely exceeded FDA's defined threshold (0.5 ng/mL) in plasma; no evidence for BEMT accumulation or steady-state concentrations above threshold; only one moderate and few mild treatment emergent adverse events (TEAEs). Therefore, maximal topical applications of 6% BEMT in a model sunscreen formulation did not contribute to meaningful systemic exposure. These results support the safety of BEMT 6% for human sunscreen use.

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (III) A Randomized Trial with Interferon Beta-1a Products

The US Food and Drug Administration (FDA) has taken steps to bring efficiency to the development of biosimilars, including establishing guidance for the use of pharmacokinetic and pharmacodynamic (PD) similarity study data without a comparative clinical study with efficacy end point(s). To better understand the potential role for PD biomarkers in biosimilar development and inform best practices for biomarker selection and analysis, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants. Eighty-four healthy participants (n = 12 per dose arm) received either placebo or one of three doses of either interferon β-1a (7.5-30 μg) or pegylated interferon β-1a (31.25-125 μg) to evaluate the maximum change from baseline and the baseline-adjusted area under the effect curve for the biomarkers neopterin in serum and myxovirus resistance protein 1 in blood. Both PD biomarkers increased following product administration with clear separation from baseline (neopterin: 3.4-fold and 3.9-fold increase for interferon β-1a and pegylated interferon β-1a, respectively; myxovirus resistance protein 1: 19.0-fold and 47.2-fold increase for interferon β-1a and pegylated interferon β-1a, respectively). The dose-response curves support that therapeutic doses were adequately sensitive to detect differences in both PD biomarkers for consideration in a PD similarity study design. Because baseline levels of both biomarkers are low compared with on-treatment values, there was little difference in using PD measures adjusted to baseline compared with the results without baseline adjustment. This study illustrates potential methodologies for evaluating PD biomarkers and an approach to address information gaps when limited information is publicly available for one or more PD biomarkers.

Evaluating the Utility of Proteomics for the Identification of Circulating Pharmacodynamic Biomarkers of IFNβ-1a Biologics

Proteomics has the potential to identify pharmacodynamic (PD) biomarkers for similarity assessment of proposed biosimilars without relying on clinical efficacy end points. In this study, with 36 healthy participants randomized to therapeutic doses of interferon-beta 1a products (IFNβ-1a) or pegylated-IFNβ-1a (pegIFNβ-1a) approved to treat multiple sclerosis or placebo, we evaluated the utility of a proteomic assay that profiles > 7,000 plasma proteins. IFNβ-1a and pegIFNβ-1a resulted in 248 and 528 differentially expressed protein analytes, respectively, between treatment and placebo groups over the time course. Thirty-one proteins were prioritized based on a maximal fold change ≥ 2 from baseline, baseline adjusted area under the effect curve (AUEC) and overlap between the 2 products. Of these, the majority had a significant AUEC compared with placebo in response to either product; 8 proteins showed > 4-fold maximal change from baseline. We identified previously reported candidates, beta-2microglobulin and interferon-induced GTP-binding protein (Mx1) with ~ 50% coefficient of variation (CV) for AUEC, and many new candidates (including I-TAC, C1QC, and IP-10) with CVs ranging from 26%-129%. Upstream regulator analysis of differentially expressed proteins predicted activation of IFNβ1 signaling as well as other cytokine, enzyme, and transcription signaling networks by both products. Although independent replication is required to confirm present results, our study demonstrates the utility of proteomics for the identification of individual and composite candidate PD biomarkers that may be leveraged to support clinical pharmacology studies for biosimilar approvals, especially when biologics have complex mechanisms of action or do not have previously characterized PD biomarkers.

Effect of Paroxetine or Quetiapine Combined With Oxycodone vs Oxycodone Alone on Ventilation During Hypercapnia: A Randomized Clinical Trial

IMPORTANCE

Opioids can cause severe respiratory depression by suppressing feedback mechanisms that increase ventilation in response to hypercapnia. Following the addition of boxed warnings to benzodiazepine and opioid products about increased respiratory depression risk with simultaneous use, the US Food and Drug Administration evaluated whether other drugs that might be used in place of benzodiazepines may cause similar effects.

OBJECTIVE

To study whether combining paroxetine or quetiapine with oxycodone, compared with oxycodone alone, decreases the ventilatory response to hypercapnia.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, crossover clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) with 25 healthy participants from January 2021 through May 25, 2021.

INTERVENTIONS

Oxycodone 10 mg on days 1 and 5 and the following in a randomized order for 5 days: paroxetine 40 mg daily, quetiapine twice daily (increasing daily doses from 100 mg to 400 mg), or placebo.

MAIN OUTCOMES AND MEASURES

Ventilation at end-tidal carbon dioxide of 55 mm Hg (hypercapnic ventilation) using rebreathing methodology assessed for paroxetine or quetiapine with oxycodone, compared with placebo and oxycodone, on days 1 and 5 (primary) and for paroxetine or quetiapine alone compared with placebo on day 4 (secondary).

RESULTS

Among 25 participants (median age, 35 years [IQR, 30-40 years]; 11 female [44%]), 19 (76%) completed the trial. The mean hypercapnic ventilation was significantly decreased with paroxetine plus oxycodone vs placebo plus oxycodone on day 1 (29.2 vs 34.1 L/min; mean difference [MD], -4.9 L/min [1-sided 97.5% CI, -∞ to -0.6]; P = .01) and day 5 (25.1 vs 35.3 L/min; MD, -10.2 L/min [1-sided 97.5% CI, -∞ to -6.3]; P < .001) but was not significantly decreased with quetiapine plus oxycodone vs placebo plus oxycodone on day 1 (33.0 vs 34.1 L/min; MD, -1.2 L/min [1-sided 97.5% CI, -∞ to 2.8]; P = .28) or on day 5 (34.7 vs 35.3 L/min; MD, -0.6 L/min [1-sided 97.5% CI, -∞ to 3.2]; P = .37). As a secondary outcome, mean hypercapnic ventilation was significantly decreased on day 4 with paroxetine alone vs placebo (32.4 vs 41.7 L/min; MD, -9.3 L/min [1-sided 97.5% CI, -∞ to -3.9]; P < .001), but not with quetiapine alone vs placebo (42.8 vs 41.7 L/min; MD, 1.1 L/min [1-sided 97.5% CI, -∞ to 6.4]; P = .67). No drug-related serious adverse events were reported.

CONCLUSIONS AND RELEVANCE

In this preliminary study involving healthy participants, paroxetine combined with oxycodone, compared with oxycodone alone, significantly decreased the ventilatory response to hypercapnia on days 1 and 5, whereas quetiapine combined with oxycodone did not cause such an effect. Additional investigation is needed to characterize the effects after longer-term treatment and to determine the clinical relevance of these findings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04310579.

Social and professional consequences of COVID-19 lockdown in patients with multiple sclerosis from 2 very different populations

Objective

Method

Results

Conclusions

Social and professional consequences of COVID-19 lockdown in patients with multiple sclerosis from two very different populations

The global lockdown measures implemented due to the COVID-19 pandemic have nearly always had negative consequences for patients with multiple sclerosis (MS).

OBJECTIVE

We compared the social and professional effects of confinement on patients with MS in 2 very different populations, from Spain and China.

METHODS

Questionnaires were administered to a group of patients with MS who consulted at the MS unit of Vithas hospital (DINAC Foundation) in Seville, and patients with MS attended in several provinces of China in April 2020, with the aim of analysing the differences and similarities between populations in the social and professional effects of confinement. To this end, a database was created and subsequently analysed.

RESULTS

The Chinese population includes a higher proportion of younger patients and no differences were identified regarding sex. Most of the variables studied behaved in the same way in both patient populations. Spanish patients presented a lesser impact (30.7%) on their socio-economic situation than Chinese patients (44%) (P < .05). There were no significant differences between populations in the remaining variables. Social networks were widely used in the majority of patients from both populations.

CONCLUSIONS

The social and professional consequences of the pandemic were very similar in both groups; the use of social networks and family support was also similar. Spanish patients seem to present greater economic stability, perhaps due to the social support they receive.

Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial

IMPORTANCE

A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA).

OBJECTIVE

To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) was conducted in 48 healthy participants. The study was conducted between January and February 2019.

INTERVENTIONS

Participants were randomized to 1 of 4 sunscreen products, formulated as lotion (n = 12), aerosol spray (n = 12), nonaerosol spray (n = 12), and pump spray (n = 12). Sunscreen product was applied at 2 mg/cm2 to 75% of body surface area at 0 hours on day 1 and 4 times on day 2 through day 4 at 2-hour intervals, and 34 blood samples were collected over 21 days from each participant.

MAIN OUTCOMES AND MEASURES

The primary outcome was the maximum plasma concentration of avobenzone over days 1 through 21. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, homosalate, octisalate, and octinoxate over days 1 through 21.

RESULTS

Among 48 randomized participants (mean [SD] age, 38.7 [13.2] years; 24 women [50%]; 23 white [48%], 23 African American [48%], 1 Asian [2%], and 1 of unknown race/ethnicity [2%]), 44 (92%) completed the trial. Geometric mean maximum plasma concentrations of all 6 active ingredients were greater than 0.5 ng/mL, and this threshold was surpassed on day 1 after a single application for all active ingredients. For avobenzone, the overall maximum plasma concentrations were 7.1 ng/mL (coefficient of variation [CV], 73.9%) for lotion, 3.5 ng/mL (CV, 70.9%) for aerosol spray, 3.5 ng/mL (CV, 73.0%) for nonaerosol spray, and 3.3 ng/mL (CV, 47.8%) for pump spray. For oxybenzone, the concentrations were 258.1 ng/mL (CV, 53.0%) for lotion and 180.1 ng/mL (CV, 57.3%) for aerosol spray. For octocrylene, the concentrations were 7.8 ng/mL (CV, 87.1%) for lotion, 6.6 ng/mL (CV, 78.1%) for aerosol spray, and 6.6 ng/mL (CV, 103.9%) for nonaerosol spray. For homosalate, concentrations were 23.1 ng/mL (CV, 68.0%) for aerosol spray, 17.9 ng/mL (CV, 61.7%) for nonaerosol spray, and 13.9 ng/mL (CV, 70.2%) for pump spray. For octisalate, concentrations were 5.1 ng/mL (CV, 81.6%) for aerosol spray, 5.8 ng/mL (CV, 77.4%) for nonaerosol spray, and 4.6 ng/mL (CV, 97.6%) for pump spray. For octinoxate, concentrations were 7.9 ng/mL (CV, 86.5%) for nonaerosol spray and 5.2 ng/mL (CV, 68.2%) for pump spray. The most common adverse event was rash, which developed in 14 participants.

CONCLUSIONS AND RELEVANCE

In this study conducted in a clinical pharmacology unit and examining sunscreen application among healthy participants, all 6 of the tested active ingredients administered in 4 different sunscreen formulations were systemically absorbed and had plasma concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. These findings do not indicate that individuals should refrain from the use of sunscreen.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03582215.

Effect of Cefiderocol, a Siderophore Cephalosporin, on QT/QTc Interval in Healthy Adult Subjects

PURPOSE

Cefiderocol is a novel siderophore cephalosporin with potent activity against gram-negative bacteria, including multidrug-resistant strains. This Phase I study was conducted to assess the tolerability of single-ascending doses of cefiderocol (part 1) and the effect of cefiderocol on cardiac repolarization, assessed using the electrocardiographic corrected QT interval (QTcF) and other ECG parameters (part 2), in healthy adult subjects.

METHODS

Part 1 was a randomized, double-blind, placebo-controlled, single-ascending dose study in healthy adult male and female subjects. Part 2 was a 4-period crossover study in which subjects received a single 2-g dose of cefiderocol (therapeutic dose), a single 4-g dose of cefiderocol (supratherapeutic dose), or saline (placebo), each infused over 3 hours, and a single oral 400-mg dose of moxifloxacin. In each treatment period, continuous cardiac monitoring was used to assess the effects of cefiderocol on ECG parameters. The QT interval corrected using the Fridericia formula (QTcF) was the primary ECG parameter; the time-matched placebo- and baseline-adjusted (dd)-QTcF interval was the primary end point. The plasma pharmacokinetic properties of cefiderocol were calculated on the basis of concentration-time profiles in all evaluable subjects.

FINDINGS

All point estimates for the ddQTcF interval were <5 ms and the upper bound of the 90% CIs were <10 ms at each timepoint after the initiation of the cefiderocol 3-hour infusion. Concentration-effect modeling showed a slightly negative slope and predicted modestly negative values of the ddQTcF interval at the Cmax of cefiderocol. Both doses of cefiderocol were well tolerated. All adverse events were mild in severity, with no deaths or serious adverse events reported.

IMPLICATIONS

Overall, therapeutic and supratherapeutic doses of cefiderocol had no apparent clinically significant effect on the QTcF.

Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial

IMPORTANCE

The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies.

OBJECTIVE

To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial conducted at a phase 1 clinical pharmacology unit in the United States and enrolling 24 healthy volunteers. Enrollment started in July 2018 and ended in August 2018.

INTERVENTIONS

Participants were randomized to 1 of 4 sunscreens: spray 1 (n = 6 participants), spray 2 (n = 6), a lotion (n = 6), and a cream (n = 6). Two milligrams of sunscreen per 1 cm2 was applied to 75% of body surface area 4 times per day for 4 days, and 30 blood samples were collected over 7 days from each participant.

MAIN OUTCOMES AND MEASURES

The primary outcome was the maximum plasma concentration of avobenzone. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, and ecamsule.

RESULTS

Among 24 participants randomized (mean age, 35.5 [SD, 1.5] years; 12 (50%] women; 14 [58%] black or African American; 14 [58%]), 23 (96%) completed the trial. For avobenzone, geometric mean maximum plasma concentrations were 4.0 ng/mL (coefficient of variation, 6.9%) for spray 1; 3.4 ng/mL (coefficient of variation, 77.3%) for spray 2; 4.3 ng/mL (coefficient of variation, 46.1%) for lotion; and 1.8 ng/mL (coefficient of variation, 32.1%). For oxybenzone, the corresponding values were 209.6 ng/mL (66.8%) for spray 1, 194.9 ng/mL (52.4%) for spray 2, and 169.3 ng/mL (44.5%) for lotion; for octocrylene, 2.9 ng/mL (102%) for spray 1, 7.8 ng/mL (113.3%) for spray 2, 5.7 ng/mL (66.3%) for lotion, and 5.7 ng/mL (47.1%) for cream; and for ecamsule, 1.5 ng/mL (166.1%) for cream. Systemic concentrations greater than 0.5 ng/mL were reached for all 4 products after 4 applications on day 1. The most common adverse event was rash, which developed in 1 participant with each sunscreen.

CONCLUSIONS AND RELEVANCE

In this preliminary study involving healthy volunteers, application of 4 commercially available sunscreens under maximal use conditions resulted in plasma concentrations that exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens. The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings. These results do not indicate that individuals should refrain from the use of sunscreen.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03582215.

Anal cytology in women: Experience from a single tertiary center

INTRODUCTION

Anal cytology (AC) can be used as a screening tool for detection of anal HPV associated lesions, mainly in men who have sex with men and in immunosuppressed patients. Our aim is to review our experience with AC in women.

MATERIAL & METHODS

We have retrospectively reviewed all AC diagnosed between 2010-2017 in a single tertiary hospital (n = 644) and selected those performed in women (n = 158).

RESULTS

24.53% of AC were performed in women. 14.7% of all women were HIV positive and 56.7% referred anal intercourse. Squamous lesions were found in 27.2% of women, most of them ASCUS and LSIL (14% and 11.5%). HPV DNA was detected in 38.6% of patients, and 63.9% of them showed positivity for multiple high-risk types. Anal biopsy showed high grade lesions in 20% of biopsied patients. We observed a significant relationship between HPV status and receptive anal sex, and the association between HPV status and anal histological diagnosis tended to significance. Sensitivity, specificity, negative predictive value and positive predictive value for anal cytology were 57%; 83%; 28% and 94%, respectively. 70.9% of women had synchronous cervical cytology, and squamous cervical lesions were detected in 46.4% of the cases, most of them LSIL or ASCUS (21.4% and 15.2%). We did not confirm a significant association between cytological diagnosis of cervical and anal samples.

CONCLUSIONS

AC is less widely used in women than in homosexual men. However, women show important rates of anal lesions, regardless of their HIV status. More studies should be performed to assess the potential impact of screening protocols in this population.

Assessment of Multi-Ion Channel Block in a Phase I Randomized Study Design: Results of the CiPA Phase I ECG Biomarker Validation Study

Balanced multi‐ion channel‐blocking drugs have low torsade risk because they block inward currents. The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative proposes to use an in silico cardiomyocyte model to determine the presence of balanced block, and absence of heart rate corrected J‐T_peak (J‐T_peakc) prolongation would be expected for balanced blockers. This study included three balanced blockers in a 10‐subject‐per‐drug parallel design; lopinavir/ritonavir and verapamil met the primary end point of ΔΔJ‐T_peakc upper bound < 10 ms, whereas ranolazine did not (upper bounds of 8.8, 6.1, and 12.0 ms, respectively). Chloroquine, a predominant blocker of the potassium channel encoded by the ether‐à‐go‐go related gene (hERG), prolonged ΔΔQTc and ΔΔJ‐T_peakc by ≥ 10 ms. In a separate crossover design, diltiazem (calcium block) did not shorten dofetilide‐induced ΔQTc prolongation, but shortened ΔJ‐T_peakc and prolonged ΔT_peak‐T_end. Absence of J‐T_peakc prolongation seems consistent with balanced block; however, small sample size (10 subjects) may be insufficient to characterize concentration‐response in some cases.

Efficient Direct Halogenation of Unsymmetrical N-Benzyl- and N-Phenylureas with Trihaloisocyanuric Acids

A simple and efficient methodology for the direct halogenation of N-phenylureas was developed using trihaloisocyanuric acids in acetonitrile at room temperature. This protocol proved to be effective for the construction of N-phenylureas with different patterns of substitution. Additionally, less reactive N-benzylureas were halogenated in the presence of a mixture of trifluoroacetic acid and acetonitrile at room temperature.

Colour and Moisture Changes during the Manufacture of Iberian Dry-Cured Ham Caused by Some Biotic and Abiotic Factors

The effects of some biotic (pig-rearing system and muscle location) and abiotic factors (processing time and drying location) on colour ( L*, a* and b*) and moisture changes during the manufacture of Iberian ham were studied. The levels of L* (from 27.14 to 44.44), a* (from 6.10 to 19.84) and b* (from 2.18 to 8.72) parameters, and moisture (from 31.71 to 75.04) decreased ( p 0.05) as processing time increased. L*, a* and b* were strongly influenced by muscle location and their values were smaller ( p 0.05) in semimembranosus than in biceps femoris, as occurred with moisture. The rearing system produced differences ( p 0.05) in a* at the first stage and in L* and b* at the final stage of processing. Drying location, probably in association with natural climatic conditions, caused differences ( p 0.05) at only the final stage of processing in a* and b* parameters. The variations in colour parameters were mainly affected by rearing system and muscle location.

Effervescent N-Acetylcysteine Tablets versus Oral Solution N-Acetylcysteine in Fasting Healthy Adults: An Open-Label, Randomized, Single-Dose, Crossover, Relative Bioavailability Study

BACKGROUND

Oral solution N-acetylcysteine (NAC) is an antidote for acetaminophen overdose, but its unpleasant taste and aroma can impede delivery even after the coadministration of antiemetic medications. Flavored effervescent NAC tablets dissolved in water might be a more palatable formulation than oral solution NAC diluted with soft drink.

OBJECTIVES

To evaluate the relative bioavailability of these 2 formulations and assess subjective preferences between them.

METHODS

Thirty healthy adult volunteers (mean [SD] = 35.2 [9.14] years) were enrolled in this open-label, randomized, single-dose, crossover study, with a 7-day washout period. Volunteers were randomized to receive 11 g effervescent test formulation or the reference product under fasting conditions, after which 19 serial blood samples were collected over 48 hours. Total plasma NAC concentrations were evaluated by LC-MS, and pharmacokinetic parameters were calculated. The 2 formulations were considered bioequivalent if the 90% CIs of log-transformed ratios of pharmacokinetic parameters were within the predetermined bioequivalence range (80%-125%) established by the US Food and Drug Administration. Within 15 minutes of dosing, subjects were also asked to rank formulation attributes on a 5-point hedonic scale, with mean group differences analyzed by Wilcoxon signed rank test. Safety-profile assessment included treatment-emergent adverse events, physical examination, chemistry, and hematology parameters.

RESULTS

The concentration-versus-time profiles were similar for the 2 formulations, with mean Cmax of 26.5 μg/mL for effervescent NAC tablets and 28.4 μg/mL for oral solution NAC. The 90% CIs for the pharmacokinetic parameters met the criteria for concluding bioequivalence, and subjects preferred effervescent NAC tablets in terms of taste (P = 0.0247), flavor (P = 0.0082), texture (P = 0.009), and overall likeability (P = 0.0012), but there was no difference for smell (P = 0.0533). All treatment-emergent adverse events were mild, with no differences between the treatment groups.

CONCLUSIONS

Data from this study of a single dose of 11 g oral NAC demonstrated that effervescent NAC tablets and oral solution NAC met the regulatory criteria for bioequivalence in fasting healthy adult subjects. Effervescent NAC tablets appear to be a more palatable alternative for treatment of acetaminophen overdose. ClinicalTrials.gov identifier: NCT02723669. (Curr Ther Res Clin Exp. 2016; 83C:1-7) © 2016 Elsevier HS Journals, Inc.

Late sodium current block for drug-induced long QT syndrome: Results from a prospective clinical trial

Drug-induced long QT syndrome has resulted in many drugs being withdrawn from the market. At the same time, the current regulatory paradigm for screening new drugs causing long QT syndrome is preventing drugs from reaching the market, sometimes inappropriately. In this study, we report the results of a first-of-a-kind clinical trial studying late sodium (mexiletine and lidocaine) and calcium (diltiazem) current blocking drugs to counteract the effects of hERG potassium channel blocking drugs (dofetilide and moxifloxacin). We demonstrate that both mexiletine and lidocaine substantially reduce heart-rate corrected QT (QTc) prolongation from dofetilide by 20 ms. Furthermore, all QTc shortening occurs in the heart-rate corrected J-Tpeak (J-Tpeak c) interval, the biomarker we identified as a sign of late sodium current block. This clinical trial demonstrates that late sodium blocking drugs can substantially reduce QTc prolongation from hERG potassium channel block and assessment of J-Tpeak c may add value beyond only assessing QTc.

Long term effect of external pituitary irradiation on IGF1 levels in patients with acromegaly free of adjunctive treatment

OBJECTIVE

It is established that external pituitary irradiation (EPI) effectively reduces serum GH levels in acromegaly. However, its effect in normalising serum IGF1 has been disputed. We looked at the number of our patients who achieved persistently normal IGF1 levels whilst free of adjunctive treatment for at least 1 year after EPI.

PATIENTS AND DESIGN

We identified 63 acromegalic patients between 1964 and 2004 who received EPI. Six were excluded: three had surgery after EPI, two had no medical records available, and one had a pituitary Yttrium implant.

MEASUREMENTS

Patients received 4500-5000 cGy in fractionated doses. IGF1 levels were correlated with their respective age-related reference ranges.

RESULTS

After EPI, the number of patients with normal IGF1 and free of adjunctive medical treatment for at least 1 year were four patients by 3 years, nine patients by 5 years and seventeen by 10 years, with the current number of 25/57 (44%). Concordance between IGF1 levels and random GH dropped from 90% at the time of EPI to 65% at 3 years, 66% at 5 years and 71% at 10 years.

CONCLUSIONS

We have demonstrated that, with time, EPI achieves a normal IGF1 in significant numbers of patients with acromegaly, thus obviating the need for life-long expensive medical therapy. For each patient this benefit has to be weighed against the possibility of new hypopituitarism as a result of the treatment. Any decision to use EPI is easier in the context of pre-existent hypopituitarism.

Rationalization of genetic testing in patients with apparently sporadic pheochromocytoma/paraganglioma

Hereditary susceptibility to pheochromocytoma (PCC) and paraganglioma (PGL) represents a very complex genetic scenario. It has been reported that the absence of familial antecedents of the disease does not preclude the existence of a mutation affecting any of the five major susceptibility genes. In fact, 11-24% of apparently sporadic cases (without familial or syndromic antecedents) harbor an unexpected germline mutation, but we do not know what is happening in "truly apparently" sporadic patients (i.e., apparently sporadic cases diagnosed with only one tumor). In the present study, we have analyzed 135 apparently sporadic patients developing a single tumor for the five major susceptibility genes: VHL, RET, SDHB, SDHC, and SDHD. Fourteen percent of cases were found to harbor a germline mutation, and only 2.2% of patients were older than 45 years at onset. By taking into account the tumor location and a threshold age at onset of 45 years, we propose a rational scheme for genetic testing. Analyzing VHL and RET genes would be recommended only in young patients developing a single PCC. On the other hand, genetic testing of SDHD should be done in all patients developing an extra-adrenal tumor before the age of 45, and SDHC could be the responsible gene in cases developing a single head and neck tumor, independently of age. Finally, the analysis of SDHB should always be performed because of its association to malignancy and the low penetrance of mutations affecting this gene.

A genomic parasite in the evolution of metazoan development

It is a challenge to understand how development emerged as a mechanism to dismantle and dismiss the intromission of foreign parasites in order to consolidate a higher-level multicellular unit of selection where more heritable variations in fitness, required for complex organization, can be procured. Levels in biological hierarchy genes, networks of genes, chromosomes, cells, organisms, etc., possess heritable variations in fitness to varying degrees, and as such, they function as units of selection in the evolutionary process [Lewontin, (1970). The units of selection. Annu. Rev. Ecol. Syst. 1: 1-18]. To proceed from each of these levels to the next constitutes a major transition in evolutionary history. When analyzing the splendid road epitomized by these transitions in units of selection, it is possible to conceive three processes: firstly, the molecular "recognition" of the "convenience" of exchanging the higher energy cost of cooperating cells with more fitness than single-cell selection (after that first recognition the emergence of cooperation among cells is possible); secondly, the establishment of the mechanisms to regulate conflict, and finally, the regulation of cell differentiation and compartmentalization.

From unicellularity to multicellularity - molecular speculations about early animal evolution

A morphological, physiological, developmental, and genetic organization of great complexity ineluctably unfolded from relatively simple phenomena invested with enormous potential. Sometime long ago in the Protererozoic times, parasitic invasions caused lower evolutionary levels to integrate into higher-level selection. Therefore, we have a multi-level selection problem that ultimately revolves around the question of how natural selection among lower-level units acts to create higher-level units of selection, in which Darwinian competition among replicators ceases to be the foremost force. The first level relinquishes its independence for the benefit of a higher-level cooperative force that is now the criterion of fitness for the new transition in the evolutionary process.

[The efficiency and cost-utility ratio of interferon beta in the treatment of multiple sclerosis in Andalusia]

INTRODUCTION

The availability of the interferon beta in its three forms at the moment available in our country and of glatiramer acetate has marked a point of flexion in the natural history of multiple sclerosis (MS), but the high cost of these treatments cause that its use is questioned. In this work we have studied the effectiveness and efficiency of the processing with interferon beta, and the cost-utility of these treatments in MS in Spain has been also analyzed.

PATIENTS AND METHODS

For this work we studied 102 patients affected of RR MS, treated with the three interferons beta which we have available in our country. We used as control 330 patients who had participated in the pivotal clinical interferon trials with both interferon beta 1a. In these patients in addition to effectiveness data, we have studied the disability measured as area below curve and the quality of life (AVACs). We also calculated the economical costs, considering the relation cost-utility in our country.

RESULTS

Besides to confirm the data of effectiveness of three interferons, in this study a saving of 23 days/year is demonstrated what corresponds to 0.063 AVACs. The additional cost of interferons is greater than the avoided cost until the fifth year of treatment in which the tendency is reversed in favor of the group of treated patients, if we assume that the same effectiveness that we found in the first years is maintained in the long term.

CONCLUSION

The use of the treatment with interferon beta is justified by its effectiveness, efficacy and efficiency. The additional cost of the treatment will be compensated in the long term if the effectiveness of the interferon beta is maintained.

Characterization of Staphylococcus spp. and Micrococcus spp. isolated from Iberian ham throughout the ripening process

The Iberian dry cured ham is an uncooked meat product highly appreciated because of its characteristic flavour. This product is obtained from highly marbled Iberian pig hindlegs after 18-24 months of maturation under natural environmental conditions. The role of Micrococcaceae in the development of the aroma characteristics of this products remains unclear. Identification of Gram-positive, catalase-positive cocci isolated from Mannitol Salt Agar plates showed that Staphylococcus xylosus followed by Staphylococcus equorum are the predominant organisms, even after 16 months of maturing. A remarkable variety of types of both staphylococci and micrococci are detected at any sampling time. The metabolic activities of these organisms could contribute to the characteristics of the final product.