Enhanced oxidative stress and increased mitochondrial mass during efavirenz-induced apoptosis in human hepatic cells

BACKGROUND AND PURPOSE

Efavirenz (EFV) is widely used in the treatment of HIV-1 infection. Though highly efficient, there is growing concern about EFV-related side effects, the molecular basis of which remains elusive.

EXPERIMENTAL APPROACH

In vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 microM) on human hepatic cells.

KEY RESULTS

Cellular proliferation and viability were reduced in a concentration-dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect.

CONCLUSION AND IMPLICATIONS

Clinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.

[Triage: a key tool in emergency care]

"Triage" is a process that enables us to manage clinical risk in order to safely and suitably handle patient flows when demand and clinical needs exceed resources. At present, triage systems that are employed are structured according to five levels of priority. Levels are allocated according to the concept that what is urgent is not always serious and that what is serious is not always urgent. This makes it possible to classify patients according to "degree of urgency", so that the more urgent patients will be attended to first and the rest will be re-evaluated until they are seen by the doctor. The Spanish triage system (SET) and the Manchester triage system (MTS) are the two standardised systems most implemented in our country. We also discuss the system of triage devised in Navarre--integrated in the computerised clinical history--and used in the hospital network of Navarre. All are multidisciplinary systems based on the reasons and urgency of consultation, but not on diagnoses, and are carried out by nursing staff with medical support when required. In addition, they all include monitoring of the quality of the accident and emergency service itself, and can be applied in the outpatient field.

Association between ACE gene I/D polymorphism and clinical presentation and prognosis of sarcoidosis

Serum angiotensin converting enzyme (SACE) concentration is considered a marker of sarcoidosis activity. This concentration is influenced by an insertion/deletion (I/D) polymorphism of the ACE gene, such that SACE levels follow the pattern DD>ID>II. The aim of our work was to study the relationship between I/D polymorphism and susceptibility to sarcoidosis, as well as the relation between this polymorphism and the clinical presentation and evolution of the disease in 177 sarcoidosis patients. A group of 104 individuals without sarcoidosis was included as control. Genotyping was done by a polymerase chain reaction (PCR) method, and SACE concentration at diagnosis was determined by a kinetic method. No differences were observed in genotype or allele distributions between patients and controls, nor between patients considering the type of presentation (Löfgren versus non-Löfgren) and evolution of the disease (acute versus chronic). As reported for healthy populations, SACE concentrations followed the pattern DD>ID>II in sarcoidosis patients, but significant differences between genotypes existed only in the Löfgren group (p = 0.003) and in acute patients (p = 0.02). SACE concentrations at diagnosis were lower in acute patients (p = 0.05) and in Löfgren's syndrome (p = 0.04), but this seemed to occur only in ID individuals (p = 0.02 and p = 0.01, respectively). No relation was thus found between I/D polymorphism and susceptibility to sarcoidosis, but ACE I/D genotyping may improve the assessment of disease activity, both at diagnosis and during the follow-up of treated and untreated patients.

Randomized, crossover, single-blind, placebo-controlled, human pharmacology clinical trial with desoxypeganine, a new cholinesterase and selective MAO-A inhibitor: multiple-dose pharmacokinetics

Desoxypeganine, a naturally occurring alkaloid, is being developed for its potential utility in the pharmacological treatment of alcohol abuse to reduce craving and depression in alcohol abusers, and might also be useful as a smoking cessation aid. During the preclinical development it was characterized as a cholinesterase inhibitor, acting preferentially on butyrylcholinesterase, and as a selective inhibitor of monoamine oxidase A but not monoamine oxidase B.

OBJECTIVE

The aim of the present human pharmacology clinical trial was to assess the oral bioavailability, pharmacokinetic profile and tolerability of desoxypeganine, administered in a multiple-dose regimen to healthy volunteers.

SUBJECTS AND METHODS

Eighteen healthy adult volunteers of both sexes received placebo, 50 mg and 100 mg desoxypeganine (b.i.d. for 3 days) in a single-blind, crossover, randomized manner. Main pharmacokinetic parameters after single and multiple doses were estimated. Clinical tolerability and clinical laboratory safety, including effect on QTc interval, were assessed.

RESULTS

Non-compartmental estimations of Cmax, AUC, tmax, t1/2 and MRT at 12-h intervals are given. No significant dose effect was observed in tmax, t1/2 and MRT. Cmax and AUC are approximately double with the dose of 100 mg comparing with the dose of 50 mg. A significant increase (p < 0.05) on Cmax and AUC was also obtained with the highest dose administered in comparison with the lowest one, revealing a slight but clinically insignificant accumulation. Steady state of drug concentration was reached in both genders during the study period. Plasma protein binding of desoxypeganine amounted to approximately 18%. No severe adverse events were recorded and none of the subjects suffered from any adverse event that led to withdrawal from the study. Most frequently recorded adverse event was dizziness. No significant effects of desoxypeganine on vital signs, laboratory parameters or QTc interval were observed.

CONCLUSIONS

The present clinical trial describes the pharmacokinetic profile of two doses of desoxypeganine, administered orally in multiple dose to healthy volunteers. The drug was well tolerated without any severe clinical, clinical laboratory, or ECG adverse events being recorded.

Results of lung transplantation in patients with chronic obstructive pulmonary disease

OBJECTIVE

The objective of this study was to evaluate the results and survival rates of patients who underwent lung transplantation (LT) to treat chronic obstructive pulmonary disease (COPD).

METHODOLOGY

We performed a retrospective analysis of 63 patients with COPD who underwent LT between 1996 and 2007. Our statistical analysis was based on descriptive statistics and survival analysis (Kaplan-Meier and log-rank test).

RESULTS

Sixty-three LTs were performed in 53 male and 10 female patients with COPD. Twenty-eight LTs were unipulmonary and 35 were bipulmonary. Four cases required extracorporeal circulation. Surgical complications arose in 18 cases. There were 3 cases of intraoperative death as a result of cardiac failure. The most frequent long-term complications were hypertension (39.7%), renal failure (42.9%), and neoplasms (20.6%). Overall survival times (mean, 2553 days) were 75.9%, 74.15%, 65.67%, 55.87%, and 42.05% at 1, 2, 3, 5, and 10 years, respectively. No differences were observed in survival according to the following: donor age >30 years (P = 8), type of transplantation (unilateral vs bilateral; P = .57), donor intubation time >48 hours (P = .2), or donor oxygenation index <450 mm Hg (P = .3).

CONCLUSIONS

No differences were observed in survival according to the type of transplantation (unilateral vs bilateral), which suggests that unipulmonary transplantation is a reasonable option, given that this procedure reduces both the ischemia time compared with bilateral transplantation and the surgery time, as well as offering more efficient use of donor organs.

Role of IκBα as a negative regulator of EGFR and a molecular determinant of prognosis in glioblastoma multiforme

2028

Background: Glioblastoma multiforme is a complex disease that involves the deregulation of overlapping signaling pathways. Constitutive activation of the transcription factor nuclear factor-κB (NF-κB) has been broadly associated with various human cancers, including glioblastomas, and their therapy resistance and may be due to cross-coupling with other oncogenic pathways, such as epidermal growth factor signaling. Methods: Multidimensional analysis involving gene and transcript data for the endogenous NF-κB modulator IκBα/NFKBIA and clinical patient profiles of 482 glioblastomas/high-grade gliomas from multiple institutions in the United States and The Cancer Genome Atlas Pilot Project. Functional analyses using LN229, U87, and U118 glioblastoma cells, and human embryonic kidney 293T cells with transgene phenotypes for IκBα. IκBα promoter and coding sequence and promoter methylation analyses in a resistance model of 15 glioblastomas cell lines with in vitro and/or in vivo resistance to O6-alkylating agents. Results: We have identified a regulatory circuit between NF-κB and EGFR signaling in glioblastomas, where IκBα binds to EGFR and attenuates EGFR signaling by immobilizing its kinase domain into an inactive conformation. We found the NFKBIA gene at 14q13.2 deleted in 25% of glioblastomas and its occurrence mutually exclusive with EGFR amplification. Loss of NFKBIA associates independently with patient survival. Functional analyses uncover a bona fide tumor suppressor role for IκBα in glioblastoma cells, where it functions to constrain tumorigenic and migratory potential, and induce spontaneous cellular senescence, and apoptosis in response to treatment. IκBα expression is an independent predictor of patient prognosis in multiple glioblastoma populations. Glioblastomas with initially high IκBα expression significantly repress IκBα upon tumor recurrence, suggesting an acquired mechanism to evade its tumor-suppressive and/or chemo-sensitizing effects during tumor progression. Conclusions: IκBα is a molecular determinant of biological tumor behavior and patient survival in glioblastoma multiforme. Deletion of NFKBIA could present an alternate mechanism to activate EGFR signaling in EGFR non-amplified glioblastomas.

No significant financial relationships to disclose.

Purification method using iodixanol (OptiPrep)-based density gradient significantly reduces cytokine chemokine production from human islet preparations, leading to prolonged beta-cell survival during pretransplantation culture

Purification is one of the most important steps in human islet isolation. Although Ficoll-based density gradients are widely used, OptiPrep-based density gradients are used in few centers. Cytokine/chemokine production from human islet preparations varies widely. Some cytokines/chemokines have been reported to have adverse effects on human islet preparations. Control of cytokine/chemokine production may be a key to improve islet quality and quantity, leading to better transplantation outcomes. The aim of the present study was to investigate the effects on islet preparations of purification methods using various density gradients on viability, cellular composition, and proinflammatory cytokine/chemokine production. After the digestion phase, the extracts were divided into 2 groups for purification using a semiautomated cell processor with Ficoll-based or OptiPrep-based density gradients. Islet preparations cultured for 2 days were assessed regarding islet cell viability (fluorescein diacetate/propidium iodide [FDA/PI]), fractional beta-cell viability by FACS, and beta-cell content using iCys. Cytokine/chemokine production from islet preparations was also measured by Bio-plex. After purification, the purity, islet equivalents (IEQ), and islet recovery rates were comparable between the 2 groups. Although FDA/PI and fractional beta-cell viability showed no significant difference, survival of beta cells during culture was significantly higher in the OptiPrep compared with the Ficoll-based density gradient group. There were significantly lower tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon (IFN)-gamma, IL-6, and MIP-1beta productions from the OptiPrep-based density gradient group. OptiPrep-based density gradients reduced cytokine/chemokine production by islet preparations. In addition, OptiPrep-based density gradient purification significantly reduced the loss of beta-cell mass during pretransplantation culture.

Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles

A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed formulation has been tested with a particle-in-cell code based on the finite-difference time-domain method, obtaining good agreement.

Use of cardiac troponin T rapid assay in the diagnosis of a myocardial injury secondary to electrical cardioversion

BACKGROUND AND HYPOTHESIS

This study was carried out to determine whether cardiac troponin T test in rapid assay gives positive results in patients previously submitted to cardioversion or electrical defibrillation.

METHODS

Forty patients with supraventricular tachyarrhythmias lasting no more than 2 days were treated with electrical cardioversion. The total creatine phosphokinase (CPK)-MB isoenzyme and troponin T in rapid assay were measured at baseline and at 6, 12, and 24 h thereafter.

RESULTS

Total CPK baseline levels were normal in all cases; within 4 h, the serum CPK levels increased by 98%, at 6 h by 111.5%, at 12 h by 168%, and at 24 h by 225% (p > 0.01). The CPK-MB isoenzyme showed no percentage increase of total CPK higher than 5%, measured at 6, 12, and 24 h after the shock, independent of the number of attempts of cardioversion. The troponin T test was also negative in all cases at baseline and at 6, 12, and 24 h after cardioversion.

CONCLUSION

We conclude that the absence of elevations in CPK-MB levels and cardiac troponin T levels matched clinical and electrocardiographic results showing absence of myocardial damage after electrical cardioversion.

[Metabolic syndrome and live kidney donor: is this syndrome a contraindication to donation?]

Living donor kidney transplantation (KT) is the treatment of choice for end-stage renal disease patients and exhaustive assessment of the potential live kidney donor leads to successful KT in most occasions. Diabetes mellitus (DM), hypertension and obesity make up contraindications to donation because all of them are associated with postsurgical complications and future development of renal failure and cardiovascular (CV) disorders. However, it is unclear how much risk there is for individuals who donate a kidney and then develop some of these complications, which are grouped under the metabolic syndrome (MS.) Indeed, MS is a cluster of CV risk factors such as obesity, dyslipidemia, hypertension where the insulin resistance is the pathogenic mainstay. MS is an entity very prevalent in the western countries (20-30%) and has been associated with the development of CV disorders, DM and renal disease. Thus, it is crucial to detect MS before living donation in order to avoid these complications in the long-term. Regardless of clinical criteria to diagnosis MS, both oral glucose tolerance test and HbA1c levels may be useful clinical tools for unmasking MS before donation. Moreover, determination of insulin resistance by HOMA could help to achieve this objective. This review will outline the next issues: 1) frequency of MS in the general population (potentially, living kidney donor); 2) the impact of MS on DM, renal function and other CV complications; 3) assessment of living donor to unmask MS before donation; and 4) interventions on risk factors for minimizing MS-related threatening complications in the long-term. In any case, if MS is detected prior to donation, prophylactic and therapeutic measurement should be performed to avoid its progression. By contrast, MS could be considered a contraindication to donation.

Does intensification improve the economic efficiency of dairy farms?

In recent decades, the dairy sector has shown a global tendency toward intensification. This structural change may have significant effects on farm efficiency and, consequently, on the economic results of the farms. The goal of this study was to offer an empirical analysis of the effect of intensification on dairy farming. To do this, we first classified a sample of dairy farms according to their level of intensification by using a cluster analysis. We then estimated independent stochastic cost frontiers for each group of farms to calculate their levels of efficiency. The methodology used in this study allowed for the presence of different technologies within a sample, which is a methodological issue frequently avoided in the agricultural economics literature. The empirical results showed that intensive farms were closer to their cost frontier than extensive ones, suggesting a positive relationship between intensification and efficiency.

Use of Barcelona Test for cognitive assessment of patients with schizophrenia

INTRODUCTION

In recent years different neuropsychological batteries have been developed to assess cognitive performance in schizophrenia. However, no test has been validated in Spanish for this purpose. The Barcelona Test has been one of the tests used. This present article has aimed to present a specific neurocognitive battery for schizophrenia by selecting specific subtests from the Barcelona Test. Normative data for patients with schizophrenia are presented and the influence of a number of variables is taken into account.

METHODS

The sample included 209 patients. The relationship between cognitive performance and gender, age, educational level, age of onset, duration of illness and symptomatology were assessed. Symptomatology was collected with the Positive and Negative Syndrome Scale for Schizophrenia.

RESULTS

More of the 50% of the sample had cognitive impairment when compared with standardized percentile scores of the Barcelona Test. No significant relationships between cognitive performance and variables assessed were found, except for in the educational level. Thus, percentile scores for the total sample and for the sample in terms of educational level were obtained.

CONCLUSIONS

The high percentage of patients with cognitive impairment when standardized percentile scores were used reinforces the need to use normative data appropriate for the schizophrenia group. The lack of relationship between cognitive performance and the variables assessed supports the hypothesis that cognitive impairment is a core feature in schizophrenia.