Prevalence of ABCB1 3435C>T polymorphism in the Cuban population.

OBJECTIVES: ABCB1 gene polymorphisms can modify P-glycoprotein function with clinical consequences. METHODS: The 3435C>T polymorphism prevalence was analyzed using oligonucleotide probes and next-generation sequencing in 421 unrelated healthy individuals living in Cuba. Data were stratified by gender, ethnic background and residence. The genotype and allelic frequencies were determined. RESULTS: The genotype distribution met the Hardy-Weinberg equilibrium assumption. The allelic frequency was 63.5% for the 3435C variant. The genotype frequencies were 41.1% for CC, 44.9% for CT and 14.0% for TT. The allele and genotype distributions differed between individuals living in La Habana and Santiago de Cuba (p<0.05) when ethnic background was analyzed. The allelic distribution was similar among Admixed and Black subjects, and they differed from Caucasians. The CC genotype was equally distributed among Admixed and Black subjects, and they differed from Caucasians. The TT genotype frequency differed between Caucasians and Admixed. The CT genotype was distributed differently among the three groups. Similar distribution was obtained in Brazilians, whereas some similarities were observed in African, Spanish and Chinese populations, consistent with the mixed Cuban ethnic origin. CONCLUSIONS: This is the first report on allele and genotype frequencies of the 3435C>T polymorphism in Cuba, which may support personalized medicine programs.

DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death.

The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan-Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p < 0.001). The effect of DNA damage on survival was modelled according to Cox proportional hazard regression model. The adjusted hazard ratio (HR) was 1.42 (1.06-1.90) for overall mortality, and 1.94 (1.04-3.59) for diseases of the circulatory system in subjects with the highest tertile of DNA damage. The findings of this study provide epidemiological evidence encouraging the implementation of the comet assay in preventive strategies for non-communicable diseases.

Unique Presentation of Microscopic Polyangiitis: Hearing and Vision Loss, Dysphagia, and Renal Dysfunction.

Microscopic polyangiitis (MPA) is an autoimmune small-vessel vasculitis often positive for perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA), or anti-myeloperoxidase (MPO), that classically affects the lungs, kidneys, and skin. Several atypical presentations of MPA involving other organs have also been reported in the literature. We report a unique case of a patient who presented with rare presentations of MPA: hearing and vision loss, dysphagia, renal dysfunction. Despite the atypical nature of her symptoms, her p-ANCA serology was positive and kidney biopsy was consistent with MPA. Regardless of the bizarre nature of a patient's symptoms, we highlight the importance of considering MPA as a differential diagnosis in the setting of positive p-ANCA serology.

Glucocorticoid receptor antagonism overcomes resistance to BRAF inhibition in BRAFV600E-mutated metastatic melanoma.

Clinical applications of glucocorticoids (GC) in Oncology are dependent on their pro-apoptotic action to treat lymphoproliferative cancers, and to alleviate side effects induced by chemotherapy and/or radiotherapy. However, the mechanism(s) by which GC may also promote tumor progression remains unclear. GC receptor (GR) knockdown decreases the antioxidant protection of highly metastatic B16-F10 melanoma cells. We hypothesize that a GR antagonist (RU486, mifepristone) could increase the efficacy of BRAF-related therapy in BRAFV600E-mutated metastatic melanoma. In vivo formed spontaneous skin tumors were reinoculated into nude mice to expand the metastases of different human BRAFV600E melanoma cells. The GR content of melanoma cell lines was measured by [3H]-labeled ligand binding assay. Nuclear Nrf2 and its transcription activity was investigated by RT-PCR, western blotting, and by measuring Nrf2- and redox state-related enzyme activities and metabolites. GR knockdown was achieved using lentivirus, and GR overexpression by transfection with the NR3C1 plasmid. shRNA-induced selective Bcl-xL, Mcl-1, AKT1 or NF-κB/p65 depletion was used to test the efficacy of vemurafenib (VMF) and RU486 against BRAFV600E-mutated metastatic melanoma. During early progression of skin melanoma metastases, RU486 and VMF induced a drastic metastases regression. However, treatment at an advanced stage of growth demonstrated the development of resistance to RU486 and VMF. This resistance was mechanistically linked to overexpression of specific proteins of the Bcl-2 family (Bcl-xL and Mcl-1 in our experimental models). We found that melanoma resistance is decreased if AKT and NF-κB signaling pathways are blocked. Our results highlight mechanisms by which metastatic melanoma cells adapt to survive.

In vitro modulation of the cytochrome P450 and ABCB1/P-glycoprotein activities of the aqueous extract of Allophylus cominia (L) Sw. leaves.

BACKGROUND: The aqueous extract of the Allophylus cominia (L) Sw (Sapindaceae) leaves has shown anti-diabetic, anti-obesity and anti-inflammatory properties. In the Caribbean region, it is typically used for the treatment of type-2 diabetes. METHODS: Considering the herb-drug interaction, the aim of this study was to evaluate the potential effects of the A. cominia extract on the cytochrome P450 (CYP) (rat hepatocyte model) and P-glycoprotein (P-gp) (4T1 cell line) systems. RESULTS: The extract did not decrease the cell viability after being assayed by the MTT test at up to 1500 µg/mL for 72 h. The exposure of the cultured rat hepatocytes to the product (up to 250 µg/mL) for 48 h increased the activities of CYP-1A2, 2C9, and 2E1 by 1.46-, 1.60-, and 1.51-fold, respectively, compared with the controls. The activities of CYP-2B6, 2D6, and 3A4 were not significantly altered, whereas the activity of P-gp decreased by 2- and 4-fold. In addition, the extracts at 100 and 200 µg/mL significantly increased doxorubicin cytotoxicity in these cells 24 h after treatment. CONCLUSIONS: The findings indicate that the A. cominia extract modulates the CYP and P-gp systems increasing sensitivity to doxorubicin. Further studies are necessary to evaluate the potential herb-drug interaction or chemosensitive properties.

Gas Chromatography-Mass Spectrometry Analysis of Ulva fasciata (Green Seaweed) Extract and Evaluation of Its Cytoprotective and Antigenotoxic Effects.

The chemical composition and biological properties of Ulva fasciata aqueous-ethanolic extract were examined. Five components were identified in one fraction prepared from the extract by gas chromatography-mass spectrometry, and palmitic acid and its ethyl ester accounted for 76% of the total identified components. Furthermore, we assessed the extract's antioxidant properties by using the DPPH, ABTS, and lipid peroxidation assays and found that the extract had a moderate scavenging effect. In an experiment involving preexposition and coexposition of the extract (1-500 µg/mL) and benzo[a]pyrene (BP), the extract was found to be nontoxic to C9 cells in culture and to inhibit the cytotoxicity induced by BP. As BP is biotransformed by CYP1A and CYP2B subfamilies, we explored the possible interaction of the extract with these enzymes. The extract (25-50 µg/mL) inhibited CYP1A1 activity in rat liver microsomes. Analysis of the inhibition kinetics revealed a mixed-type inhibitory effect on CYP1A1 supersome. The effects of the extract on BP-induced DNA damage and hepatic CYP activity in mice were also investigated. Micronuclei induction by BP and liver CYP1A1/2 activities significantly decreased in animals treated with the extract. The results suggest that Ulva fasciata aqueous-ethanolic extract inhibits BP bioactivation and it may be a potential chemopreventive agent.

Elevated intracranial pressure in patients with spontaneous cerebrospinal fluid otorrhea.

OBJECTIVES/HYPOTHESIS: To determine the prevalence of elevated intracranial hypertension in patients with spontaneous cerebrospinal fluid otorrhea (SCSFO). STUDY DESIGN: Case series with chart review at a tertiary care academic medical center following institutional review board approval. METHODS: A retrospective review was performed of patients undergoing operative repair of SCSFO between January 2007 and May 2012. RESULTS: Thirty-eight patients underwent operative repair of SCSFO. Of these, 22 underwent postoperative lumbar puncture with measurement of opening pressure. The opening pressure was elevated (> 20 cm/H2 0) in eight patients (36.4%). Preoperative magnetic resonance imaging was available for review by a neuroradiologist in 27 patients. Radiographic evidence of elevated intracranial pressure (ICP) was present in 48.1% of patients. CONCLUSION: Elevated ICP is common in patients with SCSFO. However, as only a minority of patients have elevated ICP, it is not the sole factor in the development of SCSFO.

Superior semicircular canal dehiscence in patients with spontaneous cerebrospinal fluid otorrhea.

OBJECTIVE: To determine the prevalence of superior semicircular canal dehiscence (SCD) in patients with spontaneous cerebrospinal fluid (CSF) otorrhea. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care referral center. SUBJECTS AND METHODS: Patients included have undergone a middle fossa craniotomy for repair of spontaneous CSF otorrhea between January 2007 and December 2011. The main outcome measure is the presence or absence of SCD observed during spontaneous CSF leak repair. Computed tomography (CT) imaging was also reviewed to determine the diagnostic accuracy of this modality. RESULTS: Thirty-three ears in 31 patients underwent surgical repair for spontaneous CSF otorrhea via a middle fossa craniotomy. The average age at the time of repair was 60.5 years, and 80.6% of patients were female. A dehiscence of the superior canal was observed in 15.2% of ears (16.1% of individuals). No significant difference in age, body mass index, or sex was noted between those patients with or without a superior canal dehiscence. For the diagnosis of SCD, coronal CT was 100% sensitive and 91.7% specific. The positive predictive value and negative predictive value of CT were 66.7% and 100%, respectively. CONCLUSION: The prevalence of superior semicircular canal dehiscence in ears with spontaneous otorrhea is 15.2%. This prevalence is greater than the 0.5% reported in a temporal bone study of ears not selected for CSF otorrhea.

Electric fields yield chaos in microflows.

We present an investigation of chaotic dynamics of a low Reynolds number electrokinetic flow. Electrokinetic flows arise due to couplings of electric fields and electric double layers. In these flows, applied (steady) electric fields can couple with ionic conductivity gradients outside electric double layers to produce flow instabilities. The threshold of these instabilities is controlled by an electric Rayleigh number, Ra(e). As Ra(e) increases monotonically, we show here flow dynamics can transition from steady state to a time-dependent periodic state and then to an aperiodic, chaotic state. Interestingly, further monotonic increase of Ra(e) shows a transition back to a well-ordered state, followed by a second transition to a chaotic state. Temporal power spectra and time-delay phase maps of low dimensional attractors graphically depict the sequence between periodic and chaotic states. To our knowledge, this is a unique report of a low Reynolds number flow with such a sequence of periodic-to-aperiodic transitions. Also unique is a report of strange attractors triggered and sustained through electric fluid body forces.

Paranasal sinus and skull base fibro-osseous lesions: when is biopsy indicated for diagnosis?

BACKGROUND: Paranasal sinus fibro-osseous (FO) lesions represent a heterogeneous group, often sharing overlapping radiographic and pathologic features posing a dilemma in accurate diagnosis. The objective of this study was to correlate preoperative radiologic and postoperative histologic diagnosis to help guide a diagnostic algorithm. METHODS: Retrospective analysis of 60 FO lesions between 1994 and 2010. RESULTS: The mean age was 42.3 years with average follow-up of 12.5 months. The preliminary radiologic diagnosis was osteoma in 22 (36.7%), fibrous dysplasia (FD) in 9 (15%), ossifying fibroma (OF) vs FD in 5 (8.3%), and OF in 3 (5%) cases. The diagnosis was indeterminate in 21 (35%) cases. Management consisted of excision in 29 (48.3%), observation in 17 (28.3%), and biopsy in 14 (23.3%) patients. For patients undergoing resection or biopsy, positive predictive value of preoperative radiology was 100% (10/10) for osteoma, 85.7% (6/7) for FD, and 33.3% (1/3) for OF cases. For the indeterminate lesions, most common pathologic diagnoses for 21 patients included osteoma in 4 (17.4%), arrested pneumatization in 3 (14.3%), OF in 3 (14.3%), and FD in 2 (9.5%). For FD vs OF cases, 3 underwent surgery, revealing osteoma, FD, and OF in 1 patient each. CONCLUSION: In this series, radiologic-histopathologic correlation was high for osteoma and FD and low for OF and OF vs FD. This data suggests that patients with classic radiologic characteristics of osteoma and FD may be observed, unless resection is warranted based on clinical symptomatology. Preoperative diagnosis of OF, OF vs FD, or indeterminate lesions may warrant a biopsy to establish firm diagnosis to guide definitive management, especially if preoperative computed tomography (CT) imaging is concerning for an aggressive FO neoplasm.

Visual estimation of the percentage of DNA in the tail in the comet assay: evaluation of different approaches in an intercomparison exercise.

One of the difficulties in the comparison of results between laboratories working with the comet assay is the great diversity of parameters used to express DNA damage and the lack of conversion factors between the majority of them. Here we report a scorer-independent conversion curve to transform the values of DNA damage reported in arbitrary units (AU) into estimated percentage of DNA in the tail (E%T), and the results obtained in an intercomparison exercise where the effectiveness of this curve and two others proposed in the literature (E%T=AU/4 and E%T=(AU/5)+10) were tested. To obtain the conversion curve, human lymphocytes were first treated with radiation or H(2)O(2). Percentage of DNA in tail (%T) was then measured in 2100 comets (300 comets per treatment) using Casp image analysis software. Subsequently, using these values of %T, categories of 0, 1, 2, 3, and 4 were assigned to comets with %T [0-1), [1-25), [25-45), [45-70), and >70, and DNA damage was calculated in AU, as usual. DNA damage was induced in the interval 24-315AU (1.54-65.23%T). The best-fit conversion curve obtained by regression analysis was E%T=(AU-25.87)/4.46. In the intercomparison exercise, ten scorers from nine laboratories analyzed the same comet images (recorded on a compact disc) visually. The values reported in comet categories were transformed into AU and subsequently into E%T, using the three approaches mentioned above. The best agreement between E%T and %T measured by the software (S%T) was obtained with the conversion curve reported here, where the slope of E%T versus S%T from the ten scorers was not different from 1. Using this conversion curve, the overall mean difference between E%T and S%T was 1.4±2.62 and 57 (81%) of E%T values differ from S%T by less than 5 units. These findings show the strength of the scorer-independent conversion curve as a tool to compare results reported in AU or %T by different laboratories.

Electrokinetic vortices and traveling waves in nondilute colloidal dispersions.

We report a diverse set of coherent fluid flow instabilities, particle patterns, and traveling waves that develop when an ac electric field is applied to nondilute colloidal dispersions with volume fractions that span 3 orders of magnitude. Novel observed phenomena include the following: vortices with steady and unsteady axes of rotation, unsteady time evolution of vortices formation and vortex merging, as well as traveling waves that propagate through the dispersion. Vortical flows are influenced by strong interactions between particle electrical dipoles as well as electric body forces due to electric fields coupled with gradients in particle volume fraction. We use a 1D Burgers equation to predict the existence of traveling waves in colloidal dispersions.

Computed tomographic angiography for the diagnosis of blunt cervical vascular injury: is it ready for primetime?

INTRODUCTION: Although the reported sensitivity of computed tomographic angiography (CTA) for the diagnosis of blunt cervical vascular injury (BCVI) has been inadequate, we hypothesized that advances in computed tomographic technology have improved the diagnostic sensitivity of CTA at least to that of invasive catheter angiography (CA). METHODS: Data from all patients at risk for BCVI presenting to a Level I trauma center were collected prospectively. Each patient was evaluated with CTA and these findings were confirmed with standard catheter arteriograms (CA). RESULTS: Over 11 months, 162 patients were at risk for BCVI. In all, 146 patients received both CTA and CA. Forty-six BCVIs were identified among 43 patients. In 45 of 46 cases (98%), the results of CTA and CA were concordant. There was a single false-negative CTA in a patient with a grade I vertebral artery injury (VAI). The remaining 103 patients had normal CTAs confirmed by a normal CA. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CTA for the diagnosis of BCVI were 97.7%, 100%, 100%, 99.3%, and 99.3%, respectively. CONCLUSIONS: CTA, using a 16-channel detector, can be used to accurately screen at-risk patients for BCVI.