GDC-0879, a BRAFV600E Inhibitor, Protects Kidney Podocytes from Death

Progressive kidney diseases affect approximately 500 million people worldwide. Podocytes are terminally differentiated cells of the kidney filter, the loss of which leads to disease progression and kidney failure. To date, there are no therapies to promote podocyte survival. Drug repurposing may therefore help accelerate the development of cures in an area of tremendous unmet need. In a newly developed high-throughput screening assay of podocyte viability, we identified the BRAF^V600E inhibitor GDC-0879 and the adenylate cyclase agonist forskolin as podocyte-survival-promoting compounds. GDC-0879 protects podocytes from injury through paradoxical activation of the MEK/ERK pathway. Forskolin promotes podocyte survival by attenuating protein biosynthesis. Importantly, GDC-0879 and forskolin are shown to promote podocyte survival against an array of cellular stressors. This work reveals new therapeutic targets for much needed podocyte-protective therapies and provides insights into the use of GDC-0879-like molecules for the treatment of progressive kidney diseases.

Impaired maternal hemodynamics in morbidly obese women: a case-control study

OBJECTIVE

Maternal obesity is associated with significant pregnancy complications and is a risk factor for the development of hypertensive disorders of pregnancy as well as other adverse outcomes. There are few data regarding the hemodynamic aberrations observed in maternal obesity. The aim of this study was to investigate maternal hemodynamics in morbidly obese women.

METHODS

This was a prospective, case-control study of morbidly obese women (body mass index (BMI) ≥ 40 kg/m² ) and controls (BMI 20-29.9 kg/m² ). The control population was matched for maternal age and gestational age. BMI was calculated based on maternal height and weight at the time of recruitment to the study, which occurred on the same day as the hemodynamic assessment. Pregnant women in the second or third trimester of pregnancy were included. Women who were found to be hypertensive at any time were excluded from the study. A USCOM-1A® device was used to assess hemodynamic parameters (heart rate, stroke volume (SV), cardiac output and systemic vascular resistance (SVR)). The parameters were corrected for body surface area (BSA) to provide the SV index (SVI), cardiac index (CI) and SVR index (SVRI). Mann-Whitney U-test was used to compare the medians of the hemodynamic variables between the two groups.

RESULTS

In total, 23 morbidly obese women and 327 controls were included in the analysis. There was no difference in maternal (P = 0.506) or gestational (P = 0.693) age at recruitment between the groups. Mean arterial pressure was higher both at pregnancy booking (90 vs 80 mmHg, P < 0.001) and study recruitment (91 vs 85 mmHg, P < 0.001) in the obese group compared with the controls. Heart rate was higher in the obese group (P = 0.003), but there was no difference in SV (P = 0.271), cardiac output (P = 0.238) or SVR (P = 0.635). Following correction of these parameters for BSA, compared with the control group, SVI (34 vs 45 mL/m² , P < 0.001) and CI (2.96 vs 3.64 L/min/m² , P < 0.001) were significantly reduced in the obese group, whereas SVRI was significantly higher (2354 vs 1840 dynes × s/cm⁵ , P < 0.001).

CONCLUSIONS

The findings of our study suggest that cardiac function is significantly altered in morbidly obese pregnant women. In order to make appropriate comparisons between individuals, it is imperative that hemodynamic parameters are indexed for BSA, as is standard practice in pediatric cardiology. The novel finding of reduced CI in morbidly obese pregnant women may explain the predisposition to pre-eclampsia and other adverse outcomes in this population and warrants further investigation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Brain Perivascular Spaces as Biomarkers of Vascular Risk: Results from the Northern Manhattan Study

BACKGROUND AND PURPOSE

Dilated perivascular spaces in the brain are associated with greater arterial pulsatility. We hypothesized that perivascular spaces identify individuals at higher risk for systemic and cerebral vascular events.

MATERIALS AND METHODS

Stroke-free participants in the population-based Northern Manhattan Study had brain MR imaging performed and were followed for myocardial infarction, any stroke, and death. Imaging analyses distinguished perivascular spaces from lesions presumably ischemic. Perivascular spaces were further subdivided into lesions with diameters of ≤3 mm (small perivascular spaces) and >3 mm (large perivascular spaces). We calculated relative rates of events with Poisson models and hazard ratios with Cox proportional models.

RESULTS

The Northern Manhattan Study participants who had MR imaging data available for review (n = 1228; 59% women, 65% Hispanic; mean age, 71 ± 9 years) were followed for an average of 9 ± 2 years. Participants in the highest tertile of the small perivascular space score had a higher relative rate of all deaths (relative rate, 1.38; 95% CI, 1.01-1.91), vascular death (relative rate, 1.87; 95% CI, 1.12-3.14), myocardial infarction (relative rate, 2.08; 95% CI, 1.01-4.31), any stroke (relative rate, 1.79; 95% CI, 1.03-3.11), and any vascular event (relative rate, 1.74; 95% CI, 1.18-2.56). After we adjusted for confounders, there was a higher risk of vascular death (hazard ratio, 1.06; 95% CI, 1.01-1.11), myocardial infarction (hazard ratio, 2.22; 95% CI, 1.12-4.42), and any vascular event (hazard ratio, 1.04; 95% CI, 1.01-1.08) with higher small perivascular space scores.

CONCLUSIONS

In this multiethnic, population-based study, participants with a high burden of small perivascular spaces had increased risk of vascular events. By gaining pathophysiologic insight into the mechanism of perivascular space dilation, we may be able to propose novel therapies to better prevent vascular disorders in the population.

Effect of Human Myotubes-Derived Media on Glucose-Stimulated Insulin Secretion

Fasting to postprandial transition requires a tight adjustment of insulin secretion to its demand, so tissue (e.g., skeletal muscle) glucose supply is assured while hypo-/hyperglycemia are prevented. High muscle glucose disposal after meals is pivotal for adapting to increased glycemia and might drive insulin secretion through muscle-released factors (e.g., myokines). We hypothesized that insulin influences myokine secretion and then increases glucose-stimulated insulin secretion (GSIS). In conditioned media from human myotubes incubated with/without insulin (100 nmol/L) for 24 h, myokines were qualitatively and quantitatively characterized using an antibody-based array and ELISA-based technology, respectively. C57BL6/J mice islets and Wistar rat beta cells were incubated for 24 h with control and conditioned media from noninsulin- and insulin-treated myotubes prior to GSIS determination. Conditioned media from insulin-treated versus nontreated myotubes had higher RANTES but lower IL6, IL8, and MCP1 concentration. Qualitative analyses revealed that conditioned media from noninsulin- and insulin-treated myotubes expressed 32 and 23 out of 80 myokines, respectively. Islets incubated with conditioned media from noninsulin-treated myotubes had higher GSIS versus control islets (p < 0.05). Meanwhile, conditioned media from insulin-treated myotubes did not influence GSIS. In beta cells, GSIS was similar across conditions. In conclusion, factors being present in noninsulin-stimulated muscle cell-derived media appear to influence GSIS in mice islets.

Assessment of the Role of Metabolic Determinants on the Relationship between Insulin Sensitivity and Secretion

Background

Insulin secretion correlates inversely with insulin sensitivity, which may suggest the existence of a crosstalk between peripheral organs and pancreas. Such interaction might be mediated through glucose oxidation that may drive the release of circulating factors with action on insulin secretion.

Aim

To evaluate the association between whole-body carbohydrate oxidation and circulating factors with insulin secretion to consecutive oral glucose loading in non-diabetic individuals.

Methods

Carbohydrate oxidation was measured after an overnight fast and for 6 hours after two 3-h apart 75-g oral glucose tolerance tests (OGTT) in 53 participants (24/29 males/females; 34±9 y; 27±4 kg/m²). Insulin secretion was estimated by deconvolution of serum C-peptide concentration, β cell function by mathematical modelling and insulin sensitivity from an OGTT. Circulating lactate, free-fatty acids (FFA) and candidate chemokines were assessed before and after OGTT. The effect of recombinant RANTES (regulated on activation, normal T cell expressed and secreted) and IL8 (interleukin 8) on insulin secretion from isolated mice islets was also measured.

Results

Carbohydrate oxidation assessed over the 6-h period did not relate with insulin secretion (r = -0.11; p = 0.45) or β cell function indexes. Circulating lactate and FFA showed no association with 6-h insulin secretion. Circulating chemokines concentration increased upon oral glucose stimulation. Insulin secretion associated with plasma IL6 (r = 0.35; p<0.05), RANTES (r = 0.30; p<0.05) and IL8 (r = 0.41; p<0.05) determined at 60 min OGTT. IL8 was independently associated with in vivo insulin secretion; however, it did not affect in vitro insulin secretion.

Conclusion

Whole-body carbohydrate oxidation appears to have no influence on insulin secretion or putative circulating mediators. IL8 may be a potential factor influencing insulin secretion.

Characterization of aerosols and fibers emitted from composite materials combustion

This work investigates the aerosols emitted during combustion of aircraft and naval structural composite materials (epoxy resin/carbon fibers and vinyl ester/glass fibers and carbon nanotubes). Combustion tests were performed at lab-scale using a modified cone calorimeter. The aerosols emitted have been characterized using various metrological devices devoted to the analysis of aerosols. The influence of the nature of polymer matrices, the incorporation of fibers and carbon nanotubes as well as glass reinforcements on the number concentration and the size distribution of airborne particles produced, was studied in the 5 nm-10 μm range. Incorporation of carbon fibers into epoxy resin significantly reduced the total particle number concentration. In addition, the interlaced orientation of carbon fibers limited the particles production compared to the composites with unidirectional one. The carbon nanotubes loading in vinyl ester resin composites influenced the total particles production during the flaming combustion with changes during kinetics emission. Predominant populations of airborne particles generated during combustion of all tested composites were characterized by a PN50 following by PN(100-500).

Anesthetic Implications of Ebola Patient Management: A Review of the Literature and Policies

As of mid-October 2014, the ongoing Ebola epidemic in Western Africa has affected approximately 10,000 patients, approached a 50% mortality rate, and crossed political and geographic borders without precedent. The disease has spread throughout Liberia, Guinea, and Sierra Leone. Isolated cases have arrived in urban centers in Europe and North America. The exponential growth, currently unabated, highlights the urgent need for effective and immediate management protocols for the various health care subspecialties that may care for Ebola virus disease patients. We conducted a comprehensive review of the literature to identify key areas of anesthetic care affected by this disease. The serious potential for "high-risk exposure" and "direct contact" (as defined by the Centers for Disease Control and Prevention) of anesthesiologists caring for Ebola patients prompted this urgent investigation. A search was conducted using MEDLINE/PubMed, MeSH, Cochrane Review, and Google Scholar. Key words included "anesthesia" and/or "ebola" combined with "surgery," "intubation," "laryngoscopy," "bronchoscopy," "stethoscope," "ventilation," "ventilator," "phlebotomy," "venous cannulation," "operating room," "personal protection," "equipment," "aerosol," "respiratory failure," or "needle stick." No language or date limits were applied. We also included secondary-source data from government organizations and scientific societies such as the Centers for Disease Control and Prevention, World Health Organization, American Society of Anesthesiologists, and American College of Surgeons. Articles were reviewed for primary-source data related to inpatient management of Ebola cases as well as evidence-based management guidelines and protocols for the care of Ebola patients in the operative room, infection control, and health care worker personal protection. Two hundred thirty-six articles were identified using the aforementioned terminology in the scientific database search engines. Twenty articles met search criteria for information related to inpatient Ebola virus disease management or animal virology studies as primary or secondary sources. In addition, 9 articles met search criteria as tertiary sources, representing published guidelines. The recommendations developed in this article are based on these 29 source documents. Anesthesia-specific literature regarding the care of Ebola patients is very limited. Secondary-source guidelines and policies represent the majority of available information. Data from controlled animal experiments and tuberculosis patient research provide some evidence for the existing recommendations and identify future guideline considerations.

Naive and radiolabeled antibodies to E6 and E7 HPV-16 oncoproteins show pronounced antitumor activity in experimental cervical cancer

BACKGROUND

In spite of profound reduction in incidence, cervical cancer claims >275,000 lives annually. Previously we demonstrated efficacy and safety of radioimmunotherapy directed at HPV16 E6 oncoprotein in experimental cervical cancer.

MATERIALS & METHODS

We undertook a direct comparison of targeting E7 and E6 oncoproteins with specific (188)Rhenium-labeled monoclonal antibodies in CasKi subcutaneous xenografts of cervical cancer cells in mice.

RESULTS

The most significant tumor inhibition was seen in radioimmunotherapy-treated mice, followed by the unlabeled monoclonal antibodies to E6 and E7. No hematological toxicity was observed. Immunohistochemistry suggests that the effect of unlabeled antibodies is C3 complement mediated.

CONCLUSION

We have demonstrated for the first time that radioimmunotherapy directed toward E7 oncoprotein inhibits experimental tumors growth, decreases E7 expression and may offer a novel approach to cervical cancer therapy.

Magnetic field and atomic order effect on the martensitic transformation of a metamagnetic alloy

The martensitic transformation (MT) of metamagnetic shape memory alloys is very sensitive to the applied magnetic field and atomic order. We analyze the alloy Ni50Mn34.5In15.5 in magnetic fields up to 13 T. The alloy has been prepared both in an ordered state by slow cooling, and in a disordered state by rapid quenching. In both cases the dependence of the martensitic transition temperature on the field is highly nonlinear. Such departure from linearity is due to a decrease of the entropy change at the transition, ΔS, with the applied field. This can be explained by the ordering effect of the magnetic field on the frustrated magnetic structure of the alloy in the martensitic phase. Compliance with a recent model, relying on the strong magnetoelastic interactions in these compounds, is very satisfactory.

Perivascular spaces are associated with atherosclerosis: an insight from the Northern Manhattan Study

BACKGROUND AND PURPOSE

Perivascular spaces are potential spaces found between brain blood vessels and surrounding leptomeninges that have been associated with cardiovascular risk factors and dementia, but less is known about their relationship to atherosclerosis. We tested the hypothesis that perivascular spaces are associated with atherosclerosis.

MATERIALS AND METHODS

Participants from the Northern Manhattan Study who remained stroke-free were invited to participate in an MR imaging substudy. Parenchymal hypointensities of <3 mm identified on brain axial T1-weighted MR imaging were scored as perivascular spaces. A semiquantitative score was created to express the degree of brain involvement. Generalized linear models were used to assess statistical associations with carotid plaque as a surrogate marker of atherosclerosis.

RESULTS

The studied sample included 706 participants (mean age, 72.6 ± 8.0 years; 60% women, 61% Hispanic, 68% with hypertension, 19% with diabetes, and 57% with high cholesterol). The perivascular spaces score ranged from 0 to 19 with 52% of the sample having a perivascular spaces score of ≤4. In unadjusted analysis, perivascular spaces were associated with age (β = 0.01 per year, P = < .001), non-Hispanic black race-ethnicity (β = 0.16, P = .02), hypertension (β = 0.24, P = < .001), and carotid plaque (β = 0.22, P < .001). In multivariable analysis, only age (β = 0.01, P = .02), hypertension (β = 0.17, P = .01), and carotid plaque (β = 0.22, P = < .001) remained independently associated with perivascular spaces.

CONCLUSIONS

Perivascular spaces were more frequently found in older participants, in those with hypertension, and in the presence of carotid plaque. These results suggest that mechanisms leading to atherosclerosis might also lead to an increased number of perivascular spaces. These results need confirmation in prospective studies.

A new magneto-elastic resonance based technique to determine magneto-mechanical parameters of amorphous ferromagnetic ribbons

Measurement of the magneto-mechanical parameters characteristics of amorphous ribbons often requires complex or limited methods due to their very small thickness. In this paper, it is shown how one can establish and estimate the characteristics of a magnetostrictive resonator from the experimental frequency response free of any kind of mechanical measurement (stress or elongation). This technique which is completely developed with a ribbon exhibiting good resonator properties, is suitable to estimate the magneto-mechanical coupling coefficient k33 and the Young's modulus and also to establish the magnetostriction curves λ(H) of amorphous ribbons. Results obtained from resonators made of 2605SC and 2826 from Metglas(TM) ribbons confirmed the validity of the present technique. However, measurements performed on a thin foil of nickel demonstrate that the present method cannot be extended to semi-soft magnetic materials. The technique which is proposed, has serious advantages upon others as it is non-destructive, low cost and easy to develop compared to common ones.