3071Peptidomimetic targeting of CavBeta2 improves contractility in models of senescence- or genetically (MYBPC3 KI)-induced heart failure

Background

L-type calcium channel (LTCC) trafficking controls LTCC density at T-tubule levels for optimal Excitation-Coupling (EC) and resultant adaptive heart work. In some forms of heart failure (HF), abnormalities in calcium-induced calcium-release have been proposed to arise from alteration of T-tubular dyad architecture (LTCC-RyRs) associated with impaired LTCC density. Recently, the R7W-MP peptide, working as a binder of the LTCC Cavβ2 chaperone, was shown to restore the altered density of LTCC current by both promoting forward and reducing reverse trafficking, which consequently improved cellular calcium homeostasis. Accordingly, R7W-MP improved the impaired cardiomyocyte calcium current density and the reduced Ejection Fraction (EF%) in a pharmacologically-induced diabetes model (STZ mice).

We aimed to investigate further the benefit to improve LTCC trafficking pathway with R7W-MP in a more physiological model of HF (senescent mice) and in a Dilated Cardiomyopathy (DCM) model (HO MYBPC3 targeted KI mutant).

Methods

Senescent male C57Bl/6J mice (26 months) or HO MYBPC3 KI male mice (2 months) were treated with R7W-MP (3 mg/kg/d IP for 3 days). Echocardiographies (echo) were conducted before treatment and 4-hours after the last injection. When applied, Pressure-Volume (PV)-loop investigations were conducted one day post-echo 4 hours following an additional R7W-MP injection.

Results

In senescent mice population, HF was characterized by a midrange ejection fraction (EF%= 43±2 vs 55±1 for young adult mice) associated with enlarged ventricles and decreased cardiac contractility. In contrast to a scrambled peptide (scrP), R7W-MP markedly increased EF% monitored by echo (+38%, 63±3 vs 45±1 for scrP, p≤0.001, n=6–7) without modification of heart rate. EF% improvement was confirmed by PV-loop analysis (78±3 vs 51±4 for scrP (+54%), p≤0.001, n=5), associated with a marked, although not significant, 2.5-fold increase in myocardial contractility [end systolic pressure volume relationship (ESPVR) = 12.1±3.6 vs 4.9±1.3 for scrP, p=0.10, n=4]. Stroke volume, cardiac output and end diastolic volume tended to decrease suggesting an impaired LV filling at this dose regimen. In the DCM model, HF was more severe with a dramatically low EF% (26±1, n=8), impaired myocardial contractility and a pronounced left ventricle enlargement. R7W-MP significantly increased EF% (+17%, reaching 31±1, p≤0.01, n=8) without altering heart rate. Stroke volume was significantly increased by 36% (32±3 vs 24±3 mL at baseline, p≤0.01), without any impairment of diastolic function. All parameters returned to baseline after a 2 week-washout period.

Conclusions

R7W-MP displays potent positive inotrope properties in senescent or DCM mice models. Although further asses tsments of diastolic function are needed (different dosing and duration), these data underline the potential benefit brought by LTCC trafficking modulation to treat severe dilated cardiomyopathy.

P5995A novel biased S1P1 agonist improves renal and cardiac functions in ZSF1 rats, a model of metabolic syndrome-associated Heart Failure with preserved Ejection Fraction

Background/Introduction

Heart Failure with preserved ejection fraction (HFpEF) is a major cause of death worldwide with currently no approved treatment. Diastolic dysfunction, dyspnea, intolerance to effort, high cardiac filling pressure, and lung congestion coexist with normal ejection fraction in this clinical syndrome. Ageing, obesity, type 2 diabetes, hypertension and renal dysfunction are the main comorbidities found in this heterogeneous group of patients. Microvascular endothelial dysfunction, driven by these risk factors, may be a common link with other aspects of the HFpEF pathogenesis that include oxidative stress, inflammation, cardiomyocyte stiffness/hypertrophy, and myofibroblast accumulation. Sphingosine-1-phosphate type-1 receptor (S1P1), a G protein–coupled receptor highly expressed in endothelial cells, regulates vascular integrity, vascular development and immune cell trafficking. Compound A is a novel G protein-biased S1P1 agonist that lacks functional antagonism and has endothelial-protective properties.

Purpose

S1P1 activation could promote phosphorylation of endothelial nitric oxide synthase, restoration of endothelial structure and function, and thus diminish cardiac and vascular stiffness, hypertrophy and fibrosis. The aim of this study was to investigate if compound A could improve renal and cardiac functions in a rat model of HFpEF with metabolic syndrome.

Methods

65-week-old obese ZSF1 rats were fed a chow diet containing compound A (8 mg/kg/day) or no compound for 4 weeks. Lean ZSF1 and Wistar rats were included in the study as control groups. Urinary protein/creatinine ratio was measured as an index of glomerular injury. Cardiac hypertrophy and function were assessed by two-dimensional and Doppler echocardiography. Total cardiac and atrial weights and pulmonary edema were assessed.

Results

The obese ZSF1 rat was confirmed as a relevant model of HFpEF with advanced renal dysfunction. These rats showed severe glomerular filtration impairment, left ventricular and atrial hypertrophy and pulmonary edema. Cardiac systolic function, cardiac output and chamber volumes were preserved, diastolic function was impaired, and left ventricular posterior walls and septal thicknesses were increased compared to control groups. Four weeks of compound A treatment reduced urinary protein/creatinine ratio, blunted cardiac and atrial hypertrophy, and partially restored diastolic function. Circulating lymphocytes were not reduced by compound A, confirming that these pharmacological effects were not associated with S1P1 desensitization.

Conclusion

Compound A, a novel S1P1 agonist with endothelial properties, improves cardiac and renal functions in a rat model of metabolic syndrome-associated HFpEF. Sustained S1P1 activation with compound A may be a promising strategy for HFpEF treatment.

A multidisciplinary perspective on the subcutaneous administration of trastuzumab in HER2-positive breast cancer

Trastuzumab is the standard treatment in Canada for patients with breast cancer positive for her2 (human epidermal growth factor receptor 2), dramatically improving outcomes in that patient group. However, its current intravenous (IV) administration is associated with long infusion times that place a significant burden on health care resources and patient quality of life. In an effort to provide a faster and easier administration method, a subcutaneous (sc) formulation of trastuzumab has been developed. Data from comparative trials demonstrate that the two formulations are comparable with respect to pharmacokinetics and efficacy. They also have similar safety profiles, with the exception of mild local and administration reactions with the sc formulation. Furthermore, the sc formulation is preferred by patients and health care professionals, and greatly reduces administration and chair time. Additional advantages include easier preparation and dosing, reduced drug wastage, and reduced discomfort at the injection site. By using well-thought-out administration procedures, the sc formulation can be given safely and effectively, potentially reducing the burden on health care resources and improving quality of life for patients.

Neoadjuvant Therapy for Breast Cancer: Updates and Proceedings From the Seventh Annual Meeting of the Canadian Consortium for Locally Advanced Breast Cancer

Therapy for breast cancer involves a complex interplay of three main treatment modalities: surgery, systemic therapy, and radiation therapy. The Canadian Consortium for Locally Advanced Breast Cancer (LABC) was established with the goal to convene a strong multidisciplinary team of breast oncology clinicians and scientists who are dedicated to the advancement of LABC research and treatment, with a vision to drive progress through increased collaboration across disciplines and throughout Canada. The most recent meeting in May 2017 highlighted the latest evidence and literature about the optimal use of neoadjuvant systemic therapy in breast cancer. There is a need for increased clinical and scientific collaboration and the development of guidelines for the use of emerging treatment strategies. The interactive meeting sessions fostered unique opportunities for academic debate and nurtured collaboration between the attendees.

Abstract P1-09-04: Proliferation and p21 refine risk of relapse in residual disease after HER2-directed therapies

Background: Patients (pts) with residual disease (RD) after neoadjuvant therapy are at higher risk of relapse. We investigated whether biomarkers assessed at surgery in patients pts with RD in the NeoSphere study were informative for risk of distant event free survival (DEFS)

Methods: In NeoSphere 417 HER2+ pts were randomized to neoadjuvant TD, TPD, TP or PD (T=trastuzumab, P=pertuzumab, D=docetaxel), and received FAC/FEC and trastuzumab after surgery. 296 pts had RD. Affymetrix derived gene expression profiles (GEPs) were available at surgery for 201 pts (67.9%). 176 pts (60.1%) had paired samples before and after treatment with available GEPs. We investigated the prognostic value of proliferation evaluated by Mitosis Kinase Score (MKS) (Bianchini G Cancer Res 2010), and performed a gene discovery for association between gene expression at surgery and DEFS.

Results: MKS as continuous marker was associated with significantly higher risk of relapse when assessed at surgery (HR 1.80 [1.23-2.65]; p=0.002), but not before treatment (HR 1.50 [0.80-2.78]; p=0.20). In paired samples, there was an average decrease (p=9.2E-11) of MKS after treatment, which was prominent in ER+ and chemotherapy-containing arms. In ER- and TP arm there were cases of increase and of decrease of MKS. In ER+ the 5 years DEFS was 94.3% in the Low/Int MKS tertiles group (pooled) vs 70.5% in the High MKS tertile group (HR 5.41 [1.87-15.6]; p=0.002). In ER-, the 5 years DEFS was 85.0% in the Low/Int vs 64.1% in the High group (HR 2.89 [1.08-7.76]; p=0.035). Notably, MKS at surgery after the two monoclonal alone was also prognostic.

In the gene discovery approach only the expression of CDKN1A (p21)at surgery was associated with DEFS after correction for false discovery rate (FDR=0.01). Pre-treatment p21 was not associated with DEFS. Paired comparison showed significant upregulation of p21 in all patients, treatment arms and ER groups. The Int/High p21 tertiles group (pooled) had lower risk of recurrence than the low tertile in ER+ (HR 4.31 [1.60-11.6]; p=0.004) and in ER- (HR 5.81 [1.87-18.1]; p=0.002) groups. p21 in TP arm was also prognostic. MKS and p21 expression provided independent prognostic information and remained significant after correction for clinico-pathological variables (nodes and T stage) and tumor-infiltrating lymphocytes. Combining the two markers, there was a group at very low risk (Low/Int MKS and Int/High p21) and one at high risk (High MKS and Low p21). The other tertiles combinations had intermediate risk. In ER+, the 5 yrs DEFS was 94.9% in the low risk group and 52.9% in the high risk (p=1.9E-05). In ER-, the 5 yrs DEFS was 96.5% in the low and 45.5% in the high risk group (p=0.001).The markers' combination was also prognostic in the two monoclonal only arm.

Conclusions: Proliferation (MKS) and p21 expression are modulated by trastuzumab and/or pertuzumab regimens. Tumors with high MKS and low p21 in RD after neoadjuvant therapy defined a group at very high risk of relapse. Tumors with low/int proliferation and int/high p21 had low risk of recurrence similar to that of patients achieving pCR. Whether the pharmacodynamic modulation of p21 could be used as surrogate marker of long term benefit in patients with RD deserves additional investigation.

Citation Format: Bianchini G, Pienkowski T, Im Y-H, Bianchi GV, Tseng L-M, Liu M-C, Lluch A, de la Haba-Rodríguez J, Semiglazov V, Oh D-Y, Poirier B, Pedrini JL, Valagussa P, Gianni L. Proliferation and p21 refine risk of relapse in residual disease after HER2-directed therapies [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-09-04.

Is clinical breast examination important for breast cancer detection?

BACKGROUND

Screening clinical breast examination (cbe) is controversial; the use of cbe is declining not only as a screening tool, but also as a diagnostic tool. In the present study, we aimed to assess the value of cbe in breast cancer detection in a tertiary care centre for breast diseases.

METHODS

This retrospective study of all breast cancers diagnosed between July 1999 and December 2010 at our centre categorized cases according to the mean of detection (cbe, mammography, or both). A cbe was considered "abnormal" in the presence of a mass, nipple discharge, skin or nipple retraction, edema, erythema, peau d'orange, or ulcers.

RESULTS

During the study period, a complete dataset was available for 6333 treated primary breast cancers. Cancer types were ductal carcinoma in situ (15.3%), invasive ductal carcinoma (75.7%), invasive lobular carcinoma (9.0%), or others (2.2%). Of the 6333 cancers, 36.5% (n = 2312) were detected by mammography alone, 54.8% (n = 3470) by mammography and cbe, and 8.7% (n = 551) by physician-performed cbe alone (or 5.3% if considering ultrasonography). Invasive tumours diagnosed by cbe alone were more often triple-negative, her2-positive, node-positive, and larger than those diagnosed by mammography alone (p < 0.05).

CONCLUSIONS

A significant number of cancers would have been missed if cbe had not been performed. Compared with cancers detected by mammography alone, those detected by cbe had more aggressive features. Clinical breast examination is a very low-cost test that could improve the detection of breast cancer and could prompt breast ultrasonography in the case of a negative mammogram.

Bicylindrical model of Herschel-Quincke tube-duct system: theory and comparison with experiment and finite element method

An analytical three dimensional bicylindrical model is developed in order to take into account the effects of the saddle-shaped area for the interface of a n-Herschel-Quincke tube system with the main duct. Results for the scattering matrix of this system deduced from this model are compared, in the plane wave frequency domain, versus experimental and numerical data and a one dimensional model with and without tube length correction. The results are performed with a two-Herschel-Quincke tube configuration having the same diameter as the main duct. In spite of strong assumptions on the acoustic continuity conditions at the interfaces, this model is shown to improve the nonperiodic amplitude variations and the frequency localization of the minima of the transmission and reflection coefficients with respect to one dimensional model with length correction and a three dimensional model.

Blockade of cannabinoid CB1 receptors improves renal function, metabolic profile, and increased survival of obese Zucker rats

Obesity is a major risk factor in the development of chronic renal failure. Rimonabant, a cannabinoid CB1 receptor antagonist, improves body weight and metabolic disorders; however, its effect on mortality and chronic renal failure associated with obesity is unknown. Obese Zucker rats received either rimonabant or vehicle for 12 months and were compared to a pair-fed but untreated group of obese rats. Mortality in the obese rats was significantly reduced by rimonabant along with a sustained decrease in body weight, transient reduction in food intake, and an increase in plasma adiponectin. This was associated with significant reduction in plasma total cholesterol, low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, glucose, norepinephrine, plasminogen activator inhibitor 1, and preservation of pancreatic weight and beta-cell mass index. The cannabinoid antagonist attenuated the increase in proteinuria, urinary N-acetylglucosaminidase excretion, plasma creatinine, and urea nitrogen levels while improving creatinine clearance. Renal hypertrophy along with glomerular and tubulointerstitial lesions were reduced by rimonabant. Although the drug did not modify hemodynamics, it normalized the pressor response to angiotensin II. Our study suggests that in a rat model of chronic renal failure due to obesity, rimonabant preserves renal function and increases survival.

Atheroprotective effect of adjuvants in apolipoprotein E knockout mice

Strategies aimed at treating atherosclerosis by immunization protocols are emerging. Such protocols commonly use adjuvants as non-specific stimulators of immune responses. However, adjuvants are known to modify various disease processes. The aim of this study was to determine whether adjuvants alter the development of atherosclerosis. We performed immunization protocols in apolipoprotein E knockout mice (E degrees ) following chronic administration schedules commonly employed in experimental atherosclerosis. Our results point out a dramatic effect of several adjuvants on the development of atherosclerosis; three of the four adjuvants tested reduced lesion size. The Alum adjuvant, which is the adjuvant currently used in most vaccination protocols in humans, displayed a strong atheroprotective effect. Mechanisms accounting for atheroprotective effect of Freund's adjuvants included their capacity to increase both Th2 responses and anti-MDA-LDL IgM titers, and/or to impose atheroprotective lipoprotein profiles. The present study indicates that adjuvants have potent atheromodulating capabilities, and thus, implies that the choice of adjuvant is crucial in long-term immunization protocols in experimental atherosclerosis.

Collaborative study for the establishment of the Ph. Eur. BRP batch 1 for anti-vaccinia immunoglobulin

Upon suggestion of the French Official Medicines Control Laboratory, a collaborative study was initiated by the European Directorate for the Quality of Medicines with the goal of calibrating the candidate European Pharmacopoeia biological reference preparation (Ph. Eur. BRP) for anti-vaccinia immunoglobulin batch 1 in International Units (IU) against the 1(st) British standard (anti-smallpox serum). The candidate BRP batch 1 was obtained by lyophilising a pool of four plasma samples obtained from one donor who was multi-vaccinated with smallpox vaccine (Lister strain) and who had relatively high titres of neutralising anti-vaccinia antibodies. The plasma complied with the requirements of the Ph. Eur. monograph Human plasma for fractionation. For the candidate BRP the precision of fill and the residual moisture after lyophilisation comply with the requirements for biological reference preparations. The stability of the material was shown to be satisfactory for the intended purpose in an accelerated degradation test. Eight laboratories participated in the study. Two samples had to be assayed (candidate BRP batch 1 and 1(st) British standard). All participants were requested to test the samples using a common method (plaque reduction neutralisation) that had been validated beforehand, and their own in-house anti-vaccinia immunoglobulin titration method. From the raw data returned, the potency of the candidate BRP was calculated in IU/ml using the parallel lines method. The precision (intra-assay variation), repeatability (intra-laboratory variation) and reproducibility (inter-laboratory variation) were assessed. All laboratories used the Lister strain of vaccinia virus for the plaque reduction neutralisation assay. For laboratories using cell-adapted vaccinia virus, the results were satisfactory regarding intra-assay variability, intra-laboratory variability and inter-laboratory variability. For laboratories using vaccinia virus produced on animals, results were less satisfactory. The study suggests that the candidate BRP batch 1 is suitable as a reference preparation for the potency assay of vaccinia immunoglobulin by the plaque reduction neutralisation method, using cell-adapted vaccinia virus. For this purpose, a potency of 23 IU/vial could be assigned to the candidate BRP. Based on the results of the stability testing, storage of the reference material at -20 degrees C and shipment on ice is recommended. Furthermore, it is recommended to monitor the potency of the reference material once per year. The candidate material was adopted as Ph. Eur. BRP at the Ph. Eur. Commission session in March 2005.

Role of the Intrinsic Coagulation Pathway in Atherogenesis Assessed in Hemophilic Apolipoprotein E Knockout Mice

Objective— The contribution of thrombosis and coagulation in atherogenesis is largely unknown. We investigated the contribution of the coagulation intrinsic factor VIII (FVIII)–dependent pathway in atherogenesis.

Methods and Results— Apolipoprotein E and FVIII double–deficient mice (E°/FVIII°) were generated. Aortic root lesions were analyzed in 14-week-old and 22-week-old female mice maintained for 8 or 16 weeks, respectively, on a normal chow diet or a hypercholesterolemic diet.

Conclusion— Despite a higher plasma total cholesterol concentration compared with E° mice, E°/FVIII° mice developed dramatically less early-stage atherosclerotic lesions. Whereas early lesions in E° mice contained abundant fibrin(ogen) deposits on which few platelets adhered, lesions in E°/FVIII° were almost devoid of fibrin(ogen), and no platelets could be detected. The genotype effect on development and composition of lesions tended to decrease with time. This study demonstrates that the activation of the intrinsic pathway of coagulation is potently proatherogenic at the early stage of atherogenesis.

The anti-obesity effect of rimonabant is associated with an improved serum lipid profile

We investigated the effects of chronic treatment with the CB1 receptor antagonist rimonabant (10 mg/kg/day p.o. for 10 weeks) in mice with established obesity (5-month high-fat diet). Untreated obese mice showed a weight gain of 46% (45.0 +/- 0.6 g vs. 30.8 +/- 0.5 g) compared with age-matched animals fed a standard diet. Rimonabant treatment, commencing after 5-month high-fat diet, produced a marked and sustained decrease in body weight (34.5 +/- 0.8 g vs. 47.2 +/- 0.5 g in the high-fat vehicle group, p < 0.001). The anti-obesity effect of rimonabant was similar to that obtained by switching obese mice from high-fat diet to standard laboratory diet during 10 weeks (final weight 33.7 +/- 0.6 g) and was associated with only transient (14 days) reduction in energy intake. Serum leptin, insulin and glucose levels were markedly elevated in obese animals. Rimonabant treatment significantly reduced these elevations (leptin -81%, insulin -78%, glucose -67%, p < 0.001 in all cases vs. high-fat vehicle group). In addition, rimonabant treatment modestly but significantly increased serum adiponectin levels (+18%, p < 0.05 vs. high-fat vehicle group). Obese mice demonstrated abnormal serum lipid profiles. Although rimonabant did not modify high-density lipoprotein cholesterol (HDLc) and had modest effects on total cholesterol, it significantly reduced triglycerides and low-density lipoprotein cholesterol (LDLc) and, notably, increased the HDLc/LDLc ratio (12.4 +/- 0.8 vs. 7.9 +/- 0.2 in high-fat vehicle group, p < 0.001). Therefore, in a model of established obesity, chronic rimonabant treatment produces a marked and sustained decrease in body weight (equivalent to that achieved by dietary change) which is associated with favourable modifications in serum biochemical and lipid profiles.

Non-viral gene transfer of murine spleen cells achieved by in vivo electroporation

Gene electrotranfer is an attractive physical method to deliver genes to target tissues. The aim of this study was to evaluate in vivo gene electrotransfer into spleen, one of the most important lymphoid organ, in order to create a new tool to modulate the immuno-inflammatory system. C57Bl/6 mice were submitted either to intramuscular electrotransfer (IME) as a reference method or to intrasplenic (ISE) gene electrotransfer. In the naked injected plasmids, the CMV promoter controlled the expression of luciferase, secreted alkaline phosphatase, EGFP, or IFNgamma. The ISE optimal electrotransfer conditions were first determined and ISE was found to be an efficient gene transfer method, which can be used to express secreted or intracellular proteins transiently. Although transfected cells were still present in the spleen 30 days after ISE, transfected spleen cells could recirculate since they were detected in extrasplenic locations. Using a T-lymphocyte-specific promoter controlling the expression of EGFP, splenic T cells could be targeted. Finally, it appeared that ISE procedure does not impair by itself the immune response and does not result in a significant production of antibodies directed to the transgenic proteins in C57Bl/6 mice. This strategy constitutes a new method to manipulate the immune response that can be used in various experimental designs.

Clinical and microbiological epidemiology of Streptococcus pneumoniae bacteremia in eight French counties

OBJECTIVE

To describe the incidence of pneumococcal bacteremia not associated with infection of the central nervous system, investigate the susceptibility of bacterial isolates to beta-lactams, evaluate risk factors for antibiotic resistance, and determine factors predicting patient outcome.

METHODS

Over a period of 1 year, 919 Streptococcus pneumoniae isolates were collected from 919 patients with bacteremia in eight French counties. Their clinical and microbiological features were recorded. Univariate and multivariate analyses were used to determine risk factors for penicillin-non-susceptible pneumococcal bacteremia and predictors of fatal outcome.

RESULTS

Of the 919 patients in the study, 27% were infected with penicillin-non-susceptible pneumococci (PNSP): 17.8% of the isolates were intermediate to penicillin, 7.2% were resistant to penicillin, 16% were intermediate to amoxicillin, and 11% were intermediate to cefotaxime; no PNSP were resistant to either of the last two antibiotics. The most common PNSP serotypes isolated were 14 (41%) and 23 (24%). A statistically significant relationship between PNSP infection and age below 5 years or above 60 years in the different counties was observed by univariate and multivariate analysis. Gender, origin of bacteremia, co-morbidity, immunodeficiency, previous hospitalization and nosocomial infection were not predisposing factors associated with PNSP. The mortality rate was 20.6%: there was no increase in mortality among patients with PNSP bacteremia. Age was the strongest risk factor for mortality, but immunodeficiency also seemed to have had an impact on mortality. Clinical outcome was more closely related to clinical conditions than to the susceptibility status of S. pneumoniae.

CONCLUSION

Among cases of bacteremia, 27% were caused by PNSP, but this level varies according to the counties and the age of the patients. Infection-related mortality was high, but there was no increase related to penicillin G non-susceptibility of the infecting strain.

Development of an in vitro potency test for tetanus vaccines: an immunoassay based on Hc fragment determination

In the three Rs rule context, we have developed a method to quantify tetanus toxoid by ELISA detection of the specific Hc fragment. This fragment and several anti Hc fragment antibodies have been described as protective in mice models. By developing this assay, we have detected Hc presence in tetanus toxoid. Therefore, this functional in vitro assay could replace in vivo potency assays. We have evaluated the analytical performances of this ELISA in specificity, sensitivity, precision, and linearity tests on different combined vaccine formulations. This in vitro assay has been applied to various multi-component vaccines. Results are expressed in Lf Hc/ml with reference to a purified tetanus toxoid standard expressed in Lf/ml.

Conjugated dienes: a critical trait of lipoprotein oxidizability in renal fibrosis

BACKGROUND

We assessed whether a differential oxidizability of apolipoprotein B (apo B)-containing lipoproteins (LDL and VLDL) may explain the oxidative stress that we had observed at the onset of renal fibrosis in Zucker obese (ZO) rats (Nephrol Dial Transplant 2000, 15: 467--476).

METHODS

Ex vivo copper-induced oxidation of lipoproteins was performed in 1-, 3-, and 9-month-old ZO and age-matched lean (ZL) rats. LDL/VLDL oxidizability was determined by spectrophotometry at 234 nm by monitoring the formation of conjugated diene hydroperoxides.

RESULTS

A significant increase in lag time (reflecting the resistance to oxidation) was observed in ZO rats at 3 months while the maximal diene production (reflecting the amount of hydroperoxides formed during oxidation) was higher in ZO than in ZL rats as early as 1 month. Lipoproteins were larger in ZO than in ZL rats, as shown by their core to surface component ratio. Furthermore, ZO lipoproteins had increased vitamin E and polyunsaturated fatty acid (PUFA) content, with no change in vitamin E/PUFA ratio.

CONCLUSIONS

Rather than oxidizability of apo B-containing lipoproteins, the ability of these molecules to produce high levels of conjugated dienes, which can act as toxic tissue messengers, appears to be a critical trait in the development of renal fibrosis in this rat model of obesity and renal fibrosis.

In vivo downregulation of T helper cell 1 immune responses reduces atherogenesis in apolipoprotein E-knockout mice

BACKGROUND

A chronic immune response involving proinflammatory T helper cell 1 (Th1) lymphocyte activation occurs in the atherosclerotic lesion, but whether this activation is protective or deleterious remains unclear. Methods and Results-- We modulated the immune response of the atherosclerosis-prone apolipoprotein E-deficient (apoE(-/-)) mouse. Eight-week-old apoE(-/-) mice were treated daily with pentoxifylline (PTX), a known inhibitor of the Th1 differentiation pathway, or PBS (control) for 4 weeks or 12 weeks. Twelve-week PTX treatment reduced atherosclerotic lesion size by 60% (P<0.01). PTX-treated mice developed lesions that were limited to the degree of fatty streaks. In contrast, control mice developed mature fibrofatty atherosclerotic lesions. In parallel, the proportion of interferon (IFN)-gamma-producing Th1 splenic lymphocytes was significantly reduced by PTX, and lesion size was correlated to the proportion of IFN-gamma(+) T cells. In vitro addition of PTX to cultured spleen cells did not modify the production of IFN-gamma but increased the production of IL-10 by T cells, indicating that PTX does not suppress IFN-gamma production but rather blocks Th1 polarization while promoting Th2 polarization.

CONCLUSIONS

Thus, PTX protected mice from atherosclerosis by reducing the Th1 polarization of T helper lymphocytes. This study demonstrates that the Th1 immune response associated with atherosclerosis is deleterious and that a modulation of the Th1 differentiation pathway may provide a new pharmacological tool to treat this disease.

Inflammation is probably not a prerequisite for renal interstitial fibrosis in normoglycemic obese rats

We examined the role of inflammation in the development of renal interstitial fibrosis in Zucker obese rats, which rapidly present kidney lesions in the absence of hypertension and hyperglycemia. Type I and III collagens were quantified using a polarized light and computer-assisted image analyzer. The expression of mRNA encoding matrix components, adhesion molecules, chemokines, and growth factors was followed by RT-PCR. The presence of synthesized proteins as well as lymphocytes and macrophages was determined by immunohistochemistry. Interstitial fibrosis developed in two phases. The first phase occurred as early as 3 mo and resulted from a neosynthesis of type III collagen and fibronectin and a reduction of extracellular matrix catabolism, in parallel with an overexpression of transforming growth factor-beta(1) and in the absence of any lymphocyte or macrophage infiltration. After 6 mo, interstitial fibrosis worsened with a large accumulation of type I collagen, concomitantly with a large macrophage infiltration. Thus inflammation cannot explain the onset of interstitial fibrosis that developed in young, insulinoresistant, normoglycemic, obese Zucker rats but aggravated this process afterward.

Key points for the development of mouse immunogenicity test as potency assay for acellular pertussis vaccines

According to WHO and the European Pharmacopoeia, the current potency test for acellular pertussis vaccines is a mouse immunogenicity assay assessing consistency of production from batch to batch. The assay compares the batch under control with a reference vaccine of documented clinical efficacy. This study describes and illustrates critical aspects of the assay, based on our experience on a tricomponent vaccine: validation of immunoassay to quantify mouse antibody response, choice of vaccine immunising doses in the three-doses model, treatment of non-responder mice for calculations, establishment of assay validity criteria.

In vitro potency assay for hepatitis A vaccines: development of a unique economical test

Prior to the official release of each Hepatitis A vaccine lot to the market, a quality control performed by a National Control Authority requires an in vivo or an in vitro potency assay. At the beginning of our work, no standardised in vitro test common to all hepatitis A vaccines was available for both manufacturers and National Control Laboratories. In this study, a unique polyvalent enzyme-linked immunosorbent assay (ELISA) method was developed to appraise all commercially available HAV vaccines. After comparing a direct and an indirect sandwich method with commercial antibodies, the indirect assay was selected and an evaluation of sensitivity, linearity, accuracy and precision was performed before being applied to HAV antigen determination from four different manufacturers. The results are satisfactory and incline us to use routinely this method to release Hepatitis A vaccines.

Oxidative stress occurs in absence of hyperglycaemia and inflammation in the onset of kidney lesions in normotensive obese rats

BACKGROUND

Several factors favour the development of kidney lesions. We examined the role of oxidative stress in the onset of renal alterations that occur in Zucker obese (ZO) fa/fa rats.

METHODS

Kidney structure, biological data, glycation parameters, advanced glycation end products (AGE), thiobarbituric acid-reactive substances (TBARS), circulating antibodies anti-malondialdehyde (MDA)-modified low-density lipoprotein (LDL), antioxidant defenses (Cu/Zn and Mn superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) activities, glutathione level), were determined in plasma and/or kidney of young and old ZO rats and lean (ZL) Fa/fa littermates.

RESULTS

Renal lesions and functional decline appeared at 3 months in hyperlipidaemic, hyperinsulinaemic, normotensive ZO rats, independently of any macrophage-ED(1)(+)-cell infiltration. At 6 months and thereafter, kidney lesions and functional impairment worsened while numerous ED(1)(+)-cells invaded the interstitium. At 3 and 9 months, TBARS level in the LDL/very low-density lipoprotein fraction and in the kidney was higher in ZO than in ZL rats. Anti-MDA-LDL antibodies were increased in ZO rats. At 3 months, renal activity of Cu/Zn SOD was higher, and activities of catalase and GPx lower in ZO than in ZL rats, leading to an accumulation of hydrogen peroxide (H(2)O(2)). At 9 months, a decrease in Cu/Zn SOD activity and an increase in glutathione level were observed. Blood glucose and glycated proteins, as well as AGE in kidney, remained similar in both ZL and ZO rats, whatever their age.

CONCLUSION

These data suggest that oxidative stress triggers, at an early age, the onset of kidney lesions and functional impairment in ZO rats, in absence of hyperglycaemia, hypertension and inflammation.

In vitro potency assay for yellow fever vaccines: comparison of three vero cell lines sources

Quality control of Yellow Fever vaccines performed by Control Authorities prior to marketing vaccines batches requires in vitro potency assays. The two currently available methods are the plaque formation assay and the cytopathic effect assay based on the use of porcine kidney PS cells or monkey kidney Vero cells. Among several sources of variation in virus titration, the cell systems are considered as important issues and Quality Assurance strongly recommends working with cell banks from certified suppliers. The aim of our study was to compare the behaviour and the sensitivity of three Vero cell sources obtained from ATCC, WHO and EP used at different passage levels in a plaque formation test. The conclusion of this work was that the yellow fever live attenuated virus titration, adapted in Vero cell lines appeared as a reliable method applicable for routine in vitro potency assay. The comparison of Vero cell lines, originated from three different sources, showed that they could be equally used as substrates by laboratories having the basic facility of cell culture, without influence on the final viral titre.

Modulation of endothelial cell function by normal polyspecific human intravenous immunoglobulins: a possible mechanism of action in vascular diseases

Intravenous immunoglobulin (IVIg) is increasingly used in the treatment of autoimmune and inflammatory diseases, including vasculitides and Kawasaki disease. However, the outcome of IVIg interaction with endothelial cells of the vascular bed is not clear as yet. We have investigated the effect of IVIg on the in vitro activation of human endothelial cells, as assessed by cell proliferation and reverse transcription-polymerase chain reaction-detected expression of mRNA coding for adhesion molecules (intercellular adhesion molecule-1 and vascular cellular adhesion molecule-1), chemokines (monocyte chemoattractant protein-1, macrophage colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor), and proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6). IVIg inhibited proliferation of endothelial cells in a time-dependent manner. This effect was dependent on both Fc and F(ab')2 fragments of the immunoglobulin molecule and was fully reversible. Tumor necrosis factor-alpha and interleukin-1beta also inhibited thymidine incorporation, but to a lesser degree. IVIg had no effect on basal levels of mRNA coding for the adhesion molecules, chemokines, and proinflammatory cytokines. IVIg fully down-regulated the expression induced by tumor necrosis factor-alpha or interleukin-1beta of mRNA coding for these molecules. Thus, blockade of cellular proliferation and of cytokine-induced expression of adhesion molecules, chemokines, and cytokines may explain the therapeutic effect of IVIg in vascular and inflammatory disorders.

Viral inactivation of human bone tissue using supercritical fluid extraction

A new bone tissue process using supercritical carbon dioxide fluid extraction (SFE) has been evaluated for its ability to inactivate or eliminate viruses. Four viruses, human immunodeficiency virus type 1 (HIV-1), Sindbis virus, polio Sabin type I virus, and pseudorabies virus (PRV), were exposed to four different processing steps. In addition to supercritical CO2, hydrogen peroxide, sodium hydroxide, and ethanol treatments were evaluated. The mean cumulated reduction factors (log10) for the four viruses exposed to these four steps were > 14.2 for HIV-1, > 18.2 for Sindbis virus, > 24.4 for poliovirus, and > 17.6 for PRV. The mean reduction factors obtained by the supercritical fluid extraction alone were > 4.0, > 4.3, > 6.6, and > 4.0, respectively. These results demonstrate that the SFE process is effective in inactivating viruses on human femoral heads, and provides a level of inactivation similar to that obtained by traditional cleaning methods. It is proposed that CO2 SFE be incorporated as a routine step in the processing of bone allografts for transplantation either to replace or supplement existing procedures.

Shaping a preferred future: Catholic healthcare beyond the year 2000

The Catholic Health Association of Canada recognizes that the Canadian healthcare system is changing. In a special supplement to the summer edition of the Review, we explored the forces at play within our healthcare environment and identified significant emerging trends. In Part II of this review, we look at the role for Catholic healthcare in Canada beyond the year 2000 by presenting the perspectives of four key spokespersons. These spokespersons outline the valuable contribution Catholic healthcare make within the Canadian healthcare system.

Virus inactivation during production of intravenous immunoglobulin

The effect of pepsin treatment at pH 4 on the infectivity of several enveloped viruses was assessed under the conditions used during the production of intravenous immunoglobulins. It was shown that the prototypes of four virus families--human immunodeficiency virus (Lentivirinae), herpes simplex virus type 1 and human cytomegalovirus (Herpesviridae), Semliki Forest virus (Togaviridae), and vesicular stomatitis virus (Rhabdoviridae)--were inactivated by this procedure. With vesicular stomatitis virus as a model, the contributions of both low pH and pepsin were demonstrated, and pepsin had a synergistic or additive action.

Cerebral angiography in ischemic strokes

Angiography remains a very important means of evaluation of ischemic strokes: it confirms the diagnosis showing the occluded artery. It eventually shows the anastomotic pathways for cerebral circulation and it often finds the causes of stroke, among which the most frequent are atherosclerosis (70%) and fibromuscular hyperplasia (10%). The safer way to perform angiography is the retrograde route. Indications for angiography must be discussed according to the type of stroke, its onset, and the arterial territory involved.

Spontaneous dissecting aneurysm of the extracranial vertebral artery (20 cases)

Spontaneous dissecting aneurysm of the vertebral artery is an infrequent cause of vertebro basilar ischemic strokes. Previously reported cases concern essentially occlusion of the basilar artery. Only 14 cases of spontaneous dissecting aneurysm concern the extracranial vertebral artery among these eight were angiographically documented. In this study based upon 15 patients (20 dissecting aneurysms), the authors discuss etiological factors, such as hypertension or fibromuscular dysplasia: on clinical findings they insist upon the diagnostic value of preliminary symptoms, cervical pain or posterior headaches; the most frequent angiographic appearance was a long and irregular stenosis of one or two segments of the vertebral artery. The prognosis of these aneurysms most often appears favourable in this group.

Dengue virus induced polypeptide synthesis. Brief report

Dengue 2 virus polypeptide synthesis was investigated in BHK21 cells. Nine or ten virus induced polypeptides were identified, three of which are glycoproteins as demonstrated by tunicamycin treatment of infected cells. We performed pulse chase experiments, experiments with amino-acid analogs, protease inhibitors or pactamycin treatment of infected cells, to determine whether or not large polypeptide processing occurs. In some of these experiments a large polypeptide (P 130) was immunoprecipitated by an anti-dengue 2 serum. We observed a transfer of label between small molecular weight polypeptides which might be the result of restricted proteolytic cleavage.