Human Lung Tissue Implanted on the Chick Chorioallantoic Membrane as a Novel In Vivo Model of IPF

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with no curative pharmacological treatment. Current preclinical models fail to accurately reproduce human pathophysiology and are therefore poor predictors of clinical outcomes. Here, we investigated whether the chick embryo chorioallantoic membrane (CAM) assay supports the implantation of xenografts derived from IPF lung tissue and primary IPF lung fibroblasts and can be used to evaluate the efficacy of antifibrotic drugs. We demonstrate that IPF xenografts maintain their integrity and are perfused with chick embryo blood. Size measurements indicate that the xenografts amplify on the CAM, and Ki67 and pro-collagen type I immunohistochemical staining highlight the presence of proliferative and functional cells in the xenografts. Moreover, the IPF phenotype and immune microenvironment of lung tissues are retained when cultivated on the CAM and the fibroblast xenografts mimic invasive IPF fibroblastic foci. Daily treatments of the xenografts with nintedanib and PBI-4050 significantly reduce their size, fibrosis-associated gene expression, and collagen deposition. Similar effects are found with GLPG1205 and fenofibric acid, two drugs that target the immune microenvironment. Our CAM-IPF model represents the first in vivo model of IPF that uses human lung tissue. This rapid and cost-effective assay could become a valuable tool for predicting the efficacy of antifibrotic drug candidates for IPF.

COVA1-18 neutralizing antibody protects against SARS-CoV-2 in three preclinical models

One year into the Coronavirus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), effective treatments are still needed 1-3 . Monoclonal antibodies, given alone or as part of a therapeutic cocktail, have shown promising results in patients, raising the hope that they could play an important role in preventing clinical deterioration in severely ill or in exposed, high risk individuals 4-6 . Here, we evaluated the prophylactic and therapeutic effect of COVA1-18 in vivo , a neutralizing antibody isolated from a convalescent patient 7 and highly potent against the B.1.1.7. isolate 8,9 . In both prophylactic and therapeutic settings, SARS-CoV-2 remained undetectable in the lungs of COVA1-18 treated hACE2 mice. Therapeutic treatment also caused a dramatic reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg - 1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 had a very strong antiviral activity in the upper respiratory compartments with an estimated reduction in viral infectivity of more than 95%, and prevented lymphopenia and extensive lung lesions. Modelling and experimental findings demonstrate that COVA1-18 has a strong antiviral activity in three different preclinical models and could be a valuable candidate for further clinical evaluation.

PBI-4050 reduces pulmonary hypertension, lung fibrosis, and right ventricular dysfunction in heart failure

AIMS

Heart failure with reduced ejection fraction (HFrEF) causes lung remodelling with myofibroblasts proliferation and fibrosis leading to a restrictive lung syndrome with pulmonary hypertension (PH) and right ventricular (RV) dysfunction. PBI-4050 is a first-in-class anti-fibrotic, anti-inflammatory, and anti-proliferative compound. The present study evaluated the therapeutic impact of PBI-4050 on PH in an HFrEF model.

METHODS AND RESULTS

HFrEF was induced after myocardial infarction (MI) in rats. Two weeks later, sham-operated and MI groups received PBI-4050 (200 mg/kg/day by gavage) or saline for 3 weeks. Animals were analysed according to infarct size as large (≥30% left ventricle) or medium MI (<30%). Large MI caused PH and RV hypertrophy (RVH) with a restrictive lung syndrome. PBI-4050 did not adversely affect left ventricular (LV) function but markedly reduced PH and RVH and improved RV dysfunction. PBI-4050 reduced lung remodelling and improved respiratory compliance with decreased lung fibrosis, alveolar wall cellular proliferation and α-smooth muscle actin expression. The increased expression of endothelin-1 (ET-1), transforming growth factor beta (TGF-β), interleukin-6 (IL-6) and of tissue inhibitor of metalloprotease-1 in the lungs from HFrEF were reduced with PBI-4050 therapy. Activation of isolated human lung fibroblasts (HLFs) to a myofibroblastic pro-fibrogenic phenotype was markedly reduced by PBI-4050. The fatty acid receptor GPR84 was increased in HFrEF lungs and in activated HLFs, and reduced by PBI-4050. GPR84 agonists activated fibrogenesis in HLFs and finally, PBI-4050 reduced ERK1/2 phosphorylation.

CONCLUSIONS

PBI-4050 reduces PH and RVH in HFrEF by decreasing lung fibrosis and remodelling. This novel agent decreases the associated restrictive lung syndrome and recovers RV function. A contributing mechanism involves reducing the activation of lung fibroblasts by IL-6, TGF-β, and ET-1 by antagonism of GPR84 and reduced ERK1/2 phosphorylation. PBI-4050 is a novel promising therapy for targeting lung remodelling in group II PH.

Fatty acid mimetic PBI-4547 restores metabolic homeostasis via GPR84 in mice with non-alcoholic fatty liver disease

Non-alcoholic Fatty Liver Disease (NAFLD) is the most common form of liver disease and is associated with metabolic dysregulation. Although G protein-coupled receptor 84 (GPR84) has been associated with inflammation, its role in metabolic regulation remains elusive. The aim of our study was to evaluate the potential of PBI-4547 for the treatment of NAFLD and to validate the role of its main target receptor, GPR84. We report that PBI-4547 is a fatty acid mimetic, acting concomitantly as a GPR84 antagonist and GPR40/GPR120 agonist. In a mouse model of diet-induced obesity, PBI-4547 treatment improved metabolic dysregulation, reduced hepatic steatosis, ballooning and NAFLD score. PBI-4547 stimulated fatty acid oxidation and induced gene expression of mitochondrial uncoupling proteins in the liver. Liver metabolomics revealed that PBI-4547 improved metabolic dysregulation induced by a high-fat diet regimen. In Gpr84^−/− mice, PBI-4547 treatment failed to improve various key NAFLD-associated parameters, as was observed in wildtype littermates. Taken together, these results highlight a detrimental role for the GPR84 receptor in the context of meta-inflammation and suggest that GPR84 antagonism via PBI-4547 may reflect a novel treatment approach for NAFLD and its related complications.

Phase 2 clinical trial of PBI-4050 in patients with idiopathic pulmonary fibrosis

PBI-4050 is a novel orally active small-molecule compound with demonstrated anti-fibrotic activity in several models of fibrosis, including lung fibrosis. We present results from our first clinical study of PBI-4050 in patients with idiopathic pulmonary fibrosis (IPF).

This 12-week open-label study explored the safety, efficacy and pharmacokinetics of daily oral doses of 800 mg PBI-4050 alone and in combination with nintedanib or pirfenidone in patients with predominantly mild or moderate IPF. Nine patients received PBI-4050 alone, 16 patients received PBI-4050 with nintedanib and 16 patients received PBI-4050 with pirfenidone.

PBI-4050 alone or in combination with nintedanib or pirfenidone was well tolerated. Pharmacokinetic profiles for PBI-4050 were similar in the PBI-4050 alone and PBI-4050+nintedanib groups but reduced in the PBI-4050+pirfenidone group, suggesting a drug–drug interaction. There were no significant changes in forced vital capacity (FVC), either in % predicted or mL, from baseline to week 12 for PBI-4050 alone or PBI-4050+nintedanib. In contrast, a statistically significant reduction (p<0.024) in FVC % pred was seen for PBI-4050+pirfenidone after 12 weeks.

There were no safety concerns with PBI-4050 alone or in combination with nintedanib or pirfenidone in IPF patients. The stability of FVC between baseline and week 12 looked encouraging for PBI-4050 alone and in combination with nintedanib.

PBI-4050 alone and in combination with nintedanib demonstrated no safety concerns and showed encouraging results for lung function in IPF patientshttp://ow.ly/olQD30myD0E

Design and Synthesis of New 1,3,5-Trisubstituted Triazines for the Treatment of Cancer and Inflammation

Low-molecular-weight synthetic molecules 1 with the general 2-(fluorophenylamino)-4,6-disubstituted 1,3,5-triazine structure and showing anti-inflammatory and anticancer activities were explored. Structure-activity relationship studies demonstrated the importance of the aminopentyl chain, the 3- or 4-fluorophenylaniline component, and the presence of at least one substituent, such as a tyramine moiety, attached directly to the triazine ring as essential for good activity. These compounds, represented by leads 4-{2-[4-(5-Aminopentylamino)-6-(3-fluorophenylamino)-1,3,5-triazin-2-ylamino]ethyl}phenol (6) and 4-{2-[4-(5-Aminopentylamino)-6-(4-fluorophenylamino)-1,3,5-triazin-2-ylamino]ethyl}phenol (10), displayed moderate and significant in vitro and in vivo dual activities, respectively, and address the molecular link between inflammation and cancer. Compound 10 demonstrated significant antitumor efficacy upon administration by the oral and intravenous routes in several animal models. This class of triazine compounds is new, safe, and nontoxic and offers a novel approach to the treatment of inflammation and cancer.

PBI-4050 Reduces Stellate Cell Activation and Liver Fibrosis through Modulation of Intracellular ATP Levels and the Liver Kinase B1/AMP-Activated Protein Kinase/Mammalian Target of Rapamycin Pathway

Hepatic fibrosis is a major cause of morbidity and mortality for which there is currently no effective therapy. We previously showed that 2-(3-pentylphenyl)acetic acid (PBI-4050) is a dual G protein-coupled receptor GPR40 agonist/GPR84 antagonist that exerts antifibrotic, anti-inflammatory, and antiproliferative action. We evaluated PBI-4050 for the treatment of liver fibrosis in vivo and elucidated its mechanism of action on human hepatic stellate cells (HSCs). The antifibrotic effect of PBI-4050 was evaluated in carbon tetrachloride (CCl₄)- and bile duct ligation-induced liver fibrosis rodent models. Treatment with PBI-4050 suppressed CCl₄-induced serum aspartate aminotransferase levels, inflammatory marker nitric oxide synthase, epithelial to mesenchymal transition transcription factor Snail, and multiple profibrotic factors. PBI-4050 also decreased GPR84 mRNA expression in CCl₄-induced injury, while restoring peroxisome proliferator-activated receptor γ (PPARγ) to the control level. Collagen deposition and α-smooth muscle actin (α-SMA) protein levels were also attenuated by PBI-4050 treatment in the bile duct ligation rat model. Transforming growth factor-β-activated primary HSCs were used to examine the effect of PBI-4050 and its mechanism of action in vitro. PBI-4050 inhibited HSC proliferation by arresting cells in the G0/G1 cycle phase. Subsequent analysis demonstrated that PBI-4050 signals through a reduction of intracellular ATP levels, activation of liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), and blockade of mammalian target of rapamycin (mTOR), resulting in reduced protein and mRNA levels of α-SMA and connective tissue growth factor and restored PPARγ mRNA expression. Our findings suggest that PBI-4050 may exert antifibrotic activity in the liver through a novel mechanism of action involving modulation of intracellular ATP levels and the LKB1/AMPK/mTOR pathway in stellate cells, and PBI-4050 may be a promising agent for treating liver fibrosis.

Fatty acid receptor modulator PBI-4050 inhibits kidney fibrosis and improves glycemic control

Extensive kidney fibrosis occurs in several types of chronic kidney diseases. PBI-4050, a potentially novel first-in-class orally active low-molecular weight compound, has antifibrotic and antiinflammatory properties. We examined whether PBI-4050 affected the progression of diabetic nephropathy (DN) in a mouse model of accelerated type 2 diabetes and in a model of selective tubulointerstitial fibrosis. eNOS-/- db/db mice were treated with PBI-4050 from 8-20 weeks of age (early treatment) or from 16-24 weeks of age (late treatment). PBI-4050 treatment ameliorated the fasting hyperglycemia and abnormal glucose tolerance tests seen in vehicle-treated mice. In addition, PBI-4050 preserved (early treatment) or restored (late treatment) blood insulin levels and increased autophagy in islets. PBI-4050 treatment led to significant improvements in lifespan in the diabetic mice. Both early and late PBI-4050 treatment protected against progression of DN, as indicated by reduced histological glomerular injury and albuminuria, slow decline of glomerular filtration rate, and loss of podocytes. PBI-4050 inhibited kidney macrophage infiltration, oxidative stress, and TGF-β-mediated fibrotic signaling pathways, and it also protected against the development of tubulointerstitial fibrosis. To confirm a direct antiinflammatory/antifibrotic effect in the kidney, further studies with a nondiabetic model of EGFR-mediated proximal tubule activation confirmed that PBI-4050 dramatically decreased the development of the associated tubulointerstitial injury and macrophage infiltration. These studies suggest that PBI-4050 attenuates development of DN in type 2 diabetes through improvement of glycemic control and inhibition of renal TGF-β-mediated fibrotic pathways, in association with decreases in macrophage infiltration and oxidative stress.

Abstract 672: PBI-1402, a first-in-class erythropoiesis regulating agent, inhibits tumor growth and metastasis of murine mastocytoma and does not overshoot hemoglobin: Comparison with erythropoietin

BACKGROUND: PBI-1402 reduces the need for transfusion and increases hemoglobin (Hb) level and red blood cell count (RBC) in chemotherapy-induced anemia (CIA) by a mechanism of action distinct from erythropoietin (EPO).

AIM: The objective was to compare the effect of PBI-1402 and EPO on modulation of tumor growth.

METHODS: The effect of PBI-1402 (200 mg/kg, oral, once a day) or EPO (200 or 2000 U/kg, s.c. injection, twice a week) was studied in a subcutaneous P815 mastocytoma model. P815 cells express both PBI-1402 and EPO receptors. Tumor growth, metastasis, serum nitric oxide (NO) and hematocrit (Ht) were assessed.

RESULTS: P815 tumor growth is rapid and metastasizes to the liver. Inflammation is also associated with P815 tumor growth. PBI-1402 significantly reduced tumor growth (T/C=37%) and invasion as demonstrated by a 33% reduction of mice with liver metastasis. In comparison, EPO had no effect (200 U/kg, equivalent dose used in CKD treatment). However, high dose EPO (2000 U/kg, equivalent dose used in human cancer treatment) exacerbated tumor growth (T/C: 135%). Both doses of EPO induced a significant increase in the percentage of mice with liver metastasis (2X, 200 U/kg, and 3X, 2000 U/kg) compared to control. PBI-1402 treatment had no effect on NO and did not overshoot normal hematocrit. However, treatment with high dose EPO significantly increased NO and Ht levels (Table 1).

CONCLUSION: These results suggest that oral treatment with PBI-1402 may inhibit growth and metastasis of cancer cells. As an important safety feature, PBI-1402 does not induce overshoot of hemoglobin. In contrast to EPO, PBI-1402 may offer the advantage of reducing tumor growth and metastasis while preventing anemia induced by chemotherapy. In conclusion, PBI-1402 has the potential to be a safe erythropoiesis-regulating agent useful in treating anemia in cancer patients.

Abstract 3534: PBI-1402, a first-in-class erythropoiesis regulating agent, possesses differentiation properties and demonstrates synergistic anticancer activity in combination with chemotherapy

Background: PBI-1402 reduces the need for transfusion and increases hemoglobin (Hb) level and red blood cell count (RBC) in chemotherapy-induced anemia (CIA) patients by a mechanism of action which is distinct from erythropoietin (EPO). The PBI-1402 receptor is also expressed on certain cancer cells such as leukemia (K562), lung (LL-2), prostate (PC-3) and pancreas (Panc-02).

Aim: The objective of this study was to determine the role of the PBI-1402 receptor on tumor growth.

Methods: Cell proliferation and differentiation of K562 (human erythroleukemia) was studied in presence of PBI-1402 or EPO using 2,7-diaminofluorene for hemoglobin quantification. The effect of oral administration of PBI-1402 in combination with chemotherapy agents (gemcitabine or cyclophosphamide) was studied in subcutaneous syngeneic Panc02, LL-2 and xenogeneic PC-3 models.

Results: PBI-1402 inhibits proliferation of K562 cells and promotes differentiation of the remaining cells. K562 cells express both EPO and PBI-1402 receptors. EPO increases phosphorylation of ERK1/2 and Stat3 (linked to cell proliferation) while PBI-1402 decreases it in a dose dependent manner. The antitumor efficacy of oral administration of PBI-1402 was studied in combination with gemcitabine in subcutaneous LL2 and Panc02 as well as in orthotopic Panc02 cancers. In subcutaneous Panc02, gemcitabine induced a significant inhibition (p&lt;0.05) of tumor growth from day 27 to 34 with T/C from 55% to 78%. PBI-1402 induced a significant inhibition (p&lt;0.05) of tumor growth from day 23 to 44 with T/C from 26% to 58%. The combination therapy induced a significant (p&lt;0.05) inhibition of tumor growth and T/C&lt;40% from day 23 to 37 when compared to control and at day 23, 25 and 30 to 39 when compared to gemcitabine alone. In orthotopic Panc02, mice treated with gemcitabine or a combination of gemcitabine and PBI-1402 displayed prolonged survival (71 and 88 days, respectively) compared to control (48 days). In LL-2 cancer, at day 25, mice treated with PBI-1402 or gemcitabine alone had a T/C of 94% and 72%, respectively. Mice treated with a combination of gemcitabine plus PBI-1402 displayed a significant (synergistic) reduction of tumor growth (T/C: 33%). The effect of PBI-1402 alone or in combination with cyclophosphamide was also studied in a xenograft prostate PC-3 tumor. Mice treated with PBI-1402 or cyclophosphamide alone have a significant T/C&lt;40% from day 21 to 56 and day 35 to 56, respectively. Mice treated with a combination of cyclophosphamide plus PBI-1402 displayed tumor regression from day 21 to 56.

Conclusion: These results suggest that PBI-1402 has the potential to inhibit the growth of lung, prostate and pancreatic cancer by induction of cell differentiation. PBI-1402-differentiated cancer cells appear to be more susceptible to chemotherapeutic agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3534. doi:10.1158/1538-7445.AM2011-3534

Optimizing pain relief in a specialized outpatient palliative radiotherapy clinic: contributions of a clinical pharmacist

PURPOSE

Bone metastases are the most common cause of cancer pain, with palliative radiotherapy (RT) the mainstay of treatment. However, relief from RT may be delayed, incomplete, or short-lived and therefore optimized pharmacologic therapy is essential. Our objective was to describe the contribution of the clinical pharmacist (CP) to an outpatient palliative RT clinic.

METHODS

The Edmonton Symptom Assessment System, an 11-point scale for measuring nine symptoms, and other validated screening tools were administered, and a medication history performed by the CP. Baseline CP assessment also included opioid toxicity, need for supportive medications, and drug interactions. Anonymized clinical information was collected prospectively and descriptive statistics were compiled including themes of counselling performed by the CP.

RESULTS

The CP reviewed 114 patients over 140 clinic visits (01/2007-12/2008). Median age was 68.3 years, 68.4% were male and 36.8% had prostate cancer. All symptoms improved or stabilized in ≥ 80% by 4 weeks. Median pain score was 6/10 (SD 2.6) at baseline, and 2.1/10 (SD 2.4) by week 4. Average morphine equivalent daily dose was 76.8 mg at baseline and 44.5 mg at week 4. CP assessment included screening for opioid toxicity (87.9%), recommending a change in analgesic (28.9%), and liaison with the community pharmacy (17.1%). Medication counselling took place in 84.3% of visits, on bowel routine (85.6% of the time), opioids (82.2%), and hydration (40.7%).

CONCLUSIONS

The CP plays a key role in holistic patient assessment and optimization of pharmacologic therapy, contributing to improved symptom control of patients receiving palliative RT.

2,4,6-trisubstituted triazines as protein a mimetics for the treatment of autoimmune diseases

A first-in-class series of low molecular weight trisubstituted triazines were synthesized and evaluated for their ability to mimic protein A binding to human IgG antibody. The structure-activity relationship (SAR) demonstrates that the 1,3-phenylenediamine component was essential for robust activity. Twenty-two compounds, represented by lead molecule 34, displayed significant activity compared to protein A. These compounds may prove useful for the treatment of autoimmune disease.

Enhancement of Th1 type cytokine production and primary T cell activation by PBI-1393

In previous reports, we have shown that PBI-1393 (formerly BCH-1393), N,N-Dimethylaminopurine pentoxycarbonyl D-arginine, stimulates cytotoxic T-lymphocyte (CTL) responses both in vitro and in vivo in normal immune status and immunosuppressed mice. Additionally, PBI-1393 was tested for anticancer activity in syngeneic mouse experimental tumor models and it displayed significant inhibition of tumor outgrowths when given in combination with sub-therapeutic doses of cytotoxic drugs (cyclophosphamide, 5-fluorouracil, doxorubicin and cis-platinum). However, the mechanism of action of PBI-1393 was still unknown. Here, we report that PBI-1393 enhances IL-2 and IFN-gamma production in human activated T cells by 51% and 46% respectively. PBI-1393 increases also IL-2 and IFN-gamma mRNA expression as shown by RT-PCR. The physiological relevance of IL-2 and IFN-gamma gene modulation by PBI-1393 is illustrated by the advantageous increase of T cell proliferation (39+/-0.3% above control) and human CTL response against prostate (PC-3) cancer cells (42+/-0.03%). The enhancement of human T cell proliferation and CTL activation by PBI-1393 demonstrates that this compound potentiates the immune response and in this regard, it could be used as an alternative approach to IL-2 and/or IFN-gamma therapy against cancer.

Non-algorithmic access to calendar information in a calendar calculator with autism

The possible use of a calendar algorithm was assessed in DBC, an autistic "savant" of normal measured intelligence. Testing of all the dates in a year revealed a random distribution of errors. Re-testing DBC on the same dates one year later shows that his errors were not stable across time. Finally, DBC was able to answer "reversed" questions that cannot be solved by a classical algorithm. These findings favor a non-algorithmic retrieval of calendar information. It is proposed that multidirectional, non-hierarchical retrieval of information, and solving problems in a non-algorithmic way, are involved in savant performances. The possible role of a functional rededication of low-level perceptual systems to the processing of symbolic information in savants is discussed.

Fast and robust optic disc detection using pyramidal decomposition and Hausdorff-based template matching

We report about the design and test of an image processing algorithm for the localization of the optic disk (OD) in low-resolution (about 20 micro/pixel) color fundus images. The design relies on the combination of two procedures: 1) a Hausdorff-based template matching technique on edge map, guided by 2) a pyramidal decomposition for large scale object tracking. The two approaches are tested against a database of 40 images of various visual quality and retinal pigmentation, as well as of normal and small pupils. An average error of 7% on OD center positioning is reached with no false detection. In addition, a confidence level is associated to the final detection that indicates the "level of difficulty" the detector has to identify the OD position and shape.

Effect of a low-glycaemic index--low-fat--high protein diet on the atherogenic metabolic risk profile of abdominally obese men

It has been suggested that the current dietary recommendations (low-fat-high-carbohydrate diet) may promote the intake of sugar and highly refined starches which could have adverse effects on the metabolic risk profile. We have investigated the short-term (6-d) nutritional and metabolic effects of an ad libitum low-glycaemic index-low-fat-high-protein diet (prepared according to the Montignac method) compared with the American Heart Association (AHA) phase I diet consumed ad libitum as well as with a pair-fed session consisting of the same daily energy intake as the former but with the same macronutrient composition as the AHA phase I diet. Twelve overweight men (BMI 33.0 (sd 3.5) kg/m2) without other diseases were involved in three experimental conditions with a minimal washout period of 2 weeks separating each intervention. By protocol design, the first two conditions were administered randomly whereas the pair-fed session had to be administered last. During the ad libitum version of the AHA diet, subjects consumed 11695.0 (sd 1163.0) kJ/d and this diet induced a 28 % increase in plasma triacylglycerol levels (1.77 (sd 0.79) v. 2.27 (sd 0.92) mmol/l, P<0.05) and a 10 % reduction in plasma HDL-cholesterol concentrations (0.92 (sd 0.16) v. 0.83 (sd 0.09) mmol/l, P<0.01) which contributed to a significant increase in cholesterol:HDL-cholesterol ratio (P<0.05), this lipid index being commonly used to assess the risk of coronary heart disease. In contrast, the low-glycaemic index-low-fat-high-protein diet consumed ad libitum resulted in a spontaneous 25 % decrease (P<0.001) in total energy intake which averaged 8815.0 (sd 738.0) kJ/d. As opposed to the AHA diet, the low-glycaemic index-low-fat-high-protein diet produced a substantial decrease (-35 %) in plasma triacylglycerol levels (2.00 (sd 0.83) v. 1.31 (sd 0.38) mmol/l, P<0.0005), a significant increase (+1.6 %) in LDL peak particle diameter (251 (sd 5) v. 255 (sd 5) A, P<0.02) and marked decreases in plasma insulin levels measured either in the fasting state, over daytime and following a 75 g oral glucose load. During the pair-fed session, in which subjects were exposed to a diet with the same macronutrient composition as the AHA diet but restricted to the same energy intake as during the low-glycaemic index-low-fat-high-protein diet, there was a trend for a decrease in plasma HDL-cholesterol levels which contributed to the significant increase in cholesterol:HDL-cholesterol ratio noted with this condition. Furthermore, a marked increase in hunger (P<0.0002) and a significant decrease in satiety (P<0.007) were also noted with this energy-restricted diet. Finally, favourable changes in the metabolic risk profile noted with the ad libitum consumption of the low-glycaemic index-low-fat-high-protein diet (decreases in triacyglycerols, lack of increase in cholesterol:HDL-cholesterol ratio, increase in LDL particle size) were significantly different from the response of these variables to the AHA phase I diet. Thus, a low-glycaemic index-low-fat-high-protein content diet may have unique beneficial effects compared with the conventional AHA diet for the treatment of the atherogenic metabolic risk profile of abdominally obese patients. However, the present study was a short-term intervention and additional trials are clearly needed to document the long-term efficacy of this dietary approach with regard to compliance and effects on the metabolic risk profile.

Immunostimulant oxidized β-glucan conjugates

beta-Glucans are polysaccharides that act as nonspecific immune system stimulants. However, many beta-Glucans are sparingly soluble in water. This work describes an oxidative procedure, which solubilizes the beta-Glucan from Saccharomyces cerevisiae and maintains its immunostimulatory properties. Furthermore, the carboxylates at the site of oxidation allow for the conjugation of small molecule immunostimulants. Both the parent oxidized beta-glucan and its conjugates with O-beta-alanyl-5-[6-(N,N'-dimethylamino)purin-9-yl]pentanol stimulate cytotoxic T-lymphocytes (CTLs), B cells and macrophages. In addition, they both stimulate natural killer (NK) cells, a property which the small molecule purine does not possess.

Secondary impairments after spinal cord injury: a population-based study

OBJECTIVE

To determine the prevalence of secondary impairments among individuals with long-standing spinal cord injury in Quebec and the potential relationships between these impairments and several variables.

DESIGN

A review of 2,200 medical files was conducted to determine the target population; 976 patients were selected randomly and mailed questionnaires. The results were based on 482 individuals with spinal cord injury who returned the completed questionnaire. The questionnaire included 14 subsections, such as sociodemographic, medical, psychosocial, and environmental information. The medical section, including the type and level of lesion and the presence of secondary impairments, was analyzed.

RESULTS

Urinary tract infection, spasticity, and hypotension were the most frequently reported secondary impairments, regardless of the severity of injury. Relationships between the prevalence of secondary impairments and the duration of injury, as well as perceived health status, were observed.

CONCLUSIONS

This is the first study to describe secondary impairments after long-standing spinal cord injury in Quebec. Patients with spinal cord injury still present a high prevalence of secondary impairments many years after their rehabilitation, despite preventive education or medical follow-up visits. Further studies are required to determine the specific impact that these impairments have on the patients' social role and their quality-of-life.

Synergistic anti-tumor activity of a novel immunomodulator, BCH-1393, in combination with cyclophosphamide

N,N-dimethylaminopurine pentoxycarbonyl D-arginine (BCH-1393) is a novel low molecular weight synthetic immunomodulator that has been shown to significantly stimulate cytotoxic T-lymphocyte responses both in vitro and in vivo (Zacharie B, Gagnon L, Attardo G, Connolly TP, St-Denis Y, Penney CL. Synthesis and activity of 6-substituted purine linker amine immunostimulants. J. Med. Chem. 1997;40:2883-94). Prompted by this evidence, we extended evaluation of BCH-1393 for anticancer activity in syngeneic mouse experimental tumor models. Consistent with previous findings, in vitro assessment of BCH-1393 activity demonstrated a significant increase in the CTL responses in the range of 10(-9)-10(-5) M. Treatment of mice with four consecutive daily intraperitoneal injections at 25 and 50 mg/kg resulted in a significant increase of the relative percentage of blood CD4+, CD8+, NK and monocyte subsets without any evidence of toxicity. In vivo anti-tumor activity of BCH-1393 was evaluated, either alone or in combination with subtherapeutic doses of cyclophosphamide (Cy), against weakly immunogenic mouse breast carcinoma DA-3 and strongly immunogenic colon adenocarcinoma MC38. Daily intraperitoneal injection of BCH-1393 at 50 mg/kg alone was well tolerated but produced a relatively weak anti-tumor effect in both tumor models. However, a significant inhibition of tumor outgrowth and suppression of established tumor growth was observed when BCH-1393 was administered in combination with subtherapeutic doses of Cy. Combination treatment of 50 mg/kg BCH-1393 with 100 mg/kg Cy (given as single intravenous bolus injection) starting 2 days prior to DA-3 tumor cell inoculation prevented tumor outgrowth in 70-80% of treated mice. In the remaining 20-30% of mice that had developed tumors, a nearly complete (90%) tumor growth inhibition was observed at days 22-24 post tumor implant. In the MC38 tumor model, combination treatment of established tumors with BCH-1393 and Cy (CTX) at 50 mg/kg resulted in a significant delay in tumor growth compared to CTX treatment alone. The observed concomitant anti-tumor activity of BCH-1393 with cyclophosphamide warrants further investigation of this immunomodulator as an adjunctive treatment of cancer.

Laterality effects in processing tonal and atonal melodies with affective and nonaffective task instructions

Right-handed university subjects were presented with monaural melodies that either conformed to the rules of the Western tonal system (tonal melodies) or that systematically deviated from it (atonal melodies) while containing similar contours and pitch skips. Subjects were tested under two different task instructions. One group was requested to judge whether each melody sounded correct or not (the nonaffective task); the other group had to judge whether each melody sounded pleasant or not (the affective task). The nonaffective task was found to elicit essentially no ear difference. In contrast, the affective instruction induced opposite and reliable laterality effects, depending on the valence of the response. The pleasant responses were indicative of a left hemisphere predominance and the unpleasant responses of a right hemisphere predominance. The results are consistent with the claim that the left hemisphere is biased toward positive emotions and the right to negative emotions. Moreover, the results suggest that affective appreciation of melodies is dissociable from their nonaffective judgment.

D-LysAsnProTyr tetrapeptide: a novel B-cell stimulant and stabilized bursin mimetic

The tetrapeptide I (D-lysine-L-asparaginyl-L-prolyl-L-tyrosine or D-LysAsnProTyr), and analogue sequences, were synthesized and evaluated for the ability to stimulate immune cell subsets. These sequences were selected based on their perceived ability to readily adopt a beta-turn structure. In vitro immunological assays revealed a robust stimulation of mitogen activated B-cell proliferation and a modest to significant stimulation of cytotoxic T lymphocytes (CTLs). Further, this in vitro stimulation of B-cells was accompanied by an in vivo expansion of B-cells in C57BL/6 mice, as demonstrated by immunophenotyping experiments. Interestingly, a conformational analysis of the low energy conformers of I and the endogenous B-cell stimulant bursin (LysHisGlyNH2) shows that these molecules can be superimposed. However, I displayed significantly enhanced physiological stability. For a number of reasons, I may be a particularly useful vaccine adjuvant.

Inactivation of the ampD gene in Pseudomonas aeruginosa leads to moderate-basal-level and hyperinducible AmpC beta-lactamase expression

It has been shown in enterobacteria that mutations in ampD provoke hyperproduction of chromosomal beta-lactamase, which confers to these organisms high levels of resistance to beta-lactam antibiotics. In this study, we investigated whether this genetic locus was implicated in the altered AmpC beta-lactamase expression of selected clinical isolates and laboratory mutants of Pseudomonas aeruginosa. The sequences of the ampD genes and promoter regions from these strains were determined and compared to that of wild-type ampD from P. aeruginosa PAO1. Although we identified numerous nucleotide substitutions, they resulted in few amino acid changes. The phenotypes produced by these mutations were ascertained by complementation analysis. The data revealed that the ampD genes of the P. aeruginosa mutants transcomplemented Escherichia coli ampD mutants to the same levels of beta-lactam resistance and beta-lactamase expression as wild-type ampD. Furthermore, complementation of the P. aeruginosa mutants with wild-type ampD did not restore the inducibility of beta-lactamase to wild-type levels. This shows that the amino acid substitutions identified in AmpD do not cause the altered phenotype of AmpC beta-lactamase expression in the P. aeruginosa mutants. The effects of AmpD inactivation in P. aeruginosa PAO1 were further investigated by gene replacement. This resulted in moderate-basal-level and hyperinducible expression of beta-lactamase accompanied by high levels of beta-lactam resistance. This differs from the stably derepressed phenotype reported in AmpD-defective enterobacteria and suggests that further change at another unknown genetic locus may be causing total derepressed AmpC production. This genetic locus could also be altered in the P. aeruginosa mutants studied in this work.

Thioamides: synthesis, stability, and immunological activities of thioanalogues of Imreg. Preparation of new thioacylating agents using fluorobenzimidazolone derivatives

Imreg (Tyr1-Gly2-Gly3) is a well-known immunostimulant. However, it possesses a short half-life. Stabilized analogues of Imreg were prepared by a regioselective insertion in which peptide bonds at position 1,2 or 2,3 were replaced by thioamide linkages. This was achieved by using new thioacylating agents based on thioacyl-fluoro-N-benzimidazolone. The synthesis and properties of these reagents are described herein. This peptide modification enhanced significantly the half-life of the thioanalogues relative to Imreg in blood. The thioanalogues and Imreg were tested in vitro in T and B cell proliferation assays and for their ability to stimulate cytotoxic T-lymphocytes (CTLs). Only thiotyrosyl glycyl glycine 11 displayed some activity as evidenced by a weak stimulation of CTLs. On the basis of this activity and the increased stability, an in vivo immunological evaluation was undertaken. Immunophenotyping of 11 revealed a significant increase in activated CTL and NK cell populations in the spleen. This expansion was also accompanied by a significant stimulation of NK cells and the B cell proliferative response. Thioanalogues of Imreg were generally nontoxic, as exemplified by 11. The latter is a promising immunostimulant which may be targeted for cancer and viral infections, where CTLs and NK cells play an important role, or as a vaccine adjuvant where stimulation of antibody-producing B cells is important.

Comparison of the hemodynamic effects of sevoflurane anesthesia induction and maintenance vs TIVA in CABG surgery

PURPOSE

To compare the hemodynamic effects of sevoflurane when used for induction and maintenance of anesthesia with a total intravenous technique in patients with known coronary artery disease (CAD).

METHODS

Thirty patients undergoing elective coronary artery bypass graft (CABG) were randomly allocated to receive either sevoflurane (S group, n = 15) at a minimal concentration of 4% in oxygen for induction and at 0.5-2 MAC end-tidal concentration for maintenance, or a total intravenous technique (T group, n = 15) consisting of midazolam for induction and propofol for maintenance. In both groups, anesthesia was supplemented with sufentanil and muscle relaxation with cis-atracurium. Hemodynamic measurements included systemic and pulmonary pressures, heart rate, mixed venous oxygen saturation and cardiac output at the following times: pre-induction, 7 and 25 min post-induction, chest closure, one hour after surgery and pre and post tracheal extubation.

RESULTS

More patients in the S group (8/15) presented bradycardia in the induction period (T:2/15) (P = 0.05). During maintenance of anesthesia, treatment of hypertension was more frequent in the T group (12/15) than in the S group (6/15) (P = 0.025). All other parameters were comparable.

CONCLUSION

Induction of anesthesia in patients with CAD, VCRII with sevoflurane supplemented by sufentanil provided hemodynamic responses comparable with those of TIVA although bradycardia was observed more often with sevoflurane. Intraoperative control of systemic blood pressure was achieved with fewer interventions with a sevoflurane/sufentanil maintenance than with a propofol/sufentanil technique in CABG surgery.

Long-term influence of inhaled corticosteroids on bone metabolism and density. Are biological markers predictors of bone loss?

Long-term effects of high doses of inhaled corticosteroids (ICS) on bone density and metabolism are still uncertain. Fifty-one patients (37 male, 14 female) using beclomethasone or budesonide at a daily dose > 800 microgram/d (high-dose group [Group HD] mean: 983 microgram/d [prescribed dose x estimated compliance]) or no or < 500 microgram/d (control group [Group C] mean: 309 microgram/d) for more than 5 yr were enrolled in this study. Each had, 3 yr ago and at this last evaluation, a clinical evaluation and measurements of expiratory flows and of bone density and bone metabolism markers. Lumbar spine bone density (last visit) was similar in the two groups with respective values of 0.94 +/- 0.03 (HD) and 0.96 +/- 0.03 g/cm2 (C) (p > 0.05). T and Z scores were -1.21 +/- 0.19 and -0.70 +/- 0.18 (HD), -0.95 +/- 0.25 and -0.47 +/- 0.21 (C) respectively (p > 0.05). A correlation was found between the decrease in bone density and the mean daily dose of corticosteroid in Group HD although these changes were quite small, mean bone density being unchanged over the 3-yr period. Serum and urinary parameters were similar in the two groups. Furthermore, neither initial bone density nor any of the biological parameters could predict changes in bone density over a period of 3 yr. In conclusion, bone density was similar in both study groups and not significantly different over a 3-yr period. Neither initial bone density nor biological markers of bone metabolism helped to predict changes in bone mass.

A two-center study evaluating the hemodynamic and pharmacodynamic effects of cisatracurium and vecuronium in patients undergoing coronary artery bypass surgery

OBJECTIVE

To determine the hemodynamic and pharmacodynamic effects of rapid bolus administration of cisatracurium compared with vecuronium.

DESIGN

A randomized, prospective, double-blind study.

SETTING

Tertiary-care university hospitals.

PARTICIPANTS

Seventy-nine adult patients with diagnosed coronary artery disease (CAD).

INTERVENTION

Elective coronary artery bypass graft surgery (CABG).

MEASUREMENTS AND MAIN RESULTS

Patients were randomly divided into four groups. Patients received a rapid bolus of two or four times the 95% peak depression of twitch (ED95) of either cisatracurium (groups 1 and 2) or vecuronium (groups 3 and 4). Three minutes after a midazolam induction, all patients received a rapid bolus administration of either study drug. Maintenance of anesthesia was with a standardized propofol-sufentanil-oxygen anesthetic. Patients were monitored with radial and pulmonary artery catheters and electromyography. End points of the study were hemodynamic stability at induction, after bolus administration of study drugs, and after intubation; the quality of intubating conditions; drug interventions to correct hemodynamic instability; the onset, duration, and recovery of neuromuscular function; and drug cost. Mean arterial pressure (MAP) and heart rate (HR) decreased in a similar proportion in all four groups after induction while, following study drug administration, MAP and HR did not change significantly. Both cisatracurium groups required more boluses to maintain neuromuscular block, but spontaneous recovery rates were faster. Both agents, but cisatracurium to a lesser degree, showed increased duration with repeated maintenance doses. Both agents afforded good to excellent intubating conditions, but the cost of cisatracurium was significantly less.

CONCLUSION

The authors conclude there is no evidence of a hemodynamic difference between the two neuromuscular blocking drugs (NMBDs). There are some clinical and cost advantages in favor of cisatracurium.

Music and emotion: perceptual determinants, immediacy, and isolation after brain damage

This study grew out of the observation of a remarkable sparing of emotional responses to music in the context of severe deficits in music processing after brain damage in a non-musician. Six experiments were designed to explore the perceptual basis of emotional judgments in music. In each experiment, the same set of 32 excerpts taken from the classical repertoire and intended to convey a happy or sad tone were presented under various transformations and with different task demands. In Expts. 1 to 3, subjects were required to judge on a 10-point scale whether the excerpts were happy or sad. Altogether the results show that emotional judgments are (a) highly consistent across subjects and resistant to brain damage; (b) determined by musical structure (mode and tempo); and (c) immediate. Experiments 4 to 6 were designed to asses whether emotional and non-emotional judgments reflect the operations of a single perceptual analysis system. To this aim, we searched for evidence of dissociation in our brain-damaged patient, I.R., by using tasks that do not require emotional interpretation. These non-emotional tasks were a 'same-different' classification task (Expt. 4), error detection tasks (Expt. 5A,B) and a change monitoring task (Expt. 6). I.R. was impaired in these non-emotional tasks except when the change affected the mode and the tempo of the excerpt, in which case I.R. performed close to normal. The results are discussed in relation to the possibility that emotional and non-emotional judgments are the products of distinct pathways.

Synthesis and activity of dipeptides, linked to targeting ligands, as specific NK cell enhancers

Water soluble analogues of the lipophilic immunostimulant, octadecyl D-alanyl-L-glutamine, BCH-527, were synthesized and evaluated for the ability to stimulate natural killer (NK) cells. One of these compounds in which the octadecyl chain of BCH-527 was replaced with a shorter chain alcohol, 6-(D-alanyl-L-glutaminylamino)hexan-1-ol, 9, displayed an in vitro stimulation of NK cells comparable to that of interleukin 2 (IL 2). However, when the hydroxyl of 9 was linked to L-fucose to yield 1-beta-[6-(D-alanyl-L-glutaminylamino)hex-1-yl]-L- fucopyranose (BCH-2537, 1), the observed stimulation of NK cells was greater than that observed with IL 2. Further evaluation of these compounds revealed that the improved in vitro activity of BCH-2537 was more pronounced in vivo. That is, while both compounds significantly increased splenic NK cells, only BCH-2537 significantly increased the activity of these cells in vivo. In terms of a structure-activity relationship, NK cell activity was sensitive to minor structural modifications. It was influenced by conservative substitutions within the dipeptide, the length of the hydrocarbon chain, and the functionality at the end of the chain. No other compound enhanced NK cell activity to the extent exhibited by BCH-2537, although a few were equipotent to 9.

Prophylactic tranexamic acid and epsilon-aminocaproic acid for primary myocardial revascularization

BACKGROUND

The efficacy of prophylactic epsilon-aminocaproic acid and tranexamic acid to reduce transfusions after primary myocardial revascularization was evaluated in a teaching hospital context.

METHODS

Patients (n = 134) received either epsilon-aminocaproic acid (15-g bolus + infusion of 1 g/h), high-dose tranexamic acid (10-g bolus + placebo infusion), or normal saline solution in a double-blind fashion. Anticoagulation and conduct of cardiopulmonary bypass were standardized.

RESULTS

Tranexamic acid and epsilon-aminocaproic acid produced a significant reduction in postoperative blood loss compared with placebo (median loss, 438 mL, 538 mL, and 700 mL, respectively). Transfusion of red cells was similar in all three groups. Nonetheless, the percentage of patients receiving hemostatic blood products was significantly decreased in the epsilon-aminocaproic acid group compared with the placebo group (20% versus 43%; p = 0.03). Both tranexamic acid and epsilon-aminocaproic acid significantly decreased total exposure to allogeneic blood products compared with placebo (p = 0.01 and p = 0.05, respectively), and this reduction was clinically important (median exposure, 2, 2, and 7.5 units, respectively). Fibrinolysis was inhibited significantly in both treatment groups.

CONCLUSIONS

We conclude that either high-dose tranexamic acid or epsilon-aminocaproic acid effectively reduces transfusions in patients undergoing primary, elective myocardial revascularization.

Influence of inhaled corticosteroids and dietary intake on bone density and metabolism in patients with moderate to severe asthma

OBJECTIVES

Compare the effect of high doses of inhaled corticosteroids on bone loss in subjects with moderate to severe asthma or mild asthma, and examine the influence of dietary intake on bone metabolism.

DESIGN

A survey on the effects of corticotherapy and nutrition on bone density was conducted in 74 subjects currently being treated for asthma in the asthma clinic of Hôpital Laval (Sainte-Foy, Quebec, Canada). Fifty-eight subjects completed the study (attrition rate = 15%).

MAIN OUTCOME MEASURES

In all subjects expiratory volumes were determined and urinary analysis was conducted for hydroxyproline, calcium, phosphorus, and cortisol levels. Osteocalcin, calcium, phosphorus, cortisol, alkaline phosphatase, and gamma-glutamyltransferase levels were measured in blood samples. Bone density of the lumbar spine was determined by means of dual-energy x-ray absorptiometry. Nutrition evaluation was based on a 3-day food diary analyzed using progiciel Nutri 91. The nutritional parameters examined were calcium; phosphorus; magnesium; zinc; vitamins A, C, and D; protein; total fiber; oxalates; energy; caffeine; and alcohol in relation to bone density.

SUBJECTS

Thirty-one patients with moderate to severe asthma who had been taking more than 1,000 micrograms beclomethasone per day or the equivalent for more than 2 years and 27 patients with mild asthma who were taking less than 500 micrograms beclomethasone per day or the equivalent.

STATISTICAL ANALYSES PERFORMED

Four-factor analysis of variance with hierarchized interactions of four levels, Duncan's test, Pearson correlation coefficients.

RESULTS

Blood levels of osteocalcin and protein intake were lower in patients with moderate to severe asthma than in those with mild asthma (P < .05). Significant correlations (P < .02) were observed between bone density and calcium intake (r = .40), phosphorus intake (r = .35), protein intake (r = .30), and serum alkaline phosphatase level (r = -.30). Bone density was not significantly different between the two groups of patients with asthma.

APPLICATIONS

A follow-up of patients with asthma who are taking inhaled corticosteroids is needed to assess bone density, osteocalcin levels, and dietary intakes of calcium. Verify if osteocalcin level decreases over time in patients with moderate to severe asthma, monitor possible modifications in bone density, and verify if the correlation between dietary calcium and bone density is maintained.