Neutrophil to lymphocyte ratio (NTLR) predicts local control and overall survival after stereotactic body radiotherapy (SBRT) in metastatic sarcoma

The neutrophil to lymphocyte ratio (NTLR) and absolute lymphocyte count (ALC) recovery are prognostic across many cancers. We investigated whether NLTR predicts SBRT success or survival in a metastatic sarcoma cohort treated with SBRT from 2014 and 2020 (N = 42). Wilcox Signed Rank Test and Friedman Test compare NTLR changes with local failure vs. local control (N = 138 lesions). Cox analyses identified factors associated with overall survival. If local control was successful, NLTR change was not significant (p = 0.30). However, NLTR significantly changed in patients with local failure (p = 0.027). The multivariable Cox model demonstrated higher NLTR before SBRT was associated with worse overall survival (p = 0.002). The optimal NTLR cut point was 5 (Youden index: 0.418). One-year overall survival in SBRT metastatic sarcoma cohort was 47.6% (CI 34.3%-66.1%). Patients with an NTLR above 5 had a one-year overall survival of 37.7% (21.4%-66.3%); patients with an NTLR below 5 had a significantly improved overall survival of 63% (43.3%-91.6%, p = 0.014). Since NTLR at the time of SBRT was significantly associated with local control success and overall survival in metastatic sarcoma treated with SBRT, future efforts to reduce tumor inhibitory microenvironment factors and improve lymphocyte recovery should be investigated.

Consensus recommendations in the management of Ewing sarcoma from the National Ewing Sarcoma Tumor Board

Ewing sarcoma (ES) is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. Despite an international coordinated approach, several nuances, discrepancies, and debates remain in defining the standard of care for treating ES. In this review, the authors leverage the expertise assembled by formation of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of ES. This report is focused on select topics that apply to the management of patients with newly diagnosed ES. The specific topics covered include indications for bone marrow aspirate and biopsy for initial evaluation compared with fluorodeoxyglucose-positron emission tomography, the role of interval compressed chemotherapy in patients aged 18 years and older, the role of adding ifosfamide/etoposide to vincristine/doxorubicin/cyclophosphamide for patients with metastatic disease, the data on and role of high-dose chemotherapy with autologous stem cell transplantation, maintenance therapy, and whole-lung irradiation. The data referenced are often limited to subgroup analyses and/or compiled from multiple sources. Although not intended to replace the clinical judgement of treating physicians, the guidelines are intended to provide clarity and recommendations for the upfront management of patients with ES. PLAIN LANGUAGE SUMMARY: Ewing sarcoma is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. For this review, the authors used the experience of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of Ewing sarcoma. Although not intended to replace the clinical judgement of treating physicians, the guidelines will focus on the development of consensus statements for the upfront management of patients with Ewing sarcoma.

Three Decade Single-Institution Experience of Safety and Efficacy of Radiotherapy and Adjuvant Chemotherapy for Young Adult Patients with Medulloblastoma

PURPOSE/OBJECTIVE(S)

The rarity of medulloblastoma in the adult population limits information on optimal treatment and clinical outcomes. Adjuvant chemoradiation has been correlated to improved overall survival (OS) in a recent National Cancer Database (NCDB) analysis. We performed a retrospective safety and efficacy analysis of radiation (RT) +/- adjuvant chemotherapy (aCTH) in young adult patients with medulloblastoma to better understand outcomes, prognostic factors, and possibly optimal treatment strategies.

MATERIALS/METHODS

We conducted an IRB-approved retrospective chart review on young adult (age ≥18 - 39 years old) patients with medulloblastoma treated at our institution (1992-2018) with a minimum follow-up of 6 months from completion of therapy. We gathered data on patient and disease characteristics, treatment, and clinical outcomes, including OS, progression-free survival (PFS), local control (LC), and freedom from distant metastasis (FDM). We employed Cox regression model for univariable and multivariable analyses and Kaplan-Meier (KM) test methods for survival analyses, using JMP version 15.0 software.

RESULTS

Thirty-one patients were treated with postoperative RT including craniospinal irradiation (median dose: 2340 cGy/13 fractions) followed by tumor bed/posterior fossa (median total dose: 5580 cGy/31 fractions) either alone (n = 9; 29%) or with adjuvant chemotherapy (aCTH: n = 22; 71%); mostly as per COG A9961 Regimen A: oral lomustine, intravenous cisplatin, and intravenous vincristine (n = 12). 54.6% (n = 12) were known to complete the full aCTH course. Common RT acute toxicities included G1-2 nausea and/or vomiting (N/V; n = 8) and G1-2 fatigue (n = 6). Common aCTH acute toxicities included G1-2 N/V (n = 7) and peripheral neuropathy: G1-2 (n = 6) and G3 (n = 3). Late adverse events were primarily G1-2 peripheral neuropathy and gait imbalance (22.6%), G1-2 hormonal disturbances (19.4%) and G1-2 neurocognitive impairment (16.1%). Male patients had worse OS, PFS, FDM, and LC. Age at diagnosis, tumor location (lateral vs. central), and completion of aCTH course were shown on uni- and multi-variable analysis to be significantly associated with OS; p<0.05. KM survival analysis revealed superior 10-year PFS and OS in patients who completed aCTH compared to those who received RT alone or did not complete aCTH: 72.9% vs 59.3% vs 42%, p = 0.461, and 74.1% vs 63.5% vs 40%, p = 0.033, respectively. A similar trend was noted for LC and FDM.

CONCLUSION

Our series provides a report of acute and late side effects of treatment of young adult patients with medulloblastoma. Significant OS and PFS advantage are seen of aCTH completion in this patient population. Since optimal treatment of these patients is still an unmet need, prospective studies for this rare disease entity are needed.

Neutrophil to Lymphocyte Ratio (NTLR) Predicts Local Control Failure and Overall Survival after Stereotactic Body Radiotherapy (SBRT) In Metastatic Sarcoma

The neutrophil to lymphocyte ratio (NTLR) and absolute lymphocyte count (ALC) recovery are prognostic across many cancers. We investigated whether NLTR predicts SBRT success or survival in a metastatic sarcoma cohort treated with SBRT from 2014 and 2020 (N = 42). Wilcox Signed Rank Test and Friedman Test compare NTLR changes with local failure vs. local control (N = 138 lesions). Cox analyses identified factors associated with overall survival. If local control was successful, NLTR change was not significant (p = 0.30). However, NLTR significantly changed in patients local failure (p = 0.027). The multivariable Cox model demonstrated higher NLTR before SBRT was associated with worse overall survival (p = 0.002). The optimal NTLR cut point was 5 (Youden index: 0.418). One-year overall survival in SBRT metastatic sarcoma cohort was 47.6% (CI 34.3%-66.1%). Patients with an NTLR above 5 had a one-year overall survival of 37.7% (21.4%-66.3%); patients with an NTLR below 5 had a significantly improved overall survival of 63% (43.3%-91.6%, p = 0.014). Since NTLR at the time of SBRT was significantly associated with local control success and overall survival in metastatic sarcoma treated with SBRT, future efforts to reduce tumor inhibitory microenvironment factors and improved lymphocyte recovery should be investigated.

Phase II Study of ONC201 in Neuroendocrine Tumors including Pheochromocytoma-Paraganglioma and Desmoplastic Small Round Cell Tumor

PURPOSE

Tumor dopamine-like DRD2 receptor expression is higher in pheochromocytoma-paraganglioma (PC-PG) compared with other cancers. ONC201 is a bitopic DRD2 antagonist with preclinical ONC201 activity in desmoplastic small round cell tumor (DSRCT).

PATIENTS AND METHODS

Patients (N = 30) with neuroendocrine tumors were treated on this investigator-initiated trial (NCT03034200). ONC201 dose and schedule were 625 mg orally weekly in cohorts A (PC-PG) + B (other neuroendocrine tumors) and 625 mg orally on 2 consecutive days each week in cohort C, which included 5 responding patients. The primary endpoint was radiographic response measured using RECIST. Secondary endpoints included progression-free survival, overall survival, and safety.

RESULTS

In arm A (n = 10; all PC-PG), 50% (5/10) exhibited a partial response (PR) and 2 additional patients had stable disease (SD) >3 months. Median duration of therapy for arm A patients was 9 months (range: 1.5-33 months) with 5 patients treated >1 year. In arm B (n = 12), there were 1 PR (DSRCT) and 2 SD (DSRCT; neuroblastoma) >3 months. Median duration of therapy in arm A was 18 months (range: 1-33 months) and arm B was 3 months (range: 1.5-33 months). Arm C PC-PG (N = 8) showed 1 PR and 7 SD at 3 months, with median duration of therapy >10 months. There was no decline in Karnofsky performance status at week 12 for 28 of 30 patients and no dose modification due to treatment-related adverse events.

CONCLUSIONS

Oral ONC201 was well tolerated in patients with metastatic neuroendocrine tumors and associated with clinical benefit, including tumor responses, particularly in some patients with DSRCT and the majority of patients with PC-PG. See related commentary by Owen and Trikalinos, p. 1748.

223-Radium for metastatic osteosarcoma: combination therapy with other agents and external beam radiotherapy

Background

Bone-seeking radiopharmaceuticals can deposit radiation selectively to some osteosarcoma tumours because of the bone-forming nature of this cancer.

Objectives

This is the first report of using 223-radium, an alpha-emitting calcium analogue with a high therapeutic index, in combination therapy with other agents in 15 patients with metastatic osteoblastic osteosarcoma.

Methods

Candidates for alpha-radiotherapy if ^99mTc-MDP bone scan had avid bone-forming lesions and no therapy of higher priority (eg, definitive surgery). Monthly 223-radium infusions (1.49 μCi/kg or 55.13 kBq/kg) were given.

Results

The median infusion number was three and the average time to progression was 4.3 months for this cohort receiving 223-radium+other agents. Agents provided during 223-radium included (1) drugs to reduce skeletal complications: monthly denosumab (n=13) or zolendronate (n=1); (2) agents with antivascular endothelial growth factor activity, pazopanib (n=8) or sorafenib (n=1), (3) alkylating agents: oral cyclophosphamide (n=1) or ifosfamide, given as a 14-day continuous infusion (n=1, two cycles), (4) high-dose methotrexate (n=1), pegylated liposomal doxorubicin (n=1); and (5) two other combinations: nivolumab and everolimus (n=1) and rapamycin and auranofin (n=1). Radiation therapy, including stereotactic body radiotherapy (SBRT), was also given to 11 patients concurrently with 223-radium (n=2), after 223-radium completion (n=3), or both concurrently and then sequentially for other sites (n=6). After 223-radium infusions, patients without RT had a median overall survival of 4.3 months compared with those with SBRT and/or RT, who had a median overall survival of 13.5 months.

Conclusion Although only 1/15 of patients with osteoblastic osteosarcoma still remain alive after 223-radium, overall survival

Phase II study of ONC201 in pheochromocytoma-paragangliomas (PC-PG), medullary thyroid carcinoma (MTC), and other neuroendocrine tumors

e16703

Background: ONC201 is an imipridone with specificity for the dopamine-like DRD2 receptor. Anti-cancer effects involve up-regulation of TRAIL/DR5, dual AKT/ERK pathway inhibition, and integrated stress response. Because TCGA analysis showed very high DRD2 expression in neuroendocrine tumors, especially pheochromocytoma-paragangliomas (PC-PG), an investigator initiated IND study of ONC201 in neuroendocrine tumors (CCF IRB17-808; CASE2716; IND132665; NCT03034200) was done. Methods: ONC201 dose was 625 mg po/wk. Metastatic PG-PG were enrolled in cohort A. Other neuroendocrine patients were entered in cohort B. Two additional patients had single patient IND. Because hypertension is an issue from catecholamine producing PC-PG, all PC-PG patients had combined alpha + beta blockade and bp was monitored in the clinical research unit after dose #1 ONC201. Additional data was obtained with daily home bp monitoring, often with a wireless cuff which connects into EPIC via MyChart. Labs, scans, and clinic visits were done at week 6, then every 3 months from initial ONC201 dose. Patients with clinical benefit remained on study and could get radiation for bone metastases. Results: Neuroendocrine tumors were treated with ONC201 included 10 PC-PG, 3 with MTC 13 with other varieties including sarcomas, adrenal cortical carcinoma (ACC), neuroblastoma, and GI neuroendocrine tumor (NET). ONC201 was exceptionally well tolerated. All patients were able to maintain or improve KPS while on study. No adverse effects on bp were seen. The only ONC201-related AE was temporary grade 1 neurocognitive dysfunction for ~36 hours after weekly ONC201 dosing in 2/10 PC-PG patients. 4/10 PC-PG patients remain on study at 28, 22, 22, and 4 month. 1 DSRCT patient achieved a PR at 3 months and has been treated 28 months. An ACC patient was initially responsive (PR), but rapidly progressed in liver; 1 GI NET patient had -10% reduction by RECIST at 3 months and remains on treatment. MTC may be responsive (1 no response, 2 stable and improving by RECIST at 3 months). Conclusions: ONC201 is very well tolerated with excellent quality of life and extended clinical benefit against neuroendocrine tumors. Although ONC201 has activity against neuroendocrine tumors, especially PC-PG, increased efficacy will likely require combination therapy. Clinical trial information: NCT03034200 . [Table: see text]

Spine radiosurgery in adolescents and young adults: early outcomes and toxicity in patients with metastatic Ewing sarcoma and osteosarcoma

OBJECTIVE

There are limited data on spine stereotactic radiosurgery (SRS) in treating adolescent and young adult (AYA) patients. SRS has the advantages of highly conformal radiation dose delivery in the upfront and retreatment settings, means for dose intensification, and administration over a limited number of sessions leading to a decreased treatment burden. In this study, the authors report the oncological and toxicity outcomes for AYA patients with metastatic sarcoma treated with spine radiosurgery and provide clinicians a guide for considerations in dose, volume, and fractionation.

METHODS

An institutional review board-approved database of patients treated with SRS in the period from October 2014 through December 2018 was queried. AYA patients, defined by ages 15-29 years, who had been treated with SRS for spine metastases from Ewing sarcoma or osteosarcoma were included in this analysis. Patients with follow-ups shorter than 6 months after SRS were excluded. Local control, overall survival, and toxicity were reported.

RESULTS

Seven patients with a total of 11 treated lesions were included in this study. Median patient age was 20.3 years (range 15.1-26.1 years). Three patients had Ewing sarcoma (6 lesions) and 4 patients had osteosarcoma (5 lesions). The median dose delivered was 35 Gy in 5 fractions (range 16-40 Gy, 1-5 fractions). The median follow-up was 11.1 months (range 6.8-26.0 months). Three local failures were observed within the follow-up period. No acute grade 3 or greater toxicity was observed. One patient developed late grade 3 toxicity consisting of radiation enteritis. This patient had previously received radiation to an overlapping volume with conventional fractionation. SRS re-irradiation for this patient was also performed concurrently with chemotherapy administration. No late grade 4 or higher toxicities were observed. No pain flare or vertebral compression fracture was observed. Three patients died within the follow-up period.

CONCLUSIONS

SRS for spine metastases from Ewing sarcoma and osteosarcoma can be considered as a treatment option in AYA patients and is associated with acceptable toxicity rates. Further studies must be conducted to determine long-term local control and toxicity for this treatment modality.

Virtual visits for children, adolescents, and young adults with cancer

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Background: Children, adolescents, and young adults have rare cancers and standard-of-care treatment is commonly very aggressive. Virtual visits provide include many of the nuances of face-to face communication. These are much friendlier than phone calls or email and can be scheduled and structured to provide a large amount of information efficiently. Methods: Cleveland Clinic uses HIPPA-compliant software from American Well (Boston, MA) that allows the health care provider and patient to use a phone, tablet, or desktop computer for video visits. Our intake process involves obtaining a Medical Record Number (MRN), sending a brief summary, uploading or sending a CD with images in DICOM, and having an administrative assistant schedule the virtual visit. Telemedicine sessions typically last <60 minutes. During the visit a summary is updated, images are reviewed, and this and other information shared via email after the visit. Results: In 2017+ 2018 we conducted 223 virtual visits; 85% were <30 years old (table). The summary has been a key to efficient and effective organization and includes not only contact information and past medical history, but also an “Opportunities to Improve Health" section (problem list /action plan). Topics discussed in solid tumor patients include: 1) local control, 2) medical therapy (chemotherapy), 3) imaging and tumor markers, 4) control of side effects and nutrition, 5) social issues and goals of care (which can include palliative care and hospice), and 6) follow-up. A power point with key images and the updated summary and articles are emailed at the end of the visit to the patient & caregivers and often referring physician, NP, or PA . Visit diagnoses have included osteosarcoma and Ewing sarcoma (73%), but also other rare cancers such as rhabdomyosarcoma, DSRCT, paraganglioma, and adrenal cortical carcinoma. Survivorship and cGVHD have also been discussed. Conclusions: A structured virtual visit to help young people and their caregivers understand complex multi-disciplinary cancer care is now possible for all regions of North America. A major source of satisfaction has been two-way sharing of information to improve not only cancer control, but also improved nutrition, communication, and proactive toxicity reduction. [Table: see text]

The safety and efficacy of clofarabine in combination with high-dose cytarabine and total body irradiation myeloablative conditioning and allogeneic stem cell transplantation in children, adolescents, and young adults (CAYA) with poor-risk acute leukemia

Acute leukemias in children with CR3, refractory relapse, or induction failure (IF) have a poor prognosis. Clofarabine has single agent activity in relapsed leukemia and synergy with cytarabine. We sought to determine the safety and overall survival in a Phase I/II trial of conditioning with clofarabine (doses 40 - 52 mg/m²), cytarabine 1000 mg/m², and 1200 cGy TBI followed by alloSCT in children, adolescents, and young adults with poor-risk leukemia. Thirty-seven patients; Age 12 years (1-22 years); ALL/AML: 34:3 (18 IF, 10 CR3, 13 refractory relapse); 15 related, 22 unrelated donors. Probabilities of neutrophil, platelet engraftment, acute GvHD, and chronic GvHD were 94%, 84%, 49%, and 30%, respectively. Probability of day 100 TRM was 8.1%. 2-year EFS (event free survival) and OS (overall survival) were 38.6% (CI₉₅: 23-54%), and 41.3% (CI₉₅: 25-57%). Multivariate analysis demonstrated overt disease at time of transplant (relative risk (RR) 3.65, CI₉₅: 1.35-9.89, P = 0.011) and umbilical cord blood source (RR 2.17, CI₉₅: 1.33-4.15, P = 0.019) to be predictors of worse EFS/OS. This novel myeloablative conditioning regimen followed by alloSCT is safe and well tolerated in CAYA with very poor-risk ALL or AML. Further investigation in CAYA with better risk ALL and AML undergoing alloSCT is warranted.

In vitro study of 2,3-dehydrosilybin and its galloyl esters as potential inhibitors of angiogenesis

2,3-Dehydrosilybin exhibits substantial anticancer and antiangiogenic effects, which can be potentially improved by semi-synthetic modification such as esterification with gallic acid. The aim of this study was to examine the potential antiangiogenic effect of 2,3-dehydrosilybin and its galloyl esters (3-O-galloyl-2,3-dehydrosilybin; 7-O-galloyl-2,3-dehydrosilybin; 20-O-galloyl-2,3-dehydrosilybin and 23-O-galloyl-2,3-dehydrosilybin) and to determine which molecular mechanism could be responsible for their activity. The effect on cell proliferation, tube formation, signal transduction pathways (PI3K/Akt and ERK) and the cell cycle was studied in human microvascular endothelial cells (HMEC). The results showed that all compounds decreased the growth of HMEC, but the strongest effect was observed for 20-O-galloyl-2,3-dehydrosilybin at 5 μmol/l. In addition, at 5 and 10 μmol/l, this was the only compound that significantly inhibited HMEC tube formation. Based on an assessment of Akt and ERK1/2 expression, we suggest that 20-O-galloyl-2,3-dehydrosilybin influences the angiogenic process through the Akt pathway.

Anti-angiogenic effects of novel cyclin-dependent kinase inhibitors with a pyrazolo[4,3-d]pyrimidine scaffold

BACKGROUND AND PURPOSE

Cyclin-dependent kinase 5 (CDK5) has recently emerged as an attractive target in several tumour entities. Inhibition of CDK5 has been shown to have anti-angiogenic effects in vitro and in vivo. However, potent inhibitors of CDK5, which can be applied in vivo, are still scarce. We have recently developed a new series of 5-substituted 3-isopropyl-7-[4-(2-pyridyl)benzyl]amino-1(2)H-pyrazolo[4,3-d]pyrimidines that show a preference for inhibiting CDK5 and tested them in vitro and in vivo in a murine model of hepatocellular carcinoma.

EXPERIMENTAL APPROACH

All compounds were initially examined for effects on proliferation of HUVECs. The most potent compounds were then tested on migration, and one of them, LGR2674, was selected for assessing effects on nuclear fragmentation, cell cycle, cell viability and metabolic activity. Furthermore, LGR2674 was tested in a tube formation assay and in vivo in a murine model of hepatocellular carcinoma, induced by s.c. injection of HUH7 cells (measurement of in vivo toxicity, tumour vascularization, tumour cell proliferation and tumour size).

KEY RESULTS

LGR2674 showed an EC50 in the low nanomolar range in the proliferation and migration assays. Cytotoxic effects started at 50 nM, a concentration that did not influence the cell cycle. In vivo, LGR2674 was well tolerated and caused a clear reduction in vessel density in the tumours; also tumour cell proliferation was inhibited and tumour growth retarded.

CONCLUSIONS AND IMPLICATIONS

Pyrazolo[4,3-d]pyrimidine is a novel scaffold for the development of potent CDK inhibitors with in vivo potential. Such structures are good candidates for broadening our pharmacological arsenal against various tumours.

Abstract 4913: Engineering dendritic cell-based vaccines as targeted immunotherapy against medulloblastoma, neuroblastoma, and Ewing sarcoma

Medulloblastoma (MB), Neuroblastoma (NB), and Ewing Sarcoma (ES) are malignant pediatric neuroectodermal solid tumors. Current treatments are highly intensive but toxic and subsets of patients such as metastatic and/or relapsed patients have a dismal outcome (Esiashvili N et al, 2008; Leavey PJ et al, 2008; Bernstein ML et al, 2006). Targeted treatments with reduced side effects are urgently needed. Immunotherapy is a promising approach to inducing tumor control. Among various strategies of immunotherapy, dendritic cell-based vaccines have shown promising preliminary activity in the setting of minimal residual disease (Lasky JL et al, 2013; Westers TM et al, 2011; Shumway NM et al, 2009). To evaluate the feasibility of dendritic cell based vaccine in pediatric solid tumors, we incubated HLA A02+ human peripheral blood mononuclear cells (PBMC) with monocyte-derived autologous dendritic cells (DCs) pulsed with or without whole tumor cell lysates in interferon-ã (INFã) ELISPOT assays. We demonstrated that the number of spots detected in test wells (Daoy: 141.6±3, SKPNDW: 233.3±33.5, EWS502: 157.6±22.3, TC71: 249.6±24.5) is significantly (p&lt;0.05) greater than control wells (PBS: 42±2), suggesting successful tumor antigen presenting of DCs and specific immune response from PBMC. To test T-cell responses, we isolated CD8+ T cells from PBMC and incubated them with tumor cell lysate pulsed mature DCs. Interestingly, we observed a similar trend in activation but fewer number of spots (PBS: 27±9, Daoy: 52.6±14.5, SKPNDW: 76.6±30.1, EWS502: 44.6±8.3, TC71: 68.6±19) in ELISPOT assays. Further analysis using HLA-DR blocking antibody (L243) showed that CD4+ T cell function is required for the responsive activity of PBMC because the number of spots was significantly (p = 0.03) reduced in test wells with the antibody (45.5±4.9) compared to that in control wells (352.5±17.6). These data indicate that both CD4+ and CD8+ T cells are required for the T-cell immune response to tumor antigens in whole tumor cell lysate presented by DCs. We next tested in vitro cytotoxic activity of DC-activated PBMCs to MB, NB, and ES cells by DELFIA cytotoxicity assay. PBMCs incubated with tumor lysate pulsed DCs induced significantly increased cell lysis compared to control PBMCs in Daoy (78±4.8% vs. 46.5±3.5% at E:T = 10:1, p = 0.019), SKPNDW (80±14.1% vs. 15±2.3% at E:T = 10:1, p = 0.016), and TC71 (82.5±3.5% vs. 39.5±13.4% at E:T = 20:1, p = 0.036). Taken together, our proof-of-principle studies demonstrated the efficacy of DC-based vaccines using whole tumor cell lysate as antigens in pediatric neuroectodermal solid tumors. Further investigation in the preclinical setting in a xenograft NSG model is warranted.

Citation Format: Stacey Zahler, Wen Luo, Janet Ayello, Mitchell S. Cairo. Engineering dendritic cell-based vaccines as targeted immunotherapy against medulloblastoma, neuroblastoma, and Ewing sarcoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4913.

A Phase I Study of Reduced-Intensity Conditioning and Allogeneic Stem Cell Transplantation Followed by Dose Escalation of Targeted Consolidation Immunotherapy with Gemtuzumab Ozogamicin in Children and Adolescents with CD33+ Acute Myeloid Leukemia

Myeloablative conditioning and allogeneic hematopoietic stem cell transplant (alloHSCT) in children with acute myeloid leukemia (AML) in first complete remission (CR1) may be associated with significant acute toxicity and late effects. Reduced-intensity conditioning (RIC) and alloHSCT in children is safe, feasible, and may be associated with less adverse effects. Gemtuzumab ozogamicin (GO) induces a response in 30% of patients with CD33+ relapsed/refractory AML. The dose of GO is significantly lower when combined with chemotherapy. We examined the feasibility and toxicity of RIC alloHSCT followed by GO targeted immunotherapy in children with CD33+ AML in CR1/CR2. Conditioning consisted of fludarabine 30 mg/m2 × 6 days, busulfan 3.2 to 4 mg/kg × 2 days ± rabbit antithymocyte globulin 2 mg/kg × 4 days followed by alloHSCT from matched related/unrelated donors. GO was administered ≥60 days after alloHSCT in 2 doses (8 weeks apart), following a dose-escalation design (4.5, 6, 7.5, and 9 mg/m2). Fourteen patients with average risk AML received RIC alloHSCT and post-GO consolidation: median age 13.5 years at transplant (range, 1 to 21), male-to-female 8:6, and disease status at alloHSCT 11 CR1 and 3 CR2. Eleven patients received alloHSCT from 5-6/6 HLA-matched family donors: 8 received peripheral blood stem cells, 2 received bone marrow, and 1 received related cord blood transplantation. Three patients received an unrelated allograft (two 4-5/6 and one 9/10) from unrelated cord blood unit and bone marrow, respectively. Neutrophil and platelet engraftment was observed in all assessable patients (100%), achieved at median 15.5 days (range, 7 to 31) and 21 days (range, 10 to 52), respectively. Three patients received GO at dose level 1 (4.5 mg/m2 per dose), 5 at dose level 2 (6 mg/m2 per dose), 3 at dose level 3 (7.5 mg/m2 per dose), and 3 at dose level 4 (9 mg/m2 per dose). Three of 14 patients received only 1 dose of GO after alloHSCT. One patient experienced grade III transaminitis, which resolved; no grade IV transaminitis, no grade III/IV hyperbilirubinemia, or sinusoidal obstructive syndrome were observed. The second dose of GO was given at median of 143 days (range, 120 to 209) after alloHSCT. Probability of grades II to IV acute and chronic graft-versus-host disease were 21% and 33.5%, respectively. Probability of overall survival after RIC alloHSCT and GO consolidation at 1 and 5 years was 78% and 61%, respectively. Probability of 5-year event-free survival after RIC alloHSCT and GO consolidation in patients in CR1 was 78%. No dose-limiting toxicities probably or directly related to GO were observed in this cohort. This preliminary data demonstrate that RIC followed by alloHSCT and consolidation with GO appears to be safe in children and adolescents with CD33+ AML in CR1/CR2. A phase II trial is currently underway investigating this approach with a GO dose of 9 mg/m2 per dose.

In vitro anti-cancer effects of the actin-binding natural compound rhizopodin

Several natural compound interfere with microtubules or the actin cytoskeleton. Compounds interfering with the microtubules like Vinca-alkaloids or taxanes, are extensively used for cancer therapy. In contrast, knowledge about pharmacological properties of actin binding drugs is poor and drugs interfering with actin are far from clinical use. Rhizopodin is a natural compound that strongly affects the actin cytoskeleton at nanomolar concentrations. Initial work revealed interesting anti-bacterial and cytotoxic effects, but the cellular effects and pharmacological properties of rhizopodin have not been characterized. We hypothesized that rhizopodin might exert anti-cancer activity. Therefore, the aim of this study was to characterize the cellular and pharmacological effects of rhizopodin in cancer. Effects of rhizopodin demonstrated prominent effects on the actin cytoskeleton as shown in the actin-pyrene assay and by immunostaining of cancer cells. To investigate cellular effects of rhizopodin, we analyzed cell proliferation, cell death induction by propidium iodide exclusion and western blot, as well as migration by impedance measurement using the xCELLligence device in MDA-MB-231 breast cancer and T24 bladder cancer cell lines. Rhizopodin inhibited proliferation and induced cell death of MDA-MB-231 and T24 cells at nanomolar concentrations. PARP cleavage by rhizopodin suggests caspase-dependent cell death induction. Importantly, rhizopodin potently inhibited MDA-MB-231 and T24 cancer cell migration at subtoxic doses where no actin aggregation was observed, indicating a specific underlying signaling of rhizopodin. In summary, our study elucidates rhizopodin as actin-binding natural compound that exerts potent anti-cancer effects. Therefore, our work provides the basis for further in depth characterization of rhizopodin as an antitumoral agent.

Anti-angiogenic effects of the tubulysin precursor pretubulysin and of simplified pretubulysin derivatives

BACKGROUND AND PURPOSE

The use of tubulin-binding compounds, which act in part by inhibiting tumour angiogenesis, has become an integral strategy of tumour therapy. Recently, tubulysins were identified as a novel class of natural compounds of myxobacterial origin, which inhibit tubulin polymerization. As these compounds are structurally highly complex, the search for simplified precursors [e.g. pretubulysin (Prt)] and their derivatives is mandatory to overcome supply problems hampering clinical development. We tested the anti-angiogenic efficacy of Prt and seven of its derivatives in comparison to tubulysin A (TubA).

EXPERIMENTAL APPROACH

The compounds were tested in cellular angiogenesis assays (proliferation, cytotoxicity, cell cycle, migration, chemotaxis, tube formation) and in vitro (tubulin polymerization). The efficacy of Prt was also tested in vivo in a murine subcutaneous tumour model induced with HUH7 cells; tumour size and vascularization were measured.

KEY RESULTS

The anti-angiogenic potency of all the compounds tested ran parallel to their inhibition of tubulin polymerization in vitro. Prt showed nearly the same efficacy as TubA (EC(50) in low nanomolar range in all cellular assays). Some modifications in the Prt molecule caused only a moderate drop in potency, while others resulted in a dramatic loss of action, providing initial insight into structure-activity relations. In vivo, Prt completely prevented tumour growth and reduced vascular density to 30%.

CONCLUSIONS AND IMPLICATIONS

Prt, a chemically accessible precursor of some tubulysins is a highly attractive anti-angiogenic compound both in vitro and in vivo. Even more simplified derivatives of this compound still retain high anti-angiogenic efficacy.

A novel technique for selective NF-kappaB inhibition in Kupffer cells: contrary effects in fulminant hepatitis and ischaemia-reperfusion

BACKGROUND AND AIMS

The transcription factor nuclear factor kappa B (NF-kappaB) has risen as a promising target for anti-inflammatory therapeutics. In the liver, however, NF-kappaB inhibition mediates both damaging and protective effects. The outcome is deemed to depend on the liver cell type addressed. Recent gene knock-out studies focused on the role of NF-kappaB in hepatocytes, whereas the role of NF-kappaB in Kupffer cells has not yet been investigated in vivo. Here we present a novel approach, which may be suitable for clinical application, to selectively target NF-kappaB in Kupffer cells and analyse the effects in experimental models of liver injury.

METHODS

NF-kappaB inhibiting decoy oligodeoxynucleotides were loaded upon gelatin nanoparticles (D-NPs) and their in vivo distribution was determined by confocal microscopy. Liver damage, NF-kappaB activity, cytokine levels and apoptotic protein expression were evaluated after lipopolysaccharide (LPS), d-galactosamine (GalN)/LPS, or concanavalin A (ConA) challenge and partial warm ischaemia and subsequent reperfusion, respectively.

RESULTS

D-NPs were selectively taken up by Kupffer cells and inhibited NF-kappaB activation. Inhibition of NF-kappaB in Kupffer cells improved survival and reduced liver injury after GalN/LPS as well as after ConA challenge. While anti-apoptotic protein expression in liver tissue was not reduced, pro-apoptotic players such as cJun N-terminal kinase (JNK) were inhibited. In contrast, selective inhibition of NF-kappaB augmented reperfusion injury.

CONCLUSIONS

NF-kappaB inhibiting decoy oligodeoxynucleotide-loaded gelatin nanoparticles is a novel tool to selectively inhibit NF-kappaB activation in Kupffer cells in vivo. Thus, liver injury can be reduced in experimental fulminant hepatitis, but increased at ischaemia-reperfusion.

Bid-induced release of AIF from mitochondria causes immediate neuronal cell death

Mitochondrial dysfunction and release of pro-apoptotic factors such as cytochrome c or apoptosis-inducing factor (AIF) from mitochondria are key features of neuronal cell death. The precise mechanisms of how these proteins are released from mitochondria and their particular role in neuronal cell death signaling are however largely unknown. Here, we demonstrate by fluorescence video microscopy that 8-10 h after induction of glutamate toxicity, AIF rapidly translocates from mitochondria to the nucleus and induces nuclear fragmentation and cell death within only a few minutes. This markedly fast translocation of AIF to the nucleus is preceded by increasing translocation of the pro-apoptotic bcl-2 family member Bid (BH3-interacting domain death agonist) to mitochondria, perinuclear accumulation of Bid-loaded mitochondria, and loss of mitochondrial membrane integrity. A small molecule Bid inhibitor preserved mitochondrial membrane potential, prevented nuclear translocation of AIF, and abrogated glutamate-induced neuronal cell death, as shown by experiments using Bid small interfering RNA (siRNA). Cell death induced by truncated Bid was inhibited by AIF siRNA, indicating that caspase-independent AIF signaling is the main pathway through which Bid mediates cell death. This was further supported by experiments showing that although caspase-3 was activated, specific caspase-3 inhibition did not protect neuronal cells against glutamate toxicity. In conclusion, Bid-mediated mitochondrial release of AIF followed by rapid nuclear translocation is a major mechanism of glutamate-induced neuronal death.

Ginkgo biloba extract EGb® 761 increases endothelial nitric oxide production in vitro and in vivo

Beneficial effects of Ginkgo biloba on peripheral arterial occlusive disease have been repeatedly shown in clinical trials, especially after use of EGb 761, a standardized special extract. Since the underlying mechanisms are widely unknown, we aimed to elucidate the molecular basis on which EGb 761 protects against endothelial dysfunction in vitro and in vivo. Application of therapeutically feasible doses of EGb 761 for 48 h caused endothelial nitric oxide (NO) production by increasing endothelial nitric oxide synthase (eNOS) promoter activity and eNOS expression in vitro. Phosphorylation of eNOS at a site typical for Akt (Ser 1177) was acutely enhanced by treatment with EGb 761, as was Akt phosphorylation at Ser 478. Furthermore, the extract caused acute relaxation of isolated aortic rings and NO-dependent reduction of blood pressure in vivo in rats. These influences on eNOS represent a putative molecular basis for the protective cardiovascular properties of EGb 761.

Insights from knock-out models concerning postischemic release of TNFalpha from isolated mouse hearts

The inflammatory cytokine tumor necrosis factor alpha (TNFalpha) is controversially discussed in ischemia/reperfusion damage of the heart. Purpose of this study was to elucidate cellular sources of TNFalpha and parameters which possibly influence its release in the heart following ischemia. Isolated hearts of mice were subjected to 15 min of global ischemia and 90 min of reperfusion. We employed hearts of various mice knock-out strains (interleukin-6(-/-), matrix metalloprotease-7(-/-), mast-cell deficient WBB6F1-Kit(W)/Kit(W-v), TNF-R1(-/-)) and wildtype mice, the latter perfused without and with infusion of cycloheximide or TNFalpha-cleaving-enzyme inhibitor (TAPI-2). Normoxic control hearts showed basal release of TNFalpha during the whole experiment. Immunohistology identified cardiac mast cells, macrophages and endothelial cells as main sources. TNFalpha release was stimulated during postischemic reperfusion, occurring in a two-peak pattern: directly after ischemia (0-10 min) and again after 60-90 min. The first peak mainly reflects tissue washout of TNFalpha accumulated during ischemia. The second, protracted peak arose continuously from the basal level and was abolished by protein synthesis inhibitor cycloheximide. Both properties are characteristic for de novo synthesis of TNFalpha, e.g., in cardiac muscle cells. However, immunohistological staining for TNFalpha failed in cardiomyocytes after 90 min of reperfusion. In contrast to hearts of TNF-R1(-/-) and Kit(W/W-v)-mice, those of IL-6(-/-) and MMP-7(-/-) mice lacked the late TNFalpha peak. TAPI did not suppress release of TNFalpha. While autostimulation via TNF-R1 also does not seem obligatory and mast cell can be ignored as source of the second peak, IL-6 may support de novo synthesis of TNFalpha. Additionally, TNFalpha release may essentially involve cleavage of membrane bound TNFalpha by MMP-7.

Dynamic analysis of metabolic effects of chloroacetaldehyde and cytochalasin B on tumor cells using bioelectronic sensor chips

PURPOSE

To study the interplay of drugs and energy metabolism of tumor cells, metabolic changes induced by chloroacetaldehyde and cytochalasin B were analyzed in colon carcinoma cells LS174T.

METHODS

O(2)-consumption and extracellular acidification were recorded using a bioelectronic sensor-chip system, which monitors these parameters in a culture continuously for at least 24 h. In parallel cultures cell number, cellular ATP-content, mitochondrial transmembrane potential, and the content of reactive oxygen species (ROS) were determined.

RESULTS

When cell death was induced by chloroacetaldehyde (50 muM), the rate of acidification declined gradually for the next 15 h, while O(2)-consumption decreased rapidly within 30 min. This correlated with a loss in mitochondrial potential. However, cellular ATP-level showed a transient increase at 2 h; also ROS levels increased up to 6 h. In cells treated with cytochalasin B (2 muM), which inhibits glucose uptake, the rate of O(2)-consumption increased and the acidification activity dropped, even upon glutamine depletion. Mitochondrial membrane potential transiently increased after 1 h, while ATP-content decreased; there was no change in the level of ROS.

CONCLUSION

The pattern of changes in basic energy metabolism differs with the type of cell death and growth inhibition involved in the cytotoxic action of two different drugs.

Intracoronary formation and retention of micro aggregates of leukocytes and platelets contribute to postischemic myocardial dysfunction

OBJECTIVE

Cardiac pump function and coronary regulation can be impaired after short-term ischemia. Recent studies with platelets (P) and neutrophils (PMN) yielded contradicting results about the "cellular" contribution to reperfusion injury.

METHODS

Isolated guinea pig hearts performing pressure-volume work were employed, external heart work (EHW), aortic flow (AF), coronary flow (CF) and heart rate (HR) serving as parameters of cardiac function. After global ischemia, human blood cells were given as bolus (1 min) during reperfusion (intracoronary hematocrit 7%). Expression of specific adhesion molecules (P: CD62P, CD41; PMN: integrin CD11b) was measured on cells before and after coronary passage (FACS analysis).

RESULTS

Postischemic recovery of pump function was significantly reduced in hearts with blood cell application (EHW: -cells 54 +/- 14%, +cells 41 +/-12%, p <0.05). Coronary response to bradykinin and reactive hyperemia were not effected. The blood-cell dependent functional loss was partly reduced by blocking CD18 (anti-CD 18) and completely abrogated by blockage of CD41 (lamifiban). The expression of CD11b on PMN and monocytes (M) and CD62P on platelets was significantly reduced in the coronary effluent and a significant decrease of CD41 on leukocytes occurred during coronary passage after ischemia. Increases in CD41 on PMN in the presence of lamifiban demasked intracoronary formation of micro aggregates (P/PMN). These micro aggregates were visualized by light microscopy. Electron microscopy revealed no significant microvascular plugging.

CONCLUSION

1) A specifically blood-cell induced loss of myocardial pump function has been demonstrated after short-term ischemia. 2) CD41 (= GpIIbIIIa) on P is responsible for this cardiac reperfusion damage. 3) The effect is causally linked to the formation of micro aggregates between PMN and P, but seems attenuated in the presence of erythrocytes as compared to effects reported from experiments in which PMN and P were applied singly or co-perfused. 4) Intracoronary retention of PMN, M and platelet-leukocyte micro aggregates seems to be transient, as adherence was not confirmed by electron microscopy.

Modified phosphatidylethanolamine as the active component of oxidized low density lipoprotein promoting platelet prothrombinase activity

We analyzed the influence of the atherogenic oxidized low density lipoproteins (LDL) on the activity of the platelet prothrombinase complex, a major contributor to overall thrombin formation in vivo. Platelet dependent thrombin generation was found to be strongly stimulated by in vitro oxidized LDL. The enhancement was additive to that observed with the platelet agonist thrombin. Oxidized LDL increased the platelet binding of annexin-V, suggesting that the augmented surface exposure of aminophospholipids promoted the prothrombinase activity. All of the stimulatory activity of the oxidized LDL could be recovered in the microemulsions prepared from the lipid portion of the modified particles. Phospholipid vesicles were prepared containing the total lipids of the oxidized LDL but lacking specifically in one lipid component. Following the selective removal of the ethanolamine phospholipids (PE) from the LDL lipids, the platelet-dependent thrombin formation was markedly reduced. Vesicles enriched with the isolated PE fraction alone enhanced the thrombin generation. Analyses with autoxidized phospholipids indicated that oxidation products of unsaturated diacyl-PE were mainly responsible for the increased prothrombinase activity. Oxidized LDL and its PE fraction lost their stimulatory activity after treatment with NaCNBH(3), a chemical reductant of Schiff base adducts. Phospholipid vesicles supplemented with synthetic aldehyde-PE adducts largely reproduced the stimulation of the thrombin generation. We conclude that the oxidized LDL particles elicit a pronounced prothrombotic response by increasing the activity of the platelet prothrombinase complex. Specific oxidative modifications of the LDL-associated ethanolamine phospholipids are mainly responsible for this stimulation.

Reactive oxygen species and nitric oxide in myocardial ischemia and reperfusion

Oxygen radicals and reactive oxygen species (ROS) are known to be generated in large amounts under inflammatory conditions and in the first few minutes of postischemic organ reperfusion. Due to the interaction of ROS with nitric oxide (NO), formed constitutively by endothelial cells, two alternatives are feasible. On the one hand, reaction with superoxide radicals may induce toxification (formation of peroxynitrite), and, on the other hand, by reacting with superoxide and hydroxyl radicals, NO can serve as a radical scavenger (formation of the innocuous anions, nitrate and nitrite, respectively). However, NO is considered to play a pivotal role in numerous physiological and pathophysiological processes, with effects arising from both lack and surfeit of this easily diffusible and chemically very reactive molecule. Physiologic contributions to vascular dilatation and inhibition of platelet and leukocyte activation, e.g., are infringed by enhanced inactivation of NO. Such inactivation occurs readily due to spontaneous reaction of NO with the superoxide radical, formed, e.g., by stressed endothelial cells and activated leukocytes. Conversely, overproduction of NO by induced NO synthase (iNOS) may lead to circulatory shock, cell apoptosis or even cell necrosis. Caution would, thus, seem to be warranted when attempting to interfere with homeostasis of NO. We have investigated the ability of NO to act as a radical scavenger during myocardial reperfusion in experimental and clinical settings. In the former, inhibition of angiotensin converting enzyme was employed to generate more endogenous NO (via bradykinin), in the latter, low-dose sodium nitroprusside was used as the donor of exogenous NO in patients undergoing coronary bypass grafting. Inhibition of leukocyte adhesion, attenuation of platelet activation and mitigation of redox-stress and inflammation were observed in both instances. Accordingly, modest enhancement of NO levels should afford cardioprotection during reperfusion.

Platelet-associated tissue factor contributes to the collagen-triggered activation of blood coagulation

The extravascular localization of tissue factor (TF), the central initiator of coagulation, is thought to ensure that thrombus formation is prevented in the intact vessel. We observed that during a 5-min stimulation of human blood with collagen (type I), TF antigen appeared on the surface of platelets adhering to leukocytes. The rapidly presented intravascular TF was competent to start the coagulation cascade. The isolated platelets from healthy donors contained appreciable amounts of the TF protein, while no TF antigen was detected in the neutrophils and rapidly isolated monocytes. Direct interactions with the neutrophils and monocytes were apparently necessary to activate the platelet-associated TF. This was most likely mediated by inactivation of tissue factor pathway inhibitor through leukocyte elastase. In summary, the leukocyte-elicited activation of the platelet TF participates in the rapid initiation of coagulation by collagen.

Evidence for inflammatory responses of the lungs during coronary artery bypass grafting with cardiopulmonary bypass

OBJECTIVE

The occurrence of a systemic inflammatory reaction during cardiac surgery with cardiopulmonary bypass (CPB) has been well established, and the heart itself has been shown to release inflammatory mediators after ischemia. The hypothesis of the present study was that the lungs are also a site of inflammatory responses during early reperfusion.

METHODS

In 20 consecutive patients undergoing coronary artery bypass grafting, blood was simultaneously drawn from the right atrium (RA) and the pulmonary vein (PV) before CPB and at 1 min, 10 min, and 20 min of reperfusion. The levels of interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha were determined, as well as the adhesion molecules CD41 and CD62 on platelets and CD11b and CD41 on leukocytes. As a measure of the pulmonary release, ratios of PV and RA levels were calculated.

RESULTS

Before CPB, the concentrations of cytokines tended to be lower in the PV compared with the RA. At 1 min of reperfusion, no significant concentration increases were found in the PV. At 10 min of reperfusion, the PV/RA ratio (mean +/- SEM) for IL-6 was 2.06 +/- 0.37 and 1.24 +/- 0.15 for IL-8 (p = 0.02 and p = 0.04, respectively, compared with the pre-CPB ratios of 0.89 +/- 0.4 and 0.99 +/- 0.2). At 20 min of reperfusion, PV/RA ratios for IL-6 (1.95 +/- 0.37) and IL-10 (0.99 +/- 0.4) were higher than before CPB (0.89 +/- 0.04, p = 0.05 and 0.85 +/- 0.06, p = 0.03, respectively). Adhesion molecule counts on platelets and polymorphonuclear neutrophils (PMNs) tended to be higher in the PV than in the RA before CPB. At 1 min of reperfusion, the PV/RA ratio of CD41 on monocytes (0.89 +/- 0.04) and of CD41 on PMNs (1.05 +/- 0.05) was less than before CPB (1.24 +/- 0.08, p = 0.0002 and 1.55 +/- 0.14, p = 0.0002). At 10 min and 20 min of reperfusion, similar changes were found.

CONCLUSIONS

The observed changes indicate an inflammatory response of the lungs. Proinflammatory cytokines are increased in pulmonary venous blood. At the same time, activated blood cells are retained in the pulmonary circulation. This may contribute to pulmonary dysfunction almost routinely observed after CPB.

Reduction of pro-inflammatory cytokine levels and cellular adhesion in CABG procedures with separated pulmonary and systemic extracorporeal circulation without an oxygenator

OBJECTIVE

We have recently shown that a considerable amount of pro-inflammatory cytokines is released during pulmonary passage after aortic declamping in patients undergoing coronary artery bypass grafting. The present study was performed to investigate whether bilateral extracorporeal circulation with the lungs as oxygenators can reduce the inflammatory responses of the lungs.

METHODS

Eighteen consecutive patients undergoing coronary artery bypass grafting were randomly assigned to routine extracorporeal circulation with cannulation of right atrium and aorta (routine circulation, ten patients) or to a bilateral extracorporeal circulation with additional cannulation of left atrium and pulmonary artery (bilateral circulation, eight patients). Blood was simultaneously drawn from right atrium and pulmonary vein at 1, 10 and 20 min reperfusion. The levels of interleukin (IL)-6 and IL-8 and the adhesion molecules CD41 and CD62 on platelets and CD11b and CD41 on leukocytes were determined. Because of considerable interindividual scatter, the pulmonary venous levels are normalized to percent of the respective right atrial value at each time point.

RESULTS

At 1 min reperfusion pulmonary venous levels of IL-6 and IL-8 in routine circulation were +44+/-15% and +43+/-28% of the respective right atrial values. The respective values in bilateral circulation were -3+/-4% and -6+/-7% (P=0.02 and P=0.05 vs. respective right atrium). Similar increments were found after 10 and 20 min. Platelet-monocyte coaggregates were retained during pulmonary passage at 1 min reperfusion in routine circulation (-21+/-6%), but washed out in bilateral circulation (+5+/-8%, P=0. 007). At 20 min reperfusion, activated polymorphonuclear neutrophils (PMN) were retained in routine circulation (-16+/-9%) but washed out in bilateral circulation (+19+/-29%, P=0.05; all data given as mean+/-SEM).

CONCLUSIONS

Bilateral extracorporeal circulation without an artificial oxygenator significantly reduces the inflammatory responses during pulmonary passage after aortic declamping.

Nonuniform behavior of intravenous anesthetics on postischemic adhesion of neutrophils in the guinea pig heart

Adhesion of polymorphonuclear neutrophils (PMN) to the coronary endothelium is a crucial step in the development of ischemic myocardial injury. We tested the possible effects of six widely used IV anesthetics on non- and postischemic coronary adhesion of PMN in isolated perfused guinea pig hearts. Hearts (n = 5-11/group) were perfused under conditions of constant coronary flow. After 15 min global warm ischemia, PMN (10(6)) were infused in the second minute of reperfusion. The number of cells reemerging in the coronary effluent within 2 min was expressed as a percentage of the total number of administered PMN. Anesthetics were given 20 min before ischemia and during reperfusion. In addition, the ability of the drugs to influence the oxidative burst reaction of PMN was assessed by measuring luminol-enhanced chemiluminescence in response to 0.1 microM N-formyl-L-methionyl-L-leucyl-L-phenylalanine. Under nonischemic conditions, 26.3% +/- 0.5% of the injected PMN did not acutely reemerge from the coronary system. Subjecting the hearts to ischemia augmented retention to 40.0% +/- 1.6% (P < 0.05). This postischemic stimulation of adhesion was fully prevented by ketamine (10 microM: 22.8% +/- 1.6%, 20 microM: 26.6% +/- 0.7%), thiopental (25 microM: 24.0% +/- 1.7%, 50 microM: 24.0% +/- 1.4%), and midazolam (1.5 microM: 29.0% +/- 0.9%, 3 microM: 26.4% +/- 1.4%). Propofol also inhibited the augmented postischemic retention at 25 microM (28.7% +/- 2.4%). However, 50 microM propofol, etomidate (0.5 and 1 microM), and fentanyl (1 microM) all had no effect. Only thiopental reduced the nonischemic adhesion value (14.0% +/- 3.7%). This may be linked to the direct antioxidative action of thiopental (50% reduction in oxidative burst activity). Whereas ketamine, midazolam, and propofol did not significantly influence oxidant production by PMN, etomidate and the lipid solvent Intralipid enhanced the burst reaction. This activating effect of the lipid component could explain the biphasic behavior of propofol emulsion. Despite some possible differences in efficacy, several IV anesthetics may protect the heart from PMN-mediated reperfusion injury.

IMPLICATIONS

Ketamine, thiopental, and midazolam, but not etomodate or fentanyl, reduce postischemic adhesion of neutrophils in the coronary system of isolated perfused guinea pig hearts, suggesting a role in mitigating myocardial reperfusion injury.

Sodium nitroprusside in patients with compromised left ventricular function undergoing coronary bypass: reduction of cardiac proinflammatory substances

OBJECTIVE

The aim of the present study was to investigate whether the nitric oxide donor sodium nitroprusside can reduce the cardiac inflammatory response during coronary artery bypass grafting in patients with severely compromised left ventricular function.

METHODS

Patients (n = 30) were assigned to receive placebo or sodium nitroprusside (0.5 microg. kg(-1). min(-1)) for the first 60 minutes of reperfusion. Interleukin 6, interleukin 8, and tumor necrosis factor alpha levels; platelet adhesion molecule CD41 and CD62 levels; and CD11b on leukocytes were determined in the radial artery and coronary sinus before cardiopulmonary bypass and during reperfusion (1, 5, 10, 35, and 75 minutes).

RESULTS

At 1 minute of reperfusion, coronary venous levels of CD41-positive polymorphonuclear leukocytes were 8% lower than arterial levels in the placebo group and 18% higher in the sodium nitroprusside group (P =.021). At 5 minutes of reperfusion, the respective levels were 29% and 1% for interleukin 6 (P =.015), -5% and 20% for CD41-positive monocytes (P =.032), and -2% and 16% for CD11b-positive monocytes (P =.038). At 10 minutes of reperfusion, these levels were -14% and 21% for CD41-positive monocytes (P =.006). At 35 minutes of reperfusion, these levels were -13% and 7% for CD41-positive monocytes (P =.017), -41% and 23% for CD11b-positive monocytes (P =.001), and 7% and 25% for CD62-positive platelets (P =. 041). At 75 minutes of reperfusion, the levels were 15% and -7% for tumor necrosis factor alpha (P =.025) and -10% and 10% for CD62-positive platelets (P =.041).

CONCLUSIONS

Transcardiac production of proinflammatory cytokines is reduced in patients undergoing coronary artery bypass grafting treated with the nitric oxide donor sodium nitroprusside. At the same time, less activated leukocytes and platelets are retained in the coronary circulation.

Endothelial preconditioning by transient oxidative stress reduces inflammatory responses of cultured endothelial cells to TNF-alpha

Brief episodes of ischemia can render an organ resistant to subsequent severe ischemia. This 'ischemic preconditioning' is ascribed to various mechanisms, including oxidative stress. We investigated whether preconditioning exists on an endothelial level. Human umbilical vein endothelial cells (HUVECs) were transiently confronted with oxidative stress (1 mM H(2)O(2), 5 min). Adhesion molecules ICAM-1 and E-selectin and release of cytokines IL-6 and IL-8 to subsequent stimulation with TNF-alpha (2.5 ng/ml, 4 h) were measured (flow cytometry and immunoassay), as were nuclear translocation of the transcription factor NFkappaB (Western blotting, confocal microscopy) and redox status of HUVECs (quantification of glutathione by HPLC). TNF-alpha elevated IL-6 in the cell supernatant from 8.8 +/- 1 to 41 +/- 3 pg/ml and IL-8 from 0.5 +/- 0. 03 to 3 +/- 0.2 ng/ml. ICAM-1 was increased threefold and E-selectin rose eightfold. Oxidative stress (decrease of glutathione by 50%) reduced post-TNF-alpha levels of IL-6 to 14 +/- 3 and IL-8 to 1 +/- 0.2; the rise of ICAM-1 was completely blocked and E-selectin was only doubled. The anti-inflammatory effects of preconditioning via oxidative stress were paralleled by reduction of the translocation of NFkappaB on stimulation with TNF-alpha, and antagonized by the intracellular radical scavenger N-acetylcysteine. 'Anti-inflammatory preconditioning' of endothelial cells by oxidative stress may account for the inhibitory effects of preconditioning on leukocyte adhesion in vivo.

Endothelial function and hemostasis

The vascular endothelium influences not only the three classically interacting components of hemostasis: the vessel, the blood platelets and the clotting and fibrinolytic systems of plasma, but also the natural sequelae: inflammation and tissue repair. Two principal modes of endothelial behaviour may be differentiated, best defined as an anti- and a prothrombotic state. Under physiological conditions endothelium mediates vascular dilatation (formation of NO, PGI2, adenosine, hyperpolarizing factor), prevents platelet adhesion and activation (production of adenosine, NO and PGI2, removal of ADP), blocks thrombin formation (tissue factor pathway inhibitor, activation of protein C via thrombomodulin, activation of antithrombin III) and mitigates fibrin deposition (t- and scuplasminogen activator production). Adhesion and transmigration of inflammatory leukocytes are attenuated, e.g. by NO and IL-10, and oxygen radicals are efficiently scavenged (urate, NO, glutathione, SOD). When the endothelium is physically disrupted or functionally perturbed by postischemic reperfusion, acute and chronic inflammation, atherosclerosis, diabetes and chronic arterial hypertension, then completely opposing actions pertain. This prothrombotic, proinflammatory state is characterised by vaso-constriction, platelet and leukocyte activation and adhesion (externalization, expression and upregulation of von Willebrand factor, platelet activating factor, P-selectin, ICAM-1, IL-8, MCP-1, TNF alpha, etc.), promotion of thrombin formation, coagulation and fibrin deposition at the vascular wall (expression of tissue factor, PAI-1, phosphatidyl serine, etc.) and, in platelet-leukocyte coaggregates, additional inflammatory interactions via attachment of platelet CD40-ligand to endothelial, monocyte and B-cell CD40. Since thrombin formation and inflammatory stimulation set the stage for later tissue repair, complete abolition of such endothelial responses cannot be the goal of clinical interventions aimed at limiting procoagulatory, prothrombotic actions of a dysfunctional vascular endothelium.

Ketamine does not inhibit inflammatory responses of cultured human endothelial cells but reduces chemotactic activation of neutrophils

BACKGROUND

Ketamine is a widely used general anaesthetic, which has been reported to inhibit neutrophil function and neutrophil-endothelial interaction. To date, however, it is unknown whether ketamine has any direct effects on endothelial cells with respect to inflammation. Therefore, we investigated the influence of varying concentrations of ketamine (0.5, 1, and 3 microM) on the endothelial expression of cytokines and adhesion molecules with relevance for inflammation.

METHODS

Cultured human umbilical vein endothelial cells were stimulated with tumor necrosis factor alpha (TNFalpha, 2.5 ng/ml) for 4 h in the absence or presence of ketamine. The adhesion molecules ICAM-1 and E-selectin on the endothelial cells were measured by flow cytometry. Release of the proinflammatory cytokines IL-6 and IL-8 by endothelial cells was quantified by ELISA. The acute effect of ketamine on leukocyte activation by the supernatant of endothelial cells pre-stimulated with TNFalpha (4 h) was tested by flow cytometric measurement of CD11b, a leukocyte activation marker, after 15 min of coincubation.

RESULTS

TNFalpha caused dramatic upregulation of both adhesion molecules (15-fold and 5-fold vs. control for ELAM-1 and ICAM-1, respectively) and of both cytokines (500-fold and 1.8-fold for IL-6 and IL-8, respectively). No concentration of ketamine employed in our study had any effect on these inflammatory parameters. However, activation of leukocytes by supernatant of TNFalpha-conditioned endothelial cells (70% increase of CD11b) was attenuated by coincubation of the PMN with 0.5 and 5 microM ketamine (47% and 44% increase, respectively).

CONCLUSION

These data suggest that ketamine exerts its antiinflammatory actions primarily via inhibition of leukocyte reactivity. Indeed, no inhibition of endothelial responses was detectable in our study.

ACE-inhibition attenuates cardiac cell damage and preserves release of NO in the postischemic heart

Cardioprotective effects of angiotensin-converting enzyme (ACE) inhibition have been demonstrated in postischemic reperfusion. This occurred via bradykinin and indirect evidence suggested mediation by nitric oxide (NO), which probably acts as a radical scavenger. To test this hypothesis, we measured release of lactate dehydrogenase (LDH) from isolated guinea pig hearts (constant flow perfusion, 37 degrees C) as a marker of cellular damage, before and after global ischemia (15 min), and we investigated the release of NO during reperfusion, both, without and with ACE inhibition. The main catabolites of NO, nitrate and nitrite, were also quantified. Coronary perfusion pressure (CPP) indicated coronary resistance changes. Cilazaprilat (CIL, 10 microM) was used for inhibition of ACE. Marked and protracted cellular damage occurred during reperfusion in the control group, myocardial LDH release rising nearly 10-fold from 1.5 mU/ml (basal level) to 14 mU/ml during acute reperfusion, then declining to 7 mU/ml after 5 min. ACE inhibition mitigated the acute rise of LDH (9 mU/ml), and reduced its release to preischemic values already after 3 min of reperfusion. Postischemic NO release in the 2nd min of reperfusion was about 40% of the preischemic value (approx. 200 nM) in untreated hearts, while there was 70% recovery after ACE inhibition. After 25 min, NO had recovered to 69% in controls vs. 100% with CIL. Coronary venous nitrate + nitrite was not infringed during early reperfusion (2nd min). After 25 min, nitrate + nitrite had decreased in controls (about 75% of preischemic values), but increased to 110% with CIL. In control hearts, CPP rose continuously from the 10th to the 25th min of reperfusion (from 39 to 55 mmHg), indicating progressive vasoconstriction. CIL significantly attenuated this effect. The results suggest that NO might be consumed during early reperfusion in the act of detoxifying radicals. In control hearts, "endothelial stunning" takes place. Concerning NO production and vasodilatory tone, ACE-inhibition augments postischemic NO release and mitigates disturbances caused by ischemia and reperfusion.

Selectins and beta 2-integrins mediate post-ischaemic venular adhesion of polymorphonuclear leukocytes, but not capillary plugging, in isolated hearts

Leukocytes adhering to venular endothelium and emigrating into the tissue contribute to myocardial reperfusion injury. The aim of the present study was to characterize the contribution of two different families of adhesion molecules, selectins and integrins, to post-ischaemic capillary plugging and venular adhesion of leukocytes in an isolated heart model. Guinea-pig hearts were perfused using the Langendorff technique. After 20 min stabilization global ischaemia was induced for 15 min at 37 degrees C. With the onset of reperfusion 10(7) isolated polymorphonuclear leukocytes (PMN), prelabelled with rhodamine 6G, were infused within 1 min. Perfusion was continued for 2 min to wash out all cells not firmly adhering to the vascular endothelium. Hearts were then arrested, mounted on a microscope stage and perfused with a cardioplegic solution containing 0.01% fluorescein isothiocyanate (FITC)-dextran (MW 150,000). In situ videofluorescence microscopy was used to quantify PMN plugging and adherent PMN. Four groups were studied: control (no treatment or ischaemia, n = 6); ischaemia (no treatment and 15 min ischaemia, n = 5); fucoidin (pretreatment of hearts and PMN with 0.3 mg/ml selectin inhibitor fucoidin and 15 min ischaemia, n = 5) and CD18 (pretreatment of PMN with 0.1 mg monoclonal antibody against CD18 and 15 min ischaemia, n = 5). Capillary plugging by PMN was 25 +/- 5 PMN/mm2 epicardial surface area and increased moderately to 55 +/- 6 PMN/mm2 in reperfused hearts. This increase was not affected by fucoidin or CD18 antibody. In contrast, post-ischaemic adhesion of PMN in small venules increased ninefold from 21 +/- 5 to 196 +/- 23 PMN/mm2 endothelial surface area. The increase in PMN adhesion to venular endothelium was blocked completely by pretreatment with fucoidin (19 +/- 5 PMN/mm-2) or CD18 antibody (7 +/- 2 PMN/mm-2). We conclude that selectin interaction alone is not sufficient to account for post-ischaemic PMN adhesion in the small venules of the coronary vasculature, because blocking the integrin subunit CD18 also inhibited PMN adhesion completely. On the other hand, neither integrins nor selectins seem to be involved in post-ischaemic capillary plugging by PMN in our perfused heart model.

Sevoflurane and isoflurane protect the reperfused guinea pig heart by reducing postischemic adhesion of polymorphonuclear neutrophils

BACKGROUND

Polymorphonuclear neutrophils (PMNs) contribute to reperfusion injury. Because volatile anesthetics can reduce PMN adhesion in the reperfused, nonworking heart, the authors analyzed whether this action of volatile anesthetics affects cardiac performance after ischemia and reperfusion and further clarified the underlying mechanism.

METHODS

Isolated guinea pig hearts perfused with crystalloid buffer and performing pressure-volume work were used. Hearts were subjected to 15 min global ischemia and 20 min reperfusion. In the intervention groups an intracoronary bolus of 3 x 10(6) PMNs was applied in the second min of reperfusion, either in the absence or presence of 0.5 or 1 minimum alveolar concentration sevoflurane or isoflurane. The number of sequestered PMNs was calculated from the difference between coronary input and output (coronary effluent) of PMNs. Performance of external heart work, determined pre- and postischemically, served as criterion for recovery of myocardial function. Additionally, the expression of the integrin CD11b on the cell surface of PMN was measured before and after coronary passage.

RESULTS

Injection of PMN in the reperfusion phase, but not under nonischemic conditions, reduced recovery of external heart work significantly (from 55+/-7% to 19+/-11%). Addition of sevoflurane or isoflurane in concentrations of 0.5 and 1 minimum alveolar concentration to the perfusate reduced postischemic PMN adhesion from 36+/-8% to basal values (20+/-7%) and prevented decline of cardiac function. CD11b expression on PMNs increased significantly during postischemic coronary passage under control conditions. Again, both anesthetics in both concentrations inhibited that activation.

CONCLUSIONS

Volatile anesthetics reduce PMN adhesion in the reperfused coronary system and thereby preserve cardiac function. Reduced expression of the adhesion molecule CD11b on PMNs in the presence of sevoflurane or isoflurane is, at least in part, responsible for the cardioprotective effect.

Indirect enhancement of neutrophil activity and adhesion to cultured human umbilical vein endothelial cells by isoprostanes (iPF2alpha-III and iPE2-III)

Isoprostanes are metabolites of arachidonic acid found in blood under various conditions of oxidative stress. Because arachidonic acid derivatives are major mediators of inflammation, we investigated the potential inflammatory effects of iPF2alpha-III (previously 8-isoPGF2alpha) and iPE2-III (8-isoPGE2) on human polymorphonuclear granulocytes (PMN), as well as on human umbilical vein endothelial cells (HUVECs). The early activation marker CD11b on PMN and the adhesion molecules ICAM-1, E-selectin, and P-selectin on HUVECs were quantified by flow cytometry. Levels of the cytokines interleukin (IL)-6 and IL-8 were measured in the culture supernatant by enzyme-linked immunosorbent assay. Furthermore, adhesion of PMN to HUVECs was assessed. Neither isoprostane showed any direct stimulatory effects on PMN or HUVECs at concentrations of 0.1 or 1 microM: there was no acute elevation in expression of CD11b or P-selectin and no change of ICAM-1 or E-selectin after 4 or 24 h of incubation, respectively. The levels of interleukin IL-6 and IL-8 were also unaltered. However, PMN adhesion was significantly enhanced both after 4 and 24 h of incubation of HUVECs with iPF2alpha-III, and CD11b expression on PMN was elevated by contact of these cells with the supernatant of pre-exposed HUVECs. Neither of these actions were inhibited by an endothelin receptor antagonist (bosentan) or a combined thromboxane A2/isoprostane-receptor antagonist (SQ29548). Thus, although not having a direct pro-inflammatory potential, isoprostanes might indirectly accentuate PMN stimulation. This seems to occur via a receptor-independent mechanism, perhaps the production of an active metabolite of isoprostanes by endothelial cells.

Significant leukocyte and platelet retention during pulmonary passage after declamping of the aorta in CABG patients

During reperfusion of the heart and the lungs in patients undergoing coronary artery bypass grafting, these organs have been shown to release inflammatory mediators. The present study was performed to quantitatively determine cellular retention or washout during pulmonary passage in early reperfusion. In 14 consecutive patients undergoing coronary artery bypass grafting blood was simultaneously drawn from right atrium and pulmonary vein at 1, 10 and 20 min reperfusion. The counts for platelets, leukocytes and the leukocyte subsets polymorphonuclear neutrophils (PMN), lymphocytes and monocytes were determined. Pulmonary veno-right atrial (transpulmonary) differences are given in percent with respective right atrial values being considered as 100%. Before CPB leukocyte counts were 4.7 +/- 0.5 in right atrium and 4.2 +/- 0.4 in pulmonary vein, x10(9)/l, resp. (transpulmonary difference of -8 +/- 3%). During reperfusion, pulmonary retention was in the range of 20-23% (p <0.01 vs. right atrial value). The basal values for PMN were 2.4 +/- 0.3 in right atrium and 1.9 +/- 0.3 in pulmonary vein, x10(9)/l, resp. (transpulmonary difference -15 +/- 8%). Thereafter, retention was in the range of 25-30% (p <0.01 vs. right atrium). Basal values for lymphocytes were 1.5 +/- 0.2 in right atrium and 1.6+/-0.3 in pulmonary vein, x10(9)/l, resp. (transpulmonary difference +6 +/- 10%). A tendency towards a washout of lymphocytes at 1 min reperfusion (+1 +/- 12%) was followed by retention of these cells at 10 and 20 min reperfusion (-14 +/- 12% and -10 +/- 5%, p <0.05 vs right atrium). Before ischemia monocyte counts were 0.7 +/- 0.2 in right atrium and 0.6 +/- 0.2 in pulmonary vein, x10(9)/l, resp. (transpulmonary difference -10 +/- 4%) and -9 +/- 9%, -27 +/- 12% (p <0.05 vs right atrium) and -22 +/- 14% at 1, 10 and 20 min reperfusion. During early reperfusion of the lungs after declamping of the aorta, significant amounts of leukocytes, platelets and the leukocyte subsets are retained in the pulmonary vascular bed. These retained cells may be responsible for the previously described pulmonary release of cytokines.

Inhibition of neutrophil activation by volatile anesthetics decreases adhesion to cultured human endothelial cells

BACKGROUND

Polymorphonuclear leukocytes (neutrophils, PMNs) have been shown to mediate vascular and tissue injury, leading to so-called systemic inflammatory response syndrome. The authors evaluated the effect of volatile anesthetics on neutrophil adhesion to human endothelial cells, focusing on whether the inhibitory effect observed is linked to an alteration in the function of endothelial cells or neutrophils.

METHODS

The adhesion of human PMNs was quantified using cultured human umbilical vein endothelial cells (HUVECs). The increase in the number of adhering PMNs was assessed when HUVECs (with 1 mM hydrogen peroxide), PMNs (with 10 nM N-formyl-methionyl-leucyl-phenylalanine), or both were prestimulated. To determine the influence of volatile anesthetics on the adhesion of PMNs, the experiments were performed in the absence or presence of 0.5, 1, and 2 minimum alveolar concentration halothane, isoflurane, or sevoflurane, whereby HUVECs, PMNs, or both were pretreated with gas.

RESULTS

Activation of HUVECs with hydrogen peroxide or stimulation of PMNs with N-formyl-methionyl-leucyl-phenylalanine resulted in a 2.5-fold increase in PMN adhesion. Preincubation of PMNs, separately, with halothane, isoflurane, or sevoflurane, respectively, abolished enhanced neutrophil adhesion to hydrogen peroxide-activated HUVECs and adhesion of PMNs prestimulated with N-formyl-methionyl-leucyl-phenylalanine to unstimulated HUVECs (maximal effect at 1 minimum alveolar concentration). No decrease in adhesion was detected when only HUVECs were pretreated with volatile anesthetics. Additional exposure of HUVECs and PMNs to volatile anesthetics had no inhibitory effect on adhesion greater than that seen when only PMNs were treated. Appropriately, the volatile anesthetics abolished the upward regulation of the adhesion molecule CD11b on PMNs (as evaluated at 1 minimum alveolar concentration each), whereas 1 minimum alveolar concentration halothane failed to affect the expression of P-selectin, an adhesion molecule on endothelial cells.

CONCLUSIONS

This study indicates that halothane, isoflurane, and sevoflurane inhibit neutrophil adhesion to human endothelial cells at concentrations relevant to anesthesia in a static system. The effects appear to be mediated by inhibition of PMN activation; that is, by attenuating the upward regulation of neutrophil CD11b.

S(+)-ketamine, but not R(-)-ketamine, reduces postischemic adherence of neutrophils in the coronary system of isolated guinea pig hearts

Polymorphonuclear neutrophils (PMN) play a crucial role in the initiation of reperfusion injury. In a previous study, we found that ketamine reduced the postischemic adherence of PMN to the intact coronary system of isolated guinea pig hearts. Because ketamine is a racemic mixture (1:1) of two optical enantiomers, we looked for possible differences in action between the stereoisomers. Seventy-six guinea pig hearts were perfused in the "Langendorff" mode under conditions of constant flow (5 mL/min) using modified Krebs-Henseleit buffer. After 15 min of global warm ischemia, freshly isolated human PMN (10(6)) were infused as a bolus into the coronary system during the second minute of reperfusion. PMN adhesion was expressed as the numeric difference between PMN recovered in the effluent and those applied. Series A hearts received 5 microM S(+), 5 microM R(-), or 10 microM racemic ketamine starting 20 min before ischemia and during reperfusion. In Series B hearts, 10 microM nitro-L-arginine, an inhibitor of NO synthase, was added to the perfusate. In Series C, PMN were preincubated for 15 min with 5 microM S(+)- or R(-)-ketamine. Coronary vascular leak was assessed by measuring the rate of formation of transudate on the epicardial surface. Ischemia/reperfusion without anesthetics increased coronary PMN adherence from 25.5% +/-2.3% (basal) to 35.3%+/-1.5% of the number applied. S(+)-ketamine reduced postischemic adherence in each series (A, 25.5%+/-5.1%; B, 22.5%+/-1.7%; C, 25.3%+/-7.7%), as did racemate (A, 26.4%+/-3.7%). Although 5 microM R(-)-ketamine had no effect on adhesion (A, 30.5%+/-6.7%; B, 34.3%+/-5.1%; C, 34.3%+/-4.3%), it significantly increased vascular leak in the presence of NOLAG. These findings indicate stereoselective differences in biological action between the two ketamine isomers: S(+)-ketamine inhibited PMN adherence, R(-)-ketamine worsened coronary vascular leak in reperfused isolated hearts.

IMPLICATIONS

In this study, we demonstrated stereoselective differences in the biologic action of the two ketamine isomers in an animal model of myocardial ischemia. Polymorphonuclear neutrophil adherence to the coronary vasculature after ischemia was inhibited by S(+)-ketamine, whereas R(-)-ketamine increased coronary vascular fluid leak.

Sodium nitroprusside during coronary artery bypass grafting: evidence for an antiinflammatory action

BACKGROUND

It was the aim of the present study to investigate whether a nitric oxide donor can reduce systemic inflammation and the cardiac inflammatory response during coronary artery bypass grafting with cardiopulmonary bypass.

METHODS

Patients undergoing elective coronary artery bypass grafting (n = 22) were randomly assigned to treatment with either sodium nitroprusside (0.5 microg x kg(-1) x min(-1)) or placebo (controls), both for the first 20 minutes of reperfusion. Interleukin-6 and interleukin-8 levels, the adhesion molecules CD41 and CD62 on platelets and CD41 on monocytes and PMN (as markers for coaggregate formation), CD11b on monocytes and PMN, as well as platelet and leukocyte counts were determined in radial artery and coronary sinus blood before cardiopulmonary bypass and during reperfusion (1, 5, 10, 25, and 35 minutes).

RESULTS

A reduction of systemic interleukin-6 levels (15.4+/-3.5 pg/mL, 36.7+/-5.9 pg/mL, and 46.8+/-8.0 pg/mL versus 33.4+/-7.7 pg/mL, 76.7+/-13.2 pg/mL, and 106.0+/-26.5 pg/mL, respectively, at 1, 25, and 35 minutes of reperfusion) and interleukin-8 (29.6+/-4.5 pg/mL versus 54.0+/-9.4, pg/mL, resp., at 35 minutes of reperfusion) resulted from treatment with sodium nitroprusside. No intracardiac production of interleukin-8 in sodium nitroprusside-treated patients (-1.1+/-0.4 pg/mL and -2.8+/-2.2 pg/mL, resp., for the coronary sinus-radial artery difference at 5 and 25 minutes of reperfusion) was observed, whereas cardiac production of interleukin-8 was present in controls (2.5+/-1.5 pg/mL and 5.5+/-2.8 pg/mL, resp.). Retention of platelet/leukocyte coaggregates occurred during coronary passage in controls (coronary sinus-radial artery difference for CD41-positive monocytes at 1 and 10 minutes of reperfusion, -16.3%+/-8.5% and -8.8%+/-2.6%, resp.). This was reduced in sodium nitroprusside-treated patients (with 5.8%+/-5.2% and 0.0%+/-3.2%). Retention of platelets in controls (ratio of coronary sinus to radial artery platelet count at 5 and 10 minutes of reperfusion, 88%+/-6% and 91%+/-5%) was compared to washout in treated patients (108%+/-6% and 113%+/-7%).

CONCLUSIONS

In patients undergoing routine coronary artery bypass grafting, administration of sodium nitroprusside during early reperfusion alleviates systemic inflammation and the cardiac inflammatory response.

Tumor necrosis factor-alpha contributes to ischemia- and reperfusion-induced endothelial activation in isolated hearts

-During myocardial reperfusion, polymorphonuclear neutrophil (PMN) adhesion involving the intercellular adhesion molecule-1 (ICAM-1) may lead to aggravation and prolongation of reperfusion injury. We studied the role of early tumor necrosis factor-alpha (TNF-alpha) cleavage and nuclear factor-kappaB (NF-kappaB) activation on ICAM-1 expression and venular adhesion of PMN in isolated hearts after ischemia (15 minutes) and reperfusion (30 to 480 minutes). NF-kappaB activation (electromobility shift assay) was found after 30 minutes of reperfusion and up to 240 minutes. ICAM-1 mRNA, assessed by Northern blot, increased during the same interval. Functional effect of newly synthesized adhesion molecules was found by quantification (in situ fluorescence microscopy) of PMN, given as bolus after ischemia, which became adherent to small coronary venules (10 to 50 microm in diameter). After 480 minutes of reperfusion, ICAM-1-dependent PMN adhesion increased 2.5-fold compared with PMN adhesion obtained during acute reperfusion. To study the influence of NF-kappaB on PMN adhesion, we inhibited NF-kappaB activation by transfection of NF-kappaB decoy oligonucleotides into isolated hearts using HJV-liposomes. Decoy NF-kappaB but not control oligonucleotides blocked ICAM-1 upregulation and inhibited the subacute increase in PMN adhesion. Similar effects were obtained using BB 1101 (10 microg), an inhibitor of TNF-alpha cleavage enzyme. These data suggest that ischemia and reperfusion in isolated hearts cause liberation of TNF-alpha, activation of NF-kappaB, and upregulation of ICAM-1, an adhesion molecule involved in inflammatory response after ischemia and reperfusion.