Characteristics of Health Care Settings Where Adolescents and Young Adults Receive Care for ALL

PURPOSE

Individuals diagnosed with cancer between 15 and 39 years (adolescent and young adult [AYA]) face unique vulnerability. Detail is lacking about care delivery for these patients, especially those with ALL. We address these knowledge gaps by describing AYA ALL care delivery details at National Cancer Institute Community Oncology Research Program (NCORP) (sub)affiliates by model of care.

METHODS

Participating institutions treated at least one AYA with ALL from 2012 to 2016. Study-specific criteria were used to determine the number of unique clinical facilities (CFs) per NCORP and their model of care (adult/internal medicine [IM], pediatric, mixed [both]). Surveys completed by NCORPs for each CF by model of care captured size, resources, services, and communication.

RESULTS

Among 84 participating CFs (adult/IM, n=47; pediatric, n=15; mixed, n=24), 34% treated 5-10 AYAs with ALL annually; adult/IM CFs more often treated <5 (adult/IM, 60%; pediatric, 40%; mixed, 29%). Referral decisions were commonly driven by an age/diagnosis combination (58%), with frequent ALL-specific age minimums (87%) or maximums (80%). Medical, navigational, and social work services were similar across models while psychology was available at more pediatric CFs (pediatric, 80%; adult/IM, 40%; mixed, 46%-54%). More pediatric or mixed CFs reported oncologists interacting with pediatric/adult counterparts via tumor boards (pediatric, 93%; adult/IM, 26%; mixed, 96%) or initiating contact (pediatric, 100%; adult/IM, 77%; mixed 96%); more pediatric CFs reported an affiliated counterpart (pediatric, 53%; adult, 19%). Most CFs reported no AYA-specific resources (79%) or meetings (83%-98%).

CONCLUSION

System-level aspects of AYA ALL care delivery have not been examined previously. At NCORPs, these characteristics differ by models of care. Additional work is ongoing to investigate the impact of these facility-level factors on guideline-concordant care in this population. Together, these findings can inform a system-level intervention for diverse practice settings.

Psychological distress and mental health care utilization among Hispanic/Latino survivors of adolescent and young adult cancer

PURPOSE

Survivors of adolescent and young adult (AYA) cancer experience psychological distress and insufficient access to mental health care. Few studies have investigated racial/ethnic disparities in psychological health outcomes in this population. This study compared psychological distress, mental health care use, and inability to afford mental health care between Hispanic/Latino survivors of AYA cancer and Hispanic/Latino controls.

METHODS

The National Health Interview Survey data (2010-2018) were analyzed to identify Hispanic/Latino survivors of AYA cancer and Hispanic/Latino age- and sex-matched non-cancer controls. Sociodemographic, chronic health, modifiable factors, and psychological outcomes were compared using chi-square tests. Logistic regression models with survey weights were used to assess the log-odds of psychological distress in relation to covariates, along with the cancer group. Interactions were evaluated between each variable and cancer group.

RESULTS

The study included 370 Hispanic/Latino survivors of AYA cancer (mean time since diagnosis = 12.34 years) and 3700 Hispanic/Latino controls. Compared to controls, survivors were more likely to report moderate/severe distress (OR = 2.23, p < 0.001), use of mental health care (OR = 2.11, p < 0.001) and inability to afford mental health care (OR = 3.05, p < 0.001). Forty-one percent of survivors reported moderate/severe distress and only 16% utilized mental health care. Among survivors, having more than two chronic health conditions and public insurance (compared to private insurance) were associated with the presence of moderate/severe distress. Among survivors experiencing moderate/severe distress, lack of insurance was associated with decreased utilization of mental health care.

CONCLUSIONS

Having cancer as an AYA may exacerbate disparities in psychological health within the Hispanic/Latino population.

Prevalence of Adverse Event Reporting in Adolescents and Young Adults Enrolled in Cancer Clinical Trials

PURPOSE

Survival for adolescents and young adults (AYAs) with cancer has improved over the past few decades, and targeted approaches are needed to further improve outcomes. Limited reports suggest that AYAs tolerate cancer treatment differently than older and younger patients. Lack of adverse event (AE) data prevents the optimization of treatment regimens for AYAs by maximizing drug delivery and minimizing treatment-related toxicity. The extent to which the frequency and severity of AEs are reported for AYAs in cancer trials is unknown.

METHODS

Using a retrospective, observational design we reviewed all phase II/III clinical trials published in 2021 that included cancer-directed therapy and enrolled at least one patient age 15-39 years diagnosed with one of the five common AYA cancers: breast cancer, colorectal cancer, Hodgkin lymphoma, non-Hodgkin lymphoma, or melanoma. The primary outcome was to determine the proportion of phase II/III trials that report AEs for the AYA population.

RESULTS

Of 2,540 publications identified, 182 were included in the final analysis. No studies reported AE data for AYAs separate from older adults. Given the lack of reporting of AEs by age, it was not possible to assess differences in AE frequency or severity or whether AEs were associated with differences in dose reductions, treatment delays, or discontinuation for AYAs.

CONCLUSION

Reporting of AEs for AYAs with cancer is absent in the public domain. Failure to account for differences in treatment tolerance between AYAs and older adults may lead to undertreatment or overtreatment and delay progress toward further improving outcomes for AYAs.

Left Ventricle Size Correlates with Peak Exercise Capacity in Pediatric Cancer Survivors Exposed to Anthracycline Chemotherapy

Cancer survivors exposed to anthracycline chemotherapy are at risk for developing cardiomyopathy, which may have delayed clinical manifestation. In a retrospective cross-sectional study, we evaluated the utility of cardiopulmonary exercise testing (CPET) for detecting early cardiac disease in 35 pediatric cancer survivors by examining the associations between peak exercise capacity (measured via percent predicted peak VO2) and resting left ventricular (LV) function on echocardiography and cardiac magnetic resonance imaging (cMRI). We additionally assessed the relationships between LV size on resting echocardiography or cMRI and percent predicted peak VO2 since LV growth arrest can occur in anthracycline-exposed patients prior to changes in LV systolic function. We found reduced exercise capacity in this cohort, with low percent predicted peak VO2 (62%, IQR: 53-75%). While most patients in our pediatric cohort had normal LV systolic function, we observed associations between percent predicted peak VO2 and echocardiographic and cMRI measures of LV size. These findings indicate that CPET may be more sensitive in manifesting early anthracycline-induced cardiomyopathy than echocardiography in pediatric cancer survivors. Our study also highlights the importance of assessing LV size in addition to function in pediatric cancer survivors exposed to anthracyclines.

Psychosocial impact of COVID-19 on caregivers and adolescents and young adult survivors of childhood cancer

BACKGROUND

Caregivers and adolescents and young adult (AYA) cancer survivors may be at greater psychosocial risk from the COVID-19 pandemic than healthy peers due to complex and traumatic medical histories. This study describes COVID-19-related event exposures, impact, and distress among a large sample of caregivers and AYA cancer survivors and the relationship of these variables to demographic and cancer characteristics.

PROCEDURE

From May 2020 to December 2021, 422 caregivers and 531 AYA survivors completed the COVID-19 Exposures and Family Impact Survey (CEFIS) and CEFIS-AYA, respectively. Total COVID-19-related exposures, average COVID-19-related impact, and COVID-19-related distress were calculated. Conventional content analysis was used to analyze free-text responses about the negative and positive effects of COVID-19.

RESULTS

Caregivers and AYA reported an average of 7.4-7.8 COVID-19 exposures to pandemic-related events and a slightly negative impact of COVID-19 across psychosocial domains, with some positive impacts reported. COVID-19-related distress was moderate and clinically meaningful (4.9-5.2/10) for AYA and caregivers. Racial and ethnically minoritized AYA and caregivers reported higher COVID-19-related distress than non-Hispanic white caregivers. For AYA, distress was also higher among female, college-age (18-22 years), and long-term survivors compared with males, younger AYA, White and those recently off treatment. CEFIS outcomes remained relatively stable over time.

CONCLUSIONS

COVID-19 had a significant and consistent negative impact on caregivers and AYA survivors. Racial and ethnically minoritized families and female, college-age, and long-term AYA survivors may require additional psychosocial support. Assessing for COVID-19 impact and distress is important in pediatric oncology to evaluate adjustment and plan targeted interventions.

Abstract IA15: Mobile virtual human health care guides for young adult childhood cancer survivors

Since the mid-1990s, a significant scientific literature has evolved regarding the mental/physical health outcomes from the use of what we now refer to as Clinical Virtual Reality (VR). While the preponderance of clinical work with VR has focused on building immersive virtual worlds for treating anxiety disorders with exposure therapy, providing distracting immersive experiences for acute pain management, and supporting physical rehabilitation with game-based interactive content, there are other emerging areas that have extended the impact of VR in healthcare. One such area involves the recent technological advances that have led to the evolution of intelligent virtual human (VH) agents. VH representations can now be designed to perceive and act in a 3D virtual world, engage in face-to-face spoken dialogues with real users, and in some cases, can exhibit human-like emotional reactions. We have reported positive outcomes from studies using VHs in the role of virtual patients for training novice clinicians, as job interview/social skill trainers for persons on the autism spectrum, and as online health care support agents with university students and military veterans. The computational capacity now exists to deliver similar VH interactions by way of mobile device technology. This capability can support the “anywhere/anytime” availability of VH characters as agents for engaging users with clinical care information and could provide opportunities for improving access to care and emotional support for childhood cancer survivors (CCS). With a survivorship rate of over 83%, CCS are living longer, with estimates indicating that there will be over 500,000 CCS in the United States by 2020. However, CCS are at high risk for late effects of treatment, including recurring or secondary cancers, unhealthy lifestyle, disengagement from care, and the lack of the social support that has been shown to be vital for health and well-being. The majority of CCS will have at least one chronic condition by age 40. Moreover, existing initiatives to serve the needs of CCS have had limited success as these populations can be hard to reach and difficult to engage. We conducted two preliminary studies to inform development and evaluate the usefulness of a mobile app that included VH interaction and guidance to help CCS navigate survivorship and maintain health. In Study 1, two rounds of focus group interviews were conducted with 15 CCS aged 13-30 years. In Study 2, a pilot VH-driven app was developed using the information collected in Study 1. The app was downloaded, tested, and evaluated for one week by 60 CCS between the ages of 13-29 years. The results indicated that dynamic, accessible, engaging and survivor-focused VH approaches could address the needs of young, “digitally native” CCS. We will present a brief introduction to the clinical use of VHs within the VR context (Rizzo), followed by a discussion of a new mobile-enabled VH project designed to promote access to health care information and emotional support in young adult CCS (Spruijt-Metz).

Citation Format: Skip Rizzo, Donna Spruijt-Metz, Arno Hartholt, Bill Swartout, Kayla de la Haye, Joel Milam, David Freyer, Kimberly Miller, Anamara Ritt-Olson, Stacy Schepens-Niemiec, Shinyi Wu, Maryalice Jordan-Marsh, Amie Hwang, Anya Samek, Dennis Wixon, George Tolomiczenko, Kenneth Hayashida, Marientina Gotsis, Stefan Schneider, Swaroop Samek, Yaniv Bar-Cohen. Mobile virtual human health care guides for young adult childhood cancer survivors [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr IA15.

Effect of a Daily Text Messaging and Directly Supervised Therapy Intervention on Oral Mercaptopurine Adherence in Children With Acute Lymphoblastic Leukemia: A Randomized Clinical Trial

Importance

Suboptimal adherence to oral mercaptopurine treatment in children with acute lymphoblastic leukemia (ALL) increases the risk of relapse. A frequently expressed barrier to adherence is forgetfulness, which is often overcome by parental vigilance.

Objective

To determine whether a multicomponent intervention, compared with education alone, will result in a higher proportion of patients with ALL who have mercaptopurine adherence rates 95% or higher, for all study participants and among patients younger than 12 years and vs those aged 12 years and older.

Design, Setting, and Participants

The adherence intervention trial was an investigator-initiated, multi-institutional, parallel-group, unblinded, randomized clinical trial conducted between July 16, 2012, and August 8, 2018, at 59 Children's Oncology Group institutions in the US, enrolling patients with ALL diagnosed through age 21 years and receiving mercaptopurine for maintenance. The date of final follow-up was January 2, 2019. Data analysis was performed from February to October 2019.

Interventions

Patients were randomized 1:1 to education alone or the intervention package, which consisted of education and personalized text message reminders daily to prompt directly supervised therapy. Four weeks of baseline adherence monitoring were followed with a 16-week intervention.

Main Outcomes and Measures

The primary end point was the proportion of patients with adherence rates 95% or higher over the duration of the intervention for all study participants, and for those younger than 12 years vs those aged 12 years and older.

Results

There were 444 evaluable patients (median age, 8.1 years; interquartile range, 5.3-14.3 years), including 230 in the intervention group and 214 in the education group. Three hundred two patients (68.0%) were boys, 180 (40.5%) were non-Hispanic White, 170 (38.3%) were Hispanic, 43 (9.7%) were African American, and 51 (11.5%) were Asian or of mixed race/ethnicity. The proportion of patients with adherence rates 95% or higher did not differ between the intervention vs education groups (65% vs 59%; odds ratio, 1.33; 95% CI, 1.0-2.0; P = .08). Exploratory analyses showed that among patients aged 12 years and older, those in the intervention group had higher mean (SE) adherence rates than those in the education group (93.1% [1.1%] vs 90.0% [1.3%]; difference, 3.1%; 95% CI, 0.1%-6.0%; P = .04). In particular, among patients aged 12 years and older with baseline adherence less than 90%, those in the intervention group had higher mean (SE) adherence rates than those in the education group (83.4% [2.5%] vs 74.6% [3.4%]; difference, 8.8%; 95% CI, 2.2%-15.4%; P = .008). No safety concerns were identified.

Conclusions and Relevance

Although this multicomponent intervention did not result in an increase in the proportion of patients with ALL who had mercaptopurine adherence rates 95% or higher, it did identify a high-risk subpopulation to target for future adherence intervention strategies: adolescents with low baseline adherence.

Trial Registration

ClinicalTrials.gov Identifier: NCT01503632.

Depressive Symptoms and Quality of Life Among Adolescent and Young Adult Cancer Survivors: Impact of Gender and Latino Culture

Ethnic and sex variations in depressive symptoms and quality of life (QOL) among adolescent and young adult (AYA) childhood cancer survivors were explored among a sample of Latino and non-Latino childhood cancer survivors (CCSs) (n = 194) treated at hospitals in Los Angeles County. Latinos scored higher in depressive symptoms and lower in QOL when compared with non-Latinos. Males had higher depressive symptoms. Among Latinos, higher levels of acculturation were associated with depression and a poorer QOL, and we found that more acculturated Latino males were more likely to have meaningful levels of depression than less acculturated males or females. Interventions addressing depressive symptoms may be most needed for Hispanic male CCSs.

Long-term follow-up of endocrine function among young children with newly diagnosed malignant central nervous system tumors treated with irradiation-avoiding regimens

BACKGROUND

The adverse effects of irradiation on endocrine function among patients with pediatric brain tumor are well documented. Intensive induction chemotherapy followed by marrow-ablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) without central nervous system (CNS) irradiation has demonstrated efficacy in a proportion of very young children with some malignant CNS tumors. This study assessed the long-term endocrine function of young children following chemotherapy-only treatment regimens.

PROCEDURES

A retrospective chart review was performed on 99 patients under 6 years of age with malignant brain tumors newly diagnosed between May 1991 and October 2010 treated with irradiation-avoiding strategies. Thirty patients survived post-AuHCR without cranial irradiation for a mean of 8.1 years (range 3.0-22.25 years). The patient cohort included 18 males and 12 females (mean age at AuHCR of 2.5 years, range 0.8-5.1 years).

RESULTS

All 30 surviving patients had documented normal age-related thyroid function, insulin-like growth factor binding protein 3 (IGF-BP3), prolactin, testosterone, and estradiol levels. Insulin-like growth factor 1 age-related levels were abnormal in one child with normal height. Ninety-seven percent of patients had normal cortisol levels, while follicle-stimulating hormone and LH levels among females were normal in 83% and 92%, respectively, and in 100% of males. Growth charts demonstrated age-associated growth within 2 standard deviations of the mean in 67% of patients. Of 10 patients (33%) with short stature, 6 had proportional diminutions in both height and weight.

CONCLUSIONS

These findings demonstrate that the use of relatively brief, intensive chemotherapy regimens including marrow-ablative chemotherapy with AuHCR results in fewer endocrine sequelae than treatment schemes utilizing CNS irradiation.

A novel preventive therapy for paclitaxel-induced cognitive deficits: preclinical evidence from C57BL/6 mice

Chemotherapy-induced central nervous system (CNS) neurotoxicity presents an unmet medical need. Patients often report a cognitive decline in temporal correlation to chemotherapy, particularly for hippocampus-dependent verbal and visuo-spatial abilities. We treated adult C57Bl/6 mice with 12 × 20 mg kg^-1 paclitaxel (PTX), mimicking clinical conditions of dose-dense chemotherapy, followed by a pulse of bromodesoxyuridine (BrdU) to label dividing cells. In this model, mice developed visuo-spatial memory impairments, and we measured peak PTX concentrations in the hippocampus of 230 nm l^-1, which was sevenfold higher compared with the neocortex. Histologic analysis revealed a reduced hippocampal cell proliferation. In vitro, we observed severe toxicity in slowly proliferating neural stem cells (NSC) as well as human neuronal progenitor cells after 2 h exposure to low nanomolar concentrations of PTX. In comparison, mature post-mitotic hippocampal neurons and cell lines of malignant cells were less vulnerable. In PTX-treated NSC, we observed an increase of intracellular calcium levels, as well as an increased activity of calpain- and caspase 3/7, suggesting a calcium-dependent mechanism. This cell death pathway could be specifically inhibited with lithium, but not glycogen synthase kinase 3 inhibitors, which protected NSC in vitro. In vivo, preemptive treatment of mice with lithium prevented PTX-induced memory deficits and abnormal adult hippocampal neurogenesis. In summary, we identified a molecular pathomechanism, which invokes PTX-induced cytotoxicity in NSC independent of cell cycle status. This pathway could be pharmacologically inhibited with lithium without impairing paclitaxel's tubulin-dependent cytostatic mode of action, enabling a potential translational clinical approach.

Group-Wide, Prospective Study of Ototoxicity Assessment in Children Receiving Cisplatin Chemotherapy (ACCL05C1): A Report From the Children's Oncology Group

Purpose Optimal assessment methods and criteria for reporting hearing outcomes in children who receive treatment with cisplatin are uncertain. The objectives of our study were to compare different ototoxicity classification systems, to evaluate the feasibility of including otoacoustic emissions and extended high frequency audiometry, and to evaluate a central review mechanism for audiologic results for cisplatin-treated children in the cooperative group setting. Patients and Methods Eligible participants were 1 to 30 years, with planned cisplatin-containing treatment. Hearing evaluations were conducted at baseline, before each cisplatin cycle, and at the end of therapy. Audiologic results were assessed and graded by the testing audiologist and by two central review audiologists using the American Speech-Language-Hearing Association Ototoxicity Criteria (ASHA), Common Terminology Criteria for Adverse Events, version 3.0 (CTCAE), and Brock Ototoxicity Grades (Brock). One central reviewer also used the International Society of Pediatric Oncology Ototoxicity Scale (SIOP). Results At the end of treatment, the prevalence of any degree of ototoxicity ranged from 40% to 56%, and severe ototoxicity ranged from 7% to 22%. Compared with CTCAE, SIOP detected significantly more ototoxicity ( P = .004), whereas Brock criteria detected significantly fewer patients with any or severe ototoxicity ( P < .001 for both). SIOP detected ototoxicity earlier than did the other scales. Agreement between the central reviewers and the institutional audiologist was almost perfect for ASHA and Brock, whereas the poorest agreement occurred with CTCAE. Conclusion The SIOP scale may be superior to ASHA, Brock, and CTCAE scales for classifying ototoxicity in pediatric patients who were treated with cisplatin. Future studies should evaluate inter-rater reliability of the SIOP scale.

Unsanctifying the sanctuary: challenges and opportunities with brain metastases

While the use of targeted therapies, particularly radiosurgery, has broadened therapeutic options for CNS metastases, patients respond minimally and prognosis remains poor. The inability of many systemic chemotherapeutic agents to penetrate the blood-brain barrier (BBB) has limited their use and allowed brain metastases to become a burgeoning clinical challenge. Adequate preclinical models that appropriately mimic the metastatic process, the BBB, and blood-tumor barriers (BTB) are needed to better evaluate therapies that have the ability to enhance delivery through or penetrate into these barriers and to understand the mechanisms of resistance to therapy. The heterogeneity among and within different solid tumors and subtypes of solid tumors further adds to the difficulties in determining the most appropriate treatment approaches and methods of laboratory and clinical studies. This review article discusses therapies focused on prevention and treatment of CNS metastases, particularly regarding the BBB, and the challenges and opportunities these therapies present.

Facilitating accrual to cancer control and supportive care trials: the clinical research associate perspective

Background

Accrual to Cancer Control and Supportive Care (CCL) studies can be challenging. Our objective was to identify facilitators and perceived barriers to successful Children’s Oncology Group (COG) CCL accrual from the clinical research associate (CRA) perspective.

Methods

A survey was developed that focused on the following features from the institutional perspective: (1) Components of successful accrual; (2) Barriers to accrual; (3) Institutional changes that could enhance accrual; and (4) How COG could facilitate accrual. The survey was distributed to the lead CRA at each COG site with at least 2 CCL accruals within the previous year. The written responses were classified into themes and sub-themes.

Results

57 sites in the United States (n = 52) and Canada (n = 5) were contacted; 34 (60%) responded. The four major themes were: (1) Staff presence and dynamics; (2) Logistics including adequate numbers of eligible patients; (3) Interests and priorities; and (4) Resources. Suggestions for improvement began at the study design/conception stage, and included ongoing training/support and increased reimbursement or credit for successful CCL enrollment.

Conclusions

The comments resulted in suggestions to facilitate CCL trials in the future. Soliciting input from key team members in the clinical trials process is important to maximizing accrual rates.

The evidence for the use of growth factors and active skin substitutes for the treatment of non-infected diabetic foot ulcers (DFU): a health technology assessment (HTA)

AIMS

Assessment of the safety, efficacy and effectiveness of growth factors alone or in combination with other technologies in the treatment of DFU including medical, economical, social, ethical and juridical aspects.

METHODS

We systematically searched relevant data bases limited to English and German language and publications since 1990. Review and assessment of the quality of publications followed methods conforming to widely accepted standards for evidence-based medicine and health economics.

RESULTS

We identified 25 studies comparing becaplermin, rhEGF, bFGF and the metabolically active skin grafts Dermagraft and Apligraf with standard wound care (SWC) alone or extracellular wound matrix. Study duration ranged from 12 to 20 weeks and the study population comprised between 17 and 382 patients. Treatment with becaplermin, rhEGF, Dermagraft and Apligraf resulted in a higher incidence of complete wound closure and shorter time to complete wound healing with statistically significant differences. Regarding the proportion of adverse events there was no difference between treatment groups. The methodological quality of the studies was affected by significant deficiencies. Economic evaluations showed becaplermin being cost-effective.

CONCLUSIONS

Add-on therapy with growth factors and active skin substitutes for treating uncomplicated DFU could be an alternative to SWC alone. For explicit recommendations further studies with stronger evidence are necessary.

CAD/CAM-produced surgical guides: Optimizing the treatment workflow

The increased availability of devices for 3D radiological diagnosis allows the more frequent use of CAD/CAM-produced surgical guides for implant placement. The conventional workflow requires a complex logistic chain which is time-consuming and costly. In a pilot study, the workflow of directly milled surgical guides was evaluated. These surgical guides were designed based on the fusion of an optical impression and the radiological data. The clinical use showed that the surgical guides could be accurately placed on the residual dentition without tipping movements. The conventional surgical guides were used as a control for the manual check of the deviation of the implant axis. The direct transfer of the digital planning data allows the fabrication of surgical guides in an external center without the need of physical transport, which reduces the logistic effort and expense of the central fabrication of surgical guides.

Ecstasy-induced cell death in cortical neuronal cultures is serotonin 2A-receptor-dependent and potentiated under hyperthermia

Studies on 3,4-methylenedioxymethamphetamine ("ecstasy")-induced neurotoxicity mainly focus on damage of serotonergic terminals. Less attention has been given to neuronal cell death produced by 3,4-methylenedioxymethamphetamine and other amphetamines in areas including the cortex, striatum and thalamus. In the present study we investigated 3,4-methylenedioxymethamphetamine-induced neurotoxicity in neuronal serum free cultures from rat cortex. Since 3,4-methylenedioxymethamphetamine intake induces hyperthermia in both animals and humans, the experiments were performed under normal (36.5 degrees C) and hyperthermic conditions (40 degrees C). Our findings showed a dose-, time- and temperature-dependent apoptotic cell death induced by 3,4-methylenedioxymethamphetamine in cortical neurons. 3,4-Methylenedioxymethamphetamine-induced damage was potentiated under hyperthermia. The neurotoxicity was reduced by the serotonin 2A-receptor antagonists, ketanserin and (2R,4R)-5-[2-[2-[2-(3-methoxyphenyl)ethyl]phenoxy]ethyl]-1-methyl-3-pyrrolidinol hydrochloride, in both normothermic and hyperthermic conditions. (+/-)-2,5-Dimethoxy-4-iodoamphetamine hydrochloride, a model agonist for the serotonin 2A-receptor, also induced a dose- and time-dependent apoptotic cell death. Again, protection was provided by ketanserin and (2R,4R)-5-[2-[2-[2-(3-methoxyphenyl)ethyl]phenoxy]ethyl]-1-methyl-3-pyrrolidinol hydrochloride against (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride-induced neurotoxicity, thereby indicating that the 3,4-methylenedioxymethamphetamine stimulation of the serotonin 2A-receptor leads to neurotoxicity. This study provides for the first time evidence that direct 3,4-methylenedioxymethamphetamine serotonin 2A-receptor stimulation leads to neuronal cortical death. alpha-Phenyl-N-tert-butyl nitrone a free radical scavenger and the nitric oxide synthase inhibitor Nomega-nitro-L-arginine as well as the NMDA-receptor antagonist MK-801 provided protection under normothermia and hyperthermia, thereby suggesting the participation of free radicals in 3,4-methylenedioxymethamphetamine-induced cell death. Since 3,4-methylenedioxymethamphetamine serotonin 2A-receptor agonistic properties lead to neuronal death, clinically available atypical antipsychotic drugs with serotonin 2A-antagonistic properties could be a valuable therapeutic tool against 3,4-methylenedioxymethamphetamine-induced neurodegeneration.

Successful nonoperative management of typhlitis in pediatric oncology patients

BACKGROUND/PURPOSE

The optimal management for typhlitis in pediatric oncology patients has not always been clear from the medical literature. Trends have varied between operative and nonoperative approaches. The aim of this study was to review the successful nonoperative management of these patients at our institution over the last decade to further clarify management guidelines for this difficult problem.

METHODS

Medical records of pediatric hematology and oncology patients up to 21 years of age with typhlitis diagnosed at the DeVos Children's Hospital from 1990 to 2000 were reviewed.

RESULTS

Twelve patients were included. Ten patients (83%) with computed tomography (CT) scans suggestive of the diagnosis were treated successfully nonoperatively. Management usually included bowel rest, antibiotics, and supplemental parenteral nutrition. Two patients (17%) in whom CT scans were not obtained underwent surgery for presumed appendicitis and pneumoperitoneum, respectively. Typhlitis was found incidentally. In the latter patient, the pneumoperitoneum resulted from a perforated jejunum caused by graft-versus-host disease. This patient died of septic complications and was the only mortality in the series (8%).

CONCLUSIONS

Pediatric cancer patients with typhlitis can be treated carefully nonoperatively with bowel rest, antibiotics, and supplemental nutrition. Usual indications for surgery (ie, perforation, clinical deterioration) still should be used. The early use of CT scanning helps to facilitate the diagnosis and may provide the ability to differentiate typhlitis from other abdominal diseases for which surgery would be indicated.

*NO and oxyradical metabolism in new cell lines of rat brain capillary endothelial cells forming the blood-brain barrier

To investigate the relevance of *NO and oxyradicals in the blood-brain barrier (BBB), differentiated and well-proliferating brain capillary endothelial cells (BCEC) are required. Therefore, rat BCEC (rBCEC) were transfected with immortalizing genes. The resulting lines exhibited endothelial characteristics (factor VIII, angiotensin-converting enzyme, high prostacyclin/thromboxane release rates) and BBB markers (gamma-glutamyl transpeptidase, alkaline phosphatase). The control line rBCEC2 (mock transfected) revealed fibroblastoid morphology, less factor VIII, reduced gamma-glutamyl transpeptidase, weak radical defence, low prostanoid metabolism, and limited proliferation. Lines transfected with immortalizing genes (especially rBCEC4, polyoma virus large T antigen) conserved primary properties: epitheloid morphology, subcultivation with high proliferation rate under pure culture conditions, and powerful defence against reactive oxygen species (Mn-, Cu/Zn-superoxide dismutase, catalase, glutathione peroxidase, glutathione) effectively controlling radical metabolism. Only 100 microM H2O2 overcame this defence and stimulated the formation of eicosanoids similarly as in primary cells. Some BBB markers were expressed to a lower degree; however, cocultivation with astrocytes intensified these markers (e.g., alkaline phosphatase) and paraendothelial tightness, indicating induction of BBB properties. Inducible NO synthase was induced by a cytokine plus lipopolysaccharide mixture in all lines and primary cells, resulting in *NO release. Comparing the cell lines obtained, rBCEC4 are stable immortalized and reveal the best conservation of properties from primary cells, including enzymes producing or decomposing reactive species. These cells can be subcultivated in large amounts and, hence, they are suitable to study the role of radical metabolism in the BBB and in the cerebral microvasculature.

Differential mechanisms of neuroprotection by 17 beta-estradiol in apoptotic versus necrotic neurodegeneration

The major goal of this study was to compare mechanisms of the neuroprotective potential of 17 beta-estradiol in two models for oxidative stress-independent apoptotic neuronal cell death with that in necrotic neuronal cell death in primary neuronal cultures derived from rat hippocampus, septum, or cortex. Neuronal apoptosis was induced either by staurosporine or ethylcholine aziridinium (AF64A), as models for necrotic cell death glutamate exposure or oxygen-glucose deprivation (OGD) were applied. Long-term (20 hr) pretreatment (0.1 microm 17 beta-estradiol) was neuroprotective in apoptotic neuronal cell death induced by AF64A (40 microm) only in hippocampal and septal neuronal cultures and not in cortical cultures. The neuroprotective effect was blocked by the estrogen antagonists ICI 182,780 and tamoxifen and the phosphatidylinositol 3-kinase (PI3-K) inhibitor LY294002. In glutamate and OGD-induced neuronal damage, long-term pretreatment was not effective. In contrast, short-term (1 hr) pretreatment with 17 beta-estradiol in the dose range of 0.5-1.0 microm significantly reduced the release of lactate dehydrogenase and improved morphology of cortical cultures exposed to glutamate or OGD but was not effective in the AF64A model. Staurosporine-induced apoptosis was not prevented by either long- or short-term pretreatment. The strong expression of the estrogen receptor-alpha and the modulation of Bcl proteins by 17 beta-estradiol in hippocampal and septal but not in cortical cultures indicates that the prevention of apoptotic, but not of necrotic, neuronal cell death by 17 beta-estradiol possibly depends on the induction of Bcl proteins and the density of estrogen receptor-alpha.

Melatonin is protective in necrotic but not in caspase-dependent, free radical-independent apoptotic neuronal cell death in primary neuronal cultures

To assess the neuroprotective potential of melatonin in apoptotic neuronal cell death, we investigated the efficacy of melatonin in serum-free primary neuronal cultures of rat cortex by using three different models of caspase-dependent apoptotic, excitotoxin-independent neurodegeneration and compared it to that in necrotic neuronal damage. Neuronal apoptosis was induced by either staurosporine or the neurotoxin ethylcholine aziridinium (AF64A) with a delayed occurrence of apoptotic cell death (within 72 h). The apoptotic component of oxygen-glucose deprivation (OGD) unmasked by glutamate antagonists served as a third model. As a model for necrotic cell death, OGD was applied. Neuronal injury was quantified by LDH release and loss of metabolic activity. Although melatonin (0.5 mM) partly protected cortical neurons from OGD-induced necrosis, as measured by a significant reduction in LDH release, it was not effective in all three models of apoptotic cell death. In contrast, exaggeration of neuronal damage by melatonin was observed in native cultures as well as after induction of apoptosis. The present data suggest that the neuroprotectiveness of melatonin strongly depends on the model of neuronal cell death applied. As demonstrated in three different models of neuronal apoptosis, the progression of the apoptotic type of neuronal cell death cannot be withhold or is even exaggerated by melatonin, in contrast to its beneficial effect in the necrotic type of cell death.

Role of nitric oxide in the ethylcholine aziridinium model of delayed apoptotic neurodegeneration in vivo and in vitro

The involvement of nitric oxide in neurodegenerative processes still remains incompletely characterized. Although nitric oxide has been reported to be an important mediator in neuronal degeneration in different models of cell death involving NMDA-receptor activation, increasing evidence for protective mechanisms has been obtained. In this study the role of nitric oxide was investigated in a model of NMDA-independent, delayed apoptotic cell death, induced by the neurotoxin ethylcholine aziridinium ethylcholine aziridinium both in vivo and in vitro. For the in vivo evaluation rats received bilateral intracerebroventricular injections of ethylcholine aziridinium (2nmol/ventricle) or vehicle. In the hippocampus a transient decrease in nitric oxide synthase activity occurred, reaching its lowest levels three days after ethylcholine aziridinium treatment (51.7+/-9.8% of controls). The decrease coincided with the maximal reduction in choline acetyltransferase activity as marker for the extent of cholinergic lesion. The effect of pharmacological inhibition of nitric oxide synthase was tested by application of various nitric oxide synthase inhibitors with different selectivity for the nitric oxide synthase-isoforms. Unspecific nitric oxide synthase inhibition resulted in a significant potentiation of the loss of choline acetyltransferase activity in the hippocampus measured seven days after ethylcholine aziridinium application, whereas the specific inhibition of neuronal or inducible nitric oxide synthase was ineffective. These pharmacological data are suggestive for a neuroprotective role of nitric oxide generated by endothelial nitric oxide synthase. In vitro experiments were performed using serum-free primary neuronal cell cultures from hippocampus, cortex and septum of E15-17 Wistar rat embryos. Ethylcholine aziridinium-application in a range of 5-80microM resulted in delayed apoptotic neurodegeneration with a maximum after three days as confirmed by morphological criteria, life-death assays and DNA laddering. Nitric oxide synthase activity in harvested cells decreased in a dose- and time-dependent manner. Nitric oxide production as determined by measurement of the accumulated metabolite nitrite in the medium was equally low in controls and in ethylcholine aziridinium treated cells (range 0.77-1.86microM nitrite). An expression of inducible nitric oxide synthase messenger RNA could not be detected by semiquantitative RT-PCR 13h after ethylcholine aziridinium application. The present data indicate that in a model of delayed apoptotic neurodegeneration as induced by ethylcholine aziridinium neuronal cell death in vitro and in vivo is independent of the cytotoxic potential of nitric oxide. This is confirmed by a decrease in nitric oxide synthase activity, absence of nitric oxide production and absence of inducible nitric oxide synthase expression. In contrast, evidence for a neuroprotective role of nitric oxide was obtained in vivo as indicated by the exaggeration of the cholinergic lesion after unspecific nitric oxide synthase inhibition by N-nitro-L-arginine methylester.

Induced hypothermia in experimental pneumococcal meningitis

Pneumococcal meningitis resulting from Streptococcus pneumoniae has a death rate of 28% in adults. In severe head injury and stroke, inflammatory changes and intracranial hypertension are improved by induced hypothermia, which also is neuroprotective. We hypothesized that moderate hypothermia ameliorates inflammatory changes in experimental pneumococcal meningitis. Wistar rats were cooled systemically, and meningitis was induced by pneumococcal cell wall components. The increase of regional cerebral blood flow in the meningitis animals was blocked by hypothermia at 6 hours. The reduction of intracranial pressure correlated with temperature. The influx of leukocytes into the cerebrospinal fluid and levels of tumor necrosis factor alpha in the cerebrospinal fluid were decreased. Cooling the animals 2 hours after meningitis induction to 30.5 degrees C was also protective. We conclude that hypothermia is a new adjuvant approach to reduce meningitis-induced changes, in particular intracranial pressure, in the early phase of the disease.

Cerebral endothelial cells release TNF-alpha after stimulation with cell walls of Streptococcus pneumoniae and regulate inducible nitric oxide synthase and ICAM-1 expression via autocrine loops

TNF-alpha, inducible NO synthase (iNOS), and ICAM-1 are considered to be key proteins in the inflammatory response of most tissues. We tested the hypothesis that cell walls of Streptococcus pneumoniae (PCW), the most common cause of adult bacterial meningitis, induce TNF-alpha, iNOS, and ICAM-1 expression in rat primary brain microvascular endothelial cell cultures. We detected TNF-alpha mRNA by RT-PCR already 1 h after stimulation with PCW, while TNF-alpha protein peaked at 4 h (9.4 +/- 3.6 vs 0.1 +/- 0.1 pg/microgram protein). PCW induced iNOS mRNA 2 h after stimulation, followed by an increase of the NO degradation product nitrite (18.1 +/- 4 vs 5.8 +/- 1.8 at 12 h; 18.1 +/- 4 vs 5.8 +/- 1.8 pmol/microgram protein at 72 h). The addition of TNF-alpha Ab significantly reduced nitrite production to 62.2 +/- 14.4% compared with PCW-stimulated brain microvascular endothelial cells (100%). PCW induced the expression of ICAM-1 (measured by FACS), which was completely blocked by TNF-alpha Ab (142 +/- 18.6 vs 97.5 +/- 12.4%; 100% unstimulated brain microvascular endothelial cells). Cerebral endothelial cells express TNF-alpha mRNA as well as iNOS mRNA and release the bioactive proteins in response to PCW. PCW-induced NO production is mediated in part by an autocrine pathway involving TNF-alpha, whereas ICAM-1 expression is completely mediated by this autocrine loop. By these mechanisms, cerebral endothelial cells may regulate critical steps in inflammatory blood-brain-barrier disruption of bacterial meningitis.

Tumour necrosis factor alpha induces only minor inflammatory changes in the central nervous system, but augments experimental meningitis

Although tumour necrosis factor alpha is said to play a key role in bacterial meningitis and other CNS diseases, the effects of this pro-inflammatory cytokine have only been studied in part and are incompletely understood. In a rat model, we investigated the effect of intracisternal injection of recombinant rat-specific tumour necrosis factor alpha (5, 35, 70 and 280 microg tumour necrosis factor alpha) (i) alone, (ii) combined with pneumococcal cell wall components, on regional cerebral blood flow, intracranial pressure, white blood cell count in the cerebrospinal fluid, and brain water content. Tumour necrosis factor a dose-dependently caused an increase in regional cerebral blood flow (up to 221 +/- 43% of baseline values) over the six hour observation period and mild cerebrospinal fluid leukocytosis; intracranial pressure and brain water content were unchanged. Hypothesizing that regional cerebral blood flow changes are dependent on nitric oxide, tumour necrosis factor alpha-induced regional cerebral blood flow increase was abolished by Aminoguanidine, a selective inhibitor of inducible nitric oxide synthase. Combination of the lowest tumour necrosis factor alpha dose and a low dose pneumococcal cell wall preparation magnified the inflammatory effect of both. We conclude that intrathecally injected tumour necrosis factor alpha alone results in only minor inflammatory changes, whereas it dramatically augments experimental meningitis.

Chemiluminescence detection of nitric oxide production from rat cerebral cortical endothelial cells in culture

Cultured brain microvascular endothelial cells have been used to study blood-brain barrier properties in vitro. Among several endothelial derived factors the gaseous free radical nitric oxide (NO) has been shown to regulate both vascular tone and blood-brain barrier permeability. Due to its short half-life and high reactivity with many other molecules, effects of NO have preferentially been investigated using NO synthase inhibitors, NO donors or, more recently, in NO synthase knock-out animals. In the present study we describe a rapid, sensitive and reliable protocol for chemiluminescence detection of NO2-, the stable oxydation product of NO, from the supernatant of rat cortical endothelial cells in culture. After suppression of inducible NOS activity brain endothelial cells showed low basal NO levels. After stimulation with calcium ionophore NO levels increased and were attenuated again by NOS blockade. NO release was also elicited by bradykinin or acetylcholine, albeit to a lesser extent. This protocol might prove useful to investigate calcium-dependent NO formation in cerebral endothelial cells and blood-brain barrier models in vitro. In principle, the same protocol can be applied to virtually any cell type in culture.

Lipopolysaccharide and pneumococcal cell wall components activate the mitogen activated protein kinases (MAPK) erk-1, erk-2, and p38 in astrocytes

Cell wall compounds of gram-positive bacteria are capable of inducing the biosynthesis of proinflammatory cytokines in CNS cells in a similar way as lipopolysaccharide (LPS) of gram-negative bacteria does. Astrocytes, which lack the CD14 LPS receptor, have also been shown to respond to LPS-stimulation by increased cytokine synthesis. However, almost nothing is known about signaling steps involved in this process. We have therefore examined signaling events in primary cultures of rat astrocytes and the human astrocytoma cell line U373MG, brought about by LPS and pneumococcal cell walls (PCW). Of particular interest to us was the tyrosine phosphorylation patterns and activation states of three members of the mitogen activated protein kinase (MAPK) family, i.e., extracellular signal-regulated protein kinase (erk)-1, erk-2, and the recently identified p38. We show that LPS and PCW initiate tyrosine phosphorylation and activation of erk-1, erk-2, and p38 in a dose-dependent fashion. Inhibitors of tyrosine phosphorylation were able to alleviate this effect and also blocked cytokine production of astrocytes. Both, LPS- and PCW-induced responses of astrocytic cells required the presence of soluble CD14 (sCD14) present in serum. Unraveling the signaling steps induced by bacterial compounds in cells of the CNS may potentially help to elucidate the pathomechanisms of meningitis and central nervous complications of sepsis and may offer options for novel treatment strategies.

Heparin inhibits leukocyte rolling in pial vessels and attenuates inflammatory changes in a rat model of experimental bacterial meningitis

Heparin is a natural proteoglycan that was first described in 1916. In addition to its well characterized effect on blood coagulation, it is becoming clear that heparin also modulates inflammatory processes on several levels, including the interference with leukocyte-endothelium interaction. Anecdotal observations suggest a better clinical outcome of heparin-treated patients with bacterial meningitis. The authors demonstrate that heparin, a glycosaminoglycan, inhibits significantly in the early phase of experimental pneumococcal meningitis the increase of 1) regional cerebral blood flow (125 +/- 18 versus 247 +/- 42%), 2) intracranial pressure (4.5 +/- 2.0 versus 12.1 +/- 2.2 mm Hg), 3) brain edema (brain water content: 78.23 +/- 0.33 versus 79.49 +/- 0.46%), and 4) influx of leukocytes (571 +/- 397 versus 2400 +/- 875 cells/microL) to the cerebrospinal fluid compared with untreated rats. To elucidate the possible mechanism of this observation, the authors investigated for the first time leukocyte rolling in an inflammatory model in brain venules by confocal laser scanning microscopy in vivo. Heparin significantly attenuates leukocyte rolling at 2, 3, and 4 hours (2.8 +/- 1.3 versus 7.9 +/- 3.2/100 microm/min), as well as leukocyte sticking at 4 hours (2.1 +/- 0.4 versus 3.5 +/- 1.0/100 microm/min) after meningitis induction compared with untreated animals. The authors conclude that heparin can modulate acute central nervous system inflammation and, in particular, leukocyte-endothelium interaction, a key process in the cascade of injury in bacterial meningitis. They propose to evaluate further the potential of heparin in central nervous system inflammation in basic and clinical studies.

Olfactory discrimination ability for aliphatic esters in squirrel monkeys and humans

Using a behavioral paradigm designed to simulate olfactory-guided foraging, the ability of five squirrel monkeys to distinguish iso-amyl acetate from n- and iso-forms of other acetic esters (ethyl acetate to decyl acetate) and from other esters carrying the iso-amyl group (iso-amyl propionate to iso-amyl capronate) was investigated. We found (i) that all five animals were clearly able to discriminate between all odor pairs tested; (ii) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length of both the aliphatic alcohol group and the aliphatic acid group of the esters; and (iii) that iso- and n-amyl acetate were perceived as qualitatively similar despite different steric conformation. Using a triple-forced choice procedure, 20 human subjects were tested on the same tasks in parallel and showed a very similar pattern of discrimination performance compared with the squirrel monkeys. Thus, the results of this study provide evidence of well-developed olfactory discrimination ability in squirrel monkeys for aliphatic esters and support the assumption that human and non-human primates may share common principles of odor quality perception.

Rapid Ca2+-dependent NO-production from central nervous system cells in culture measured by NO-nitrite/ozone chemoluminescence

We have established simple and reliable measurement of constitutive nitric oxide (NO) synthase-dependent nitrite formation in supernatants from primary central nervous system (CNS) cells in culture using NO-ozone chemoluminescence. We found that: (1) astrocytes, endothelial cells and cerebellar granule cells produce NO upon stimulation with the calcium ionophore A23187 (1 microM); (2) application of 100 microM glutamate for 2 min results in NO-production in cerebellar granule cells and cortical neurons. NO-formation upon application of 50 mM KCl was found in cortical neurons; (3) in cultivated cerebral endothelial cells, an inducible form of NO-synthase (iNOS) is found under standard culture conditions. This induction was blocked by dexamethasone applied for at least 48 h and stimulation of constitutive NOS was detectable while iNOS was inhibited. The activity of iNOS was selectively inhibited by application of aminoguanidine for 48 h. Our results suggest that all major CNS cells implied in cerebral blood flow regulation and neurovascular coupling are capable of rapidly producing the vasodilator NO upon intracellular increases of the universal second messenger calcium.

Pneumococcal cell wall components induce nitric oxide synthase and TNF-alpha in astroglial-enriched cultures

Astroglia and microglia, the most numerous cells in the central nervous system (CNS), have been shown to produce the inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) upon stimulation with the cytokines IFN-gamma, IL-1-beta, or bacterial lipopolysaccharides (LPS). However, it is not known whether gram-positive bacteria like Streptococcus pneumoniae cause astroglial cells to release nitric oxide (NO) and TNF-alpha. S. pneumoniae meningitis still has a high incidence and mortality in spite of antibiotic therapy. Cell wall components from S. pneumoniae (pneumococcal cell-wall components, PCW) and TNF-alpha have been shown to cause meningeal inflammation and cerebrovascular changes in experimental meningitis. Addition of PCW to cultured rat astroglial cells increased nitrite in the supernatant significantly after 24 h, from 17 +/- 21 to 133 +/- 62 nM/micrograms protein. Nitrite release was dose-dependent in a range shown to cause meningeal inflammation in vivo and was inhibited by the competitive NO synthase inhibitor NW-nitro-L-arginine (L-NA 10(-4 M)) and dexamethasone (10(-6 M)), with transcriptional and translational inhibition by actinomycin D and cycloheximide, respectively. PCW caused a significant increase in the release of TNF-alpha from astroglial cells after 4 h, from 2 +/- 3.5 pg/ml to 102 +/- 13.5 pg/ml, which was inhibited by dexamethasone (10(-6 M)). Our results suggest a role for astroglial-derived NO and TNF-alpha as mediators of vascular and inflammatory response in the early phase of experimental pneumococcal meningitis.

Global cerebral ischemia in the rat: online monitoring of oxygen free radical production using chemiluminescence in vivo

Using online in vivo chemiluminescence (CL), we studied for the first time continuously the production of reactive oxygen species (ROS) after global cerebral ischemia and the relationship of ROS production to CBF. In anesthetized rats equipped with a closed cranial window, the CL enhancer, lucigenin (1 mM), was superfused onto the brain topically. CL was measured through the cranial window with a cooled photomultiplier, and CBF was measured simultaneously with laser-Doppler flowmetry. Reperfusion after 10 min (n = 8) of global cerebral ischemia led to a CL peak to 188 +/- 77% (baseline = 100%) within 10 +/- 4 min. After 2 h of reperfusion, CL had returned to 102 +/- 28%. Reperfusion after 20 min (n = 8) of ischemia increased CL to 225 +/- 48% within 12 +/- 3 min. After 2 h, CL was still increased (150 +/- 44%, p < 0.05 compared with 10 min of ischemia). CL after 10 min of ischemia was neither affected by brain topical free CuZn-superoxide dismutase (SOD) (100 U/ml, n = 3) nor by i.v. administration of free CuZn-SOD (104 U/kg, followed by 104 U/kg/h, n = 3). The CBF hyperfusion peak on reperfusion preceded the CL peak in all experiments by several minutes. In additional in vitro experiments we investigated the source of CL: Intracellular loading of lucigenin was demonstrated in cultured CNS cells, and a very similar pattern of CL as in the in vivo preparation after ischemia developed in rat brain slices after 15 min of hypoxia, which was unaffected by free CuZn-SOD (100 U/ml) but strongly attenuated by liposome-entrapped CuZn-SOD. We conclude that lucigenin-enhanced CL is a promising tool to study ROS production continuously from the in vivo brain of experimental animals and brain slices, and that the CL signal most likely derives from the intracellular production of superoxide. The production of ROS is preceded by reperfusion, is burst-like, and is dependent on the duration of the ischemic interval.

Fucoidin, a polysaccharide inhibiting leukocyte rolling, attenuates inflammatory responses in experimental pneumococcal meningitis in rats

It is presumed that adjuvant therapy rather than new antibiotics will improve the prognosis of pneumococcal meningitis. We investigated the effect of fucoidin, a polysaccharide inhibiting leukocyte rolling, on inflammatory changes in experimental meningitis in rats. After induction of meningitis by pneumococcal cell wall components, regional cerebral blood flow and intracranial pressure increased over the observation period of 6 h. At the end of the experiments, cerebrospinal fluid pleocytosis and brain water content were higher in animals with meningitis than without. Fucoidin treatment in the meningitis group reduced all inflammatory changes, whereas fucoidin treatment of animals without meningitis increased blood white cell count, but had no effect on any other parameter. Our results confirm that selectins are involved in the early phase of pneumococcal meningitis and possibly are a target for adjunctive therapy.