Clinical Outcomes and Toxicity in Older Adults Receiving Chimeric Antigen Receptor T Cell Therapy

Chimeric antigen receptor T cell therapy (CAR-T) has transformed the treatment landscape for adults with relapsed/refractory hematologic malignancies, but few studies have examined outcomes in older adults. We aimed to evaluate clinical outcomes and treatment toxicity in older adults receiving CAR-T for hematologic malignancies and to describe outcomes and toxicities in older adults age 75+ years compared to those age 65 to 74 years. We conducted a retrospective analysis of 141 adult patients age 65+ years (46.1% age 75+ years) who received commercial CAR-T at Massachusetts General Hospital between December 2017 and June 2023. We abstracted clinical outcomes from a review of the electronic health record, including (1) toxicity (ie, cytokine release syndrome [CRS] and immune effector cell-associated neurotoxicity syndrome [ICANS]); (2) health care utilization; (3) overall survival (OS); and (4) event-free survival (EFS). We analyzed the association of age (65 to 74 years versus 75+ years) with toxicity and health care utilization using the Mann-Whitney U test for continuous variables and the Fisher exact test for categorical variables. We examined the association of age with OS and EFS using multivariable Cox regression, controlling for covariates. The median patient age was 77 years (range, 75 to 91 years) in the 75+ year group and 69 years (ranges, 65 to 74 years) in the 65 to 74 year group. There were no statistically significant differences between the 75+ year group and the 65 to 74 year group in the rates of CRS (75.4% versus 84.2%; P = .21), grade 3+ CRS (1.5% versus 6.6%; P = .24), ICANS (38.5% versus 48.7%; P = .24), grade 3+ ICANS (16.9% versus 21.1%; P = .49), or infections (23.1% versus 29.0%; P = .45). There were no significant between-group differences in hospital readmissions within 30 days of CAR-T (10.8% versus 21.1%; P = .11), intensive care unit admissions within 30 days of CAR-T (7.7% versus 9.2%; P = 1.000), or median hospital length of stay (13 days versus 14 days; P = .29) among age groups. In a multivariable Cox regression analysis controlling for CAR-T product, Eastern Cooperative Oncology Group Performance Status, lactate dehydrogenase level, bridging therapy use, and history of deep venous thromboembolism, age 75+ years was not associated with OS (hazard ratio [HR], .95; P = .86) or EFS (HR, 1.28; P = .30). We identified favorable OS and toxicity outcomes across age categories in older adults receiving CAR-T for B cell non-Hodgkin lymphoma or multiple myeloma, underscoring that age alone is not a contraindication for CAR-T.

A novel psychosocial virtual reality intervention (BMT-VR) for patients undergoing hematopoietic stem cell transplantation: Pilot randomized clinical trial design and methods

BACKGROUND

Although patients undergoing hematopoietic stem cell transplantation (HSCT) must cope with psychological distress and isolation during an extended transplant hospitalization, psychosocial interventions to address these unmet needs are lacking. Virtual reality offers an innovative modality to deliver a patient-centered psychosocial intervention to address psychosocial needs of patients undergoing HSCT. However, there are currently no supportive care interventions leveraging virtual reality in patients undergoing HSCT.

OBJECTIVE

To describe the methods of a randomized clinical trial (RCT) to assess the feasibility and preliminary efficacy of a self-administered, virtual reality-delivered psychosocial intervention (BMT-VR) to improve psychological distress and quality of life (QOL) for patients hospitalized for HSCT.

METHODS

This study entails a single-center RCT of BMT-VR compared to usual transplant care in 80 patients hospitalized for HSCT. Adult patients with hematologic malignancies hospitalized for autologous or allogeneic HSCT are eligible. BMT-VR includes psychoeducation about the HSCT process, psychosocial skill building to promote effective coping and acceptance, and self-care and positive psychology skills to promote post-HSCT recovery. The primary aim is to assess the feasibility defined a priori as ≥60% of eligible patients enrolling in the study, and of those enrolled and randomized to the BMT-VR, ≥ 60% completing 4/6 BMT-VR modules. Secondary objectives include assessing the preliminary effects on psychological distress and QOL.

DISCUSSION

This is the first RCT of a virtual reality-delivered psychosocial intervention for the HSCT population. If deemed feasible, a future larger multi-site clinical trial can evaluate the efficacy of BMT-VR on outcomes for patients hospitalized for HSCT.

Coping in patients with hematologic malignancies undergoing hematopoietic cell transplantation

ABSTRACT

Patients undergoing hematopoietic cell transplantation (HCT) must cope with physical and psychological symptoms. Yet, studies examining pre-HCT coping are limited. We aimed to characterize pre-HCT coping, evaluate the association of coping with baseline quality of life (QOL) and psychological distress, and identify sociodemographic factors associated with pre-HCT coping. We conducted a cross-sectional analysis of baseline data from a multisite randomized supportive care intervention trial among patients with hematologic malignancies undergoing allogeneic or autologous HCT. We assessed patient-reported QOL, psychological distress, and coping within 72 hours of admission for HCT. We used the median split method to dichotomize coping and multivariate regression analyses to characterize the association of coping with psychological distress and QOL. Of patients awaiting HCT (n = 360; mean age, 55.4 years; 49.7% autologous), 43.5% were high users of approach-oriented coping, whereas 31.3% were high users of avoidant coping. Patients reported high use of emotional support (60.9%), acceptance (51.2%), self-blame (33%), and denial (31.3%). Older age (≥65 years) was associated with less frequent use of avoidant coping (odds ratio, 0.5; P = .01). Approach-oriented coping was associated with better pre-HCT QOL (Beta(B) = 6.7; P = .001), and lower depression (B = -1.1; P = .001) and anxiety (B = -0.9; P = .02) symptoms. Avoidant coping was associated with worse pre-HCT QOL (B = -13.3; P < .001) and symptoms of depression (B = 1.9; P < .001), anxiety (B = 3.1; P < .001), and posttraumatic stress disorder (B = 8.1; P < .001). Pre-HCT coping is strongly associated with psychological distress and QOL. These data support the need for interventions to address coping during HCT hospitalization. This clinical trial was registered at www.clinicaltrials.gov as #NCT03641378.

Protocol for multi-site randomized trial of inpatient palliative care for patients with hematologic malignancies undergoing hematopoietic stem cell transplantation

BACKGROUND

Patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT) commonly experience debilitating physical and psychological symptoms during a 3-4-week-hospitalization. During hospitalization, caregivers (i.e., family and friends) also endure immense emotional stress as they witness their loved one struggle with HSCT toxicities. Yet interventions to improve quality of life (QOL) and reduce psychological distress during HSCT are limited.

METHODS

We are conducting a multi-site randomized controlled trial of inpatient integrated palliative and transplant care versus usual care in 360 patients hospitalized for HSCT and their caregivers at three academic centers. Intervention participants meet with a palliative care clinician at least twice weekly during the HSCT hospitalization to address their physical and psychological symptoms. Patients assigned to usual care receive all supportive care measures provided by the HSCT team and could be seen by palliative care upon request. We assess patient QOL (Functional Assessment of Cancer Therapy (FACT) - Bone Marrow Transplant), depression and anxiety symptoms (Hospital Anxiety and Depression Scale), post-traumatic stress (PTSD) symptoms (PTSD checklist), symptom burden (Edmonton Symptom Assessment Scale), and fatigue (FACT-Fatigue) as well as caregiver-reported outcomes at baseline, 2 weeks, 3-months, 6-months, and 12-months post-HSCT. The primary endpoint is to compare QOL at week-2 during HSCT hospitalization between the two groups when patients typically experience their QOL nadir during HSCT.

CONCLUSIONS

This multi-site trial will define the role of palliative care for improving QOL and care for patients with hematologic malignancies undergoing HSCT and their caregivers.

AKI treated with kidney replacement therapy in critically Ill allogeneic hematopoietic stem cell transplant recipients

Acute kidney injury (AKI) is a frequent complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT), but few studies have focused on AKI treated with kidney replacement therapy (AKI-KRT), particularly among critically ill patients. We investigated the incidence, risk factors, and 90-day mortality associated with AKI-KRT in 529 critically ill adult allo-HSCT recipients admitted to the ICU within 1-year post-transplant at two academic medical centers between 2011 and 2021. AKI-KRT occurred in 111 of the 529 patients (21.0%). Lower baseline eGFR, veno-occlusive disease, thrombotic microangiopathy, admission to an ICU within 90 days post-transplant, and receipt of invasive mechanical ventilation (IMV), total bilirubin ≥5.0 mg/dl, and arterial pH <7.40 on ICU admission were each associated with a higher risk of AKI-KRT. Of the 111 patients with AKI-KRT, 97 (87.4%) died within 90 days. Ninety-day mortality was 100% in each of the following subgroups: serum albumin ≤2.0 g/dl, total bilirubin ≥7.0 mg/dl, arterial pH ≤7.20, IMV with moderate-to-severe hypoxemia, and ≥3 vasopressors/inotropes at KRT initiation. AKI-KRT was associated with a 6.59-fold higher adjusted 90-day mortality in critically ill allo-HSCT vs. non-transplanted patients. Short-term mortality remains exceptionally high among critically ill allo-HSCT patients with AKI-KRT, highlighting the importance of multidisciplinary discussions prior to KRT initiation.

Positive Psychological Well-Being in Hematopoietic Stem Cell Transplantation Survivors

Positive thoughts and emotions contribute to overall psychological health in diverse medical populations, including patients undergoing HSCT. However, few studies have described positive psychological well-being (eg, optimism, gratitude, flourishing) in patients undergoing HSCT using well-established, validated patient-reported outcome measures. We conducted cross-sectional secondary analyses of baseline data in 156 patients at 100 days post-HSCT enrolled in a randomized controlled trial of a psychological intervention (ClinicalTrials.gov identifier NCT05147311) and a prospective study assessing medication adherence at a tertiary care academic cancer center from September 2021 to December 2022. We used descriptive statistics to outline participant reports of positive psychological well-being (PPWB) using validated measures for optimism, gratitude, positive affect, life satisfaction, and flourishing. The participants had a mean age of 57.4 ± 13.1 years, and 51% were male (n = 79). Many, but not all, participants reported high levels of PPWB (ie, optimism, gratitude, positive affect, life satisfaction, and flourishing), defined as agreement with items on a given PPWB measure. For example, for optimism, 29% of participants did not agree that "overall, I expect more good things to happen to me than bad." Aside from life satisfaction, mean PPWB scores were higher in the HSCT population than in other illness populations. Although many patients with hematologic malignancies undergoing HSCT report high levels of PPWB, a substantial minority of patients reported low PPWB (i.e., no agreement with items on a given PPWB measure). Because PPWB is associated with important clinical outcomes in medical populations, further research should determine whether an intervention to promote PPWB can improve quality of life in HSCT recipients.

Quality of Life, Physical Functioning, and Psychological Distress of Older Adults Undergoing Hematopoietic Stem Cell Transplantation

BACKGROUND

With advances in therapies for hematologic cancers, older adults increasingly undergo hematopoietic stem cell transplantation (HSCT). Older adults may potentially experience an exaggerated burden of toxicity from HSCT. Studies examining the quality of life (QOL), physical functioning, and psychological symptom trajectory for older adults undergoing HSCT are limited.

OBJECTIVES

Our primary aim was to describe the trajectory of QOL, physical functioning, and psychological distress of older adults undergoing HSCT. Secondarily, we aimed to compare the trajectory of QOL, physical functioning, and psychological distress of older and younger adults undergoing HSCT and to evaluate factors associated with QOL trajectory in older adults undergoing HSCT.

STUDY DESIGN

We conducted secondary analyses of two prospective studies conducted at Massachusetts General Hospital. From 2011 to 2016, we enrolled 250 adults undergoing allogeneic or autologous HSCT. Older age was defined as age ≥ 65 years. We collected patient reported outcomes (PROs) within 72 hours of admission for HSCT, at hematologic nadir (2 weeks), and at 6 months post HSCT. To assess QOL, physical functioning, and psychological symptoms, we used the Functional Assessment of Cancer Therapy - Bone Marrow Transplant (FACT-BMT), FACT-Trial Outcome Index (TOI), and Patient Health Questionnaire - 9 (PHQ9) respectively. We used the posttraumatic stress disorder (PTSD) Checklist-Civilian Version to assess PTSD symptoms. We fit linear mixed effects models to characterize trajectories of changes in PROs across timepoints and to evaluate baseline factors associated with QOL trajectories in older adults.

RESULTS

30.4% (76/250) of our cohort was 65 years or older. All older adults undergoing allogeneic HSCT received a reduced intensity conditioning regimen. At two weeks post-HSCT, older patients experienced a decline in QOL (Δ = -16.6, p< 0.001), physical functioning (Δ = -15.4, p<0.001) and an increase in depression symptoms (Δ=3.8, p<0.001). At six months post-HSCT, QOL (Δ = 1.4, p = 0.7), physical functioning (Δ = 1.7, p = 0.5), and depression symptoms (Δ = 0.4, p = 0.6) recovered to baseline values. At six months post-HSCT, the proportion of older patients with PTSD symptoms increased from 5.3% (4/76) at baseline to 13.2% (10/76). There was no significant difference in slopes or trajectories of PROs between older and younger patients. In older adults, baseline psychological distress was associated with significantly worse QOL trajectory (Δ= -21.6, p = <0.001).

CONCLUSION(S)

Older adults experienced a sharp decline in QOL and physical functioning and an increase in depression symptoms within two weeks of HSCT hospitalization. Baseline psychological distress was associated with a pronounced worsening in post-HSCT QOL trajectory. These findings underscore the need for supportive care interventions to improve the experience of older adults undergoing HSCT.

Relationship Between Longitudinal Coping Strategies and Outcomes in Patients With Acute Myeloid Leukemia

Background: Patients with acute myeloid leukemia (AML) face an abrupt life-threatening illness and experience immense physical and psychological symptoms. However, no data describe how patients with AML cope longitudinally with their illness or the relationship between longitudinal coping and outcomes. Methods: We conducted a secondary analysis of longitudinal data from 160 patients with high-risk AML enrolled in a supportive care intervention trial to describe coping strategies longitudinally across the illness course. We used the Brief COPE questionnaire, the Hospital Anxiety and Depression Scale, the Post-Traumatic Stress Disorder (PTSD) Checklist-Civilian Version, and the Functional Assessment of Cancer Therapy-Leukemia to measure coping strategies, psychological distress, and quality of life (QoL) at baseline and at weeks 2, 4, 12, and 24 after diagnosis. Electronic health records were used to assess healthcare utilization and end-of-life (EoL) outcomes, and multivariate analyses were used to assess the relationship between coping and outcomes. Results: Longitudinal utilization of approach-oriented coping strategies was significantly associated with less distress (anxiety: β, –0.18; P<.001; depression symptoms: β, –0.42; P<.001; PTSD symptoms: β, –0.60; P<.001) and better QoL (β, 2.00; P<.001). Longitudinal utilization of avoidant coping strategies was significantly associated with greater distress (anxiety: β, 0.64; depression symptoms: β, 0.54; PTSD symptoms: β, 2.13; P<.001 for all) and worse QoL (β, –4.27; P<.001). Although the use of approach-oriented and avoidant coping strategies was not significantly associated with hospitalization, chemotherapy administration, or hospice use in the last 30 days of life, approach-oriented coping was associated with lower odds of ICU admissions (odds ratio, 0.92; P=.049). Conclusions: Longitudinal use of approach-oriented coping strategies was associated with less psychological distress, better QoL, and a lower likelihood of ICU admission, suggesting a possible target for supportive oncology interventions. Coping strategies did not impact EoL outcomes, and further research is needed to elucidate which patient factors impact EoL decision-making.

Psychological mobile app for patients with acute myeloid leukemia (AML): A randomized clinical trial

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Background: Patients with AML experience substantial decline in their quality of life (QOL) and mood during their hospitalization for intensive chemotherapy. Yet, few interventions have been developed to enhance patient-reported outcomes during treatment. Methods: We conducted a randomized trial of a psychological mobile app (DREAMLAND) for patients with a new diagnosis of AML receiving intensive chemotherapy at Massachusetts General Hospital and Dana-Farber Cancer Institute. Patients were randomly assigned to DREAMLAND or usual care. DREAMLAND was tailored to the AML trajectory and included four required modules focused on 1) supportive psychotherapy to help patients deal with the initial shock of diagnosis; 2) psychoeducation to manage illness expectations; 3) psychosocial skill-building to promote effective coping; and 4) self-care. The primary endpoint was feasibility defined as at least 60% of eligible patients enrolling, and 60% of those enrolled completing at least 60% of the required modules. We assessed patient QOL (Functional-Assessment-of-Cancer-Therapy-Leukemia), psychological distress (Hospital-Anxiety-and-Depression-Scale [HADS] and Patient-Health-Questionnaire-9 [PHQ-9]), symptom burden (Edmonton-Symptom-Assessment-Scale), and self-efficacy (Cancer Self-Efficacy Scale) at baseline and day +20 post chemotherapy. We used ANCOVA to assess the effect of DREAMLAND on outcomes. Results: We enrolled 66.7% (60/90) of eligible patients and 62.1% completed ≥ 75% of intervention modules. At day +20 after intensive chemotherapy, patients randomized to DREAMLAND reported improved QOL (132.06 vs. 110.72, P = 0.001), lower anxiety (3.54 vs. 5.64, P = 0.010) and depression (HADS: 4.76 vs. 6.29, P = 0.121; PHQ-9: 4.62 vs. 8.35, P < 0.001) symptoms, and improved symptom burden (24.89 vs. 40.60, P = 0.007) and self-efficacy (151.84 vs. 135.43, P = 0.004) compared to the usual care group. Conclusions: A psychological mobile app for patients newly diagnosed with AML is feasible to integrate during hospitalization for intensive chemotherapy and may improve QOL, mood, symptom burden, and self-efficacy. Clinical trial information: NCT03372291.

Abstract P4-12-04: Healthcare utilization and symptoms among hospitalized patients with breast cancer

Background: Patients with breast cancer generally receive most of their care in an outpatient setting, but unplanned hospitalizations may occur to help manage uncontrolled symptoms. We sought to investigate healthcare utilization and symptoms among patients with breast cancer experiencing an unplanned hospitalization. Methods: We enrolled patients with cancer and unplanned hospitalizations from 9/2014 to 2/2017. The current study focuses on the patients with breast cancer in this cohort. Following hospital admission, we assessed patient-reported symptoms using the Edmonton Symptom Assessment System (ESAS). We reviewed the electronic health record to obtain information about patient demographics, clinical characteristics, healthcare utilization, and reasons for hospital admission (elicited from primary and secondary diagnoses listed on the hospitalization discharge summary). We examined the associations among patients’ symptoms, healthcare utilization (i.e., hospital length of stay and 90-day readmissions), and survival using regression models. Results: We identified 101 patients with breast cancer (median age=60 years [range 22-86]. In this cohort, 74% had metastatic breast cancer. Primary/secondary reasons for hospitalization included fever/infection (34%), pain (18%), dyspnea (12%), gastrointestinal diagnoses (constipation, diarrhea, bowel obstruction, biliary obstruction, ascites, 10%), nausea/vomiting (7%), failure to thrive (6%), pleural effusion (5%), renal failure (4%), blood clot (3%), cardiac diagnoses (atrial fibrillation, cardiomyopathy, 3%), lightheadedness/hypotension (3%), neurologic diagnoses (altered mental status, seizure, subdural hematoma, 3%), fracture (2%), lower extremity swelling (2%), and other (i.e., rash, ptosis, SVC syndrome, fall, 1% each). Table 1 describes the baseline ESAS symptoms collected upon hospital admission. The mean length of hospital stay was 6.2 days and 90-day readmission rates were 28%. Patient disposition post hospitalization included discharge to home (76%), post-acute care facility (12%), hospice (5%), and death in the hospital (6%). We found that patients’ ESAS-physical symptoms were associated with longer hospital length of stay (B=0.08, p=0.029), greater risk of death or readmission within 90-days (OR=1.07, p&lt;0.001), and worse overall survival (HR=1.04, p=0.001). Similarly, patients’ ESAS-total symptoms were associated with longer hospital length of stay (B=0.07, p=0.013), greater risk of death or readmission within 90-days (OR=1.05, p=0.001), and worse overall survival (HR=1.02, p=0.003). Conclusions: In this cohort of hospitalized patients with breast cancer, the majority had metastatic disease and presented with a high symptom burden. Unplanned admissions in these patients with breast cancer commonly occurred for fever/infection, pain, dyspnea, and gastrointestinal reasons. We identified novel associations among patients’ symptoms upon admission with their hospital length of stay, risk of readmissions/death, and overall survival. These findings highlight the need for timely outpatient interventions that address patient symptoms when seeking to enhance health care utilization and survival outcomes in this population.

Table 1.Baseline symptom% of patients with moderate or severe symptomsMedian ESAS scoreTiredness*90%8 (Severe)Pain*78%7 (Severe)Well-being76%5 (Moderate)Drowsiness*71%6 (Moderate)Lack of appetite*68%5 (Moderate)Anxiety61%5 (Moderate)Depression52%4 (Moderate)Nausea*45%2 (Mild)Shortness of breath*45%2 (Mild)Constipation*44%0 (None)Total ESAS scoreMedian score 47 Total ESAS_physical score. . Median score 34*components included in ESAS_physical score

Citation Format: Neelima Vidula, Emilia Kaslow-Zieve, Carolyn Qian, Isabel Neckermann, Eva Gaufberg, Charu Vyas, Richard Newcomb, Patrick C Johnson, Daniel Lage, Jennifer Shin, Ryan Nipp. Healthcare utilization and symptoms among hospitalized patients with breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-12-04.

Associations of patient-reported care satisfaction with symptom burden and healthcare use in hospitalized patients with cancer

BACKGROUND

Hospitalized patients with cancer often experience a high symptom burden, which may impact care satisfaction and healthcare utilization.

METHODS

We prospectively enrolled patients with cancer and unplanned hospitalizations from September 2014 to April 2017. Upon admission, we assessed patients' care satisfaction (FAMCARE items: satisfaction with care coordination and speed with which symptoms are treated) and physical (Edmonton Symptom Assessment System [ESAS]) and psychological (Patient Health Questionnaire-4 [PHQ-4]) symptoms. We used regression models to identify factors associated with care satisfaction and associations of satisfaction with symptom burden and hospital length of stay (LOS).

RESULTS

Among 1,576 participants, most reported being "satisfied"/ "very satisfied" with care coordination (90%) and speed with which symptoms are treated (89%). Older age (coordination: B < 0.01, P = 0.02, speed: B = 0.01, P < 0.01) and admission to a dedicated oncology service (B = 0.20, P < 0.01 for each) were associated with higher satisfaction. Higher satisfaction with care coordination was associated with lower ESAS-physical (B =  - 1.28, P < 0.01), ESAS-total (B =  - 2.73, P < 0.01), PHQ4-depression (B =  - 0.14, P = 0.02), and PHQ4-anxiety (B =  - 0.16, P < 0.01) symptoms. Higher satisfaction with speed with which symptoms are treated was associated with lower ESAS-physical (B =  - 1.32, P < 0.01), ESAS-total (B =  - 2.46, P < 0.01), PHQ4-depression (B =  - 0.14, P = 0.01), and PHQ4-anxiety (B =  - 0.17, P < 0.01) symptoms. Satisfaction with care coordination (B =  - 0.48, P = 0.04) and speed with which symptoms are treated (B =  - 0.44, P = 0.04) correlated with shorter LOS.

CONCLUSIONS

Hospitalized patients with cancer report high care satisfaction, which correlates with older age and admission to a dedicated oncology service. Significant associations among higher care satisfaction, lower symptom burden, and shorter hospital LOS highlight the importance of improving symptom management and care coordination in this population.

Patient-reported care satisfaction and symptom burden in hospitalized patients with cancer

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Background: Hospitalized patients with cancer often experience a high symptom burden, which may impact care satisfaction and healthcare utilization. However, research describing these patients’ care satisfaction, symptom burden, and health care use is lacking. We sought to investigate relationships among care satisfaction, physical and psychological symptom burden, and hospital length of stay (LOS) in hospitalized patients with cancer. Methods: We prospectively enrolled patients with cancer and unplanned hospitalizations from 9/2014 to 4/2017. Upon admission, we assessed patients’ care satisfaction (FAMCARE items: satisfaction with care coordination and the speed with which symptoms are treated) as well as their physical (Edmonton Symptom Assessment System [ESAS]) and psychological (Patient Health Questionnaire-4 [PHQ-4]) symptoms. We used regression models to identify factors associated with care satisfaction, and we also examined associations of care satisfaction with patients’ symptom burden and hospital length of stay (LOS). Results: Among 1,576 participants (median age = 65.0 years [range:19-96], 46.3% female, 70.9% with incurable cancer, 58.4% admitted to a dedicated oncology service), most reported being “satisfied” or “very satisfied” with care coordination (90.1%) and the speed with which symptoms are treated (89.0%). Older age (care coordination: B < 0.01, P = 0.022, speed with which symptoms are treated: B = 0.01, P = 0.001) and admission to a dedicated oncology service (B = 0.20, P < 0.001 for each) were associated with higher care satisfaction. Higher satisfaction with care coordination was associated with lower ESAS-physical (B = -1.28, P = 0.007), ESAS-total (B = -2.73, P < 0.001), PHQ4-depression (B = -0.14, P = 0.022), and PHQ4-anxiety (B = -0.16, P = 0.008) symptoms. Higher satisfaction with the speed with which symptoms are treated was associated with lower ESAS-physical (B = -1.32, P = 0.003), ESAS-total (B = -2.46, P < 0.001), PHQ4-depression (B = -0.14, P = 0.014), and PHQ4-anxiety (B = -0.17, P = 0.004) symptoms. Greater satisfaction with care coordination (B = -0.48, P = 0.040) and the speed with which symptoms are treated (B = -0.44, P = 0.041) were both associated with shorter LOS. Conclusions: Hospitalized patients with cancer report high care satisfaction, which correlates with older age and admission to a dedicated oncology service. Significant associations among higher care satisfaction, lower symptom burden, and shorter hospital LOS highlight the importance of improving symptom management and care coordination in this population.

Post-COVID-19 Syndrome (Long Haul Syndrome): Description of a Multidisciplinary Clinic at Mayo Clinic and Characteristics of the Initial Patient Cohort

OBJECTIVE

To describe characteristics of a series of patients reporting prolonged symptoms after an infection with coronavirus disease 2019 (COVID-19).

PATIENTS AND METHODS

This study describes the multidisciplinary COVID-19 Activity Rehabilitation Program, established at Mayo Clinic to evaluate and treat patients with post-COVID syndrome, and reports the clinical characteristics of the first 100 patients receiving evaluation and management during the timeframe of June 1, 2020, and December 31, 2020.

RESULTS

The cohort consisted of 100 patients (mean age, 45.4±14.2 years; 68% women; mean body mass index, 30.2 kg/m2; presenting a mean of 93 days after infection). Common preexisting conditions were respiratory (23%) and mental health, including depression and/or anxiety (34%). Most (75%) had not been hospitalized for COVID-19. Common presenting symptoms ware fatigue (80%), respiratory complaints (59%), and neurological complaints (59%) followed by subjective cognitive impairment, sleep disturbance, and mental health symptoms. More than one-third of patients (34%) reported difficulties in performing basic activities of daily living. Only 1 in 3 patients had returned to unrestricted work duty at the time of the analysis. For most patients, laboratory and imaging tests showed no abnormalities or were nondiagnostic despite debilitating symptoms. Most patients required physical therapy, occupational therapy, or brain rehabilitation. Face-to-face and virtual care delivery modalities were feasible.

CONCLUSION

Most of the patients did not have COVID-19-related symptoms that were severe enough to require hospitalization, were younger than 65 years, and were more likely to be female, and most had no preexisting comorbidities before severe acute respiratory syndrome coronavirus 2 infection. Symptoms including mood disorders, fatigue, and perceived cognitive impairment resulted in severe negative impacts on resumption of functional and occupational activities in patients experiencing prolonged effects.

Survival outcomes, treatment toxicity, and healthcare utilization in older adults with aggressive non-Hodgkin lymphoma (NHL)

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Background: Aggressive NHLs frequently affect older adults, and are often treated with intensive systemic therapy that is potentially curative but can cause substantial toxicities. Although balancing treatment efficacy with the risk of complications is critically important for older adults with NHL, few studies have described these patients’ survival outcomes, rates of toxicities, and healthcare utilization. Methods: We conducted a retrospective analysis of adults > 65 years diagnosed with aggressive NHL and treated with systemic therapy at Massachusetts General Hospital from 4/2000-7/2020. We abstracted patient demographic and clinical information, survival outcomes, treatment toxicity (rates and grade), and healthcare utilization outcomes (intensive care unit [ICU] admissions and unplanned hospitalizations within six months of treatment initiation) from the electronic health record. Using multivariable logistic regression, we examined patient and disease factors associated with rates of grade 3+ non-hematologic toxicity and unplanned hospitalization. Results: Of 295 patients (median age = 73 years [age 65-69: 32.5%; age 70-74: 26.1%; age 75-79: 20.0%; age 80+: 21.4%], 39.0% female), most had advanced stage disease (59.5%) and an ECOG performance status of 0 or 1 (83.1%). The most common diagnosis was de novo diffuse large B-cell lymphoma (DLBCL) or grade 3B follicular lymphoma (69.2%). Most common therapies were CHOP (65.8%) and EPOCH (17.0%) with or without Rituximab. With a median follow up of 5.9 years, 5-year overall survival (OS) was 74.2%. Among patients age 65-69, 70-74, 75-79, and 80+ years, 5-year OS by age group were 82.1%, 72.2%, 73.5%, and 66.3%, respectively. Overall, 42.4% had grade 3+ toxicity, while 8.1% had grade 4 or 5 toxicity. The rates of unplanned hospitalization and ICU admission during the first 6 months of therapy were 41.0% and 6.1%, respectively. In multivariable analysis, hypoalbuminemia (OR 4.22, 95%, p < 0.001) and number of comorbidities (OR 1.75, p < 0.001) were associated with a greater likelihood of grade 3+ toxicity. Hypoalbuminemia (OR 2.76, p = 0.003), number of comorbidities (OR 1.61, p = 0.001), and receipt of EPOCH (OR 5.41, p = 0.012) were associated with a greater likelihood of unplanned hospitalization. Conclusions: The majority of older adults receiving upfront therapy for aggressive NHL survive beyond 5 years, yet nearly half experience substantial treatment toxicities and unplanned hospitalizations. Our findings underscore the need to develop supportive care interventions to enhance the care experience for older adults with NHL.

Association between baseline geriatric domains and survival in older adults with chronic lymphocytic leukemia (CLL)

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Background: CLL is a disease that commonly affects older adults. Although the value of geriatric assessment is increasingly being recognized in older adults with cancer, few studies have examined the relationship between baseline geriatric domains and clinical outcomes in older adults with CLL. Methods: We conducted a secondary data analysis of 369 adults diagnosed with CLL and treated in a phase 3 randomized trial of patients age ≥65 with bendamustine plus rituximab versus ibrutinib plus rituximab versus ibrutinib alone. We evaluated geriatric domains of functional status (activities of daily living [ADL], instrumental activities of daily living [IADL], Timed “Up and Go,” and number of falls in last 6 months), psychological status (Mental Health Inventory), social activity (Medical Outcomes Study [MOS] Social Activity Survey), cognition (Blessed Orientation Memory Concentration Test), social support (MOS Social Support Tangible and Emotional/Informational subscales), and nutritional status ( > 5% weight loss in the preceding 6 months). We examined associations among baseline geriatric domains with overall survival (OS) and progression-free survival (PFS) using multivariable Cox regression models. Results: The median age of patients was 71 years (range: 65-89). Most were male (67.1%) and had an ECOG performance status of 0 or 1 (96.9%). In multivariable models, the following geriatric domains were significantly associated with OS: better functional status (ADL score: HR 0.67, p = 0.012; IADL score: HR 0.98, p = 0.007); social activity score (HR 0.97, p = 0.004); and nutritional status (HR 2.58, p = 0.008). Similarly, functional status (ADL score: HR 0.77, p = 0.028; IADL score: HR 0.99, p = 0.007); social activity score (HR 0.97, p < 0.001); and nutritional status (HR 2.87, p < 0.001) were all associated with PFS. Additionally, the number of impaired geriatric domains was also associated with OS (HR 1.50, p = 0.004) and PFS (HR 1.45, p < 0.001). Timed “Up and Go”, number of falls in last 6 months, psychological status, cognition, and social support were not significantly associated with clinical outcomes. Conclusions: Geriatric domains of functional status, social activity, and nutritional status were associated with OS and PFS in this cohort of older adults with CLL. These findings highlight the importance of assessing geriatric domains to identify high-risk patients with CLL who may benefit from additional support during their treatment.

Associations of Skeletal Muscle With Symptom Burden and Clinical Outcomes in Hospitalized Patients With Advanced Cancer

BACKGROUND

Low muscle mass (quantity) is common in patients with advanced cancer, but little is known about muscle radiodensity (quality). We sought to describe the associations of muscle mass and radiodensity with symptom burden, healthcare use, and survival in hospitalized patients with advanced cancer.

METHODS

We prospectively enrolled hospitalized patients with advanced cancer from September 2014 through May 2016. Upon admission, patients reported their physical (Edmonton Symptom Assessment System [ESAS]) and psychological (Patient Health Questionnaire-4 [PHQ-4]) symptoms. We used CT scans performed per routine care within 45 days before enrollment to evaluate muscle mass and radiodensity. We used regression models to examine associations of muscle mass and radiodensity with patients' symptom burden, healthcare use (hospital length of stay and readmissions), and survival.

RESULTS

Of 1,121 patients enrolled, 677 had evaluable muscle data on CT (mean age, 62.86 ± 12.95 years; 51.1% female). Older age and female sex were associated with lower muscle mass (age: B, -0.16; P<.001; female: B, -6.89; P<.001) and radiodensity (age: B, -0.33; P<.001; female: B, -1.66; P=.014), and higher BMI was associated with higher muscle mass (B, 0.58; P<.001) and lower radiodensity (B, -0.61; P<.001). Higher muscle mass was significantly associated with improved survival (hazard ratio, 0.97; P<.001). Notably, higher muscle radiodensity was significantly associated with lower ESAS-Physical (B, -0.17; P=.016), ESAS-Total (B, -0.29; P=.002), PHQ-4-Depression (B, -0.03; P=.006), and PHQ-4-Anxiety (B, -0.03; P=.008) symptoms, as well as decreased hospital length of stay (B, -0.07; P=.005), risk of readmission or death in 90 days (odds ratio, 0.97; P<.001), and improved survival (hazard ratio, 0.97; P<.001).

CONCLUSIONS

Although muscle mass (quantity) only correlated with survival, we found that muscle radiodensity (quality) was associated with patients' symptoms, healthcare use, and survival. These findings underscore the added importance of assessing muscle quality when seeking to address adverse muscle changes in oncology.

Cancer and thrombosis: new insights to an old problem

Venous thromboembolism (VTE) is a common complication in patients with cancer and portends a poor prognosis. Our understanding of the underlying pathophysiology of VTE in cancer has advanced since Trousseau first described hypercoagulability in patients with malignancy and Virchow described his famous triad of thrombosis formation. Malignancy itself induces a thrombophilic state by increasing the risk of venous stasis, endothelial injury and an imbalance of pro and anti-thrombotic factors leading to a hypercoaguable state. Additional insults to this thrombotic balance are introduced by patient-specific, treatment related and tumor-specific factors. The importance of understanding the factors associated with increased thrombosis in cancer is paramount in order to adequately identify patients who will benefit from thromboprophylaxis.

Relationships among skeletal muscle, symptom burden, health care use, and survival in hospitalized patients with advanced cancer

7006

Background: Loss of skeletal muscle mass (quantity) is common in patients with advanced cancer, but little is known about muscle density (quality). Hospitalized patients with advanced cancer are a highly symptomatic population at risk for the adverse effects of muscle loss. Thus, we sought to describe associations between muscle mass and density, symptom burden, health care use, and survival in these patients. Methods: We prospectively enrolled hospitalized patients with advanced cancer from 9/2014-4/2017. Upon admission, patients reported their physical (Edmonton Symptom Assessment System [ESAS]) and psychological (Patient Health Questionnaire 4 [PHQ4]) symptoms. We used computed tomography (CT) scans performed per routine care ≤45 days prior to enrollment to evaluate muscle mass and density at the level of the third lumbar vertebral body. We categorized patients as sarcopenic using validated sex specific cutoffs. We used regression models to examine associations between muscle mass and density and patients’ symptom burden, health care use, and survival. Results: Of 1,121 patients enrolled, 677 had evaluable CT scan data (mean age = 62.86±12.95 years; 51.1% female). The most common cancer types were gastrointestinal (36.8%) and lung (16.7%) cancer. Most met criteria for sarcopenia (64.0%). Older age and female sex were associated with lower muscle mass (age: B = -0.16, p < .01; female: B = -6.89, p < .01) and density (age: B = -0.33, p < 0.01; female: B = -1.66, p = .01), while higher BMI was associated with higher muscle mass (B = 0.58, p < .01) and lower muscle density (B = -0.61, p < .01). Higher muscle mass was significantly associated with improved survival (HR = 0.97, p < .01), but not with symptom burden or health care use. Higher muscle density was significantly associated with lower ESAS physical (B = -0.17, p = .02), ESAS total (B = -0.29, p < .01), PHQ4 depression (B = -0.03, p < .01) and PHQ4 anxiety (B = -0.03, p < .01) symptoms. Higher muscle density was also associated with decreased hospital length of stay (B = -0.07, p < .01), risk of readmission or death in 90 days (OR = 0.97, p < .01), and improved survival (HR = 0.97, p < .01). Conclusions: Most hospitalized patients with advanced cancer have muscle loss consistent with sarcopenia. We found that muscle mass (quantity) correlated with survival, whereas muscle density (quality) was associated with patients’ symptoms, health care use, and survival. These findings underscore the added importance of assessing muscle quality when seeking to address the adverse effects of muscle loss in oncology.

Patient-reported care satisfaction and symptom burden in hospitalized patients with cancer

2013

Background: Hospitalized patients with cancer often experience high symptom burden, which may impact their care satisfaction and use of health care services. Yet, studies describing these patients’ care satisfaction, symptom burden, and health care utilization are lacking. Methods: We prospectively enrolled patients with cancer and unplanned hospitalizations from 9/2014-4/2017. Upon admission, patients self-reported their care satisfaction (FAMCARE items asking about satisfaction regarding speed with which symptoms are treated and coordination of care) and physical (Edmonton Symptom Assessment System [ESAS]) and psychological (Patient Health Questionnaire 4 [PHQ4]) symptom burden. We used regression models to identify patient factors associated with care satisfaction. We also explored associations between patients’ care satisfaction, symptom burden, and hospital length of stay (LOS) in models adjusted for age, sex, marital status, comorbidity score, cancer type, cancer documented as curable/incurable, time since cancer diagnosis, and admission to a dedicated oncology service. Results: We enrolled 1,576 of 1,749 (90.1%) consecutive patients (mean age = 63.19±13.39 years, 46.3% female). Most reported being very satisfied/satisfied with the speed with which symptoms are treated (89.0%) and coordination of care (90.1%). Older age (B = 0.01, P < .02 for both) and admission to a dedicated oncology service (B = 0.20, P < .01 for both) were each independently associated with higher satisfaction with the speed with which symptoms are treated and coordination of care. Higher satisfaction with the speed with which symptoms are treated was associated with lower PHQ4 depression (B = -0.14, P = .01), PHQ4 anxiety (B = -0.11, P < .01), ESAS physical (B = -1.30, P < .01), and ESAS total (B = -2.44, P < .01) symptoms. Higher satisfaction with coordination of care was associated with lower PHQ4 depression (B = -0.14, P = .02), PHQ4 anxiety (B = -0.16, P < .01), ESAS physical (B = -1.30, P < .01), and ESAS total (B = -2.75, P < .01) symptoms. Satisfaction with the speed with which symptoms are treated (B = -0.47, P = .03) and coordination of care (B = -0.50, P = .03) were both associated with shorter hospital LOS. Conclusions: Most hospitalized patients with cancer reported high care satisfaction, which was associated with older age and admission to a dedicated oncology service. We found relationships among higher care satisfaction, lower symptom burden, and shorter hospital LOS, underscoring the importance of efforts to enhance symptom management and care coordination in this population.

Functional impairment on admission and associated symptom burden and health outcomes among hospitalized patients with advanced cancer

11554

Background: Hospitalized patients with cancer often have impaired function, as measured by activities of daily living (ADLs), related to age, comorbidities, and both cancer and treatment-related morbidity. However, the relationship between functional impairment and patients’ symptom burden and clinical outcomes has not been well described. Methods: We prospectively enrolled patients with advanced cancer with unplanned hospitalizations at an academic medical center. Upon admission, nurses assessed patients’ ADLs (mobility, feeding, bathing, dressing, and grooming). We used the Edmonton Symptom Assessment Scale (ESAS) and Patient Health Questionnaire-4 to assess physical and psychological symptoms, comparing symptom burden between patients with and without ADL impairment. We used regression models adjusted for age, sex, education, Charlson comorbidity index, months since advanced cancer diagnosis, and cancer type to assess the relationship between any ADL impairment on admission and hospital length of stay, the composite outcome of death or readmission within 90 days of discharge, and survival. Results: Among 932 patients, 40.2% had at least one ADL impairment. Patients with ADL impairment were older (Mean = 67.2 vs 60.8 years, p < 0.001), had higher Charlson comorbidity index (Mean = 1.1 vs 0.7, p < 0.001), and higher physical symptom burden (ESAS Physical Mean = 35.2 vs 30.9, p < 0.001). Those with ADL impairment were more likely to have moderate to severe constipation (46.7% vs. 36.0%, p < 0.01), pain (74.9% vs. 63.1%, p < 0.01), drowsiness (76.6% vs. 68.3%, p < 0.01), as well as symptoms of depression (38.3% vs. 23.6%, p < 0.01) and anxiety (35.9% vs. 22.4%, p < 0.01). In adjusted models, ADL impairment was associated with longer hospital length of stay (B = 1.30, p < 0.01), higher odds of death or readmission within 90 days (odds ratio = 2.26, p < 0.01), and higher mortality (hazard ratio = 1.73, p < 0.01). Conclusions: Hospitalized patients with advanced cancer who have functional impairment experience a significantly higher symptom burden and worse health outcomes compared to those without functional impairment. These findings highlight the need to assess and address functional impairment among this population to enhance their quality of life and care.

Association of impairments in activities of daily living (ADLs) with symptom burden, health care utilization, and survival among hospitalized patients with advanced cancer

203

Background: Hospitalized patients with cancer often have impaired ADLs related to age, comorbidities, and both cancer and treatment-related morbidity. However, the relationship between ADL impairment and patients’ symptom burden and clinical outcomes has not been well described. Methods: We prospectively enrolled patients with advanced cancer with unplanned hospitalizations at an academic medical center. Upon admission, nurses assessed patients’ ADLs (mobility, feeding, bathing, dressing, and grooming). We used the Edmonton Symptom Assessment Scale (ESAS) and Patient Health Questionnaire-4 to assess physical and psychological symptoms, comparing symptom burden between patients with and without ADL impairment. We used regression models adjusted for age, sex, education, Charlson comorbidity index, months since advanced cancer diagnosis, and cancer type to assess the relationship between any ADL impairment and hospital length of stay, the composite outcome of death or readmission within 90 days of discharge, and survival. Results: Among 932 patients, 40.2% had at least one ADL impairment. Patients with ADL impairment were older (67.2 vs. 60.8 years, p<0.001), had higher Charlson comorbidity index (1.1 vs. 0.7, p<0.001), and higher physical symptom burden (ESAS Physical 35.2 vs. 30.9, p<0.001). Those with ADL impairment were more likely to have moderate to severe constipation (46.7% vs. 36.0%, p<0.01), pain (74.9% vs. 63.1%, p<0.01), drowsiness (76.6% vs. 68.3%, p<0.01), as well as symptoms of depression (38.3% vs. 23.6%, p<0.01) and anxiety (35.9% vs. 22.4%, p<0.01). In adjusted models, ADL impairment was associated with longer hospital length of stay (B=1.30, p<0.01), higher odds of death or readmission within 90 days (odds ratio=2.26, p<0.01), and worse survival (hazard ratio=1.73, p<0.01). Conclusions: Hospitalized patients with advanced cancer who have ADL impairment experience a significantly higher symptom burden and worse health outcomes compared to those without ADL impairment. These findings highlight the need to assess and address ADL impairment among this population to enhance their quality of life and care.

Symptom burden in hospitalized patients with curable and incurable cancers

190

Background: Inpatient supportive care interventions are targeted to patients with advanced solid tumors due to perceived higher symptom burden. Yet, few studies have characterized symptom prevalence in hospitalized patients with curable cancers. We aimed to describe and compare symptom burden and palliative care utilization in hospitalized patients with curable and incurable cancers to determine the allocation of such supportive care resources. Methods: We conducted a single center study of 1549 patients (238 curable hematologic, 239 curable solid, 123 incurable hematologic, 949 incurable solid cancers) who experienced an unplanned hospitalization between 9/14 - 4/17. On admission, we assessed patients’ physical symptoms (Edmonton Symptom Assessment System) and psychological distress (Patient Health Questionnaire - 4 and Primary Care PTSD Screen). Results: The median number of moderate to severe symptoms reported by patients with curable hematologic, curable solid, incurable hematologic, and incurable solid cancers were 5 [3-6], 5 [3-7], 5 [4-6], and 6 [4-7], respectively. Most patients reported moderate to severe fatigue (83.6%, 82.9%, 81.3%, 86.9%). Table 1 depicts rates of psychological distress. In adjusted analyses patients with incurable solid cancers reported higher symptom burden (β = 7.6, p < 0.01), depression (β = 0.4, p = 0.01), and anxiety (β = 0.3, p = 0.03) symptoms, but no difference in PTSD symptoms. Among patients in top quartile of symptom burden, palliative care was consulted in 16.2%, 7.9%, 23.8%, and 49.6% (p < 0.01) of patients with curable hematologic, curable solid, incurable hematologic, and incurable solid cancers, respectively. Conclusions: Hospitalized patients with solid and hematologic cancers experience substantial physical and psychological symptoms regardless of the curability of their illness. Palliative care is rarely consulted for highly symptomatic patients with curable cancers. Inpatient supportive care interventions should target the needs of all highly symptomatic patients with cancer. [Table: see text]

The effect of red-blood-cell transfusion on fatigue in hospitalized patients with anaemia

BACKGROUND AND OBJECTIVE

Guidelines suggest that red-blood-cell transfusion decisions for most hospitalized patients be based on haemoglobin (Hb) concentration and the presence of symptoms of anaemia, including fatigue. However, studies differ in whether transfusion is associated with improvements in fatigue. One explanation is that the benefit of transfusion varies by baseline fatigue levels, which existing studies have not examined. The objective of this study was to determine whether the association between transfusion during hospitalization and improvements in fatigue 30 days postdischarge varies by baseline fatigue level.

METHODS

A prospective observational study of hospitalized general medicine patients with any Hb <9 g/dl. Patients with sickle cell anaemia and gastrointestinal bleeding were excluded since these diagnoses have alternative transfusion practices. Patients with depression were excluded because their fatigue is not primarily due to anaemia. Fatigue was measured during an in-person interview and a 30-day postdischarge phone interview. Hb values and receipt of a transfusion were collected from hospital administrative data. Linear regression was used to test associations between 'change in fatigue', Hb concentration and receipt of a transfusion.

RESULTS

Transfusion interacted with nadir Hb was associated with reduced fatigue postdischarge for patients with higher baseline fatigue (20% most fatigued: β = 12, P = 0·02; 10% most fatigued: β = 17, P = 0·02). Patients <50 years old with high baseline fatigue had large reductions in fatigue from transfusion (20%: β = 23, P = 0·02; 10%: β = 29, P = 0·03).

CONCLUSIONS

Transfusion during hospitalization is associated with reduced fatigue 30 days postdischarge in patients with higher levels of baseline fatigue.

Association Between Anemia and Fatigue in Hospitalized Patients: Does the Measure of Anemia Matter?

OBJECTIVE

To assess multiple Hb-based measures of anemia in hospitalized patients and test whether these are associated with fatigue.

DESIGN

Prospective observational study.

SETTING

Urban, academic medical center.

PATIENTS

Hospitalized general medicine patients, age =50 years, with any Hb < 9 g/dL.

MEASUREMENTS

Measures of anemia were created for each patient based on the Hb values from their hospitalization (mean, median, minimum, maximum, admission, and discharge). Fatigue was measured using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue subscale.

RESULTS

Seven hundred eighty-four patients participated. Minimum Hb was strongly associated with fatigue. Patients with a minimum Hb of < 8 g/dL had higher fatigue levels (mean FACIT [standard deviation] Hb < 7 g/dL: 25 [13], 7 g/ dL = Hb <8 g/dL: 25 [14] Hb =8 g/dL: 29 [14], P = 0.001) and were more likely to report high levels of fatigue (FACIT-Fatigue < 27) (56% vs 41%; P = 0.002). Mean Hb had a less robust association with fatigue than minimum Hb, and no other measure of Hb was associated with patients' fatigue levels.

CONCLUSIONS

Minimum Hb is associated with fatigue while hospitalized and may help identify patients for interventions to address anemia-related fatigue.

Profiles of glutamate and GABA efflux in core versus peripheral zones of focal cerebral ischemia in mice

Efflux of glutamate during cerebral ischemia is known to contribute to brain cell death via processes of excitotoxicity. However, gamma-aminobutyric acid (GABA) is also released during ischemia, and may be protective. In this study, we used in vivo microdialysis to map the efflux of glutamate and GABA from central core and peripheral zones of focal ischemia in mouse brain. We show that the temporal profiles of glutamate and GABA efflux are significantly different in core versus peripheral zones. Calculation of glutamate/GABA ratios demonstrate that, in the core, there is a significant increase above baseline ratios during the first 30 mm of ischemia, which then rapidly renormalizes. In contrast, no significant changes in glutamate/GABA ratios were seen in the ischemic periphery. These data suggest that imbalances in glutamate versus GABA efflux may be an initial trigger of excitotoxic brain damage in the core but not the peripheral zones of focal cerebral ischemia.

The acetylcholinesterase gene and organophosphorus resistance in the Australian sheep blowfly, Lucilia cuprina

Acetylcholinesterase (AChE), encoded by the Ace gene, is the primary target of organophosphorous (OP) and carbamate insecticides. Ace mutations have been identified in OP resistants strains of Drosophila melanogaster. However, in the Australian sheep blowfly, Lucilia cuprina, resistance in field and laboratory generated strains is determined by point mutations in the Rop-1 gene, which encodes a carboxylesterase, E3. To investigate the apparent bias for the Rop-1/E3 mechanism in the evolution of OP resistance in L. cuprina, we have cloned the Ace gene from this species and characterized its product. Southern hybridization indicates the existence of a single Ace gene in L. cuprina. The amino acid sequence of L. cuprina AChE shares 85.3% identity with D. melanogaster and 92.4% with Musca domestica AChE. Five point mutations in Ace associated with reduced sensitivity to OP insecticides have been previously detected in resistant strains of D. melanogaster. These residues are identical in susceptible strains of D. melanogaster and L. cuprina, although different codons are used. Each of the amino acid substitutions that confer OP resistance in D. melanogaster could also occur in L. cuprina by a single non-synonymous substitution. These data suggest that the resistance mechanism used in L. cuprina is determined by factors other than codon bias. The same point mutations, singly and in combination, were introduced into the Ace gene of L. cuprina by site-directed mutagenesis and the resulting AChE enzymes expressed using a baculovirus system to characterise their kinetic properties and interactions with OP insecticides. The K(m) of wild type AChE for acetylthiocholine (ASCh) is 23.13 microM and the point mutations change the affinity to the substrate. The turnover number of Lucilia AChE for ASCh was estimated to be 1.27x10(3) min(-1), similar to Drosophila or housefly AChE. The single amino acid replacements reduce the affinities of the AChE for OPs and give up to 8.7-fold OP insensitivity, while combined mutations give up to 35-fold insensitivity. However, other published studies indicate these same mutations yield higher levels of OP insensitivity in D. melanogaster and A. aegypti. The inhibition data indicate that the wild type form of AChE of L. cuprina is 12.4-fold less sensitive to OP inhibition than the susceptible form of E3, suggesting that the carboxylesterases may have a role in the protection of AChE via a sequestration mechanism. This provides a possible explanation for the bias towards the evolution of resistance via the Rop-1/E3 mechanism in L. cuprina.

Fitness, training, and the growth hormone-->insulin-like growth factor I axis in prepubertal girls

We recently demonstrated that a brief endurance type training program led to increases in thigh muscle mass and peak oxygen uptake (VO(2)) in prepubertal girls. In this study, we examined the effect of training on the GH-->insulin-like growth factor I (GH-->IGF-I) axis, a system known to be involved both in the process of growth and development and in the response to exercise. Healthy girls (mean age 9.17 +/- 0.10 yr old) volunteered for the study and were randomized to control (n = 20) and training groups (n = 19) for 5 weeks. Peak VO(2), thigh muscle volume, and blood samples [for IGF-I, IGF-binding proteins (IGFBP)-1 to -6, and GHBP] were measured. At baseline, IGF-I was significantly correlated with both peak VO(2) (r = 0.44, P < 0.02) and muscle volume (r = 0.58, P < 0.004). IGFBP-1 was negatively correlated with muscle volume (r = -0.71, P < 0.0001), as was IGFBP-2. IGFBP-4 and -5 were significantly correlated with muscle volume. We found a threshold value of body mass index percentile (by age) of about 71, above which systematic changes in GHBP, IGFBP-1, and peak VO(2) per kilogram were noted, suggesting decreases in the following: 1) GH function, 2) insulin sensitivity, and 3) fitness. Following the training intervention, IGF-I increased in control (19.4 +/- 9.6%, P < 0.05) but not trained subjects, and both IGFBP-3 and GHBP decreased in the training group (-4.2 +/- 3.1% and -9.9 +/- 3.8%, respectively, P < 0.05). Fitness in prepubertal girls is associated with an activated GH-->IGF-I axis, but, paradoxically, early in a training program, children first pass through what appears to be a neuroendocrine state more consistent with catabolism.

Muscle size and cardiorespiratory response to exercise in cystic fibrosis

The mechanism responsible for diminished exercise performance in cystic fibrosis (CF) is not clear. We hypothesized that reduced muscle size, rather than an intrinsic muscle defect, was the primary factor in such diminished exercise performance. Twenty-two subjects with CF (14 females and eight males, aged 6.5 to 17.7 yr, with FEV(1) of 46% to 111% predicted) participated in a study of this hypothesis, and were compared with healthy children tested in the same laboratory. Muscle size was estimated from midthigh muscle cross-sectional area (CSA) obtained by magnetic resonance imaging, and fitness was determined by progressive cycle ergometer exercise testing with breath-by-breath measurements of gas exchange. Peak oxygen consumption (V O(2)) was reduced in CF subjects (956 +/- 81 [mean +/- SEM] ml/min, as compared with 1,473 +/- 54 ml/min in controls; p < 0.00001). Surprisingly, CF subjects had a lower peak V O(2) per CSA (mean for CF subjects 70 +/- 3% predicted, p < 0.0001) than did controls, whereas muscle CSA in CF subjects was not significantly smaller than in controls. The scaling parameters of peak V O(2) and muscle CSA did not differ significantly between healthy controls (0.80 +/- 0.16) and CF subjects (1.03 +/- 0.12). Indexes of aerobic function that are less effort-dependent than peak V O(2) were also lower in the CF subjects (e.g., the slope of V O(2) versus work rate [WR] (DeltaV O(2)/DeltaWR) was 68 +/- 2% predicted; p < 0.005). The study data did not support the initial hypothesis, and suggest a muscle-related abnormality in oxygen metabolism in patients with CF.

Molecular phylogenetics of leafrollers application to DNA diagnostics

Accurate and rapid diagnosis of taxa whether they be welldefined species or biotypes is of crucial importance to quarantine pest management and research Recent developments in DNA technology has resulted in a range of molecular techniques being available for use in such applications We have employed a phylogenetically focussed approach in the development of a diagnostic key to distinguish a range of leafroller species (Lepidoptera Tortricidae) using DNA sequence data derived from a 23 kb region of the mitochondrial genome containing the genes cytochrome oxidase I and II Phylogenetic analysis has revealed clear relationships between taxa although the genus Apoctena does not appear monophyletic The most appropriate diagnostic characters are either those which are phylogenetically informative either synapomorphies or autapomorphies A standardised approach to data collection is advocated for future studies

Bioavailability of Ziconotide in brain: influx from blood, stability, and diffusion

Ziconotide is a selective peptide antagonist of the N-type calcium channel currently in clinical trials for analgesia. Ziconotide reached a maximal brain concentration of between 0.003 and 0.006% of the injected material per gram of tissue at 3-20 min after i.v. injection, and this decayed to below 0.001%/g after 2 h. The structurally distinct conopeptide SNX-185 (synthetic TVIA) was considerably more persistent in brain after i.v. administration, with 0.0035% of the injected material present at 2-4 h after i.v. injection, and 0.0015% present at 24 h. Similar results (i.e. greater persistence of SNX-185) were obtained when the peptides were perfused through in vivo dialysis probes implanted into the hippocampus. Image analysis and serial sectioning showed that diffusion of Ziconotide in the extracellular fluid around the dialysis probe was minimal, with the peptide located within 1 mm of the probe after 2 h. In vitro diffusion through cultured bovine brain microvessel endothelial cells (BBMEC) verified that a close structural analog of Ziconotide (SNX-194) passed through this blood-brain barrier (BBB) model as expected for peptides of similar physical properties (permeability coefficient of 6.5 x 10(-4) cm/g). Passage from blood to brain was also verified by in situ perfusion through the carotid artery. A statistically greater amount of radioactivity was found to cross the BBB after perfusion of radioiodinated Ziconotide compared to [14C]inulin. Capillary depletion experiments and HPLC analysis defined the brain location and stability.

A novel alpha-amylase gene is transiently upregulated during low temperature exposure in apple fruit

An alpha-amylase gene product was isolated from apple fruit by reverse-transcriptase PCR using redundant primers, followed by 5' and 3' RACE. The gene is a member of a small gene family. It encodes a putative 46.9 kDa protein that is most similar to an alpha-amylase gene from potato (GenBank accession M79328). In apple fruit this new gene was expressed at low levels, as detected by reverse-transcriptase PCR, in a number of plant tissues and during fruit development. Highest levels of mRNA for this transcript were observed 3 to 9 days after placing apple fruit at 0.5 degrees C. Phylogenetic analysis of amino acid sequence places the potato and apple proteins as a distinct and separate new subgroup within the plant alpha-amylases, which appears to have diverged prior to the split between monocotyledonous and dicotyledonous plants. These two divergent alpha-amylases lack the standard signal peptide structures found in all other plant alpha-amylases, and have sequence differences within the B-domain and C-domain. However, comparisons with structures of known starch hydrolases suggest that these differences are unlikely to affect the enzymatic alpha-1,4-amylase function of the protein. This is the first report of upregulation of a dicotyledonous alpha-amylase in response to low temperature, and confirms the presence of a new family of alpha-amylases in plants.

An R-type Ca(2+) current in neurohypophysial terminals preferentially regulates oxytocin secretion

Multiple types of voltage-dependent Ca(2+) channels are involved in the regulation of neurotransmitter release (Tsien et al., 1991; Dunlap et al., 1995). In the nerve terminals of the neurohypophysis, the roles of L-, N-, and P/Q-type Ca(2+) channels in neuropeptide release have been identified previously (Wang et al., 1997a). Although the L- and N-type Ca(2+) currents play equivalent roles in both vasopressin and oxytocin release, the P/Q-type Ca(2+) current only regulates vasopressin release. An oxytocin-release and Ca(2+) current component is resistant to the L-, N-, and P/Q-type Ca(2+) channel blockers but is inhibited by Ni(2+). A new polypeptide toxin, SNX-482, which is a specific alpha(1E)-type Ca(2+) channel blocker (Newcomb et al., 1998), was used to characterize the biophysical properties of this resistant Ca(2+) current component and its role in neuropeptide release. This resistant component was dose dependently inhibited by SNX-482, with an IC(50) of 4.1 nM. Furthermore, SNX-482 did not affect the other Ca(2+) current types in these CNS terminals. Like the N- and P/Q-type Ca(2+) currents, this SNX-482-sensitive transient Ca(2+) current is high-threshold activated and shows moderate steady-state inactivation. At the same concentrations, SNX-482 blocked the component of oxytocin, but not of vasopressin, release that was resistant to the other channel blockers, indicating a preferential role for this type of Ca(2+) current in oxytocin release from neurohypophysial terminals. Our results suggest that an alpha(1E) or "R"-type Ca(2+) channel exists in oxytocinergic nerve terminals and, thus, functions in controlling only oxytocin release from the rat neurohypophysis.

Characterization of mitochondrial glutaminase and amino acids at prolonged times after experimental focal cerebral ischemia

The mitochondrial enzyme glutaminase is a significant contributor to extracellular glutamate after neuronal injury in vitro [R. Newcomb, X. Sun, L. Taylor, N. Curthoys, R.G. Giffard, Increased production of extracellular glutamate by the mitochondrial glutaminase following neuronal death, J. Biol. Chem. 272 (1997) 11276-11282.]. As a step towards characterizing the role of the enzyme in neuronal injury in vivo, glutaminase activity was measured in central and peripheral regions of the ischemic distribution in rat brain at 6, 24, and 48 h after permanent focal ischemia. Although glutaminase activity decreases in the central ischemic area, significant activity remains in peripheral areas of evolving damage, even after 24 and 48 h ischemia. Western blots show no detectable change in glutaminase molecular weight or total immunoreactivity, regardless of the degree of inactivation. Significant amounts of glutamine remain in ischemic tissue at prolonged times after focal ischemia, while reductions in tissue amounts of glutamate are highly correlated with decreases in glutaminase activity. In vivo microdialysis probes were inserted into the ischemic periphery after 24 h focal ischemia. Glutamate is significantly elevated in these dialysates. Perfusion of the glutaminase substrate glutamine and the enzyme activator phosphate results in further and specific elevations in dialysate glutamate. In sum, significant mitochondrial glutaminase activity remains in the periphery of the ischemic lesion at 24 and 48 h, where it can contribute directly to elevated extracellular glutamate. Inactivation of the glutaminase in central areas of the ischemic lesion does not involve significant proteolytic degradation, and likely involves a specific molecular event.

Selective peptide antagonist of the class E calcium channel from the venom of the tarantula Hysterocrates gigas

We describe the first potent and selective blocker of the class E Ca2+channel. SNX-482, a novel 41 amino acid peptide present in the venom of the African tarantula, Hysterocrates gigas, was identified through its ability to inhibit human class E Ca2+ channels stably expressed in a mammalian cell line. An IC50 of 15-30 nM was obtained for block of the class E Ca2+ channel, using either patch clamp electrophysiology or K+-evoked Ca2+ flux. At low nanomolar concentrations, SNX-482 also blocked a native resistant or R-type Ca2+ current in rat neurohypophyseal nerve terminals, but concentrations of 200-500 nM had no effect on R-type Ca2+ currents in several types of rat central neurons. The peptide has the sequence GVDKAGCRYMFGGCSVNDDCCPRLGCHSLFSYCAWDLTFSD-OH and is homologous to the spider peptides grammatoxin S1A and hanatoxin, both peptides with very different ion channel blocking selectivities. No effect of SNX-482 was observed on the following ion channel activities: Na+ or K+ currents in several cultured cell types (up to 500 nM); K+ current through cloned potassium channels Kv1.1 and Kv1. 4 expressed in Xenopus oocytes (up to 140 nM); Ca2+ flux through L- and T-type Ca2+ channels in an anterior pituitary cell line (GH3, up to 500 nM); and Ba2+ current through class A Ca2+ channels expressed in Xenopus oocytes (up to 280 nM). A weak effect was noted on Ca2+ current through cloned and stably expressed class B Ca2+ channels (IC50 > 500 nM). The unique selectivity of SNX-482 suggests its usefulness in studying the diversity, function, and pharmacology of class E and/or R-type Ca2+ channels.

Alterations in K+ evoked profiles of neurotransmitter and neuromodulator amino acids after focal ischemia-reperfusion

Secondary elevations in extracellular amino acids occur during reperfusion after transient cerebral ischemia. The delayed accumulation of excitatory amino acids may contribute to the progressive development of neuronal injury. In this study, we explored the mechanisms that may be involved in this phenomenon. Microdialysis samples from probes located in rabbit cortex were analysed with a chiral amino acid procedure. Concentrations of neurotransmitters (L-Glu, GABA), N-methyl-D-aspartate receptor modulators (D-Ser, Gly), an inhibitory neuromodulator (Tau), the lipid component phosphoethanolamine, and L-Gln, L-Ser and L-Ala were measured. Depolarization via perfusion with potassium was used to assess the status of release/reuptake systems at 2 and 4 h reperfusion after 2 h transient focal ischemia. Background experiments classified potassium evoked responses as calcium dependent or calcium-independent by inclusion of 30 microM omega-conopeptide MVIIC or by inclusion of 20 mM magnesium and ommision of calcium. During ischemia, large elevations of almost all amino acids occurred. During reperfusion, secondary elevations in transmitter amino acids (L-Glu, GABA) and N-methyl-D-aspartate receptor modulators (D-Ser, Gly) occurred. Tau remained slightly elevated whereas the lipid component phosphoethanolamine remained high and stable during reperfusion. Reperfusion significantly potentiated the potassium response for amino acids with calcium-dependent responses (L-Glu and GABA). In contrast, calcium-independent responses (Tau, phosphoethanolamine, L-Gln) were significantly attenuated. Intermediate behavior was observed with Gly, while no potassium responses were observed for D-Ser, L-Ser or L-Ala. These data demonstrate that perturbations in evoked amino acid profiles after ischemia-reperfusion are selective. Reduction of calcium-independent responses implicate a general decline in efficacy of transporter mechanisms that restore transmembrane gradients of ions and transmitters. Decreased efficacy of transporter systems may reduce transmitter reuptake and account for the amplified release of L-Glu and GABA, thus contributing to progressive neural dysfunction after cerebral ischemia.

Role of Q-type Ca2+ channels in vasopressin secretion from neurohypophysial terminals of the rat

1. The nerve endings of rat neurohypophyses were acutely dissociated and a combination of pharmacological, biophysical and biochemical techniques was used to determine which classes of Ca2+ channels on these central nervous system (CNS) terminals contribute functionally to arginine vasopressin (AVP) and oxytocin (OT) secretion. 2. Purified neurohypophysial plasma membranes not only had a single high-affinity binding site for the N-channel-specific omega-conopeptide MVIIA, but also a distinct high-affinity site for another omega-conopeptide (MVIIC), which affects both N- and P/Q-channels. 3. Neurohypophysial terminals exhibited, besides L- and N-type currents, another component of the Ca2+ current that was only blocked by low concentrations of MVIIC or by high concentrations of omega-AgaIVA, a P/Q-channel-selective spider toxin. 4. This Ca2+ current component had pharmacological and biophysical properties similar to those described for the fast-inactivating form of the P/Q-channel class, suggesting that in the neurohypophysial terminals this current is mediated by a 'Q'-type channel. 5. Pharmacological additivity studies showed that this Q-component contributed to rises in intraterminal Ca2+ concentration ([Ca2+]i) in only half of the terminals tested. 6. Furthermore, the non-L- and non-N-component of Ca(2+)-dependent AVP release, but not OT release, was effectively abolished by the same blockers of Q-type current. 7. Thus Q-channels are present on a subset of the neurohypophysial terminals where, in combination with N- and L-channels, they control AVP but not OT peptide neurosecretion.

Increased production of extracellular glutamate by the mitochondrial glutaminase following neuronal death

Elevated extracellular concentrations of the excitatory transmitter glutamate are an important cause of neuronal death in a variety of disorders of the nervous system. The concentrations and rates of clearance and production of extracellular glutamate were measured in the medium of primary cultures from mouse neocortex containing neurons, astrocytes, or both cell types. Measurements were performed in the presence and absence of 2 mM glutamine with or without neuronal injury caused by 5-h exposure to hypoxia or 500 microM N-methyl-D-aspartate or a freeze-thaw cycle. High rates of glutamate generation (0.5-0.8 microM/min in the 0.4-ml culture well) occurred if neurons were both damaged and exposed to glutamine. Intact neurons or glia exposed to glutamine generated only small amounts of glutamate (0.03 microM/min). Glutamate generation by damaged neurons was dependent on the presence of glutamine, activated by phosphate, and inhibited by 6-diazo-5-oxo-L-norleucine and p-chloromercuriphenylsulfonic acid (pCMPS), strongly implicating the mitochondrial glutaminase. Following 5-h exposure to 500 microM N-methyl-D-aspartate, the glutaminase was localized to fragments of damaged neurons and was accessible to inhibition by the membrane-impermeant pCMPS. The glutaminase activity from damaged neurons is sufficient to account for the neurotoxic concentrations of glutamate in hypoxic mixed neuronal-glial cultures exposed to 2 mM glutamine. Finally, pCMPS is neuroprotective and also prevents the increased rate of generation of glutamate observed in neuronal cultures after prolonged exposure to glutamine. The cumulative data indicate the following: 1) excitotoxic neuronal death activates the hydrolysis of extracellular glutamine by the mitochondrial glutaminase, and 2) the glutaminase in damaged neurons is sufficient to cause neuronal death in in vitro models of neuronal injury.

Secondary elevation of extracellular neurotransmitter amino acids in the reperfusion phase following focal cerebral ischemia

The purpose of this study was to evaluate amino acid neurotransmitter dynamics in the reperfusion phase after transient cerebral ischemia. In vivo microdialysis was used to measure extracellular amino acid levels in a rabbit model of focal ischemia. During 30 min of transient ischemia (n = 5), small but significant (p < 0.05) increases in glutamate, aspartate, gamma-aminobutyric acid (GABA), and taurine were noted. These elevations rapidly returned to baseline levels upon recirculation and remained constant for up to 5.5 h of reperfusion. In rabbits subjected to 2 h of transient ischemia (n = 5), two phases of amino acid release were seen. During ischemia, large (5- to 50-fold) elevations in glutamate, aspartate, GABA, and taurine occurred, as expected. These elevations rapidly normalized upon unocclusion. However, significant (p < 0.05) secondary elevations in glutamate, aspartate, and GABA occurred after 2-4 h of reperfusion. Regression analysis demonstrated significant correlations between primary (ischemic) and secondary (reperfusion) efflux. In permanent ischemia (n = 5), amino acid levels remained elevated throughout the entire experiment. Secondary elevations in excitatory amino acids may further contribute to the excitotoxic cascade during reperfusion.

SNX-325, a novel calcium antagonist from the spider Segestria florentina

A novel selective calcium channel antagonist peptide, SNX-325, has been isolated from the venom of the spider Segestria florentina. The peptide was isolated using as bioassays the displacement of radioiodinated omega-conopeptide SNX-230 (MVIIC) from rat brain synaptosomal membranes, as well as the inhibition of the barium current through cloned expressed calcium channels in oocytes. The primary sequence of SNX-325 is GSCIESGKSCTHSRSMKNGLCCPKSRCNCRQIQHRHDYLGKRKYSCRCS, which is a novel amino acid sequence. Solid-phase synthesis resulted in a peptide that is chromatographically identical with the native peptide and which has the same configuration of cysteine residues as the spider venom peptide omega-Aga-IVa [Mintz, I. M., et al., (1992) Nature 355, 827-829]. At micromolar concentrations, SNX-325 is an inhibitor of most calcium, but not sodium or potassium, currents. At nanomolar concentrations, SNX-325 is a selective blocker of the cloned expressed class B (N-type), but not class C (cardiac L), A, or E, calcium channels. SNX-325 is approximately equipotent with the N-channel selective omega-conopeptides (GVIA and MVIIA as well as closely related synthetic derivatives) in blocking the potassium induced release of tritiated norepinephrine from hippocampal slices (IC50s, 0.1-0.5 nM) and in blocking the barium current through cloned expressed N-channels in oocytes (IC50s 3-30 nM). By contrast, SNX-325 is 4-5 orders of magnitude less potent than is SNX-111 (synthetic MVIIA) at displacing radioiodinated SNX-111 from rat brain synaptosomal membranes. SNX-325 will be a useful comparative tool in further defining the function and pharmacology of the N- and possibly other types of high-voltage activated calcium channels.

Structural and biosynthetic properties of peptides in cone snail venoms

Venoms of the predatory cone snails Conus textile, Conus striatus, and Conus magus were subjected to comprehensive analysis of peptide content. With the fish-eating cone snails C. magus and C. striatus, the most abundant venom peptides were of > 30-50 residues, whereas the predominant peptides in the venom of the mollusc-eating snail, C. textile, were of 20-35 residues. Amino acid sequencing revealed an identical but unusual amino acid in a conserved position in four novel omega-type peptides from the C. textile venom. Two conserved amino acid sequences were obtained from the venoms of both C. magus and C. striatus. The amino acid compositions of the isolated C. textile peptides and the expected processing products of the propeptides (42) were compared. Despite the recovery in abundance of the carboxyl-terminal omega-type peptides, none of the isolated peptides had compositions expected from the propeptide amino-terminal fragments. We conclude that there are likely mechanisms for excluding the amino-terminal propeptide fragments from this venom, resulting in a venom with greater potency. Amounts of the different omega-type peptides in the venom vary widely, suggesting a distinct mechanism that results in the selective synthesis of different bioactive carboxyl-terminal propeptide fragments at elevated levels.

Calcium channel antagonist peptides define several components of transmitter release in the hippocampus

The use of subtype-selective voltage-sensitive calcium channel (VSCC) antagonists has established that neurotransmitter release in mammalian brain is mediated by N-like and P-like VSCCs, and that other subtypes also contribute significantly. To determine the roles presynaptic VSCCs play in nervous system function and to evaluate the therapeutic potential of their selective inhibition, it is necessary to define further the contributions of VSCC subtypes to neurotransmitter release. The novel conopeptide, SNX-230 (omega-conopeptide MVIIC), has revealed a new VSCC subtype, the Q-type, in cerebellar granule cells. We have compared the effects of SNX-230 on release of tritiated D-aspartate ([3H]D-Asp; a non-metabolizable analog of glutamate), gamma-aminobutyric acid ([3H]GABA), and norepinephrine ([3H]NE) from rat hippocampal slices to those of the N-type VSCC blocker, SNX-111 (omega-conopeptide MVIIA), and the P-type blocker, omega-agatoxin-IVA (AgaIVA). SNX-230 blocks both [3H]D-Asp and [3H]GABA release completely, whereas AgaIVA blocks them potently but partially and SNX-111 has no effect. These results suggest that glutamate and GABA release are mediated by two VSCC subtypes, a P-type and another, perhaps Q-like. SNX-111 blocks [3H]NE release potently but partially, while SNX-230 blockade is complete, consisting of one very potent phase and one less potent phase. AgaIVA also blocks [3H]NE release potently but partially. These results suggest that at least two VSCC subtypes, an N-type and a novel non-N-type, mediate NE release. Pair-wise combinations of the three ligands indicate that at least three pharmacologically distinct components comprise [3H]NE release in the hippocampus.

Effects of diverse omega-conopeptides on the in vivo release of glutamic and gamma-aminobutyric acids

omega-Conopeptides are antagonists of subtypes of neuronal calcium channels. Two omega-conopeptides, SVIB and MVIIC, have recently been identified which have a novel specificity for these ionophores. We have tested the actions these peptides, as well as the more selective MVIIA, on the release of glutamic acid and gamma-aminobutyric acid (GABA) in the hippocampus in vivo. For the assay of peptide effects on release, we used microdialysis to deliver multiple pulses of elevated potassium to the brain extracellular fluid. Peptide effects were quantitated from the decrement of the release with peptide perfused through the probes, in comparison to that in control experiments. Synthetic MVIIC caused a 40-50% decrement in the release of both glutamate and GABA at a probe concentration of about 200 nM. Synthetic SVI-B caused a 50% block at about 20-40 microM, while about 200 microM of MVIIA was required for 50% block. Chromatographic experiments showed that differences in potency between MVIIC and MVIIA were not explained by differential degradation. Blockade of release was also observed in the thalamus. MVIIC provides a tool for investigating the role of calcium mediated release of glutamate and GABA in physiological and pathological processes in the mammalian brain in vivo.

A selective N-type calcium channel antagonist protects against neuronal loss after global cerebral ischemia

Calcium influx is believed to play a critical role in the cascade of biochemical events leading to neuronal cell death in a variety of pathological settings, including cerebral ischemia. The synthetic omega-conotoxin peptide SNX-111, which selectively blocks depolarization-induced calcium fluxes through neuronal N-type voltage-sensitive calcium channels, protected the pyramidal neurons in the CA1 subfield of the hippocampus from damage caused by transient forebrain ischemia in the rat model of four-vessel occlusion. SNX-111 provided neuroprotection when a single bolus injection was administered intravenously up to 24 hr after the ischemic insult. These results suggest that the window of opportunity for therapeutic intervention after cerebral ischemia may be much longer than previously thought and point to the potential use of omega-conopeptides and their derivatives in the prevention or reduction of neuronal damage resulting from ischemic episodes due to cardiac arrest, head trauma, or stroke. Microdialysis studies showed that SNX-111 was 3 orders of magnitude less potent in blocking potassium-induced glutamate release in the hippocampus than the conopeptide SNX-230, which, in contrast to SNX-111, failed to show any efficacy in the four-vessel occlusion model of ischemia. These results imply that the ability of a conopeptide to block excitatory amino acid release does not correlate with its neuroprotective efficacy.

Profiles of extracellular amino acid changes in focal cerebral ischaemia: effects of mild hypothermia

Mild hypothermia has been recently proposed as a therapeutic approach for ameliorating ischaemic cerebral damage. The protective potential of mild hypothermia, however, may be dependent on its ability to reduce the efflux of potentially excitotoxic amino acids and the severity of ischaemia. In this study, we examined the effects of mild brain hypothermia (33 degrees C) in a rabbit model of permanent focal ischaemia. In vivo microdialysis was used to measure extracellular amino acids in central and peripheral regions of the ischaemic cortex. In normothermic ischaemia (n = 7), glutamate, alanine, taurine, and phosphoethanolamine increased above baseline levels by about 2 h post-ischaemia. Mild hypothermia (n = 7) reduced glutamate efflux only in the central regions and increased alanine efflux in the peripheral regions of ischaemia. There were no significant differences in other amino acid levels between the two temperature groups. Haematoxylin-eosin histology did not demonstrate hypothermic protection in the ischaemic hemisphere. The lack of neuroprotection in this study may correspond with the sustained release of glutamate in the peripheral regions of ischaemia even with lowered brain temperature. These results suggest that hypothermic reduction of excitotoxic perturbations may be more important in the ischaemic periphery than the core.

A normative sample using the Loong Computerized Tapping Program

This article provides results of a comparison between the Halstead-Reitan tapper and a 1988 computerized tapping program by Loong. Care should be taken in using the computerized tapper in diagnosis or assessment.