Outcomes Following Radiation Therapy (RT) for Very Young Age CNS Embryonal Tumors on COG ACNS0334 According to Molecular-Confirmed Diagnosis

PURPOSE/OBJECTIVE(S)

The outcomes of upfront or relapse radiation therapy (RT) for the Children's Oncology Group ACNS0334 protocol based on molecular diagnosis were assessed. Therapy included maximal safe surgery, high-dose chemotherapy with stem cell rescue, randomization for inclusion of high dose methotrexate (MTX) and optional RT.

MATERIALS/METHODS

There were 24 patients that received RT on COG ACNS0334 of 77 evaluable patients with a diagnosis of either high-risk medulloblastoma (MB) or supratentorial primitive neuroectodermal tumor (SPNET). RT was a recommendation (M0: Focal, M+: CSI 18 Gy) given young patient age <36 months at enrollment. Seven RT patients were excluded for ineligible pathology (1 ATRT, 1 HGG) or insufficient tissue. The aim of this report is to review outcomes of 17 patients on ACNS0334 receiving RT (8 Upfront, 9 at relapse) with a molecular diagnosis that included MB, Pineoblastoma (PB), or Embryonal tumor with multilayered rosettes (ETMR).

RESULTS

In the MB group, there were 9 patients irradiated with MB (Group 3 = 8, SHH = 1). 5-year OS for MB Group 3 receiving RT (median primary dose 54 Gy) was 62.5% with no difference observed comparing 6 patients treated with upfront RT versus 2 treated at relapse (p = 0.27). All upfront RT for MB Group 3 had initial partial response (PR) to 0334 chemotherapy. RT delivery for upfront RT MB Group 3 included craniospinal radiation (CSI) in 5 patients and 1 patient who received focal RT to the primary (50 Gy) and metastatic site (44 Gy). Eighty percent of CSI for upfront RT in Group 3 was 18 Gy or 23.4 Gy. Relapse RT for MB Group 3 (2 patients) utilized full dose CSI (36 Gy, 39.6 Gy) and both patients are survivors with 5+ years follow-up. CSI dose for Group 3 MB was higher for relapse RT (mean 37.8 Gy) as compared to upfront RT (mean 19.8 Gy, p = 0.013). Use of MTX was 50% in both upfront RT and relapse RT Group 3 MB cohorts. One patient with MB SHH (classic histology) underwent upfront focal RT (54 Gy) after initial PR to systemic therapy (without MTX) and is surviving 5+ years. PB: Of 4 PB patients (median primary dose 48.8 Gy) 1 had RT upfront (CSI 18 Gy) and 3 had RT at relapse (1 patient received CSI, 21 Gy). All patients with PB expired within 2 years. MTX was given in 75% (including 1 upfront RT PB). Two of 3 patients treated at relapse had prior complete response (CR). ETMR: All 4 patients (median primary dose 54 Gy) with ETMR were treated at relapse, with CSI given in 1 patient (23.4 Gy). All patients with ETMR expired within 2 years, and 2 (50%) had received MTX. Two patients (50%) had initial CR.

CONCLUSION

The RT cohort for Group 3 MB on ACNS0334 exhibited long-term survival both for both upfront and relapse RT, however relapsed Group 3 MB received higher dose CSI. RT upfront for MB, including one surviving MB SHH patient receiving focal RT, was solely given for incomplete initial chemotherapy response. There were no survivors for either PB or ETMR when the majority (88%) were treated at relapse.

Disparities in cancer incidence by rurality in California

BACKGROUND

Cancer rates in rural areas across the United States have different patterns than in urban areas. This study examines associations between rurality and incidence for the top 5 cancers in California and evaluates whether these associations vary jointly by sex, race, and ethnicity.

METHODS

We used 2015-2019 California Cancer Registry data to compare incidence rate ratios (IRRs) and trends for breast, prostate, lung, colorectal, and skin (melanoma) cancers. We leveraged census tract aggregation zones and 7 levels of percentage rural population (0%, >0% to <10%, 10% to <20%, 20% to <30%, 30% to <40%, 40% to <50%, and 50+%).

RESULTS

Zones with higher proportions of rural population were significantly associated with lower incidence of female breast cancer and prostate cancer, though the trends were not statistically significant overall. Zones with higher proportions of rural population were significantly associated with higher incidence of lung cancer and melanoma. There were no statistically significant trends for colorectal cancer overall. Comparing areas with 50% and over rural population with areas with 0% rural population, the IRR for lung cancer in Hispanic females was higher (IRR = 1.43, 95% confidence interval [CI] = 1.17 to 1.74) than in Hispanic males (IRR = 0.90, 95% CI = 0.72 to 1.11). Also, in areas with 50% or more rural population, the IRR for melanoma was higher in Hispanic females (IRR = 1.75, 95% CI = 1.23 to 2.45) than non-Hispanic White females (IRR = 0.87, 95% CI = 0.80 to 0.95).

CONCLUSIONS

Our findings show that rurality is associated with cancer incidence and underscore the importance of jointly examining rural disparities with sex, race, and ethnicity by cancer site.

National audit of non-melanoma skin cancer excisions performed by plastic surgery in the UK

A national, multi-centre audit of non-melanoma skin cancer excisions by plastic surgery.

Initial psychometric testing of the Head and Neck Cancer Patient Self-Management Inventory (HNC-PSMI)

PURPOSE

Head and neck cancer (HNC) and its treatment are associated with significant symptom burden and functional impairment. HNC patients must engage in intensive and complex self-management protocols to minimize acute and late treatment effects. Self-management among HNC patients is understudied due to the limited availability of disease-specific self-management measures. This article describes the initial psychometric testing of the HNC Patient Self-Management Inventory (HNC-PSMI), an instrument that characterizes self-management tasks in the HNC population.

METHOD

A cross-sectional survey design was used. One hundred HNC patients completed the HNC-PSMI, the Vanderbilt Head and Neck Cancer Symptom Survey plus General Symptom Survey, and the Profile of Mood States-Short Form. To evaluate the psychometric properties of the HNC-PSMI, the relevance of items, internal consistency of domain item responses, and the direction and strength of associations between domain scores and other measures were examined.

RESULTS

There was variability both in the number of self-management tasks performed overall and in each domain as well as in the reported difficulty completing those tasks. Kuder-Richardson values for domains with > 3 items ranged from 0.61 to 0.86. Hypothesized associations were supported.

CONCLUSIONS

Overall, the psychometric properties for the HNC-PSMI were acceptable. The HNC-PSMI can be used to advance an understanding of self-management requirements and challenges in HNC patients.

A new conceptual model of experiences of aging in place in the United States: Results of a systematic review and meta-ethnography of qualitative studies

OBJECTIVES

The purpose of this systematic review was to synthesize the evidence on experiences of aging in place in the United States.

DESIGN

Systematic review and meta-ethnography of qualitative studies.

DATA SOURCES

We searched six bibliographic databases (PubMed, Embase, PsycINFO, CINAHL, Web of Science, Sociological Abstracts), with no limits on publication date. Eligible studies reported peer-reviewed qualitative research on experiences of aging in place in the United States with full-text available in English.

REVIEW METHODS

Three reviewers independently used Covidence software to screen titles and abstracts followed by full texts. We assessed quality and risk of bias using a modified version of the Joanna Briggs Institute Checklist for Qualitative Research. Qualitative data analysis was conducted using meta-ethnography, following Noblit and Hare's seven-step method of translation and synthesis to generate a novel conceptual model.

RESULTS

Of 2659 papers screened, 37 unique studies were eligible for inclusion, reported in 38 publications. The studies were conducted in 16 states and published between 1994 and 2018. The included samples represented 1199 participants in total, with mean ages ranging from 48 to 91 years. The gender of the samples ranged from 20% to 100% female, with a median of 77%. One-third of the included studies did not report participants' race/ethnicity, and half of the remaining study samples were at least 90% white; however, 20% of the studies focused exclusively on experiences of racial/ethnic minority older adults. Using meta-ethnography, we developed a new conceptual model of aging in place in the United States as a dynamic process of balancing threats and agency in relation to experiences of identity, connectedness, and place. We found that people aging in place were engaged in significant work to cope with unpredictable needs and challenges by changing their mindset, adapting their home environment to accommodate new needs, and finding different ways to connect with important people in their lives. Agency was shaped by resources and restrictions on choice, and where threats to aging in place outweighed an individual's sense of agency, the consequences included feelings of uncertainty, isolation, and dislocation.

CONCLUSIONS

To the best of our knowledge, this is the first systematic review of qualitative studies to evaluate experiences of aging in place in the United States. The findings of our meta-ethnographic synthesis led to the development of a new conceptual model of aging in place highlighting the dynamic tensions involved in balancing threats and agency.

Impact of patient symptoms and caregiving tasks on psychological distress in caregivers for head and neck cancer (HNC)

OBJECTIVE

To determine the association of caregiving task burden and patient symptom burden with psychological distress among caregivers of head and neck cancer (HNC) patients.

METHODS

Adults with HNC and their primary caregivers were included. Patient symptom burden was assessed with the Vanderbilt Head and Neck Symptom Survey-2.0. Caregiving task burden was quantified as task number and task difficulty/distress using the HNC Caregiving Task Inventory. Psychological distress was measured with the Profile of Mood States-Short Form. Two-step clustering analysis was conducted for patient symptom burden, caregiving task burden, and psychological distress. Associations of the resultant clusters of task burden and patient symptoms with caregiver distress were tested using logistic regressions.

RESULTS

Eighty-nine HNC caregivers and 84 patients were included. Among patients, two clusters of symptom burden were found (51% mod-high, 49% low). Among caregivers, two clusters of caregiving task burden (40% mod-high, 60% low) and caregiver psychological distress (40% mod-high, 60% low) were found. Caregivers with mod-high task numbers and task difficulty/distress reported higher levels of psychological distress. After controlling for caregiver number of tasks, respective difficulty/distress, and patient symptom burden, caregiver perceived task difficulty/distress had the strongest association with caregiver psychological distress (adjusted OR = 3.83; 95% CI, 1.0-14.64; P = 0.049).

CONCLUSIONS

Psychological distress in HNC caregivers is associated with caregiving task burden, with caregivers experiencing high task difficulty/distress at greatest risk. Further study of the caregiver and task characteristics leading to psychological distress should inform supportive interventions for HNC patients and caregivers.

Experiences of aging in place in the United States: protocol for a systematic review and meta-ethnography of qualitative studies

BACKGROUND

By 2035, older adults will outnumber children for the first time in the United States (US). In light of its aging population, the US has supported services focused on enabling older adults to continue living in their current homes, a model commonly described as "aging in place." The lived experience of aging in place is not well documented in existing systematic reviews. The aims of this systematic review are to synthesize and evaluate the existing qualitative evidence on experiences of aging in place in the US and identify knowledge gaps and directions for future studies.

METHODS

Six electronic bibliographic databases (PubMed, PsycINFO, CINAHL, Web of Science, EMBASE, and Sociological Abstracts) will be searched. Studies presenting qualitative data on the experiences of older adults currently aging in place in the US will be included. Covidence software will be used to screen studies and extract data. The Joanna Briggs Institute checklist for qualitative research will be used to assess quality and risk of bias of included studies. We will use meta-ethnography, following the method described by Noblit and Hare, to synthesize and evaluate the results of the included studies.

DISCUSSION

To the best of our knowledge, this is the first systematic review to integrate and synthesize the findings of qualitative studies of aging in place focusing on older adults in the US. The findings of this review will provide in-depth knowledge on lived experiences of aging in place and address important gaps in existing work.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42018102847.

Chromatographic Isolation of the LDH-Isoenzymes of Human Blood Platelets and an Investigation of Their Enzyme Kinetics

The LDH-isoenzymes of human blood platelets show a distinct predominance of the isoenzymes 2 and 3 upon chromatography on DEAE-cellulose. Small amounts of LDH-1 are also present, while only traces of LDH-4 and -5 can be detected.

Enzyme kinetic investigations of the principal isoenzymes LDH-1, -2 and -3 clearly show that the differences in inhibition constants with pyruvate as substrate which are demonstrable at 25° largely disappear at 37°. On the other hand, the differences among the isoenzymes in their affinity for pyruvate and lactate as substrate as well as in with respect to the optimal substrate concentrations of pyruvate are more marked at 37° than at 25°. Also, the type of inhibition found with lactate as substrate is increasingly the expression of a higher order reaction in going from LDH-1 to LDH-3. A dependence of the LDH distribution pattern upon the metabolism of the cell is discussed. A comparison of our results with thrombocytes with those of other workers with erythrocytes and leucocytes makes it unlikely that the LDH pattern is directly dependent upon the existence of an oxidative metabolism. Rather, the redox potential of the cell could be of importance for the nature of the pattern of isoenzymes and for their differing kinetic properties.

Untersuchungen über das Verteilungsmuster der Laktatdehydrogenase-Isoenzyme menschlicher Blutplättchen

Mit Hilfe der Polyacrylamid-Disc-Elektrophorese wurde das LDH-Isoenzymver-teilungsmuster normaler menschlicher Blutplättchen untersucht und eine Verteilung mit starkem Überwiegen der Banden 2 und 3 bei deutlich geringerem Anteil der LDH-1 gefunden. LDH-4 konnte nur in Spuren, LDH-5 in diesem System nicht nachgewiesen werden. Folgende Anteile wurden für die einzelnen Isoenzyme bestimmt (x ± s, n = 16): LDH-1 = 9,8 ± 7,3, LDH-2 =50,7 ± 7,7, LDH-3 = 38,3 ± 7,5, LDH-4 = 1,2 ± 1,2 rel. %.

Die Versuchsplanung bei der therapeutischen Forschung im Bereich der Leukämien

Die therapeutische Versuchsplanung bei Leukämien bietet in Anbetracht der sehr variablen Spontanabläufe besondere Probleme. Einem individuellen Vergleich sind vorzugsweise die chronischen Formen zugänglich. Er bietet bei der Vielzahl objektiver Kriterien relativ geringe Schwierigkeiten, wenn genügend lange Therapie-Perioden geplant und durchgeführt wurden. Die Kriterien für die Herstellung homogener Kollektive als Basis des sehr viel schwierigeren Gruppenvergleichs werden besprochen. Mangels einer Stadieneinteilung kann die Anamnesendauer als Ersatz-Kriterium herangezogen werden. Inhomogenität in dieser Beziehung führt — wie ein praktisches Beispiel zeigt — zu falschen Resultaten. Wichtig ist auch die Beachtung therapeutischer und nicht-therapeutischer Mitursachen, die bereits in der Planung zu berücksichtigen sind. Die Befunddokumentation sollte in einem speziellen Formular erfolgen; ein eigener Entwurf wird zur Diskussion gestellt, Abschließend werden die Notwendigkeit der Zusammenarbeit mehrerer Kliniken auf therapeutischem Sektor und die spezielle Problematik eines solchen Vorhabens erörtert.

The neurokinin-2 receptor antagonist ibodutant improves overall symptoms, abdominal pain and stool pattern in female patients in a phase II study of diarrhoea-predominant IBS

BACKGROUND

Tachykinins have been implicated in the pathophysiology of IBS with diarrhoea (IBS-D). Our aim was to study the efficacy and safety of ibodutant, a selective neurokinin-2 (NK2) receptor antagonist, in patients with IBS-D.

METHODS

This multinational double-blind, placebo-controlled study recruited 559 patients with IBS-D according to Rome III criteria. After a 2-week treatment-free run-in, patients were randomised to ibodutant 1 mg, 3 mg, 10 mg or placebo once daily for eight consecutive weeks. Responders were those with a combined response of satisfactory relief (weekly binary question yes/no) of overall IBS symptoms and abdominal pain/discomfort on ≥75% weeks (primary end point). Secondary end points included abdominal pain and stool pattern. Data were also analysed according to US Food and Drug Administration (FDA)-approved interim end points (improvement of pain and stool consistency). Safety was assessed by monitoring adverse events and laboratory tests. Prespecified statistical analysis involved the whole group as well as gender subgroups.

RESULTS

Demographics and baseline characteristics were comparable for all treatment arms. In the overall population, responsiveness tended to increase with escalating ibodutant doses. In the prespecified analysis by gender, ibodutant 10 mg demonstrated significant superiority over placebo in females (p=0.003), while no significant effect occurred in males. This was confirmed for secondary end points and for the responder analysis according to FDA-approved end points. The tolerability and safety of ibodutant was excellent at all doses.

CONCLUSIONS

Ibodutant showed dose-dependent efficacy response in IBS-D, reaching statistical significance at the 10 mg dose in female patients. The safety and tolerability profile of ibodutant was similar to placebo.

TRIAL REGISTRATION NUMBER

NCT01303224.

[High fidelity simulation : a new tool for learning and research in pediatrics]

Caring for a sick child represents a high risk activity that requires technical and non-technical skills related to several factors such as the rarity of certain events or the stress of caring for a child. As regard these conditions, medi¬cal simulation provides a learning environment without risk, the control of variables, the reproducibility of situations, and the confrontation with rare events. In this article, we des¬cribe the steps of a simulation session and outline the current knowledge of the use of simulation in paediatrics. A session of simulation includes seven phases following the model of Peter Dieckmann, particularly the scenario and the debriefing that form the heart of the learning experience. Several studies have shown the advantages of simulation for paediatric trai¬ning in terms of changes in attitudes, skills and knowledge. Some studies have demonstrated a beneficial transfer to prac¬tice. In conclusion, simulation provides great potential for training and research in paediatrics. The establishment of a collaborative research program by the whole simulation com¬munity would help ensure that this type of training improves the quality of care.

Effects of partners together in health intervention on physical activity and healthy eating behaviors: a pilot study

BACKGROUND

Despite proven efficacy of cardiac rehabilitation (CR) in helping patients initiate physical activity and healthy eating changes, less than 50% of CR participants maintain changes 6 months later.

OBJECTIVE

The objective of this feasibility study was to test the Partners Together in Health (PaTH) intervention versus usual care in improving physical activity and healthy eating behaviors in coronary artery bypass graft surgery patients and their spouses.

METHODS

An experimental, 2-group (n = 17 couples/group), repeated-measures design was used. Coronary artery bypass surgery patients in both groups participated in phase II outpatient CR. Spouses in the PaTH group attended CR with the patient and were asked to make the same physical activity and healthy eating changes as patients did. Spouses in the usual care attended educational classes with patients. It was theorized that "2 persons would be better than 1" at making changes and sticking with them in the long-term. Physical activity behavior was measured using the Actiheart accelerometer; the activity biomarker was an exercise tolerance test. Eating behavior was measured using 3-day food records; the biomarker was the lipid profile. Data were collected at baseline (entrance in CR), at 3 months (post-CR), and at 6 months. Changes over time were examined using Mann-Whitney U statistics and effect sizes.

RESULTS

The PaTH intervention was successful primarily in demonstrating improved trends in healthy eating behavior for patients and spouses. No differences were found between the PaTH and usual care patients or spouses at 3 or 6 months in the number of minutes per week of physical activity. By 6 months, patients in both groups were, on average, below the national guidelines for PA recommendations (≥150 min/wk at >3 metabolic equivalents).

CONCLUSIONS

The couple-focused PaTH intervention demonstrated promise in offsetting the decline in dietary adherence typically seen 6 months after CR.

HealthViEWS: mortality study of female US Vietnam era veterans, 1965-2010

We conducted a retrospective study among 4,734 women who served in the US military in Vietnam (Vietnam cohort), 2,062 women who served in countries near Vietnam (near-Vietnam cohort), and 5,313 nondeployed US military women (US cohort) to evaluate the associations of mortality outcomes with Vietnam War service. Veterans were identified from military records and followed for 40 years through December 31, 2010. Information on underlying causes of death was obtained from death certificates and the National Death Index. Based on 2,743 deaths, all 3 veteran cohorts had lower mortality risk from all causes combined and from several major causes, such as diabetes mellitus, heart disease, chronic obstructive pulmonary disease, and nervous system disease relative to comparable US women. However, excess deaths from motor vehicle accidents were observed in the Vietnam cohort (standardized mortality ratio = 3.67, 95% confidence interval (CI): 2.30, 5.56) and in the US cohort (standardized mortality ratio = 1.91, 95% CI: 1.02, 3.27). More than two-thirds of women in the study were military nurses. Nurses in the Vietnam cohort had a 2-fold higher risk of pancreatic cancer death (adjusted relative risk = 2.07, 95% CI: 1.00, 4.25) and an almost 5-fold higher risk of brain cancer death compared with nurses in the US cohort (adjusted relative risk = 4.61, 95% CI: 1.27, 16.83). Findings of all-cause and motor vehicle accident deaths among female Vietnam veterans were consistent with patterns of postwar mortality risk among other war veterans.

Insulinotropic effect of high potassium concentration beyond plasma membrane depolarization

The question whether K⁺ depolarization is an appropriate experimental substitute for the physiological nutrient-induced depolarization of the β-cell plasma membrane was investigated using primary mouse β-cells and islets. At basal glucose 40 mM K⁺ induced a massive monophasic response, whereas 15 mM K⁺ had only a minimal insulinotropic effect, even though the increase in the cytosolic Ca²⁺ concentration ([Ca²⁺]i) was not inferior to that by 20 mM glucose. In voltage-clamp experiments, Ca²⁺ influx appeared as nifedipine-inhibitable inward action currents in the presence of sulfonylurea plus TEA to block compensatory outward K⁺ currents. Under these conditions, 15 mM K⁺ induced prolonged action currents and 40 mM K⁺ transformed the action current pattern into a continuous inward current. Correspondingly, 15 mM K⁺ led to an oscillatory increase and 40 mM K⁺ to a plateau of [Ca²⁺]i superimposed on the [Ca²⁺]i elevated by sulfonylurea plus TEA. Raising K⁺ to 15 or 40 mM in the presence of sulfonylurea (±TEA) led to a fast further increase of insulin secretion. This was reduced to basal levels by nifedipine or CoCl₂. The effects of 15 mM K⁺ on depolarization, action currents, and insulin secretion were mimicked by adding 35 mM Cs⁺ and those of 40 mM K⁺ by adding 35 mM Rb⁺, in parallel with their ability to substitute for K⁺ as permeant cation. In conclusion, the alkali metals K⁺, Rb⁺, or Cs⁺ concentration-dependently transform the pattern of Ca²⁺ influx into the β-cell and may thus generate stimuli of supraphysiological strength for insulin secretion.

Randomized controlled trial to assess reduction of cardiovascular disease risk in patients with bipolar disorder: the Self-Management Addressing Heart Risk Trial (SMAHRT)

OBJECTIVES

Persons with bipolar disorder experience a disproportionate burden of medical conditions, notably cardiovascular disease (CVD), leading to impaired functioning and premature mortality. We hypothesized that the Life Goals Collaborative Care (LGCC) intervention, compared to enhanced usual care, would reduce CVD risk factors and improve physical and mental health outcomes in US Department of Veterans Affairs patients with bipolar disorder.

METHOD

Patients with an ICD-9 diagnosis of bipolar disorder and ≥ 1 CVD risk factor (N = 118) enrolled in the Self-Management Addressing Heart Risk Trial, conducted April 2008-May 2010, were randomized to LGCC (n = 58) or enhanced usual care (n = 60). Life Goals Collaborative Care included 4 weekly self-management sessions followed by tailored contacts combining health behavior change strategies, medical care management, registry tracking, and provider guideline support. Enhanced usual care included quarterly wellness newsletters sent during a 12-month period in addition to standard treatment. Primary outcome measures included systolic and diastolic blood pressure, nonfasting total cholesterol, and physical health-related quality of life.

RESULTS

Of the 180 eligible patients identified for study participation, 134 were enrolled (74%) and 118 completed outcomes assessments (mean age = 53 years, 17% female, 5% African American). Mixed effects analyses comparing changes in 24-month outcomes among patients in LGCC (n = 57) versus enhanced usual care (n = 59) groups revealed that patients receiving LGCC had reduced systolic (β = -3.1, P = .04) and diastolic blood pressure (β = -2.1, P = .04) as well as reduced manic symptoms (β = -23.9, P = .01). Life Goals Collaborative Care had no significant impact on other primary outcomes (total cholesterol and physical health-related quality of life).

CONCLUSIONS

Life Goals Collaborative Care, compared to enhanced usual care, may lead to reduced CVD risk factors, notably through decreased blood pressure, as well as reduced manic symptoms, in patients with bipolar disorder.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00499096.

Determination of cutpoints for low and high number of symptoms in patients with advanced cancer

While patients with advanced cancer experience a wide range of symptoms, no work has been done to determine an optimal cutpoint for a low versus a high number of symptoms. Analytic approaches that established clinically meaningful cutpoints for the severity of cancer pain and fatigue provided the foundation for this study. The purpose of this study was to determine the optimal cutpoint for low and high numbers of symptoms using a range of potential cutpoints and to determine if those cutpoints distinguished between the two symptom groups on demographic and clinical characteristics and depression, anxiety, and quality of life (QOL). Patients with advanced cancer (n=110) completed a symptom assessment scale, and measures of depression, anxiety, and QOL. Combinations of cutpoints were tested to yield one- and two-cutpoint solutions. Using analysis of variance for QOL scores, the F-ratio that indicated the highest between-group difference was determined to be the optimal cutpoint between low and high number of symptoms. A cutpoint of ≤ 12 symptoms (i.e., 0-12 is low, 13-32 is high) was the optimal cutpoint for total number of symptoms. Significant differences in depression, anxiety, and QOL scores validated this cutpoint. Psychological symptoms had higher occurrence rates in the high symptom group. Findings suggest that a threshold exists between a low and a high number of symptoms in patients with advanced cancer. Psychological symptoms were significantly different between patients in the low versus high symptom groups and may play an important role in QOL outcomes in patients with advanced cancer.

Ca(2+)-dependent desensitization of insulin secretion by strong potassium depolarization

Depolarization by a high K(+) concentration is a widely used experimental tool to stimulate insulin secretion. The effects occurring after the initial rise in secretion were investigated here. After the initial peak a fast decline occurred, which was followed by a slowly progressive decrease in secretion when a strong K(+) depolarization was used. At 40 mM KCl, but not at lower concentrations, the decrease continued when the glucose concentration was raised from 5 to 10 mM, suggesting an inhibitory effect of the K(+) depolarization. When tolbutamide was added instead of the glucose concentration being raised, a complete inhibition down to prestimulatory values was observed. Equimolar reduction of the NaCl concentration to preserve isoosmolarity enabled an increase in secretion in response to glucose. Unexpectedly, the same was true when the Na(+)-reduced media were made hyperosmolar by choline chloride or mannitol. The insulinotropic effect of tolbutamide was not rescued by the compensatory reduction of NaCl, suggesting a requirement for activated energy metabolism. These inhibitory effects could not be explained by a lack of depolarizing strength or by a diminished free cytosolic Ca(2+) concentration ([Ca(2+)](i)). Rather, the complexation of extracellular Ca(2+) concomitant with the K(+) depolarization markedly diminished [Ca(2+)](i) and attenuated the inhibitory action of 40 mM KCl. This suggests that a strong but not a moderate depolarization by K(+) induces a [Ca(2+)](i)-dependent, slowly progressive desensitization of the secretory machinery. In contrast, the decline immediately following the initial peak of secretion may result from the inactivation of voltage-dependent Ca(2+) channels.