Advanced or metastatic biliary tract cancer in Japan: a study using the Japan Medical Data Center payer claims database

Aim: Biliary tract cancers are aggressive, with poor prognosis. This study describes clinical characteristics, treatment patterns and healthcare resource utilization in patients with metastatic biliary tract cancer in Japan. Materials & methods: This cohort-based study collected data from the Japan Medical Data Center claims database (2014-2018). Results: A total of 325 patients were included; 65.2% were male and the mean age was 59.2 years. A 47.6% had an Elixhauser Comorbidity Index score ≥5. Most frequent regimens were gemcitabine + cisplatin (52.9%) for first-line therapy and tegafur + gimeracil + oteracil for second-line therapy (48.6%) and third-line therapy (27.2%). Approximately 77% of patients had ≥1 hospital admission, with a median length of 57 days. Conclusion: This study provides insights on the characteristics and burden of metastatic biliary tract cancer in Japan, highlighting high disease burden in a younger population.

Real-world outcomes among patients with advanced or metastatic biliary tract cancers initiating second-line treatment

BACKGROUND

Limited data are available regarding second-line (2 L) treatment for advanced or metastatic biliary tract cancers (BTC) in the US real-world setting. This study explores the rapidly evolving and growing treatment landscape in the 2 L setting for advanced or metastatic BTC with a large cohort of patients treated in a community oncology setting.

METHODS

Adult patients with BTC initiating 2 L treatment after a platinum-containing first-line between 1/1/10- and 6/30/19 were identified from the US Oncology Network electronic healthcare record database and followed through 12/31/19. Baseline patient and treatment characteristics were analyzed descriptively, including overall response rate (ORR) in the real-world clinical setting. Kaplan-Meier methods were used to measure duration of response, progression-free survival (PFS), and overall survival (OS).

RESULTS

The overall population (N = 160) included 74 patients (46.3%) with intrahepatic cholangiocarcinoma, 41 (25.6%) with extrahepatic cholangiocarcinoma, and 45 (28.1%) with gallbladder cancer. Thirty unique 2 L regimens were recorded for the study population, with folinic acid, fluorouracil and oxaliplatin (FOLFOX, 34.4%) and capecitabine monotherapy (20.0%) being the most common. ORR was 7.5% (95% CI, 3.9%-12.7%). From 2 L initiation, median PFS was 2.8 months (95% CI, 2.4-3.3 months), and median OS was 5.2 months (95% CI, 4.2-6.7 months).

CONCLUSION

Results from this study provide real-world evidence that although patients treated in the community oncology setting receive a wide variety of 2 L treatments, the regimens are consistent with those recommended by guidelines. Although responses are observed with 2 L treatment, duration is brief and associated with poor OS in patients with advanced or metastatic disease.

Second-line treatments in advanced biliary tract cancer: systematic literature review of efficacy, effectiveness and safety

Background: A systematic review was conducted to understand clinical, economic and health-related quality-of-life outcomes in second-line biliary tract cancer. Materials & methods: The review followed established recommendations. The feasibility of network meta-analysis revealed limited networks, thus synthesis was limited to a summary of reported ranges, percentiles and medians. Results: The review included 62 trials and observational studies highly variable with respect to key baseline characteristics. Commonly evaluated second-line treatments included fluoropyrimidine-, gemcitabine- and S-1-based regimens. Across active treatment arms, median overall survival ranged from 3.5 to 15.0 months (median: 6.9), median progression-free survival from 1.4 to 6.5 months (median: 2.9) and objective response from 0 to 36.4%. Outcomes were similar between study types, with a few notable outliers. Treatment-related/-emergent adverse events were infrequently reported; no studies reported economic or health-related quality-of-life outcomes. Conclusions: Biliary tract cancer is a difficult-to-treat disease with poor prognosis. Despite evolving treatment landscapes, more recent studies did not show clinical outcome improvement, highlighting an unmet need among advanced/metastatic patients.

Cost saving, patient centered algorithm for progenitor cell mobilization for autologous hematopoietic cell transplantation

Administration of plerixafor with granulocyte-colony stimulating factor (G-CSF) mobilizes CD34+ cells much more effectively than G-CSF alone, but cost generally limits plerixafor use to patients at high risk of insufficient CD34+ cell collection based on low peripheral blood (PB) CD34+ counts following 4 days of G-CSF. We analyzed costs associated with administering plerixafor to patients with higher day 4 CD34+ cell counts to decrease apheresis days and explored the use of a fixed split dose of plerixafor instead of weight-based dosing. We analyzed 235 patients with plasma cell disorders or non-Hodgkin's lymphoma who underwent progenitor cell mobilization and autologous hematopoietic cell transplantation (AHCT) between March 2014 and December 2017. Two hundred ten (89%) received G-CSF plus Plerixafor and 25 (11%) received G-CSF alone. Overall, 180 patients (77%) collected in 1 day, 53 (22%) in 2 days and 2 (1%) in 3 days. Based on our data, we present a probabilistic algorithm to identify patients likely to require more than one day of collection using G-CSF alone. CD34+ cell yield, ANC and platelet recovery were not significantly different between fixed and standard dose plerixafor. Plerixafor enabled collection in 1 day and with estimated savings of $5000, compared to patients who did not receive plerixafor and required collection for three days. While collection and processing costs and patient populations vary among institutions, our results suggest re-evaluation of current algorithms.

Evaluation of CYP2C19 Genotype-Guided Voriconazole Prophylaxis After Allogeneic Hematopoietic Cell Transplant

There is a high risk of voriconazole failure in those with subtherapeutic drug concentrations, which is more common in CYP2C19 (cytochrome P450 2C19) rapid/ultrarapid metabolizers (RMs/UMs). We evaluated CYP2C19 genotype-guided voriconazole dosing on drug concentrations and clinical outcomes in adult allogeneic hematopoietic cell transplant recipients. Poor (PMs), intermediate (IMs), and normal metabolizers (NMs) received voriconazole 200 mg twice daily; RMs/UMs received 300 mg twice daily. Steady-state trough concentrations were obtained after 5 days, targeting 1.0-5.5 mg/L. Of 89 evaluable patients, 29% had subtherapeutic concentrations compared with 50% in historical controls (P < 0.001). Zero, 26%, 50%, and 16% of PMs, IMs, NMs, and RMs/UMs were subtherapeutic. Voriconazole success rate was 78% compared with 54% in historical controls (P < 0.001). No patients experienced an invasive fungal infection (IFI). Genotype-guided dosing resulted in $4,700 estimated per patient savings as compared with simulated controls. CYP2C19 genotype-guided voriconazole dosing reduced subtherapeutic drug concentrations and effectively prevented IFIs.

The emerging relevance of heterogeneity of treatment effect in clinical care: a study using stage IV prostate cancer as a model

AIM

Heterogeneity of treatment effect (HTE) occurs when patient factors modify a treatment's effect on health outcomes due to interactions between these factors and the treatment. This article reviews evidence regarding HTE in stage IV prostate cancer (S4PC).

METHOD

A systematic literature review was conducted in the MEDLINE and PubMed databases. Inclusion criteria required that articles examine the treatment-related impact of HTE factors on survival, adverse events or health-related quality of life in S4PC patients. The quality of evidence was graded good, fair or poor based on Agency for Healthcare Research and Quality guidelines.

RESULTS

The search identified 2659 articles, of which 92 met the inclusion/exclusion criteria. HTE in S4PC was studied for biologic factors including age, race, clinical signs/symptoms, measures of S4PC disease severity, genetic factors, laboratory data, prior treatment, concurrent medications and comorbidities. Nonbiologic factors that were studied included social, geographic and dietary factors. Age and race seldom showed any correlation with S4PC outcomes.

CONCLUSION

Diverse biologic and nonbiologic factors contribute to HTE in S4PC. This review in S4PC also provides an approach for examining HTE for other medical conditions. Ultimately, such knowledge can help oncologists prescribe more personalized medicine, help patients make more informed treatment choices, and inform policy-making and treatment coverage decisions.

Does the type of first-line regimens influence the receipt of second-line chemotherapy treatment? An analysis of 3211 metastatic colon cancer patients

With new agents entering the market, the sequencing of first-line (Tx1), second-line (Tx2), and subsequent chemotherapy/biologics regimens are being examined. We examined how Tx1 regimens impacted the likelihood of receiving Tx2 among metastatic colon cancer (mCC) patients. Surveillance, Epidemiology and End Results (SEER)-Medicare data were used to identify elderly mCC patients between 2003 and 2007. The inverse probability weighting Cox regression method was utilized to study the relationship between receipt of Tx2 and Tx1 regimens, controlling for patient-level factors. Of the 7895 elderly patients identified, 3211 (41%) received Tx1 of which 1440 proceeded to Tx2. The impact of Tx1 on receipt of Tx2 varied by the specific regimens utilized. As compared to 5FU/LV users, IROX (Hazard Ratio [HR] = 0.03; P < 0.01) and IROX + Biologics (HR = 0.20; P < 0.01) users were less likely to receive Tx2; (oxaliplatin) OX + Biologics (HR = 1.26; P < 0.01) users were more likely to receive Tx2. Significant patient-level factors included: Hispanic ethnicity (HR = 0.67; P < 0.01); being married (HR = 0.87; P = 0.01); proxy for poor performance status (HR = 0.82; P = 0.05); each 10-year age increment (HR = 1.14; P < 0.01); and State buy-in status (HR = 1.21; P = 0.01). The specific first-line regimen does impact mCC patients' likelihood of receiving Tx2 in clinical practice. Elderly mCC patients, their health care providers, and policy makers will benefit from new evidence about the impact of sequencing of treatment lines.

Clinical and demographic characteristics associated with the receipt of chemotherapy treatment among 7951 elderly metastatic colon cancer patients

Among older individuals diagnosed with metastatic colon cancer (mCC) there is limited evidence available that describes the characteristics associated with advancing to second- and subsequent lines of treatment with chemotherapy/biologics. Our objective was to describe the trends and lines of treatment received among elderly mCC patients. Elderly beneficiaries diagnosed with mCC from 2003 to 2007 were identified in the Surveillance, Epidemiology and End Results (SEER)-Medicare dataset. Beneficiaries were followed up until death or censoring. Treatment lines were classified in combinations of chemotherapies and biologics. Modified Poisson regression was used to predict receipt of lines of treatment. Analyses controlled for age, race/ethnicity, gender, marital status, state buy-in during diagnosis year, SEER-registry site, Charlson comorbidity index (CCI), poor performance indicators, surgery of primary site, and surgery of regional/distal sites. Among 7951 Medicare beneficiaries identified with mCC, 3266 initiated therapy. Of these, 1440 advanced to second-line treatment. Of these, 274 advanced to a subsequent-line treatment. Surgeries of the primary tumor site and of the regional/distal sites and marital status were the most significant variables associated with advancing through second- and subsequent-line treatments. Greater than 80 years of age, African American race, SEER-registry area, less than 6 months state buy-in assistance in mCC diagnosis year, and having poor performance indicators were inversely associated with receipt of second- or subsequent-line treatments. Among elderly individuals diagnosed with mCC, we identified demographic, clinical, and regional factors associated with receipt of second- and subsequent-line chemotherapy/biologics. Additional research is warranted to understand the role of physician versus patient preferences as well as geographic differences explaining why patients advance through lines of chemotherapy.

Heterogeneity of treatment effects (HTE) in stage IV prostate cancer (S4PC)

180

Background: HTE occurs when individual patient factors modify a treatment’s effect on health outcomes in a non-random and predictable manner. HTE results in specific subgroups of patients in the same study having different responses to the same treatment due to interactions between their individual factors and the treatment. Methods: A systematic literature review was conducted of articles published between 1946 and 2011. Inclusion criteria required that articles examine the impact of HTE factors on survival outcomes (OS, TTP, PFS) or QOL among S4PC patients, in the context of a specific treatment. The quality of evidence was graded as good, fair or poor, per AHRQ guidelines. Results: The search identified 2,659 articles of which 92 met study inclusion criteria. Most articles (46%) were post-hoc analyses of randomized clinical trials. PC treatments included chemotherapy, radiation, hormonal therapy (74%) and bone-modifying agents. HTE in S4PC was identified for both biologic and non-biologic factors. Factors related to clinical signs/symptoms, laboratory tests and disease severity have been extensively studied in the literature (Table). Age and race seldom showed any correlation with PC outcomes. Conclusions: Current evidence reveals diverse factors contributing to HTE in S4PC. Ultimately, such knowledge can help oncologists prescribe more personalized medicine, help patients make more informed treatment choices, and inform policy making and treatment coverage decisions. [Table: see text]

How do first-line treatment and other factors affect the receipt of second-line treatment for elderly metastatic colon cancer patients?

592

Background: Metastatic colon cancer (mCC) patients might receive multiple lines of chemotherapy to improve survival or quality of life. However, factors associated with receipt of 1st and 2nd line treatment (TX) haven’t been fully investigated. Methods: Elderly (65+) SEER-Medicare patients diagnosed with mCC in 2003-2007 were followed until death or 12/31/2009 to examine factors for receipt of 1st and 2nd line TX. A Cox regression framework and inverse probability weighting (IPW) method were used to adjust for patients’ informative (death) and non-informative (dropout or end-of-study) censoring histories. Additionally, we controlled for patients’ 1st line TX in the IPW to determine factors for receipt of 2nd line TX. Results: Of 7,951 mCC patients, 3,266 patients received at least 1 line TX, and 1,440 went on to 2nd line TX. For 1st line TX, significant clinical factors were CCI = 2 (HR = 0.86; p = 0.02), oxygen use (HR = 0.74; p = 0.04), walking aid use (HR = 0.58; p = 0.02), and wheel chair use (HR = 0.50; p < 0.01); significant demographic characteristics were age groups 95+ (HR = 0.11; p < 0.01), 85-94 (HR = 0.24; p < 0.01), 75-84 (HR = 0.70; p < 0.01), as compared to 65+-74, female (HR = 1.12; p < 0.01), married (HR = 1.43; p < 0.01), and African American (AA) (HR = 0.80; p < 0.01); significant factors for socio-economics status were state buy-in status (SBI) (HR = 0.97; p < 0.01), and zip code level household median income (HR = 1.03; p < 0.01). For 2nd line TX, significant factors were hospital bed use (HR = 2.82; p = 0.05), oxygen use (HR = 0.68; p = 0.02), age group 85-94 (HR = 0.718; p = 0.02) as compared to 65+-74, and days delayed for 1stline TX (HR = 0.998; p < 0.01). Conclusions: Various factors were associated with receipt of 1st line TX. Conditional on the receipt of 1st line TX, many factors became insignificant for receipt of 2nd line TX, such as age, female, marriage status, AA, SBI, and zip code level household income. Hospital bed use reduced the probability of receipt of 1st line TX, but increased the probability of receipt of 2nd line TX.

Predictors of second- and third-line chemotherapy receipt in stage IV colon cancer Medicare beneficiaries

588

Background: The prognosis for elderly patients with metastatic colon cancer (mCC) is poor with 5-year survival rate of 6 %. There is limited evidence to explain why some elderly mCC patients progress through multiple lines of treatment and others with similar clinical characteristics do not. This study examines the predictors of second- and third-line chemotherapy receipts in Medicare beneficiaries with mCC who initiate treatment. Methods: Using the SEER-Medicare dataset, elderly beneficiaries diagnosed with mCC from 2003-2007, were followed until death or censoring in 2009. Treatment lines were classified in combinations of chemotherapy and biologics. Logistic regression was used to predict receipt of treatment and subsequent treatment. Results: Among 3,266 beneficiaries diagnosed with mCC and initiated therapy, 1,440 progressed to 2nd line treatment and 274 progressed to 3rd line treatment. The strongest predictors of progressing to 2nd line treatment was surgery of the primary tumor site (OR: 2.42, 95% CI: 2.17-2.70) and regional/distal sites (OR: 1.32, 95% CI: 1.14-1.53) and marital status (OR: 1.64, 95% CI: 1.47-1.83). Older beneficiaries (80-84 years (OR: 0.31, 95% CI: 0.26-0.37) and > 85 years (OR: 0.10, 95%CI: 0.08-0.12)) and those with poor performance status indicators (walk aid (OR: 0.46, 95% CI: 0.26-0.82), wheelchair use (OR: 0.43, 95% CI: 0.29-0.64), and use of oxygen (OR: 0.54, 95% CI: 0.41-0.69)) were less likely to proceed to 2nd line treatment. Older age was the biggest predictor of not proceeding to third-line treatment (80-84 years (OR: 0.42, 95% CI: 0.28-0.61) & > 85 years (OR: 0.10, 95%CI: 0.05-0.19)). No variables were statistically significant in predicting receipt of third-line chemotherapy. Conclusions: Surgery of the primary tumor site and of regional/distal sites were the most significant clinical variables predicting whether or not elderly patients proceed to second-line chemotherapy. Sociodemographic variables also predicted receipt of second-line chemotherapy.

Heterogeneity of treatment effects (HTE) in stage IV prostate cancer (S4PC)

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Background: HTE occurs when patient factors modify a treatment’s effect on health outcomes so patients in the same study have different responses to a specific treatment. Variation in outcomes is caused by interactions between the factors causing HTE and the treatment. HTE may explain some of the heterogeneity in S4PC prognosis. The HTE literature is evolving; hence some factors causing HTE in S4PC are not yet documented. Methods: A systematic literature review (1946-2011) of published trials and observational studies identified evidence of statistically significant factors influencing HTE in S4PC. Inclusion criteria required that articles examine the impact of HTE factors on survival (OS, DSS, PFS) or health-related quality-of-life measures among S4PC patients. Factors that influenced outcomes but were not specifically evaluated in the context of HTE were excluded. Results: Of 398 articles that included key words, 33 met inclusion/exclusion criteria. Treatments included chemotherapy, radiation, hormonal therapy and bone-modifying agents. Both biologic and non-biologic factors (Table) were found to be associated with HTE in S4PC. Evidence was mixed regarding whether HTE in S4PC is influenced by race or by confounding factors correlated with race or both. As no articles examined prognostic factors such as bcl2, PTEN, p53, Pgp and EGFR status in the context of a specific treatment, such factors were excluded. Conclusions: Current evidence reveals diverse factors influencing HTE in S4PC.Ultimately, such knowledge can help oncologists prescribe more personalized medicine, help patients make more informed treatment choices, and aid policy making and treatment coverage decisions. [Table: see text]

Cost-effectiveness of cytochrome P450 2C19 genotype screening for selection of antiplatelet therapy with clopidogrel or prasugrel

STUDY OBJECTIVE

To estimate the cost-effectiveness of genotype-guided selection of antiplatelet therapy compared with selecting clopidogrel or prasugrel irrespective of genotype.

DESIGN

Decision model based on event occurrence in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI) 38.

PATIENTS

Simulated cohort of patients with acute coronary syndrome scheduled to undergo percutaneous coronary intervention (PCI), consisting of three arms: those receiving genotype-guided antiplatelet therapy with clopidogrel or prasugrel, those receiving clopidogrel regardless of genotype, and those receiving prasugrel regardless of genotype.

MEASUREMENTS AND MAIN RESULTS

All three arms of the model incorporated the probability that patients would experience a cardiovascular event (death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke), a bleeding event (major or minor bleeding), or no event while receiving antiplatelet therapy during the 15 months after the scheduled PCI. The cytochrome P450 (CYP) 2C19 genotype determined antiplatelet drug selection in the genotyping group. Cost-effectiveness was expressed as the incremental cost-effectiveness ratio (ICER) for each event avoided in the genotype-guided therapy arm versus the other two arms. Genotype-guided antiplatelet therapy was dominant, or more effective and less costly, when compared with the selection of clopidogrel (ICER -$6760 [95% confidence interval (CI) -$6720 to -$6790]) or prasugrel (ICER -$11,710 [95% CI -$11,480 to -$11,950]) for all patients without regard to genotype. Genotype-guided therapy that included generic clopidogrel was dominant to prasugrel for all patients (ICER -$27,160 [95% CI -$27,890 to -$26,420]). Cost savings were not evident when genotype-guided therapy that included generic clopidogrel was compared with generic clopidogrel for all patients (ICER $2300 [95% CI $2290 to $2320]). [Correction added after online publication 12-Mar-2012: In the previous sentence -$2300 has been corrected as $2300.].

CONCLUSION

Genotype-guided antiplatelet therapy selection may be more cost-effective and may provide more clinical value due to fewer adverse outcomes.

Generating evidence for comparative effectiveness research using more pragmatic randomized controlled trials

Comparative effectiveness research (CER), or research design to meet the needs of post-regulatory decision makers, has been brought into the spotlight with the introduction of the American Recovery and Reinvestment Act, which provided $US1.1 billion over 2 years to support CER. In the short run, the majority of this money will be invested in observational studies and building of infrastructure; however, in the long run, we will likely see an increase in the number of randomized controlled trials (RCTs), as this method is arguably the most unbiased approach for establishing causal effect between treatments and health outcomes. RCTs are an integral component of CER for generating credible evidence on the relative value of alternative interventions in order to meet the needs of post-regulatory decision makers (patients, physicians, payers and policy makers). Explanatory phase III RCTs are fit for purpose; researchers make use of guidance documents produced by the US FDA to inform the design of these clinical trials. Historically, without explicit FDA guidance, broad patient populations, including women and minorities, often were not considered in trial design. In addition, attempts to minimize cost and maximize efficiency have led to smaller sample sizes, as is clear from the increase in 'creeping phase II-ism'. To demonstrate effectiveness, RCTs must be reflective of how an intervention will be used in the healthcare market. The concept of pragmatic clinical trials has emerged to describe those trials that are designed explicitly with this need in mind. Use of pragmatic trials will be most impactful if post-regulatory decision makers are engaged in the development of recommendations for trial design features, such as indicating outcomes measures and articulating patient populations of interest, which clearly express their evidence needs.

Caspase inhibition attenuates contractile dysfunction following cardioplegic arrest and rewarming in the setting of left ventricular failure

Hyperkalemic cardioplegic arrest (HCA) and rewarming evokes postoperative myocyte contractile dysfunction, a phenomenon of particular importance in settings of preexisting left ventricular (LV) failure. Caspases are intracellular proteolytic enzymes recently demonstrated to degrade myocardial contractile proteins. This study tested the hypothesis that myocyte contractile dysfunction induced by HCA could be ameliorated with caspase inhibition in the setting of compromised myocardial function. LV myocytes were isolated from control pigs (n = 9, 30 kg) or pigs with LV failure induced by rapid pacing (n = 6, 240 bpm for 21 days) and were randomized to the following: (1) normothermia (2003 myocytes), incubation in cell culture medium for 2 hours at 37 degrees C; (2) HCA only (506 myocytes), incubation for 2 hours in hypothermic HCA solution (4 degrees C, 24 mEq K); or (3) HCA + z-VAD, incubation in hypothermic HCA solution supplemented with 10 microM of the caspase inhibitor z-VAD (z-Val-Ala-Asp-fluoromethyl-ketone, 415 myocytes). Inotropic responsiveness was examined using beta-adrenergic stimulation (25 nM isoproterenol). Ambient normothermic myocyte shortening velocity (microm/s) was reduced with LV failure compared with control values (54 +/- 2 versus 75 +/- 2, respectively, P < 0.05). Following HCA, shortening velocity decreased in the LV failure and control groups (27 +/- 5 and 45 +/- 3, P < 0.05). Institution of z-VAD increased myocyte shortening velocity following HCA in both the LV failure and control groups (49 +/- 5 and 65 +/- 5, P < 0.05). Moreover, HCA supplementation with z-VAD increased beta-adrenergic responsiveness in both groups compared with HCA-only values. This study provides proof of concept that caspase activity contributes to myocyte contractile dysfunction following simulated HCA. Pharmacologic caspase inhibition may hold particular relevance in the execution of cardiac surgical procedures requiring HCA in the context of preexisting LV failure.

Myocyte contractility with caspase inhibition and simulated hyperkalemic cardioplegic arrest

BACKGROUND

Exposure of left ventricular (LV) myocytes to simulated hyperkalemic cardioplegic arrest (HCA) has been demonstrated to perturb ionic homeostasis and adversely affect myocyte contractility on rewarming. Altered ionic homeostasis can cause cytosolic activation of the caspases. While caspases participate in apoptosis, these proteases can degrade myocyte contractile proteins, and thereby alter myocyte contractility. Accordingly, this study tested the hypothesis that caspase inhibition during HCA would attenuate the degree of myocyte contractile dysfunction upon rewarming, independent of a loss in myocyte viability.

METHODS

Porcine (n = 8) LV myocytes were isolated and assigned to the following treatment groups: normothermic control: incubation in cell culture media for 2 hours at 37 degrees C; HCA only: incubation for 2 hours in hypothermic HCA solution (4 degrees C, 24 mEq K(+)); or incubation in hypothermic HCA solution supplemented with 10 microM of the caspase inhibitor, z-VAD (z-Val-Ala-Asp-fluoromethyl-ketone, HCA+zVAD). Myocyte viability, assayed as a function of mitochondrial function, was determined to be similar in the normothermic and both HCA groups.

RESULTS

The HCA caused a significant reduction in myocyte shortening velocity compared with normothermic control values (41 +/- 6 versus 86 +/- 8 microm/s, p < 0.05). The HCA+zVAD group had significantly improved myocyte shortening velocity compared with the HCA only group (63 +/- 7 microm/s, p < 0.05).

CONCLUSIONS

Independent of changes in viability, caspase inhibition attenuated myocyte contractile dysfunction after HCA and rewarming. Thus, caspase activation during HCA contributes, at least in part, to impaired myocyte contractility with rewarming. Supplementation of HCA with caspase inhibitors may provide a means to preserve myocyte contractile function after cardioplegic arrest.

The analysis of methamphetamine hydrochloride by thermal desorption ion mobility spectrometry and SIMPLISMA

Ion mobility spectrometry (IMS) has been successfully developed to yield an advanced portable instrument. Such instruments may detect trace quantities of regulated substances at the crime scene. The atmospheric ion chemistry that occurs within the instrument may hinder the determination of analytes in real-world samples. The use of temperature programming adds an extra dimension to the data that improves the selectivity of the IMS data when chemometric processing is applied. The SIMPLISMA (SIMPLe-to-use-Interactive Self-Modeling Mixture Analysis) method is demonstrated for modeling variances in IMS data that are introduced from the temperature program. Methamphetamine hydrochloride IMS peaks are obscured by chemical interferences that arise from cigarette smoke residue. Cigarette smoke residue is pervasive at crime scenes. The ability of SIMPLISMA to resolve the analyte peaks that correspond to methamphetamine hydrochloride from interfering cigarette smoke has been demonstrated. A reduced mobility of 1.62 cm2V-1s-1 was observed for a methamphetamine hydrochloride monomer. With the IMS drift tube at room temperature, a second peak was observed at 1.24 cm2V-1s-1, which is consistent with a dimer ion. This peak has not been previously reported.

A comparative field study of the social behavior and related ecology of reef fishes of the family Chaetodontidae1)2)

20 Species of Chaetodontidae were observed in the field for a total of about 150 hrs at Eniwetok Atoll in the Marshall Islands, at Heron Island on the Great Barrier Reef, and at Johnson Island. During observations the diver either stayed in one place for 30 min, swam transects or followed individual fish. Social groupings of the different species, their intra- and interspecific agonistic interactions and their feeding are described. The frequent occurrence of Chaetodontidae in pairs and the relatively low observed level of agonistic encounters are discussed.

Shell Use: An Adaptation for Emigration from the Sea by the Coconut Crab

The coconut crab. Birgus latro (L.) emigrates from the sea during the postlarval glaucothoe stage. Glaucothoes show ancestral hermit crab behavior of living in empty gastropod shells which protect them during this vulnerable time.