Effects of feeding frequency on life processes of the planktonic foraminifer Globigerinoides sacculifer in laboratory culture

1981 ◽  
Vol 61 (1) ◽  
pp. 257-277 ◽  
Author(s):  
A. W. H. Bé ◽  
D. A. Caron ◽  
O. R. Anderson
Keyword(s):  
Survival Time ◽  
Survival Data ◽  
Inverse Correlation ◽  
Laboratory Culture ◽  
Control Group ◽  
Feeding Frequency ◽  
Planktonic Foraminifer ◽  
Shell Size ◽  
Average Survival ◽  
Feeding Regimes

Globigerinoides sacculifer (Brady), a common planktonic foraminifer collected by SCUBA off Barbados, was maintained under six feeding regimes at constant light and temperature conditions. Five groups of 63 specimens each were fed 1-day-old Anemia at the rate of one nauplius per specimen every 1, 2, 3, 4 or 7 days. A starved control group received no Anemia. The rate of chamber formation and shell size increased proportional to the feeding frequency. However, an inverse correlation existed between survival time and feeding frequency. Normally, survival time ends with gametogenesis which terminates the life of the mother cell. Organisms fed more frequently reached maturity and underwent gametogenesis more rapidly than those fed less frequently. The average survival time of G. sacculifer in culture ranged from 7 days for the daily-fed group to 11 days for the group fed every 7 days. While the latter grew more slowly they eventually reached maturity. Starved individuals rarely formed chambers and often died without undergoing gametogenesis. Symbiotic zooxanthellae presumably prolonged survival of starved organisms. Extrapolation of survival data suggests G. sacculifer has a variable life span of 2 to 4 weeks depending on food availability.

THE EFFECT OF CHLORPROMAZINE GIVEN WITH REINFUSION ON THE MORTALITY RATE FROM STANDARDIZED HEMORRHAGIC SHOCK IN THE RAT

1956 ◽  
Vol 34 (2) ◽  
pp. 217-221 ◽  
Author(s):  
G. F. Carruthers ◽  
C. W. Gowdey
Keyword(s):  
Mortality Rate ◽  
Arterial Pressure ◽  
Hemorrhagic Shock ◽  
Survival Time ◽  
Group Differences ◽  
Control Group ◽  
Control Groups ◽  
Average Survival Time ◽  
Anesthetized Rats ◽  
Average Survival

Anesthetized rats were subjected to a standardized hemorrhagic shock procedure; one group (20 animals) served as controls and another group (eight animals) was injected with chlorpromazine. The treated animals died very quickly: only one survived more than 12 hr. and none 48 hr.; the average survival time of 18 control fatalities was 14.0 hr., and two lived. Of the various cardiovascular and respiratory indices measured, only the post-reinfusion arterial pressure was different in the treated from that in the control group. Differences between the control groups in this and in an earlier series (Downie and Stevenson (1955)) can probably be accounted for by differences in the temperature of the laboratory.

Effects of variations in light intensity on life processes of the planktonic foraminifer Globigerinoides sacculifer in laboratory culture

1982 ◽  
Vol 62 (2) ◽  
pp. 435-451 ◽  
Author(s):  
David A. Caron ◽  
Allan W. H. Bé ◽  
O. Roger Anderson
Keyword(s):  
Light Intensity ◽  
Shell Growth ◽  
Euphotic Zone ◽  
Rapid Onset ◽  
Feeding Frequency ◽  
Planktonic Foraminifer ◽  
Continuous Darkness ◽  
Shell Size ◽  
Growth And Reproduction ◽  
Effect On Growth

The planktonic foraminifer Globigerinoides sacculifer (Brady) was cultured under two different light intensities and in continuous darkness. High light intensity (HLI = 400–500 μeinsteins/m2/s) resulted in a longer lifespan, a greater number of chambers formed, and a larger final shell size compared with individuals cultured under low light intensity (LLI = 20–50 μeinsteins/m2/s) or in continuous darkness. Shell growth rates were unaffected by increasing light intensity, but gametogenesis was delayed. Continuous darkness induced a rapid onset of gametogenesis in organisms with shell lengths larger than 250 μm. Feeding frequency had a greater effect on growth and reproduction than light intensity under conditions of LLI and HLI, but continuous darkness had an overriding effect on growth and reproduction owing to the rapid onset of gametogenesis which terminated the life of the mother cell. Our previous data indicated that the longevity of G. sacculifer was dependent on feeding frequency, and that G. sacculifer cultured under LLI had a lifespan of approximately 2–4 weeks. Present results suggest that the lifespan can vary from a minimum of 8 days for organisms fed daily in continuous darkness to a maximum of 54 days for organisms fed once every 7 days and maintained in HLI. It is concluded that individual G. sacculifer attain a shell size greater than 600 μm only if they maintain their position in the euphotic zone. Prolonged existence below the euphotic zone would result in premature death or gametogenesis following stunted shell growth.

THE EFFECT OF CHLORPROMAZINE GIVEN WITH REINFUSION ON THE MORTALITY RATE FROM STANDARDIZED HEMORRHAGIC SHOCK IN THE RAT

1956 ◽  
Vol 34 (1) ◽  
pp. 217-221
Author(s):  
G. F. Carruthers ◽  
C. W. Gowdey
Keyword(s):  
Mortality Rate ◽  
Arterial Pressure ◽  
Hemorrhagic Shock ◽  
Survival Time ◽  
Group Differences ◽  
Control Group ◽  
Control Groups ◽  
Average Survival Time ◽  
Anesthetized Rats ◽  
Average Survival

Anesthetized rats were subjected to a standardized hemorrhagic shock procedure; one group (20 animals) served as controls and another group (eight animals) was injected with chlorpromazine. The treated animals died very quickly: only one survived more than 12 hr. and none 48 hr.; the average survival time of 18 control fatalities was 14.0 hr., and two lived. Of the various cardiovascular and respiratory indices measured, only the post-reinfusion arterial pressure was different in the treated from that in the control group. Differences between the control groups in this and in an earlier series (Downie and Stevenson (1955)) can probably be accounted for by differences in the temperature of the laboratory.

scholarly journals Tracking Study on the Relapse and Aftercare Effect of Drug Patients Released From a Compulsory Isolated Detoxification Center

2022 ◽  
Vol 12 ◽  
Author(s):  
Nian Liu ◽  
Zekai Lu ◽  
Ying Xie
Keyword(s):  
Survival Time ◽  
Relapse Rate ◽  
Social Worker ◽  
Control Variable ◽  
Control Group ◽  
Survival Times ◽  
Average Survival ◽  
Professional Social Worker ◽  
Time To Relapse ◽  
Experimental Group

Background and AimsThere are no accurate statistical data on the relapse rate of drug abstainers after compulsory detoxification in China. This study aimed to collect relapse data for drug abstainers through follow-up visits, verify the effectiveness of professional social worker services and explore significant factors affecting relapse.Design and SettingThe drug abstainers released from Guangzhou T Compulsory Isolated Detoxification Center were randomly divided into two groups. The difference between the experimental group and the control group is that assistance services were provided by social workers to the former.ParticipantsThe study included 510 drug abstainers released from T Center, including 153 in the experimental group and 357 in the control group.MeasurementsDemographic information, history of drug abuse, and motivation for drug rehabilitation (SOCRATES) were collected 1 month prior to drug abstainer release from compulsory detoxification. Then, the relapse situation after their release was tracked according to fixed time points.FindingsThe overall relapse rate of 510 drug abstainers after their release from compulsory detoxification was 47.6%. The average survival time to relapse based on survival analysis was 220 days (N = 486), as calculated with Bayesian estimation by the MCMC method. The average survival times to relapse of the experimental group and control group were 393 and 175 days, respectively. By taking the specific survival time as the dependent variable and the group as the control variable (OR = 25.362), logistic regression analysis showed that marital status (OR = 2.666), previous compulsory detoxification experience (OR = 2.329) and location of household registration (OR = 1.557) had a significant impact on the survival time to relapse.ConclusionsThe occurrence of relapse among drug patients released from compulsory detoxification can be delayed effectively through the intervention of professional social worker services. Regardless of whether patients receive aftercare after compulsory detoxification, drug-using patients who are single, have multiple detoxification experiences and whose households are registered in other provinces deserve special attention. Relevant suggestions to avoid relapse are provided.

Treatment of ovarian cancer patients with malignant ascites using the trifunctional antibody catumaxomab: Results of a phase II/III study

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 5520-5520 ◽  
Author(s):  
S. L. Parsons ◽  
E. Kutarska ◽  
P. Koralewski ◽  
M. Gore ◽  
P. Wimberger ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Cell ◽  
Survival Time ◽  
Tumor Cells ◽  
Survival Data ◽  
Progression Free Survival ◽  
Malignant Ascites ◽  
Control Group ◽  
Free Survival ◽  
Time To Death

5520 Background: Malignant ascites in ovarian carcinoma patients (pts.) is associated with a poor prognosis and reduced quality of life. Catumaxomab (anti-EpCAM × anti-CD3) is known to effectively eliminate tumor cells within ascites by simultaneously activating T cells and Fc gamma-receptor positive cells and redirecting them against the tumor. Methods: A total of 129 ovarian cancer pts. with recurrent symptomatic malignant ascites containing EpCAM+ tumor cells were enrolled in the study; 85 were randomized to treatment with catumaxomab (paracentesis plus intraperitoneal infusions of 10, 20, 50 and 150 μg for 11 days), and 44 to the control arm (paracentesis alone). The primary endpoint was puncture free survival (time to first need for paracentesis after treatment or time to death, which ever occurred first). Results: Pts. characteristics were well balanced in both arms. Median puncture free survival was 52 days for catumaxomab vs. 11 days for control (p<0.0001) whereas the median time to first need for paracentesis was 71 days vs. 11 days l (p<0.0001). There was a pronounced decrease of tumor cell load accompanied by a distinct increase of leukocyte count during catumaxomab treatment within the ascites fluid. Overall and progression free survival data suggest longer survival for catumaxomab-treated pts. compared to control. Follow-up data will be presented. The most frequent AEs were symptoms related to cytokine release (pyrexia, nausea, vomiting). These were generally mild to moderate in intensity, and fully reversible. Transient increases in liver enzymes and bilirubin, and transient WBC abnormalities such as leukocytosis, neutrophilia and a decrease in peripheral lymphocyte were regularly observed as abnormal laboratory values but rarely considered clinically significant. Conclusions: Intraperitoneal therapy with catumaxomab resulted in a significant and clinically relevant improvement of puncture-free survival time, tumor cell load, and time to first need for puncture compared to the control group of best available treatment. The safety profile reflects catumaxomabs mode of action and reveals a low and acceptable toxicity. No significant financial relationships to disclose.

A Maximum Entropy Estimator for the Average Survival Time Differences between Two Groups

2020 ◽  
Vol 7 (2) ◽  
pp. 107-112
Author(s):  
Marian Manciu ◽  
Sorour Hosseini ◽  
Joscelyne Guzman-Gonzalez
Keyword(s):  
Survival Time ◽  
Maximum Entropy ◽  
Time Difference ◽  
Reliable Estimate ◽  
Average Survival Time ◽  
Sample Number ◽  
Time To Event Data ◽  
Entropy Estimator ◽  
Average Survival ◽  
The Difference

Background: Statistical methods commonly used in survival analysis typically provide the probability that the difference between groups is due to chance, but do not offer a reliable estimate of the average survival time difference between groups (the difference between median survival time is usually reported). Objective: We suggest a Maximum-Entropy estimator for the average Survival Time Difference (MESTD) between groups. Methods: The estimator is based on the extra survival time, which should be added to each member of the group, to produce the maximum entropy of the result (resulting in the groups becoming most similar). The estimator is calculated only from time to event data, does not necessarily assume hazard proportionality and provides the magnitude of the clinical differences between the groups. Results: Monte Carlo simulations show that, even at low sample numbers (much lower than the ones needed to prove that the two groups are statistically different), the MESTD estimator is a reliable predictor of the clinical differences between the groups, and therefore can be used to estimate from (low sample numbers) preliminary data whether or not the large sample number experiment is worth pursuing. Conclusion: By providing a reasonable estimate for the efficacy of a treatment (e.g., for cancer) even for low sample data, it might provide useful insight in testing new methods for treatment (for example, for quick testing of multiple combinations of cancer drugs).

scholarly journals Effect of Systemic Corticosteroid Therapy on the Efficacy and Safety of Nivolumab in the Treatment of Non-Small-Cell Lung Cancer

2021 ◽  
Vol 28 ◽  
pp. 107327482098579
Author(s):  
Kengo Umehara ◽  
Kaori Yama ◽  
Keisuke Goto ◽  
Azusa Wakamoto ◽  
Tae Hatsuyama ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Adverse Events ◽  
Small Cell Lung Cancer ◽  
Survival Time ◽  
Cell Lung Cancer ◽  
Objective Response ◽  
Small Cell ◽  
Control Group ◽  
Small Cell Lung ◽  
Corticosteroid Administration

Introduction: Corticosteroids are used to treat immune-related adverse events (irAEs) associated with nivolumab. However, patients with non-small-cell lung cancer who are administered corticosteroids before the initiation of nivolumab treatment are commonly excluded from clinical trials. The appropriate timing for corticosteroid administration in relation to nivolumab treatment, effects of corticosteroids on the efficacy of nivolumab, and resulting adverse events are not clearly understood. In this study, the effects of differences in the timing of corticosteroid administration on nivolumab efficacy and the resulting adverse events were examined. Methods: A retrospective study was conducted with 109 patients who were treated with nivolumab at Sapporo Minami-Sanjo Hospital between December 2015 and March 2018. Results: Of the 109 patients treated with nivolumab, 12 patients were administered corticosteroids before the first cycle of nivolumab (pre-CS), and 33 patients were administered corticosteroids after the first cycle of nivolumab (post-CS). These 2 groups were compared with the control group comprising 64 patients who were not administered corticosteroids (non-CS). The objective response rate in the post-CS group was significantly higher than that in the non-CS group, and the disease control rate in the pre-CS group was significantly lower than that in the non-CS group. The overall survival time and progression-free survival time in the pre-CS group were significantly shorter than those observed in the non-CS group; however, these did not differ from those in the post-CS group. Conclusions: These results suggest that corticosteroids administered to patients with non-small-cell lung cancer after initiation of nivolumab treatment did not affect the disease prognosis. Thus, corticosteroids can be administered immediately for rapid treatment of irAEs.

scholarly journals Extrapolating Parametric Survival Models in Health Technology Assessment Using Model Averaging: A Simulation Study

2021 ◽  
Vol 41 (4) ◽  
pp. 476-484
Author(s):  
Daniel Gallacher ◽  
Peter Kimani ◽  
Nigel Stallard
Keyword(s):  
Survival Time ◽  
Survival Data ◽  
Mean Squared Error ◽  
Model Averaging ◽  
Information Criterion ◽  
Health Technology ◽  
Weighted Averaging ◽  
Health Technologies ◽  
Mean Survival Time ◽  
Restricted Mean Survival Time

Previous work examined the suitability of relying on routine methods of model selection when extrapolating survival data in a health technology appraisal setting. Here we explore solutions to improve reliability of restricted mean survival time (RMST) estimates from trial data by assessing model plausibility and implementing model averaging. We compare our previous methods of selecting a model for extrapolation using the Akaike information criterion (AIC) and Bayesian information criterion (BIC). Our methods of model averaging include using equal weighting across models falling within established threshold ranges for AIC and BIC and using BIC-based weighted averages. We apply our plausibility assessment and implement model averaging to the output of our previous simulations, where 10,000 runs of 12 trial-based scenarios were examined. We demonstrate that removing implausible models from consideration reduces the mean squared error associated with the restricted mean survival time (RMST) estimate from each selection method and increases the percentage of RMST estimates that were within 10% of the RMST from the parameters of the sampling distribution. The methods of averaging were superior to selecting a single optimal extrapolation, aside from some of the exponential scenarios where BIC already selected the exponential model. The averaging methods with wide criterion-based thresholds outperformed BIC-weighted averaging in the majority of scenarios. We conclude that model averaging approaches should feature more widely in the appraisal of health technologies where extrapolation is influential and considerable uncertainty is present. Where data demonstrate complicated underlying hazard rates, funders should account for the additional uncertainty associated with these extrapolations in their decision making. Extended follow-up from trials should be encouraged and used to review prices of therapies to ensure a fair price is paid.

scholarly journals Astragalus Polysaccharide Injection (PG2) Normalizes the Neutrophil-to-Lymphocyte Ratio in Patients with Advanced Lung Cancer Receiving Immunotherapy

2021 ◽  
Vol 20 ◽  
pp. 153473542199525
Author(s):  
Shih Ming Tsao ◽  
Tz Chin Wu ◽  
JiZhen Chen ◽  
Feichi Chang ◽  
Thomos Tsao
Keyword(s):  
Lung Cancer ◽  
Overall Survival ◽  
Survival Data ◽  
Treatment Initiation ◽  
Checkpoint Inhibitors ◽  
Neutrophil To Lymphocyte Ratio ◽  
Advanced Lung Cancer ◽  
Control Group ◽  
Lymphocyte Ratio ◽  
Astragalus Polysaccharide

Objectives: The neutrophil-to-lymphocyte ratio (NLR) is a prognostic marker in patients with cancer receiving immunotherapy. Recent studies have shown that a high NLR was associated with a poor response and decreased survival. However, there is no intervention to reverse abnormally high NLR and improve clinical outcomes. Astragalus polysaccharide injection (PG2) is an immunomodulatory therapy for cancer-related fatigue. This study aimed to examine whether PG2 might normalize the NLR and affect the overall survival of patients with lung cancer treated with immunotherapy. Materials and Methods: We retrospectively examined the medical records of patients with lung cancer treated with immune checkpoint inhibitors (ICIs) between October 1, 2015 and November 30, 2019. All patients received ICI combination chemotherapies, and some similarly received PG2 (Control vs PG2). The NLR was assessed before treatment and 6 weeks after ICI initiation, and the survival data was collected at least 4 years after treatment initiation for the first enrolled patient. Results: Fifty-three patients were included. Six weeks after ICI initiation, 91.3% of the patients in the PG2 group exhibited a predefined “Decrease or no change” in the NLR, which was 28% higher than that in the Control group (63.3%) ( P = .028). The NLR significantly decreased by 31.60% from baseline in the PG2 group ( P = .012), whereas it increased by 5.80% in the Control group ( P = .572). Six weeks after ICI treatment initiation, both groups had a median NLR of 3.73, and the overall survival was also similar (PG2 vs Control, 26.1 months vs 25.4 months, respectively); however, the PG2 group had a higher median baseline NLR than the Control group (PG2 vs Control, 4.51 vs 2.81, respectively). Conclusion: This study demonstrated that PG2 could normalize the NLR in patients with lung cancer receiving ICI combination treatments.

Abstract 320: End-Tidal Carbon Dioxide Can Guide Fluid Resuscitation in a Cecal Ligation and Puncture Induced Rat Model of Sepsis

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Jing Xu ◽  
Guanghui Zheng ◽  
Liangliang Wu ◽  
Xiangshao Fang ◽  
Yue Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Survival Time ◽  
Fluid Resuscitation ◽  
Rat Model ◽  
Cecal Ligation ◽  
Control Group ◽  
Cecal Ligation And Puncture ◽  
End Tidal Carbon Dioxide ◽  
Lactate Levels ◽  
End Tidal

Introduction: Abnormal levels of end-tidal carbon dioxide (ETCO 2 ) may reflect a derangement in perfusion, metabolism, or gas exchange. It is unclear if ETCO 2 can be used for fluid resuscitation (FR) compared with traditional mean arterial pressure (MAP) as an outcome predictor in sepsis. Hypothesis: Use of ETCO2 is better than MAP in guiding fluid resuscitation to improve lactate levels and microcirculatory blood flow in sepsis. Methods: Thirty-five male Sprague-Dawley rats weighing 350-400g were randomized to: 1) SHAM, n=5; 2) cecal ligation and puncture (CLP) Control group (with CLP, without FR, n=10); 3) ETCO 2 group (with CLP, FR began when ETCO 2 ≤25 mmHg, n=10) and 4) MAP group (with CLP, FR began when MAP≤100 mmHg, n=10). Lactate level, cardiac output (CO), perfused small vessel density (PSVD) and sublingual microvascular flow index (MFI) was assessed at baseline, 2 h, 4 h, 8 h, 10 h and 12 h post-CLP. Survival duration was recorded. Results: After FR,CO in the ETCO 2 group increased compared with the MAP group 12h after CLP while lactate levels decreased compared with the Control and MAP groups (p<0.05) (Figure-1). Both sublingual PSVD and MFI decreased after CLP in the control group and MAP group but significantly improved in the ETCO 2 group 8h post-CLP. The average survival time in the ETCO 2 group was significantly greater than MAP group (Figure-2). Conclusions: ETCO 2 guided FR was associated with improved CO, lactate, microcirculatory flow, and survival time compared to MAP guided FR in a CLP-induced rat model of sepsis.

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