scholarly journals Clinical Chemistry of Congenic Mice with Quantitative Trait Loci for Predicted Responses to Trypanosoma congolense Infection

2009 ◽  
Vol 77 (9) ◽  
pp. 3948-3957 ◽  
Author(s):  
Birgit Rathkolb ◽  
Harry A. Noyes ◽  
Andy Brass ◽  
Paul Dark ◽  
Helmut Fuchs ◽  
...  
Keyword(s):  
Survival Time ◽  
Clinical Chemistry ◽  
Inbred Mice ◽  
Protozoan Parasite ◽  
Physiological Effect ◽  
Trypanosoma Congolense ◽  
Survival Times ◽  
Inflammatory Reactions ◽  
Congenic Mice ◽  
Trait Loci

ABSTRACT Trypanosoma congolense is a protozoan parasite that causes severe diseases in livestock. Three major quantative trait loci (QTL), Tir1, Tir2, and Tir3, control the survival time of mice after infection with T. congolense. Congenic mice carrying the C57BL/6 resistance alleles on the A/J background were developed for each of these loci. The congenic mice were used to physically map the regions containing the QTL gene(s) and to investigate the physiological effect of each locus. Clinical chemistry data for infected A/J, C57BL/6, and BALB/c mice were obtained for 15 analytes at five time points. Congenic mice were assessed for survival, parasitemia, and anemia as well as seven clinical-chemical analytes. The survival times were significantly increased in the Tir1 and Tir2 mice but not Tir3 congenic mice. The survival time of the parental inbred mice correlated negatively with parasitemia but positively with alanine aminotransferase activities in serum, suggesting that inflammatory reactions in the liver had a beneficial effect possibly associated with reduced parasitemia. However, there was no difference in parasitemia or liver enzyme activities of Tir1 and Tir2 congenic mice relative to their controls, showing that survival, parasitemia, and degree of liver damage are not associated with each other, despite the correlation in the parental lines. These data suggest that the congenic loci affect survival but do not affect control of parasite number. They may therefore act by limiting the pathological consequences of T. congolense infection.

Non-specific induction of increased resistance in mice toTrypanosoma congolenseandTrypanosoma bruceiby immunostimulants

Parasitology ◽  
1979 ◽  
Vol 79 (3) ◽  
pp. 349-366 ◽  
Author(s):  
Max Murray ◽  
W. I. Morrison
Keyword(s):  
Survival Time ◽  
Trypanosoma Brucei ◽  
Bordetella Pertussis ◽  
Trypanosoma Congolense ◽  
Bacillus Calmette Guerin ◽  
Survival Times ◽  
Patent Period ◽  
Specific Induction ◽  
Domestic Livestock ◽  
Pre Treatment

SUMMARYAdministration of the immunostimulantsCorynebacterium parvum, Bacillus Calmette-Guérin(BCG) orBordetella pertussisprior to, or at the same time as, challenge withTrypanosoma congolensesignificantly increased survival times in mice, both of trypano-susceptible (A/J) and trypano-resistant (C57Bl) strains. The increased survival time was associated with significant alterations in parasitaemia, which included lengthening of the pre-patent period, a delay in the time taken to reach the first peak of parasitaemia and a reduction in the level of parasitaemia. Similar results were obtained when these strains of mice were challenged withTrypanosoma bruceifollowing pre-treatment withC. parvum. Thus, by the use of immunostimulants it was possible to reduce the susceptibility of mice to trypanosomiasis and the hope is that this can also be achieved with domestic livestock.

scholarly journals Culex quinquefasciatus (Diptera: Culicidae) survivorship following the ingestion of bird blood infected with Haemoproteus sp. parasites

2021 ◽  
Author(s):  
Dayvion R. Adams ◽  
Andrew J. Golnar ◽  
Sarah A. Hamer ◽  
Michel A. Slotman ◽  
Gabriel L. Hamer
Keyword(s):  
Survival Time ◽  
Median Survival ◽  
Culex Quinquefasciatus ◽  
Median Survival Time ◽  
Bird Species ◽  
Protozoan Parasite ◽  
Cardinalis Cardinalis ◽  
Vector Borne ◽  
And Behavior ◽  
Negative Controls

AbstractArthropod vectors are frequently exposed to a diverse assemblage of parasites, but the consequence of these infections on their biology and behavior are poorly understood. We experimentally evaluated whether the ingestion of a common protozoan parasite of avian hosts (Haemoproteus spp.; Haemosporida: Haemoproteidae) impacted the survivorship of Culex quinquefasciatus (Say) (Diptera: Culicidae). Blood was collected from wild northern cardinals (Cardinalis cardinalis) in College Station, Texas, and screened for the presence of Haemoproteus spp. parasites using microscopic and molecular methods. Experimental groups of Cx. quinquefasciatus mosquitoes were offered Haemoproteus-positive cardinal blood through an artificial feeding apparatus, while control groups received Haemoproteus-negative cardinal blood or domestic canary (Serinus canaria domestica) blood. Culex quinquefasciatus mosquitoes exposed to Haemoproteus infected cardinal blood survived significantly fewer days than mosquitoes that ingested Haemoproteus-negative cardinal blood. The survival of mosquitoes fed on positive cardinal blood had a median survival time of 18 days post-exposure and the survival of mosquitoes fed on negative cardinal blood exceeded 50% across the 30 day observation period. Additionally, mosquitoes that fed on canary controls survived significantly fewer days than cardinal negative controls, with canary control mosquitoes having a median survival time of 17 days. This study further supports prior observations that Haemoproteus parasites can be pathogenic to bird-biting mosquitoes, and suggests that Haemoproteus parasites may indirectly suppress the transmission of co-circulating vector-borne pathogens by modulating vector survivorship. Our results also suggest that even in the absence of parasite infection, bloodmeals from different bird species can influence mosquito survivorship.

scholarly journals 3217 Catatonia, Delirium and Coma: Implications for Mortality

2019 ◽  
Vol 3 (s1) ◽  
pp. 37-37
Author(s):  
Jo Ellen Wilson ◽  
Sarasota Mihalko ◽  
Stephan Heckers ◽  
Pratik P. Pandharipande ◽  
Timothy D. Girard ◽  
...  
Keyword(s):  
Survival Time ◽  
Critically Ill ◽  
Median Survival ◽  
Critically Ill Patients ◽  
Median Survival Time ◽  
Rating Scale ◽  
Brain Dysfunction ◽  
Survival Times ◽  
Dsm 5 ◽  
Acute Brain Dysfunction

OBJECTIVES/SPECIFIC AIMS: Delirium, a form of acute brain dysfunction, characterized by changes in attention and alertness, is a known independent predictor of mortality in the Intensive Care Unit (ICU). We sought to understand whether catatonia, a more recently recognized form of acute brain dysfunction, is associated with increased 30-day mortality in critically ill older adults. METHODS/STUDY POPULATION: We prospectively enrolled critically ill patients at a single institution who were on a ventilator or in shock and evaluated them daily for delirium using the Confusion Assessment for the ICU and for catatonia using the Bush Francis Catatonia Rating Scale. Coma, was defined as a Richmond Agitation Scale score of −4 or −5. We used the Cox Proportional Hazards model predicting 30-day mortality after adjusting for delirium, coma and catatonia status. RESULTS/ANTICIPATED RESULTS: We enrolled 335 medical, surgical or trauma critically ill patients with 1103 matched delirium and catatonia assessments. Median age was 58 years (IQR: 48 - 67). Main indications for admission to the ICU included: airway disease or protection (32%; N=100) or sepsis and/or shock (25%; N=79. In the unadjusted analysis, regardless of the presence of catatonia, non-delirious individuals have the highest median survival times, while delirious patients have the lowest median survival time. Comparing the absence and presence of catatonia, the presence of catatonia worsens survival (Figure 1). In a time-dependent Cox model, comparing non-delirious individuals, holding catatonia status constant, delirious individuals have 1.72 times the hazards of death (IQR: 1.321, 2.231) while those with coma have 5.48 times the hazards of death (IQR: 4.298, 6.984). For DSM-5 catatonia scores, a 1-unit increase in the score is associated with 1.18 times the hazards of in-hospital mortality. Comparing two individuals with the same delirium status, an individual with a DSM-5 catatonia score of 0 (no catatonia) will have 1.178 times the hazard of death (IQR: 1.086, 1.278), while an individual with a score of 3 catatonia items (catatonia) present will have 1.63 times the hazard of death. DISCUSSION/SIGNIFICANCE OF IMPACT: Non-delirious individuals have the highest median survival times, while those who are comatose have the lowest median survival times after a critical illness, holding catatonia status constant. Comparing the absence and presence of catatonia, the presence of catatonia seems to worsen survival. Those individual who are both comatose and catatonic have the lowest median survival time.

scholarly journals Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Purity K. Gitonga ◽  
Kariuki Ndung’u ◽  
Grace A. Murilla ◽  
Paul C. Thande ◽  
Florence N. Wamwiri ◽  
...  
Keyword(s):  
Survival Time ◽  
Trypanosoma Brucei ◽  
Acute Infection ◽  
Glossina Pallidipes ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Economic Losses ◽  
Entire Group ◽  
Tsetse Flies ◽  
African Countries

African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4–11) and 4.5 ± 0.2 (range, 4–6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

Combined cyclotron fast-neutron and BCNU therapy in a rat brain-tumor model

1981 ◽  
Vol 54 (4) ◽  
pp. 461-467 ◽  
Author(s):  
Alexander M. Spence ◽  
Joseph P. Geraci
Keyword(s):  
Gamma Irradiation ◽  
Survival Time ◽  
Fast Neutron ◽  
Combined Therapy ◽  
Tumor Model ◽  
Survival Times ◽  
Gamma Photon ◽  
Maximum Enhancement ◽  
Content Type ◽  
Fine Print

✓ The combination of cyclotron fast-neutron radiotherapy with BCNU chemotherapy was compared to 137Cs gamma photon radiotherapy combined with BCNU in the 36B-10, F-344 rat-transplanted glioma model. Radiation and drug treatments were administered 7 to 8 days after intracerebral tumor implantation. Increase in animal survival time was used as the measure of the effectiveness of various treatment schedules. Single-dose neutron or gamma radiotherapy was tested on Day 7 over the ranges 0 to 900 rads and 0 to 2000 rads, respectively. This therapy produced increases in mean survival times up to 70% at the highest radiation doses. When BCNU (10 mg/kg body weight) was administered intravenously on Day 8, 1 day following radiotherapy, mean survival times were increased by an additional 35% to 50%, irrespective of the dose or type of irradiation. In contrast, by using the same radiation and drug doses but scheduling combined therapy trials so that BCNU was administered 1 hour before either neutron or gamma irradiation on Day 7, there was enhancement of the radiation effect by BCNU. Under these conditions, the maximum enhancement of the mean survival time was 70% to 75% in neutron-treated animals and 120% to 150% in gamma-treated animals. Treatment with BCNU 1 hour before or 1 day after neutron irradiation proved to be no more effective in improving the survival time of tumor-bearing animals than the drug similarly combined with conventional gamma irradiation.

Effect of Cytokine Therapy on Survival for Patients With Advanced Renal Cell Carcinoma

2000 ◽  
Vol 18 (9) ◽  
pp. 1928-1935 ◽  
Author(s):  
Robert J. Motzer ◽  
Madhu Mazumdar ◽  
Jennifer Bacik ◽  
Paul Russo ◽  
William J. Berg ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Survival Time ◽  
Median Survival ◽  
Renal Cell ◽  
Interleukin 2 ◽  
Interferon Alfa ◽  
Cytokine Therapy ◽  
Survival Times ◽  
Long Term Survivors

PURPOSE: To evaluate the relationship between treatment with cytokine therapy and survival, investigate the effect of nephrectomy on survival, and identify long-term survivors among a cohort of 670 patients with advanced renal cell carcinoma (RCC). PATIENTS AND METHODS: A total of 670 patients with advanced RCC treated on 24 clinical trials of systemic chemotherapy or cytokine therapy were the subjects of this retrospective analysis. Treatment was categorized as cytokine (containing interferon alfa and/or interleukin-2) in 396 patients (59%) and as chemotherapy (cytotoxic or hormonal therapy) in 274 (41%). Among the 670 patients, those with survival times of greater than 5 years were identified as long-term survivors. RESULTS: Patients treated with cytokine therapy had a longer survival time than did those treated with chemotherapy, regardless of the year of treatment or risk category based on pretreatment features. The median survival times for favorable-, intermediate-, and poor-risk patients were 27, 12, and 6 months for those treated with cytokines and 15, 7, and 3 months for those treated with chemotherapy, respectively. The magnitude of difference in median survival was greater in the favorable- and intermediate-risk groups. The median survival time was less than 6 months in the poor-risk group for both treatment programs. Median survival time was 14 months among patients with prior nephrectomy plus time from diagnosis to treatment greater than 1 year versus 8 months among those with time from diagnosis to treatment less than 1 year, regardless of pretreatment nephrectomy status. Thirty patients (4.5%) among the 670 patients were identified as long-term survivors; 12 were free of disease after nephrectomy and treatment with interferon alfa, interleukin-2, or surgical resection of metastasis. CONCLUSION: The low proportion of patients with advanced RCC who achieve long-term survival emphasizes the need for clinical investigation to identify more effective therapy.

Effect of Intravenous Iron in Experimental Traumatic Shock

1956 ◽  
Vol 186 (3) ◽  
pp. 554-556
Author(s):  
Donn L. Smith ◽  
Irvin I. Kibbey ◽  
Max E. Bierwagen ◽  
J. R. Cruse
Keyword(s):  
Heavy Metal ◽  
Survival Time ◽  
Metal Toxicity ◽  
Intravenous Iron ◽  
Traumatic Shock ◽  
Survival Times ◽  
Albino Rat ◽  
Liver Iron ◽  
Mean Survival Time ◽  
The Mean

Intravenous administration of colloidal saccharated iron oxide prior to intestinal traumatization in the albino rat resulted in a significant reduction of the mean survival time. Sodium gold thiosulfate and colloidal manganese hydroxide employed in the same manner did not significantly alter mean survival times. ACTH and cortisone did not modify the deleterious effects of iron in experimental traumatic shock. A decrease in soluble liver iron was observed when traumatization followed the injection of iron. It was concluded that the reduction of mean survival time in iron injected, traumatized animals was due to a specific action of iron and is not the result of generalized heavy metal toxicity.

A permutation test based on the restricted mean survival time for comparison of net survival distributions in non-proportional excess hazard settings

2019 ◽  
Vol 29 (6) ◽  
pp. 1612-1623
Author(s):  
Anna Wolski ◽  
Nathalie Grafféo ◽  
Roch Giorgi ◽  
Keyword(s):  
Survival Time ◽  
Proportional Hazards ◽  
Permutation Test ◽  
Survival Times ◽  
Test Statistic ◽  
Specific Test ◽  
Net Survival ◽  
Mean Survival Time ◽  
Restricted Mean Survival Time ◽  
Type Test

Net survival is used in epidemiological studies to assess excess mortality due to a given disease when causes of death are unreliable. By correcting for the general population mortality, it allows comparisons between regions or periods and thus evaluation of health policies. The Pohar-Perme non-parametric estimator of net survival has been recently proposed, soon followed by an appropriate log-rank-type test. However, log-rank tests are known to be under-optimal in non-proportional settings (e.g. crossing of the hazard functions). In classical survival analysis, one solution is to compare the restricted mean survival times. A difference in restricted mean survival time represents a life benefit or loss over the studied period. In the present article the restricted mean net survival time was used to derive a specific test statistic to compare net survivals in proportional and non-proportional hazards settings. The new test was generalized to more than two groups and to stratified analysis. The test performance was assessed on simulation study, compared to the log-rank-type test, and its use illustrated on a population-based colorectal cancer registry. The new test for net survival comparisons proved robust to non-proportionality and well-performing in proportional hazards situations. Furthermore, it is also suited to the classical survival framework.

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