scholarly journals Distinct Persistence Fate of Mycobacterium tuberculosis in Various Types of Cells

mSystems ◽  
2021 ◽  
Author(s):  
Xi Chen ◽  
Xiaojian Cao ◽  
Yingying Lei ◽  
Aikebaier Reheman ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Host Cell ◽  
Intracellular Pathogen ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Immune Clearance ◽  
Multiple Strategies ◽  
New Approaches

As an intracellular pathogen, Mycobacterium tuberculosis could avoid host cell immune clearance using multiple strategies for its long-term survival. Understanding these processes could facilitate the development of new approaches to restrict intracellular M. tuberculosis survival.

The influence of sex and the presence of giant cells on postoperative long-term survival in adult patients with supratentorial glioblastoma multiforme

2004 ◽  
Vol 101 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Naoki Shinojima ◽  
Masato Kochi ◽  
Jun-Ichiro Hamada ◽  
Hideo Nakamura ◽  
Shigetoshi Yano ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Giant Cell ◽  
Adult Patients ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Free Interval ◽  
Younger Age ◽  
Fine Print

Object. Glioblastoma multiforme (GBM) remains incurable by conventional treatments, although some patients experience long-term survival. A younger age, a higher Karnofsky Performance Scale (KPS) score, more aggressive treatment, and long progression-free intervals have been reported to be positively associated with long-term postoperative patient survival. The aim of this retrospective study was the identification of additional favorable prognostic factors affecting long-term survival in surgically treated adult patients with supratentorial GBM. Methods. Of 113 adult patients newly diagnosed with histologically verified supratentorial GBM who were enrolled in Phase III trials during the period between 1987 and 1998, six (5.3%) who survived for longer than 5 years were defined as long-term survivors, whereas the remaining 107 patients served as controls. All six were women and were compared with the controls; they were younger (mean age 44.2 years, range 31–60 years), and their preoperative KPS scores were higher (mean 85, range 60–100). Four of the six patients underwent gross-total resection. In five patients (83.3%) the progression-free interval was longer than 5 years and in three a histopathological diagnosis of giant cell GBM was made. This diagnosis was not made in the other 107 patients. Conclusions. Among adult patients with supratentorial GBM, female sex and histopathological characteristics consistent with giant cell GBM may be predictive of a better survival rate, as may traditional factors (that is, younger age, good KPS score, more aggressive resection, and a long progression-free interval).

Adult cerebellar medulloblastomas: the pathological, radiographic, and clinical disease spectrum

1989 ◽  
Vol 70 (4) ◽  
pp. 536-544 ◽  
Author(s):  
Jerry L. Hubbard ◽  
Bernd W. Scheithauer ◽  
David B. Kispert ◽  
Sandra M. Carpenter ◽  
Mark R. Wick ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Spinal Metastases ◽  
Tumor Location ◽  
Major Effect ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Disease Spectrum ◽  
Imaging Characteristics

✓ The records of 34 patients over 16 years of age with cerebellar medulloblastoma were retrospectively reviewed. All patients were treated by surgery, and all surviving patients were given radiation therapy. The imaging characteristics of this rare entity were evaluated with regard to the tumor location in the cerebellum, and the prognostic effects of histological characteristics such as neuronal or glial differentiation and the presence of desmoplasia were investigated. Neither histological parameters nor tumor location (median, paramedian, or lateral cerebellar) affected patient survival. The desmoplastic variant was encountered in 38% of these adult medulloblastomas and occurred in all three cerebellar locations. The degree of surgical resection did not have a major effect on long-term survival; long-term survival was possible even in patients who had received only a biopsy. The extent of initial radiation therapy was positively correlated with recurrence-free survival; full neuraxis irradiation was associated with a 13% incidence of delayed spinal metastases, whereas 75% of patients treated with irradiation of only the posterior fossa and/or the whole brain developed spinal deposits. A similar local recurrence rate (12.5%) was noted in both irradiation groups. Chemotherapy resulted in palliation in some patients with metastatic disease.

Enterprise survival in the high-tech community: persuasion and power in board decisions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ronit Yitshaki ◽  
Eli Gimmon ◽  
Susanna Khavul
Keyword(s):  
High Tech ◽  
Structured Interviews ◽  
Board Size ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Board Processes ◽  
Start Up ◽  
Start Ups

Purpose This study aims to examine the extent to which board size, the use of power by venture capital investors and entrepreneurs’ interpersonal tactics such as persuasion to sway board decisions, influence the long-term survival of start-ups. Design/methodology/approach This study used a mixed-methods approach. The quantitative part is based on data collected from 179 chief executive officers (CEOs) of high-tech start-ups community financed by venture capitalists (VCs) in Israel of which 59 did not survive. To achieve a better understanding of these findings, semi-structured interviews with 12 entrepreneurs were conducted. Findings Smaller boards were positively associated with venture survival. The use of power by VC investors positively influenced start-up survival. CEO persuasion had a negative effect on venture survival; however, its interaction with board size suggests that it had a lesser effect on very small boards. Practical implications Although investors’ control over decision-making contributes to long-term survival, entrepreneurs should be aware of the possible detrimental effects of exercising a high level of persuasion in board processes. The findings also suggest that a small board size is preferable for start-up survival. Originality/value Exploring the effect of board processes on venture survival is considered complex. A unique sample of high-technology start-ups consisting of both surviving and failed start-ups was analyzed to explore the effects of persuasion and power in board processes.

Corporate sustainability management under market uncertainty

2019 ◽  
Vol 32 (5) ◽  
pp. 1023-1037 ◽  
Author(s):  
Honglei Liu ◽  
Sang Jin Kim ◽  
Huanzhang Wang ◽  
Kyung Hoon Kim
Keyword(s):  
Social Responsibility ◽  
Corporate Sustainability ◽  
Environmental Responsibility ◽  
Market Uncertainty ◽  
Term Survival ◽  
Sustainability Management ◽  
Long Term Survival ◽  
Content Type ◽  
Survival And Growth

Purpose The purpose of this paper is to understand how market uncertainty affects sustainability management for long-term survival and growth. Design/methodology/approach Structural equation modeling is applied to evaluate the research model using data from a survey of 210 firms in China. Findings Empirical findings show that market uncertainty encourages entrepreneurship, which is an impetus for sustainability management. Economic and environmental responsibility positively affects balanced scorecard, but social responsibility does not. Research limitations/implications The study results show that economic and environmental responsibility is essential for success, but social responsibility appears to lack effect. Therefore, future research might further explore why social responsibility fails to enhance corporate performance. Practical implications When firms consider sustainability management for long-term survival and growth, they should not only strive to grow regional economic benefits but also adhere to environmental regulations and protect the local ecosystem. Originality/value This study observes how market uncertainty, entrepreneurship and corporate sustainability (economic, environmental and social responsibility) affect the overall performance of firms in China.

scholarly journals Desiccation as a Long-Term Survival Mechanism for the Archaeon Methanosarcina barkeri

2011 ◽  
Vol 78 (5) ◽  
pp. 1473-1479 ◽  
Author(s):  
Kimberly L. Anderson ◽  
Ethel E. Apolinario ◽  
Kevin R. Sowers
Keyword(s):  
Survival Rates ◽  
Extracellular Polysaccharide ◽  
Significant Loss ◽  
Methanosarcina Barkeri ◽  
Stress Factors ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Protection Mechanisms

ABSTRACTViable methanogens have been detected in dry, aerobic environments such as dry reservoir sediment, dry rice paddies and aerobic desert soils, which suggests that methanogens have mechanisms for long-term survival in a desiccated state. In this study, we quantified the survival rates of the methanogenic archaeonMethanosarcina barkeriafter desiccation under conditions equivalent to the driest environments on Earth and subsequent exposure to different stress factors. There was no significant loss of viability after desiccation for 28 days for cells grown with either hydrogen or the methylotrophic substrates, but recovery was affected by growth phase, with cells desiccated during the stationary phase of growth having a higher rate of recovery after desiccation. Synthesis of methanosarcinal extracellular polysaccharide (EPS) significantly increased the viability of desiccated cells under both anaerobic and aerobic conditions compared with that of non-EPS-synthesizing cells. DesiccatedM. barkeriexposed to air at room temperature did not lose significant viability after 28 days, and exposure ofM. barkerito air after desiccation appeared to improve the recovery of viable cells compared with that of desiccated cells that were never exposed to air. DesiccatedM. barkeriwas more resistant to higher temperatures, and although resistance to oxidative conditions such as ozone and ionizing radiation was not as robust as in other desiccation-resistant microorganisms, the protection mechanisms are likely adequate to maintain cell viability during periodic exposure events. The results of this study demonstrate that after desiccationM. barkerihas the innate capability to survive extended periods of exposure to air and lethal temperatures.

scholarly journals The Stringent Response of Mycobacterium tuberculosis Is Required for Long-Term Survival

2000 ◽  
Vol 182 (17) ◽  
pp. 4889-4898 ◽  
Author(s):  
Todd P. Primm ◽  
Susan J. Andersen ◽  
Valerie Mizrahi ◽  
David Avarbock ◽  
Harvey Rubin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mycobacterium Tuberculosis ◽  
Stringent Response ◽  
Wild Type ◽  
Liquid Media ◽  
Term Survival ◽  
Long Term Survival ◽  
Starvation Conditions

ABSTRACT The stringent response utilizes hyperphosphorylated guanine [(p)ppGpp] as a signaling molecule to control bacterial gene expression involved in long-term survival under starvation conditions. In gram-negative bacteria, (p)ppGpp is produced by the activity of the related RelA and SpoT proteins. Mycobacterium tuberculosis contains a single homolog of these proteins (RelMtb) and responds to nutrient starvation by producing (p)ppGpp. A relMtb knockout strain was constructed in a virulent strain of M. tuberculosis, H37Rv, by allelic replacement. The relMtb mutant displayed a significantly slower aerobic growth rate than the wild type in synthetic liquid media, whether rich or minimal. The growth rate of the wild type was equivalent to that of the mutant when citrate or phospholipid was employed as the sole carbon source. These two organisms also showed identical growth rates within a human macrophage-like cell line. These results suggest that the in vivo carbon source does not represent a stressful condition for the bacilli, since it appears to be utilized in a similar RelMtb-independent manner. In vitro growth in liquid media represents a condition that benefits from RelMtb-mediated adaptation. Long-term survival of therelMtb mutant during in vitro starvation or nutrient run out in normal media was significantly impaired compared to that in the wild type. In addition, the mutant was significantly less able to survive extended anerobic incubation than the wild-type virulent organism. Thus, the RelMtb protein is required for long-term survival of pathogenic mycobacteria under starvation conditions.

scholarly journals Transcriptomic Response of Listeria monocytogenes during the Transition to the Long-Term-Survival Phase

2011 ◽  
Vol 77 (17) ◽  
pp. 5966-5972 ◽  
Author(s):  
Jia Wen ◽  
Xiangyu Deng ◽  
Zengxin Li ◽  
Edward G. Dudley ◽  
Ramaswamy C. Anantheswaran ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Envelope ◽  
Growth Stages ◽  
Transcriptomic Response ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Serotype 4B ◽  
Underlying Mechanisms

ABSTRACTListeria monocytogenescan change its cellular morphology from bacilli to cocci during the transition to the long-term-survival (LTS) phase. The LTS cells demonstrated increased baro- and thermotolerance compared to their vegetative counterparts. So far, the underlying mechanisms that trigger this morphological and physiological transition remain largely unknown. In this study, we compared the transcriptomic profiles ofL. monocytogenesserotype 4b strain F2365 at different growth stages in tryptic soy broth with yeast extract (TSBYE) using a whole-genome DNA chip approach. We identified a total of 225 differentially expressed genes (≥4-fold;P< 0.05) during the transition to the LTS phase in TSBYE. Genes related to cell envelope structure, energy metabolism, and transport were most significantly upregulated in the LTS phase. The upregulation of compatible solute transporters may lead to the accumulation of cellular solutes, lowering intracellular water activity and thus increasing bacterial stress resistance during the transition to the LTS phase. The downregulation of genes associated with protein synthesis may indicate a status of metabolic dormancy of the LTS cells. The transcriptomic profiles of resuscitated LTS cells in fresh TSBYE resembled those of log-phase cells (r=0.94), as the LTS cells rapidly resume metabolic activities and transit back to log phase with decreased baro- and thermotolerance.

scholarly journals Culture Volume and Vessel Affect Long-Term Survival, Mutation Frequency, and Oxidative Stress of Escherichia coli

2013 ◽  
Vol 80 (5) ◽  
pp. 1732-1738 ◽  
Author(s):  
Karin E. Kram ◽  
Steven E. Finkel
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Stationary Phase ◽  
Mutation Frequency ◽  
Physiological Responses ◽  
Culture Vessel ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type

ABSTRACTBacteria such asEscherichia coliare frequently studied during exponential- and stationary-phase growth. However, many strains can survive in long-term stationary phase (LTSP), without the addition of nutrients, from days to several years. During LTSP, cells experience a variety of stressors, including reactive oxidative species, nutrient depletion, and metabolic toxin buildup, that lead to physiological responses and changes in genetic stability. In this study, we monitored survival during LTSP, as well as reporters of genetic and physiological change, to determine how the physical environment affectsE. coliduring long-term batch culture. We demonstrate differences in yield during LTSP in cells incubated in LB medium in test tubes versus Erlenmeyer flasks, as well as growth in different volumes of medium. We determined that these differences are only partially due to differences in oxygen levels by incubating the cells in different volumes of media under anaerobic conditions. Since we hypothesized that differences in long-term survival are the result of changes in physiological outputs during the late log and early stationary phases, we monitored alkalization, mutation frequency, oxidative stress response, and glycation. Although initial cell yields are essentially equivalent under each condition tested, physiological responses vary greatly in response to culture environment. Incubation in lower-volume cultures leads to higheroxyRexpression but lower mutation frequency and glycation levels, whereas incubation in high-volume cultures has the opposite effect. We show here that even under commonly used experimental conditions that are frequently treated as equivalent, the stresses experienced by cells can differ greatly, suggesting that culture vessel and incubation conditions should be carefully considered in the planning or analysis of experiments.

Multiple intracranial metastases of malignant melanoma with long-term survival

1984 ◽  
Vol 60 (3) ◽  
pp. 621-624 ◽  
Author(s):  
Eduardo Fernandez ◽  
Giulio Maira ◽  
Alfredo Puca ◽  
Andrea Vignati
Keyword(s):  
Malignant Melanoma ◽  
Brain Metastases ◽  
Term Survival ◽  
Long Term Survival ◽  
Content Type ◽  
Multiple Brain Metastases ◽  
Intracranial Metastases ◽  
Fine Print

✓ The authors present a case of multiple brain metastases and an extracranial secondary localization from malignant melanoma. The patient was operated on three times for the intracranial masses and had a 49-month survival with a good quality of life after the first of the three operations. She lived a total of 80 months from the time of diffusion of the primary tumor. The course of malignant melanoma is unpredictable, and long-term survival can be achieved in some cases, even in the presence of multiple brain metastases.

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