scholarly journals Survival of the Fittest: The Relationship of (p)ppGpp With Bacterial Virulence

2020 ◽  
Vol 11 ◽  
Author(s):  
Shivani Kundra ◽  
Cristina Colomer-Winter ◽  
José A. Lemos

The signaling nucleotide (p)ppGpp has been the subject of intense research in the past two decades. Initially discovered as the effector molecule of the stringent response, a bacterial stress response that reprograms cell physiology during amino acid starvation, follow-up studies indicated that many effects of (p)ppGpp on cell physiology occur at levels that are lower than those needed to fully activate the stringent response, and that the repertoire of enzymes involved in (p)ppGpp metabolism is more diverse than initially thought. Of particular interest, (p)ppGpp regulation has been consistently linked to bacterial persistence and virulence, such that the scientific pursuit to discover molecules that interfere with (p)ppGpp signaling as a way to develop new antimicrobials has grown substantially in recent years. Here, we highlight contemporary studies that have further supported the intimate relationship of (p)ppGpp with bacterial virulence and studies that provided new insights into the different mechanisms by which (p)ppGpp modulates bacterial virulence.

1932 ◽  
Vol 78 (320) ◽  
pp. 12-95 ◽  
Author(s):  
W. M. Ford-Robertson

The subject of this thesis is the outcome of what might be termed a hereditary interest in the complex problem of the relationship of chronic infections to the psychoses and allied mental disorders. Circumstances enabled me, while still a student, to undertake very humbly the continuation of my father's researches in the Scottish Asylums' Laboratory at a point where his illness and death might have proved the closing of a long and arduous chapter. That this would have been so is, as far as I know, borne out by the fact that up to the present no work directly bearing on his later bacteriological studies has been published. The researches I have undertaken during the past six years have been an attempt to elucidate more clearly what exactly are the bacteriological factors at work, and, further, in what manner they attack the economy generally, and with what result. In my endeavour to verify and extend Ford-Robertson's views I have been singularly fortunate.


2019 ◽  
Vol 70 ◽  
pp. 08002
Author(s):  
Tatyana Aparchina ◽  
Tatyana Kiseleva ◽  
Sergey Talanov ◽  
Dmitry Berezin

The article presents the results of a comparative analysis of the personal characteristics of children who find themselves in a difficult life situation. The subject of the study was the coping strategies for behavior in stressful situations. The authors used the method of diagnosis of coping mechanisms of E. Heim and Lazarus coping test. The testee’s dominant strategy was confrontation, which exacerbates social deviations and affects the formation of the personality of a child. Features of the formation of the personality of such children is an increased level of psychoticism and neuroticism. Emotional instability and imbalance of children makes it complicated to form constructive communication skills, and leads to social isolation. The latter, in turn, becomes the trigger for the formation of secondary social disorders. Dominant selfish and egocentric manifestations strengthen the increased level of conflict, not contributing to the formation of skills for constructive solutions to difficulties. Material support from the state do not solve, but exacerbate the situation, provoking the formation of a consumer position. The authors of the article believe that changing the situation requires comprehensive psychological and pedagogical support and follow up throughout childhood, not only for the child, but also his family.


1903 ◽  
Vol 49 (204) ◽  
pp. 52-70
Author(s):  
J. Lougheed Baskin

There has been a considerable amount of attention called to the subject of phthisis in asylums lately, and since the publication of the report of the Tuberculosis Committee the subject has appeared in a broader light. Although much is being and has been done for the prevention of phthisis by means of the Sanatorium movement, and the varieties of the technique of hygiene which are included in that treatment, yet there are still many aspects of the disease (both in the sane and insane) which require precise investigation, such as the variations in the composition of the secretions and excretions when the body is in the state of phthisical toxæmia; the relationship of the tuberculous toxæmia to other toxæmias, such as the influenzal (27), gouty, etc.; the accumulation of toxins, and its relations to recurrent forms of disease. The number of deaths from tubercle here during the past year we find to be ten; in 1900 it was nine, and 1899 it was fifteen, so that from a percentage of 1.3 in 1899 it has dropped to 0'85 in 1901. On examining the position of this asylum in the tables drawn up by the Tuberculosis Committee (1) we find it tenth in the asylums in England and Wales which are classified under Division i, which asylums have a tubercular death-rate of from 0.5 to 2.2, the county asylum at Exminster having a percentage of 1.3. This compares favourably with other asylums, some in the Division 2 having a tubercular death-rate of 5.1 and 8 per cent. respectively.


2020 ◽  
Vol 38 (2) ◽  
Author(s):  
Dirk Kohnert

Much has been written on the relationship of China and Africa in the past decade. However, the subject of Chinese migrant entrepreneurs in Africa and their articulation with African counterparts was little explored up to the early 2010s. Apparently, this research gap has been closed, as shown by four publications in recent years: three edited volumes and one monograph, focusing on this subject. In view of early prejudices on the passive or even disapproving reception of Chinese migrants by Africans, the state of the art underlines the importance and scope of African agency vis à vis Chinese migrant entrepreneurs in Africa. This has been underlined unison in the four books under review.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


2020 ◽  
Author(s):  
Ananta Addala ◽  
Marie Auzanneau ◽  
Kellee Miller ◽  
Werner Maier ◽  
Nicole Foster ◽  
...  

<b>Objective:</b> As diabetes technology use in youth increases worldwide, inequalities in access may exacerbate disparities in hemoglobin A1c (HbA1c). We hypothesized an increasing gap in diabetes technology use by socioeconomic status (SES) would be associated with increased HbA1c disparities. <p> </p> <p><b>Research Design and Methods: </b>Participants aged <18 years with diabetes duration ≥1 year in the Type 1 Diabetes Exchange (T1DX, US, n=16,457) and Diabetes Prospective Follow-up (DPV, Germany, n=39,836) registries were categorized into lowest (Q1) to highest (Q5) SES quintiles. Multiple regression analyses compared the relationship of SES quintiles with diabetes technology use and HbA1c from 2010-2012 and 2016-2018. </p> <p> </p> <p><b>Results: </b>HbA1c was higher in participants with lower SES (in 2010-2012 & 2016-2018, respectively: 8.0% & 7.8% in Q1 and 7.6% & 7.5% in Q5 for DPV; and 9.0% & 9.3% in Q1 and 7.8% & 8.0% in Q5 for T1DX). For DPV, the association between SES and HbA1c did not change between the two time periods, whereas for T1DX, disparities in HbA1c by SES increased significantly (p<0.001). After adjusting for technology use, results for DPV did not change whereas the increase in T1DX was no longer significant.</p> <p> </p> <p><b>Conclusions: </b>Although causal conclusions cannot be drawn, diabetes technology use is lowest and HbA1c is highest in those of the lowest SES quintile in the T1DX and this difference for HbA1c broadened in the last decade. Associations of SES with technology use and HbA1c were weaker in the DPV registry. </p>


1893 ◽  
Vol 10 (9) ◽  
pp. 401-412 ◽  
Author(s):  
Karl A. von Zittel

In a spirited treatise on the ‘Origin of our Animal World’ Prof. L. Rütimeyer, in the year 1867, described the geological development and distribution of the mammalia, and the relationship of the different faunas of the past with each other and with that now existing. Although, since the appearance of that masterly sketch the palæontological material has been, at least, doubled through new discoveries in Europe and more especially in North and South America, this unexpected increase has in most instances only served as a confirmation of the views which Rutimeyer advanced on more limited experience. At present, Africa forms the only great gap in our knowledge of the fossil mammalia; all the remaining parts of the world can show materials more or less abundantly, from which the course followed by the mammalia in their geological development can be traced with approximate certainty.


2021 ◽  
Vol 22 (12) ◽  
pp. 6222
Author(s):  
Kacper Szewczyk ◽  
Aleksandra Chojnacka ◽  
Magdalena Górnicka

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers’ interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.


2021 ◽  
Vol 10 (4) ◽  
pp. 561
Author(s):  
Aliyah Snyder ◽  
Christopher Sheridan ◽  
Alexandra Tanner ◽  
Kevin Bickart ◽  
Molly Sullan ◽  
...  

Dysregulation of the autonomic nervous system (ANS) may play an important role in the development and maintenance of persistent post-concussive symptoms (PPCS). Post-injury breathing dysfunction, which is influenced by the ANS, has not been well-studied in youth. This study evaluated cardiorespiratory functioning at baseline in youth patients with PPCS and examined the relationship of cardiorespiratory variables with neurobehavioral outcomes. Participants were between the ages of 13–25 in two groups: (1) Patients with PPCS (concussion within the past 2–16 months; n = 13) and (2) non-injured controls (n = 12). Capnometry was used to obtain end-tidal CO2 (EtCO2), oxygen saturation (SaO2), respiration rate (RR), and pulse rate (PR) at seated rest. PPCS participants exhibited a reduced mean value of EtCO2 in exhaled breath (M = 36.3 mmHg, SD = 2.86 mmHg) and an altered inter-correlation between EtCO2 and RR compared to controls. Neurobehavioral outcomes including depression, severity of self-reported concussion symptoms, cognitive catastrophizing, and psychomotor processing speed were correlated with cardiorespiratory variables when the groups were combined. Overall, results from this study suggest that breathing dynamics may be altered in youth with PPCS and that cardiorespiratory outcomes could be related to a dimension of neurobehavioral outcomes associated with poorer recovery from concussion.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Rie Ishikawa ◽  
Masako Iseki ◽  
Rie Koga ◽  
Eiichi Inada

Postherpetic itch (PHI), or herpes zoster itch, is an intractable and poorly understood disease. We targeted 94 herpes zoster patients to investigate their pain and itch intensities at three separate stages of the condition (acute, subacute, and chronic). We used painDETECT questionnaire (PDQ) scores to investigate the correlation between PHI and neuropathic pain. Seventy-six patients were able to complete follow-up surveys. The prevalence of PHI was 47/76 (62%), 28/76 (37%), and 34/76 (45%) at the acute, subacute, and chronic stages, respectively. PHI manifestation times and patterns varied. We investigated the relationship of PHI with neuropathic pain using the visual analog scale (VAS), which is a measure of pain intensity, and the PDQ, which is a questionnaire used to evaluate the elements of neuropathic pain. The VAS and PDQ scores did not differ significantly between PHI-positive and PHI-negative patients. A large neuropathic component was not found for herpes zoster itch, suggesting that neuropathic pain treatments may not able to adequately control the itch. Accordingly, we suggest that a more PHI-focused therapy is required to address this condition.


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