scholarly journals MALARIAL PIGMENT (HEMATIN) AS A FACTOR IN THE PRODUCTION OF THE MALARIAL PAROXYSM

1912 ◽  
Vol 15 (6) ◽  
pp. 579-597 ◽  
Author(s):  
Wade H. Brown
Keyword(s):  
Human Subject ◽  
Toxic Substance ◽  
Malarial Parasite ◽  
Striking Similarity ◽  
Conservative Estimate ◽  
Experimental Conditions ◽  
Malarial Infection ◽  
Sequence Of Events ◽  
Abundant Evidence ◽  
The One

The paroxysm of hematin intoxication in the rabbit undoubtedly presents many features of striking similarity to the paroxysm of human malaria; still one must hesitate to apply such results unreservedly in an attempt to identify the causative agent of the malarial paroxysm. When, in addition to the character of the paroxysm, we consider the sequence of events in the two instances, the analogy becomes so close that it seems impossible to regard the matter as a mere coincidence. The injection of hematin, especially in fractional doses, is in a measure comparable to the liberation of hematin into the human circulation by the malarial parasite. In these experiments, See PDF for Structure both solution and finely divided suspensions of hematin have been found equally effective in eliciting the phenomena of the paroxysm, and while it seems possible that a portion of the malarial pigment might be dissolved in the alkaline human serum, such an assumption is probably not essential. It might be objected that the toxic action of foreign hematin thus injected into the circulation would probably be greater than that of hematin derived from an animal's own blood, but as far as I have been able to determine, this objection does not seem valid, as rabbit hematin, dog hematin, and ox hematin produce in the rabbit effects that are alike in both character and degree. The dose of hematin remains as the one factor to which it is possible to attach some degree of uncertainty, but even here the author feels that the range of experimental conditions has been kept within the bounds of legitimate analogy with conditions existing in the human subject of malarial infection. Finally, the most conservative estimate of the value of such experiments points strongly to the fact that we have at least a potentially toxic substance in the pigment hematin as liberated by the malarial parasite into the circulation of the human host. There is also abundant evidence to show that the action of hematin is not confined to the paroxysmal phenomena of malaria, but that other features of the disease may find their explanation in the action of this pigment. For the present, however, it seems advisable to confine the discussion to this one phase of the question.

THE RELATION BETWEEN THE HYPOTHALAMIC NEUROSECRETION AND THE CORTICOTROPHIN RELEASE IN EXPERIMENTAL CONDITIONS

1960 ◽  
Vol XXXIV (I) ◽  
pp. 8-18 ◽  
Author(s):  
E. Kivalo ◽  
U. K. Rinne
Keyword(s):  
Paraventricular Nucleus ◽  
Median Eminence ◽  
Supraoptic Nucleus ◽  
Acute Stress ◽  
Neurosecretory Material ◽  
Experimental Conditions ◽  
Hypothalamic Cells ◽  
The One ◽  
Hypophysial Portal ◽  
Acth Release

ABSTRACT Acute stress, chronic stress plus hydration, cortisone treatment, cortisone treatment plus dehydration were used as methods of investigation and the relation between the neurosecretory activity of the hypothalamic supraoptic nucleus and paraventricular nucleus and the neurosecretory material around the hypophysial portal vessels of the median eminence on the one hand and the corticotrophin release on the other hand, has been studied in the rat. Whereas stress stimulates both the activity of the above mentioned cells of the hypothalamus and the ACTH release, stress plus hydration causes a depression of these hypothalamic cells but nevertheless causes a marked ACTH release. Cortisone inhibits the activity of the cells in the supraoptic nucleus and the paraventricular nucleus as well as the ACTH release whereas cortisone plus dehydration causes stimulation but inhibits the ACTH release. In some stress and cortisone treatment groups the variations of the neurosecretory material around the hypophysial portal vessels and of the ACTH release were found to show a correlation. It is concluded that the activity of the cells of the supraoptic nucleus and the paraventricular nucleus and the ACTH release do not seem to have any definite connection, whereas some observations indicate that the neurosecretory material in the region of the median eminence around the hypophysial portal vessels may have some significance in ACTH release.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

Deleuze and Italian Thought

2019 ◽  
Vol 13 (4) ◽  
pp. 495-507 ◽  
Author(s):  
Felice Cimatti
Keyword(s):  
Human Subject ◽  
Gilles Deleuze ◽  
The Political ◽  
The World ◽  
Giacomo Leopardi ◽  
The One

The tradition of Italian Thought – not the political one but the poetic and naturalistic one – finds in the philosophy of Gilles Deleuze a way to enter into the new century, the century of immanence and animality. In fact, Deleuze himself remained outside the main philosophical traditions of his own time (structuralism and phenomenology). The tradition to which Deleuze refers is the one that begins with Spinoza and ends with Nietzsche. It is an ontological tradition, which deals mainly with life and the world rather than with the human subject and knowledge. Finally, the text sketches a possible dialogue between Deleuze and the poet-philosopher Giacomo Leopardi, one of the most important (and still unknown) figures of Italian Thought.

scholarly journals Alpha EEG Frontal Asymmetries during Audiovisual Perception in Cochlear Implant Users

2015 ◽  
Vol 54 (06) ◽  
pp. 500-504 ◽  
Author(s):  
A. G. Maglione ◽  
A. Scorpecci ◽  
P. Malerba ◽  
P. Marsella ◽  
S. Giannantonio ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Alpha Rhythm ◽  
Normal Hearing ◽  
Experimental Conditions ◽  
Audiovisual Perception ◽  
Audiovisual Stimuli ◽  
The Difference ◽  
Eeg Alpha ◽  
The One ◽  
Hearing Children

SummaryObjectives: The aim of the present study is to investigate the variations of the electroencephalographic (EEG) alpha rhythm in order to measure the appreciation of bilateral and unilateral young cochlear implant users during the observation of a musical cartoon. The cartoon has been modified for the generation of three experimental conditions: one with the original audio, another one with a distorted sound and, finally, a mute version.Methods: The EEG data have been recorded during the observation of the cartoons in the three experimental conditions. The frontal alpha EEG imbalance has been calculated as a measure of motivation and pleasantness to be compared across experimental populations and conditions.Results: The EEG frontal imbalance of the alpha rhythm showed significant variations during the perception of the different cartoons. In particular, the pattern of activation of normal-hearing children is very similar to the one elicited by the bilateral implanted patients. On the other hand, results related to the unilateral subjects do not present significant variations of the imbalance index across the three cartoons.Conclusion: The presented results suggest that the unilateral patients could not appreciate the difference in the audio format as well as bilaterally implanted and normal hearing subjects. The frontal alpha EEG imbalance is a useful tool to detect the differences in the appreciation of audiovisual stimuli in cochlear implant patients.

Insights into the Relation between Oxidative Stress and Malaria: A Mechanistic and Therapeutic Approach

2021 ◽  
Vol 11 ◽  
Author(s):  
Abhijit Sarkar ◽  
Swarnendu Basak ◽  
Sumit Ghosh ◽  
Sushweta Mahalanobish ◽  
Parames C. Sil
Keyword(s):  
Oxidative Stress ◽  
Defense Mechanisms ◽  
Preventive Measures ◽  
Host Immunity ◽  
Malarial Parasite ◽  
Malarial Infection ◽  
Parasitic Load ◽  
Therapeutic Mechanisms ◽  
Antioxidant Effects ◽  
Oxidative Insult

The mortality rate due to malaria has increased tremendously in the last decade. Even though the causative agent of this disease is known, the preventive measures are not potent enough to control the spread of this disease. Malarial infection involves a strong interrelationship between oxidative stress and pathogenesis. This review addresses the various oxidative stress-related mechanisms associated with vector defense, host immunity, plasmodial pathogenesis, and corresponding therapeutic strategies. The mechanisms involving host and vector defense show both similarity and contradiction to the processes involving plasmodial pathogenesis under different circumstances. Therefore, corresponding ameliorative peculiarities are observed in the therapeutic mechanisms adopted by the anti-malarial drugs. The malarial parasite augments oxidative stress to weaken the host and exerts antioxidant effects against host defense mechanisms. However, the anti-malarial drugs induce oxidative insult to reduce parasitic load and exert antioxidant effects against parasite infection-induced oxidative stress in host. Thus, the anti-malarial drugs exhibit antioxidant activity in hosts and/or pro-oxidant activity in parasites.

scholarly journals Social engineers and myth-busters: A comparative research on Lithuanian, Norwegian and Serbian language experts

2020 ◽  
pp. 292-344
Author(s):  
Vuk Vukotić
Keyword(s):  
News Media ◽  
Language Ideologies ◽  
Great Majority ◽  
Online News ◽  
The Other ◽  
Striking Similarity ◽  
The Public ◽  
Other Hand ◽  
The Public Sphere ◽  
The One

This article compares the language ideologies of language experts (both academic and non-academic) in online news media in Lithuania, Norway and Serbia. The results will reveal that language is understood in diametrically opposed ways amongst Lithuanian and Serbian academic experts on the one, and Norwegian academic experts on the other hand. Lithuanian and Serbian academic experts are influenced by modernist ideas of language as a single, homogenous entity, whose borders ideally match the borders of an ethnic group. Norwegian academic experts function in the public sphere as those who try to deconstruct the modernist notion of language by employing an understanding of language as a cognitive tool that performs communicative and other functions. On the other hand, non-academic experts in all the three countries exhibit a striking similarity in their language ideologies, as the great majority expresses modernist ideals of language.

The story of humanity and the challenge of posthumanity

2018 ◽  
Vol 32 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Zoltán Boldizsár Simon
Keyword(s):  
Human Subject ◽  
Large Scale ◽  
Historical Narrative ◽  
Historical Narratives ◽  
Small Scale ◽  
Historical Understanding ◽  
New Era ◽  
And Gender ◽  
The One ◽  
Better Than

Today’s technological-scientific prospect of posthumanity simultaneously evokes and defies historical understanding. On the one hand, it implies a historical claim of an epochal transformation concerning posthumanity as a new era. On the other, by postulating the birth of a novel, better-than-human subject for this new era, it eliminates the human subject of modern Western historical understanding. In this article, I attempt to understand posthumanity as measured against the story of humanity as the story of history itself. I examine the fate of humanity as the central subject of history in three consecutive steps: first, by exploring how classical philosophies of history achieved the integrity of the greatest historical narrative of history itself through the very invention of humanity as its subject; second, by recounting how this central subject came under heavy criticism by postcolonial and gender studies in the last half-century, targeting the universalism of the story of humanity as the greatest historical narrative of history; and third, by conceptualizing the challenge of posthumanity against both the story of humanity and its criticism. Whereas criticism fragmented history but retained the possibility of smaller-scale narratives, posthumanity does not doubt the feasibility of the story of humanity. Instead, it necessarily invokes humanity, if only in order to be able to claim its supersession by a better-than-human subject. In that, it represents a fundamental challenge to the modern Western historical condition and the very possibility of historical narratives – small-scale or large-scale, fragmented or universal.

The utilization of an inhibitor of spermidine and spermine synthesis as a tool for the study of the determination of cavitation in the preimplantation mouse embryo

Development ◽  
1979 ◽  
Vol 53 (1) ◽  
pp. 145-162
Author(s):  
H. Alexandre
Keyword(s):  
Biological Clock ◽  
Duration Of Treatment ◽  
Experimental Conditions ◽  
Cell Stage ◽  
Cytoplasmic Factor ◽  
Average Cell ◽  
Length Of Treatment ◽  
Preimplantation Mouse ◽  
The One

The inhibition of spermidine and spermine synthesis by methylglyoxal-Bis(guanylhydrazone) (MeGAG) at concentrations of 5, 10 and 20 µM, induces a reversible metabolic quiescence of mouse embryos, cultured in vitro from the 2-cell stage, at an average of 10·2, 8·5 and 6·9 cell stages respectively. In contrast, the inhibition of putrescine synthesis by α-methylornithine (α-MeOrn) at concentrations up to 10 mM fails to inhibit blastocyst formation, as shown previously. Complete reversibility of this induced arrest of development is observed for treatments up to 31 h with MeGAG at 10 µM. In agreement with the biological clock theory of Smith & MacLaren's hypothesis, the delay in cavitation is proportional to the length of treatment. However, the average cell numbers of the ‘delayed nascent blastocysts’ of all treated embryos (21·8–24·2) are consistently lower than that of control embryos (33·6) irrespective of the duration of treatment. It seems therefore that under some experimental conditions, DNA and chromosome replication on the one hand and cytoplasmic maturation on the other may be desynchronized. This suggests a role for a cytoplasmic factor in the induction of cavitation.

The Rise of the Muslim Brotherhood and the Potential for Violent Escalation

2020 ◽  
pp. 37-78
Author(s):  
Ioana Emy Matesan
Keyword(s):  
Muslim Brotherhood ◽  
Early History ◽  
The Other ◽  
Religious Movement ◽  
Dual Effect ◽  
Sequence Of Events ◽  
History Of ◽  
The Muslim Brotherhood ◽  
The One ◽  
Gamal Abdel Nasser

This chapter revisits the early history of the Muslim Brotherhood to understand why an organization that started out as a nonviolent religious movement came to be associated with violence. Many blame this on the harsh repression under President Gamal Abdel Nasser. However, the analysis shows that the drift toward violence started much earlier. Reconstructing the sequence of events between 1936 and 1948, the chapter reveals that what initially politicized the Brotherhood was the presence of British troops in Egypt and Palestine. The formation of an armed wing led to competition over authority within the group, which incentivized violent escalation. The chapter then focuses on the period between 1954 and 1970 and shows that repression had a dual effect. On the one hand, it inspired new jihadi interpretations, which were particularly appealing to younger members. On the other hand, the prisons were also the backdrop against which the Brotherhood became convinced that violence was futile.

scholarly journals 5-Phenyl-10,15,20-Tris(4-sulfonatophenyl)porphyrin: Synthesis, Catalysis, and Structural Studies

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3363 ◽  
Author(s):  
Aitor Arlegui ◽  
Zoubir El-Hachemi ◽  
Joaquim Crusats ◽  
Albert Moyano
Keyword(s):  
Alder Reaction ◽  
Water Soluble ◽  
Experimental Conditions ◽  
One Pot ◽  
Force Microscopy ◽  
Diels Alder Reaction ◽  
Transmission Electron ◽  
Porphyrin Synthesis ◽  
The One ◽  
Water Soluble Porphyrin

A convenient protocol for the preparation of 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphyrin, a water-soluble porphyrin with unique aggregation properties, is described. The procedure relies on the one-pot reductive deamination of 5-(4-aminophenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, that can be in turn easily obtained from 5,10,15,20-tetraphenylporphyrin by a known three-step sequence involving mononitration, nitro to amine reduction and sulfonation of the phenyl groups. This method provides the title porphyrin in gram scale, and compares very favorably with the up to now only described procedure based on the partial sulfonation of TPP, that involves a long and tedious chromatographic enrichment of the final compound. This has allowed us to study for the first time both the use of its zwitterionic aggregate as a supramolecular catalyst of the aqueous Diels–Alder reaction, and the morphology of the aggregates obtained under optimized experimental conditions by atomic force microscopy and also by transmission electron cryomicroscopy.

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