Echo Type Research Articles

Problems of the theory of linear and nonlinear transformation of waves in inhomogeneous media

The review is devoted to effects that occur when waves propagate in inhomogeneous media. The types of linear transformation of waves by the inhomogeneities of the medium are classified, and the conditions under which they are realized are indicated. Linear transformation of oscillations in a non-equilibrium medium, leading to wave amplification, is investigated. The linear transformation is consistently analyzed on the basis of a fourth-order differential equation. Attention is called to the singularities of linear wave transformation in a plasma-beam system, particularly the anisotropy of the radiation of transverse waves following passage of a modulated beam through an inhomogeneous plasma. The generation of the second harmonic of an electromagnetic wave in an inhomogeneous plasma and decay processes in inhomogeneous media are considered. Kinetic nonlocal effects (of the echo type) in an inhomogeneous plasma, wherein the focusing action of the inhomogeneity makes possible linear nonlocal effects as well as echo at the summary frequency are described. The indicated nonlinear and kinetic nonlocal effects lead to transparentization of the inhomogeneous media. Certain experimental studies dealing with the problems touched upon in the review are discussed.

Properties of a multicomponent excitable medium

The present paper is concerned with the problem of excitation propagation in a multicomponent excitable medium, which is considered as a model of neuron nets of the syncytial type. The best example is the cardiac tissues, which form a heterogeneous system of different units with common axoplasma. The sundry cardiac tissues differ quantitatively in their properties such as excitation threshold and refractory time. If units of each type are uniformly distributed in space and sufficiently “mixed” with one another, the medium proves to be macroscopically homogeneous. In the first part of the paper a method is described which is suitable for consideration of an excitable medium. In the case of a one-component system the velocity of excitation and profile of nerve impulse is obtained by this method. It is interesting to note that the impulse can have two velocities, but only the larger velocity proves to be stable. In the second part of the paper, complicated types of excitation in a two-component medium are considered. It is generally assumed that the complex behaviour of excitation of the echo or rhythm transformation type may arise only in macroscopically inhomogeneous media. In this paper is shown that similar phenomena can be observed also in macroscopically homogeneous media consisting of units of different types. In a two-component medium a moving “ectopic centre” arises, which is a source of nerve impulses. This theory explains some experimental results on cardiac arrhythmia.

ECHO viruses, carditis, and acute pleurodynia

Statistical analysis of 833 cases of echovirus infection showed a significantly greater association of type-6 infection with acute pleurodynia, and a suggestive association of type 19 and some other types with cardiac disease and pleurodynia. Published reports and international data from W.H.O. support the suggestion that echo type 6 and 19 viruses share the potentiality of type-B Cox-sackie viruses causing acute carditis and pleurodynia.

E‐H‐Zyklotronechos in Plasmen

A new echo type with free electrons in a slight inhomogeneous magnetic field excited by one electric and one magnetic pulse is calculated. Thus features of cyclotron echos and spin echoes are combined. The first electric pulse accelerates all (cold) particles to the same velocity as in the case of usual cyclotron echoes. The second magnetic pulse (at t = τ) rotates the plane of precession in phase space, quite in analogy to the motion of magnetic moments in the case of spin echoes. The echo arises at t = 2τ.The E‐H echoes make relaxation and diffusion measurements in plasmas possible, using the methods proved useful in spin echo technique. There are no complications as in the case of E‐E cyclotron echoes which are based on the fact that a velocity‐dependent collision frequency is necessary for the nonlinearity of that echo mechanism.

E - H cyclotron echoes as a new echo type in plasmas

Abstract A new cyclotron-like echo type not based on velocity-dependent collision frequency mechanism is proposed for relaxation and diffusion measurements in plasmas.

Echoviruses, carditis, and acute pleurodynia.

Abstract Statistical analysis of 833 cases of echovirus infection showed a significantly greater association of type-6 infection with acute pleurodynia, and a suggestive association of type 19 and some other types with cardiac disease and pleurodynia. Published reports and international data from W.H.O. support the suggestion that echo type 6 and 19 viruses share the potentiality of type-B Cox-sackie viruses causing acute carditis and pleurodynia.

Isolated myocarditis with recovery of ECHO type 9 virus from the myocardium.

ISOLATED myocarditis is a clinicopathological entity, diagnosed at autopsy, in which the heart is the sole target organ.1 By and large, the etiology of the condition in the adult population is a diagnostic enigma.2 This paper reports the isolation of ECHO Type 9 virus from the myocardium of a patient with isolated myocarditis.Case ReportA 34-year-old dentist was admitted to University Hospital for the 1st time because of complete heart block and marked respiratory distress. He had been well all his life. Ten days previously, after a physical examination, he had been accepted for additional life insurance. Six days . . .

Acute cerebellar ataxia associated with Echo type 6 infection in two children.

Acta PaediatricaVolume 56, Issue 5 p. 547-551 Acute Cerebellar Ataxia Associated with Echo Type 6 Infection in Two Children G. MARZETTI, G. MARZETTI Institute of Pediatrics (Head: A. Colarizi), University of Rome, ItalySearch for more papers by this authorM. MIDULLA, M. MIDULLA Institute of Pediatrics (Head: A. Colarizi), University of Rome, ItalySearch for more papers by this author G. MARZETTI, G. MARZETTI Institute of Pediatrics (Head: A. Colarizi), University of Rome, ItalySearch for more papers by this authorM. MIDULLA, M. MIDULLA Institute of Pediatrics (Head: A. Colarizi), University of Rome, ItalySearch for more papers by this author First published: September 1967 https://doi.org/10.1111/j.1651-2227.1967.tb15421.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume56, Issue5September 1967Pages 547-551 RelatedInformation

DIAGNOSIS AND TREATMENT: EPIDEMIC GASTROENTERITIS, PRESUMABLY VIRAL

EPIDEMIC GASTROENTERITIS is a frequent problem in the pediatric office and outpatient department. It is known to the public by numerous synonyms ("intestinal flu," "gi. grippe," "the winter vomiting disease," "epidemic vomiting," "acute nonspecific gastroenteritis," "the stomach virus," or, simply, "the bug"). Despite the scant references to this disorder as an entity in pediatric literature, it seems now to be the most frequent gastrointestinal infection, past 1 year of age, in this country. Sporadic occurrence is year-round but the season of greatest frequency is November through April. During this season, epidemic gastroenteritis generally ranks next to viral respiratory infection, otitis media, and streptococcal disease among pediatric infections. The seasonal incidence, the sudden endemics, the short incubation period of less than a week, and the occasional respiratory symptoms have suggested that viral agents of the respiratory group are responsible for the disease, but attempts to isolate a specific agent have been fruitless. When enteroviruses have been implicated, especially ECHO type 18, the epidemics have been minor and have occurred during the summer months. Recurrent attacks in the same child, during a given winter on in subsequent years, indicate that the etiology is multiple or that solid immunity seldom develops from a single attack. SYMPTOMS AND CLINICAL COURSE The cardinal symptoms are nausea, vomiting, diarrhea, fever, abdominal pain, and anorexia. Less often, aching, dizziness and malaise are noted. The onset is typically with explosive vomiting, occurring at intervals of 10 to 30 minutes oven the first 4 to 8 hours, then spontaneously diminishing in frequency.

The Role of ECHO Type 21 Virus in Patients with “Infectious Column Myelitis”, a Myelitis following Abdominal Signs

The Role of ECHO Type 21 Virus in Patients with “Infectious Column Myelitis”, a Myelitis following Abdominal Signs

A single-cell study of chemical inhibition of enterovirus multiplication

The effects of viral inhibitors, guanidine and 2-(α-hydroxybenzyl)-benzimidazole (HBB), on enterovirus RNA synthesis and multiplication were studied in single HeLa or monkey kidney cells. Guanidine interrupted ongoing synthesis of viral RNA and production of infectious virus in single cells infected with poliovirus. Similarly, HBB halted ongoing replication of ECHO type 12 virus in single cells. Conversely, the presence of guanidine was necessary for continued synthesis of viral RNA and replication of virus in single cells infected with guanidine-dependent poliovirus type 1. Puromycin and guanidine inhibited ongoing poliovirus RNA synthesis with equal rapidity. The demonstrated effects of these drugs in single cells during the incremental phase in the viral growth cycle add evidence in support of the hypothesis that enterovirus RNA polymerase is synthesized throughout the exponential increase of virus.

Acute respiratory illness in the premature nursery associated with ECHO type 22 virus infection

Acute respiratory illness in the premature nursery associated with ECHO type 22 virus infection

TOLUCA-3, A NEWLY RECOGNIZED ENTEROVIRUS.

Discussion and summaryThe data presented indicate that Toluca-3 virus has properties characteristic of the enteroviruses but that it is antigenically distinct from all previously described serotypes. Despite the absence of generally accepted definitions of the polioviruses, Coxsackie viruses, and ECHO viruses (4) this agent has been designated tentatively as the prototype strain of ECHO type 33 by the Panel for Picornaviruses of the National Institute of Allergy and Infectious Diseases.

Isolation of Echo Type 21 Virus from Patients with “Infectious Column Myelitis”, a Myelitis following Abdominal Signs

Isolation of Echo Type 21 Virus from Patients with “Infectious Column Myelitis”, a Myelitis following Abdominal Signs

Viral Diseases as Hospital-Acquired Infections.

s1 October 1964Viral Diseases as Hospital-Acquired Infections.John D. Millar, M.D.John D. Millar, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-61-4-809_2 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptDespite intensive recent interest in hospital-acquired bacterial infections, there has been much less interest in hospital-acquired viral illnesses. Hospital related outbreaks or instances of disease transmission in the hospital situation have been described for poliomyelitis, enteroviruses of the Coxsackie and ECHO type, herpes and vaccinia viruses, as well as respiratory syncytial virus. In many of these situations, the infections were of little clinical importance.There are two disease whose epidemiologic patterns mark them as peculiarly hospital-acquired. The first, serum hepatitis, is related primarily to the receipt of blood and blood products, almost all of which are administered in hospitals. In... This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Atlanta, Ga. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics 1 October 1964Volume 61, Issue 4Page: 809-809KeywordsBloodEpidemiologyHepatitisInfectious diseasesPoliomyelitisPulmonary diseasesRespiratory syncytial virusViral diseases Issue Published: 1 October 1964 PDF DownloadLoading ...

ECHO 9 VIRUS INFECTION AND CONGENITAL MALFORMATIONS.

The properties of enteroviruses justify their consideration as possible causes of foetal damage: they are highly prevalent and cause infections which, although usually of minor severity, are often associated with viraemia. Of the enteroviruses, ECHO type 9 is of particular interest because of its periodic epidemic prevalence and the similarity to of many of the infections it causes. Studies by Rantasalo, Penttinen, Saxen, and Ojala (1960) and by Kleinman, Prince, Mathey, Rosenfield, Bearman, and Sy verton (1962) did not reveal unequivocal evidence of association between ECHO 9 virus infection during pregnancy and malformation of the infant born subsequently. The possibility that this infection may not cause foetal damage is also of importance to the clinician assessing the implications of a rubelliform illness during pregnancy, and to the epidemiologist evaluating the risk of congenital abnormality complicating rubella in studies in which an unknown proportion of maternal illnesses might have been due to ECHO 9 infection with fever, rash, and lymph-node enlargement. An epidemic of ECHO 9 infection in Glasgow in 1960 (Landsman and Bell, 1962; Combined Scottish Study, 1964) provided an opportunity to investigate the possible association of maternal infection with foetal damage.

SUDDEN UNEXPECTED DEATH IN INFANCY. ISOLATIONS OF ECHO TYPE 7 VIRUS.

SummaryViral isolations were made from 7 of 10 infants dying a sudden and unexpected death. Forty-five specimens, including brain, lung, liver, whole blood, and stool, were included for the study. Nine of 12 isolations were identified as ECHO 7 virus—2 isolations from the brain, 2 from the lung, 2 from the liver, and 3 from stool. Two of the remaining isolates were identified as polio 1 virus and polio 2 virus, respectively, the former obtained from both liver and stool in one individual and the latter from the stool only of a second infant. The final isolate was ECHO 22 virus obtained from a single stool specimen.

LABORATORY DIAGNOSIS OF ECHO TYPE 9 VIRUS INFECTION.

During 1960 the West of Scotland experienced a large outbreak of ECHO 9 infection. ECHO 9 virus strains were readily recovered from faeces, cerebrospinal fluids and throat swabs. Results of the comparison of human amnion and rhesus monkey kidney tissue cultures for the isolation of ECHO 9 suggested that monkey kidney was more sensitive than human amnion.

ECHO virus type I and aseptic meningitis: Report of a case with virus isolation from the cerebrospinal fluid

ECHO virus, type I was isolated from the cerebrospinal fluid and feces of an infant with aseptic meningitis. A fourfold rise in neutralizing antibody to the prototype virus occurred. This virus has been recovered from sick and well individuals but its isolation from cerebrospinal fluid has not been reported previously in the English literature. The patient subsequently appeared retarded but other possible responsible factors were present. Our findings contribute to the evidence that ECHO Type I may be etiologically related to aseptic meningitis.

The Resistance of A2G Mice to Myxoviruses

Summary Inbred A2G mice were found to be more resistant than other laboratory mice with respect to the following viral infections: neurotropic influenza A virus given intracerebrally (strains NWS, WSNF and Neuro-Kunz) and intranasally (strains NWS and WSNF); pneumotropic influenza A virus given intranasally (strains Swine, WS and PR8); and Sendai parainfluenza 1 virus given intranasally. Two mouse-adapted strains of Asian influenza (A/Singapore/1/57) were the only myxoviruses studied to which there was no difference in susceptibility between A2G and control animals. Not many more virus particles were required to initiate neuro-infection in A2G mice as compared to control mice. Virus titers reached in the brains after inoculation of neurotropic influenza virus were 100 times lower in A2G mice; similarly, 100 times less virus was recovered from lungs of A2G mice inoculated with Lee influenza B virus of low mouse virulence. No differences were found in the susceptibility to the toxic action of influenza A virus between A2G and control animals. After comparable inocula of influenza A virus given intranasally, A2G mice developed lower levels of hemagglutination-inhibiting and complement-fixing antibodies than did surviving controls. A2G and control mice proved equally susceptible to the following viruses: Yellow Fever 17 D, West Nile, EMC, Polio type 2 (mouse-adapted), Herpes simplex and ECHO type 9.