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Current Topics in Microbiology and Immunology, 47 (English, German, Paperback, Softcover Reprint of the Original 1st 1969 ed.)
W. Arber, W. Henle, P.H. Hofschneider, J.H. Humphrey, J. Klein, …
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R2,786
Discovery Miles 27 860
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Ships in 10 - 15 working days
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This article is concerned with the use of viral models for the
study of the mechanism of protein biosynthesis and its regulation.
The scope is restricted mainly to general aspects of animal viral
systems and how these systems may be used to approach the question
of cellular regulation. Most information on the regulation of
metabolic processes in eukaryotic cells comes from the study of
bacteria and from the successful application of this knowledge to
higher systems. However, differences in regulation of the
translation of genetic information from the messenger RNA into
protein may be expected between prokaryotes and eukaryotes. Due to
the short half-life of prokaryotic mRNAs, transcription has been
considered as the main mechanism controlling gene expression.
Nevertheless, during recent years firm evidence has been
accumulated for additional regu latory factors operating during
translation. This topic was recently reviewed by HASELKORN and
ROTHMAN-DENES (1973) and by KOZAK and NATHANS (1972)."
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Current Topics in Microbiology and Immunology, 45 - Ergebnisse der Mikrobiologie und Immunitatsforschung (English, German, Paperback, Softcover reprint of the original 1st ed. 1968)
W. Arber, W. Henle, P.H. Hofschneider, J.H. Humphrey, N K Jerne, …
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R2,783
Discovery Miles 27 830
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Ships in 10 - 15 working days
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In lymphoiden Zellen Tb-sensibilisierter Meerschweinchen sind
sessile Antikorper vorhanden, die in der Lage sind nach Kontakt mit
Tuberkulin Komplement zu binden. Dieser Nachweis ist sowohl
fluorescenzserologisch als auch - unter Verwendung von Extrakten
aus solchen Zellen - mit der Hamagglutination und der
Coombs-Technik oder mit dem Konglutinations- verfahren moglich. Sie
konnen ferner mit dem Hamaggregationsverfahren nachgewiesen werden.
Die sessilen Antikorper besitzen mindestens zwei, nach ihrer
immunologischen Spezifitat und dem Mechanismus ihrer cytolytischen
Funktion distinkte immunologische Spezifitaten. Die eine ist gegen
den Haupt- bestandteil von Alttuberkulin (Tuberkulopolysaccharide)
und die andere gegen den von gereinigtem Tuberkulin
(Tuberkuloproteine) gerichtet. Beide Anti- korper konnen auf weisse
Zellen nicht sensibilisierter Tiere ubertragen werden. Sie sind
mercaptoathanolempfindlich und konnen deswegen den Antikorpern vom
19 S-Typ zugerechnet werden. Sie sind nicht identisch mit den
cytophilen Antikorpern; auch scheint keine direkte kausale
Beziehung zur Tuberkulin- Hautreaktion zu bestehen. Ihre mogliche
Bedeutung wird diskutiert. Lymphoide Zellen von Tb-sensibilisierten
Meerschweinchen enthalten ausserdem noch einen Faktor, der in vitro
Agglutinationsreaktion und in vivo PCA-Reaktionen hemmt. Literatur
BAlL, 0.: Ubertragung der Tuberkulinempfindliehkeit. Z.
Immun.-Forseh. 1. Orig. 4,470 (1910). BLAZKOVEC, A. A., E. SORKIN,
and J. L. TURK: A study of the passive eellular transfer of loeal
eutaneous hypersensitivity. Int. Areh. Allergy 27, 289 (1965).
BLOOM, B. R., and B. BENNETT: Meehanism of areaction in vitra
associated with delayed type hypersensitivity. Scienee 153, 80
(1966). - - Delayed hypersensitivity in vitra: the meehanism of
inhibition by antigen of eell migration. Fed. Prae. 25, 355 (1966).
"When we give a definition it is for the purpose of using it."
HENRI POINCARE in Science and Method A. Objectives The first
version of this paper was written to introduce new students and
fellows of my laboratory to the mysteries of herpesviruses.
Consonant with this design sections dealing with well documented
data were trimmed to the bone whereas many obscure phenomena,
controversial data and seemingly trivial observations were
discussed generously and at length. There is some doubt as to
whether it was meant to be published, but it was not a review. The
objective of reviews is frequently to bring order. But alas, even
the most fluent summation of credible data frequently makes dull
reading and too much plausible order, like very little entropy in
chemical reactions, is not the most suitable environment on which
to nurture the urge to discover. This version is more charitable
but not less inbalanced. The bibliography reflects the intent of
the paper and was updated last in December of 1968. It should be
obvious without saying that no single account such as this can do
justice or injustice, as the case may be, to the several hundred
papers published on herpesviruses each year or to the many thousand
papers published on herpesviruses since the first of the members of
the family was experimentally transmitted to a heterologous host
more than half a century ago (GRUTER, 1924). B. Definition 1.
The study of streptococcal infections and their sequelae has in the
last two decades yielded several important findings on the
biological properties of cellular and extracellular products of
group A streptococci. These findings have contributed to a better
knowledge of the pathological reactions occurring in the
macroorganism during host-parasite interactions. Nevertheless, the
pathogenesis of streptococcal infections is not fully understood.
So far there has been no success in eliciting experimentally,
either through the action of the substances isolated from the cell,
or from broth culture filtrate of group A streptococci, symptoms
that are fully identical with any type of acute streptococcal
infection. It also has not been possible to explain the
mUltiplicity of clinical and histological changes caused by
streptococci as being due solely to anyone of these substances or a
combination thereof. The same applies to the sequelae of
streptococcal infections, rheumatic fever and acute
glomerulonephritis. We do not know how the group A strepto coccus
elicits these diseases and we have only a partial understanding of
the pathological processes, initiated by this streptococcus, and
resulting in cardiac or renal lesions. It is clear that an organism
infected by streptococci is exposed to the action of a complex of
substances. A more detailed recognition of the biological activity
of the single components and their combination under defined
experimental conditions may be capable, it is hoped, to explain the
pathologic processes triggered in the course. of the development of
group A streptococcal infection."
Ever since arbovirus infections became known and their relative
importance assessed, experiments were designed to elucidate the
mode of transmission and the most important natural hosts
responsible for perpetuating the infection in nature. Human
infections and the disease in wild rodents, birds, and domestic
animals were studied in relation to viremia and distribution of the
infectious agent in the organism. With increasing epidemiological
studies it became apparent that the neural manifestations of the
disease are very uncommon, confined only to a small percentage of
individuals of the most susceptible species. Various factors have
been proposed to explain why in certain instances the virus becomes
establish ed in the central nervous system and causes a serious or
lethal disease. For example, differences in the virulence of the
virus strains, varying susceptibility of individuals of one
species, or intercurrent circumstances facilitating access of the
virus to the central nervous system were alleged. Also, various
possible routes of entry of the virus into the brain and spinal
cord have been considered."
Expression of an immune response is the net result of complex
synergis tic and antagonistic activities performed by a variety of
cell types. It includes macrophages, T and B populations which may
interact in performance of a response, and suppressor cells
interfering with it. Accordingly, a lack of res ponse may not
necessarily indicate absence of immunocompetent cells, but rather
nonexpression of competence. Thus, one should consider two possible
situations, which are by no means mutually exclusive, to account
for immuno logic unresponsiveness: (a) one or more of the cell
populations composing the synergistic unit is absent or immature,
and (b) an antagonistic unit which interferes with the response is
dominating. In view of this, an approach to development of immune
reactivity necessitates parallel surveys of development of cells
with the potential to perform, as well as of cells which can
suppress the response. Classification of the various cell types has
been based so far on their phenotypic properties (e. g., membrane
antigen markers, cell receptors, pro duction and secretion of
immunoglobulins, etc. ). Genotypically, T and B cells may represent
either separate, independent cell lines, or different stages of
development within the same cell lineage."
The study of the genetic regulation of immune response to natural
multidetermi nant immunogens was undertaken by the method of
bidirectional selective breed ing of High or Low antibody responder
lines of mice. Five Selections are described: Selection I, carried
out for agglutinin responsiveness to sheep erythrocytes and pigeon
erythrocytes alternated in each generation. Selection II, carried
out for agglutinin responsiveness to sheep erythrocytes repeated in
each generation. Selection III and Selection IV performed
respectively for agglutinin response to flagellar or somatic
antigens of Salmonella typhimurium and Salmonella oranienburg
alternated in each generation. Selection V, performed for passive
agglutinin response to bovine serum albumin and rabbit gamma
globulin alternated in each generation. In each Selection the
character investigated is polygenic. High and Low responder lines
diverge progressively during the selective breeding. The maximal
interline separation (selection limit) is reached in the 7th-16th
generations. High and Low responder lines at selection limit are
considered homozygous for the character submitted to se ection.
Their variance is therefore only due to environ mental effects. The
difference in agglutinin titre between High and Low lines is
220-fold in Selection I, 103-fold in Selection II, 90-fold in
Selection III, 85-fold in Selection IV and 275-fold in Selection V.
The partition of genetic and environmental variances in the
foundation popu lations of the five Selections is established. The
proportion of genetic variance is 60% in Selection I; 49% in
Selection II; 51% in Selection III; 47% in Selection IV and 76% in
Selection V."
Phenomena as diverse as tuberculin sensitivity, delayed sensitivity
to soluble proteins other than tuberculin, contact allergy,
homograft rejection, experimental autoallergies, and the response
to many microorganisms, have been classified as members of the
class of immune reactions known as delayed or cellular
hypersensitivity. Similarities in time course, histology, and
absence of detectable circulating immunoglobulins characterize
these cell-mediated immune reactions in vivo. The state of delayed
or cellular hypersensitivity can be transferred from one animal to
another by means of sensitized living lymphoid cells (CHASE, 1945;
LANDSTEINER and CHASE, 1942; MITCHISON, 1954). The responsible cell
has been described by GOWANS (1965) as a small lymphocyte. Passive
transfer has also been achieved in the human with extracts of
sensitized cells (LAWRENCE, 1959). The in vivo characteristic of
delayed hypersensitivity from which the class derives its name is
the delayed skin reaction. When an antigen is injected
intradermally into a previously immunized animal, the typical
delayed reaction begins to appear after 4 hours, reaches a peak at
24 hours, and fades after 48 hours. It is grossly characterized by
induration, erythyma, and occasionally necrosis. The histology of
the delayed reaction has been studied by numerous investigators
(COHEN et al. , 1967; GELL and HINDE, 1951; KOSUNEN, 1966; KOSUNEN
et al. , 1963; MCCLUSKEY et al. , 1963; WAKSMAN, 1960; WAKSMAN,
1962). Initially dilatation of the capillaries with exudation of
fluid and cells occurs.
Prominent progress in molecular biology was only made when it
became possible to separate functionally distinct molecules by
taking advantage of their biophysical properties. Likewise, the
analysis of the functions of hetero geneous populations of
immunocompetent cells, as to the functional properties of their
various subpopulations, can not be done until these can be isolated
in reasonably pure form by selective fractionation. During the last
few years significant advances have been made in this field, and
cells have been separated according to size, density or charge
(MILLER et aI., 1969; SHORTMAN, 1968; ANDERSSON, 1973 c), or by
taking advantage of more specific surface markers to allow
selective depletion or enrichment of a given subpopulation of cells
(WIGZELL and ANDERSSON, 1971). Although separation techniques have
been used in a variety of cellular systems, they have been
particularly useful in the study of reticuloendothelial cells and
primarily in the study of cells partici pating in the immune
responses. Quite extensive reviews have been written which well
cover the methods used for separation of cells and the results
obtained with the various approaches (WIGZELL and ANDERSSON, 1971;
SHORTMAN, 1972). To review this work is becoming a more and more
voluminous task. As data rapidly accumulate, we will not try to
make such a complete review."
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