IdeaWazaWiki - User contributions [en]

Immunology basics

2009-02-13T11:22:21Z

59.167.126.223: /* Clinical immunology */

'''Immunology''' is a broad branch of [[biomedical science|biomedical]] [[science]] that covers the study of all aspects of the [[immune system]] in all [[organism]]s. It deals with, among other things, the [[physiology|physiological]] functioning of the immune system in states of both health and disease; malfunctions of the immune system in immunological disorders ([[autoimmune diseases]], [[hypersensitivity|hypersensitivities]], [[immune deficiency]], [[transplant rejection]]); the physical, chemical and physiological characteristics of the components of the immune system [[in vitro]], [[in situ]], and [[in vivo]]. Immunology has applications in several disciplines of science, and as such is further divided.

==Histological examination of the immune system==
Even before the concept of [[immunity (medical)|immunity]] (from ''immunis'', Latin for "exempt") was developed, numerous early physicians characterized organs that would later prove to be part of the immune system. The key primary lymphoid organs of the immune system are [[thymus]] and [[bone marrow]], and secondary lymphatic tissues such as [[spleen]], [[tonsil]]s, [[lymphatic system|lymph vessels]], [[lymph node]]s, [[adenoid]]s, and [[skin]]. When health conditions warrant, immune system organs including the thymus, spleen, portions of bone marrow, lymph nodes and secondary lymphatic tissues can be [[surgery|surgically]] excised for examination while patients are still alive.

Many components of the immune system are actually [[cell (biology)|cell]]ular in nature and not associated with any specific organ but rather are embedded or circulating in various [[tissue (anatomy)|tissues]] located throughout the body.

==Classical immunology==

Classical immunology ties in with the fields of [[epidemiology]] and [[medicine]]. It studies the relationship between the body systems, [[pathogen]]s, and immunity. The earliest written mention of immunity can be traced back to the [[Pandemic|plague]] of [[Athens]] in 430 BCE. [[Thucydides]] noted that people who had recovered from a previous bout of the disease could [[nurse]] the sick without contracting the illness a second time. Many other ancient societies have references to this phenomenon, but it was not until the 19th and 20th centuries before the concept developed into scientific theory.

The study of the molecular and cellular components that comprise the immune system, including their function and interaction, is the central science of immunology. The immune system has been divided into a more primitive [[innate immunity|innate immune system]], and [[adaptive immunity|acquired or adaptive immune system]] of vertebrates, the latter of which is further divided into [[humoral immunity|humoral]] and [[cell-mediated immunity|cellular components]].

The humoral (antibody) response is defined as the interaction between [[antibody|antibodies]] and [[antigen]]s. Antibodies are specific proteins released from a certain class of immune cells (B lymphocytes). Antigens are defined as anything that elicits generation of antibodies, hence they are '''Anti'''body '''Gen'''erators. Immunology itself rests on an understanding of the properties of these two biological entities. However, equally important is the cellular response, which can not only kill infected cells in its own right, but is also crucial in controlling the antibody response. Put simply, both systems are highly interdependent.

In the 21st century, immunology has broadened its horizons with much research being performed in the more specialized niches of immunology. This includes the immunological function of cells, organs and systems not normally associated with the immune system, as well as the function of the immune system outside classical models of immunity.

==Clinical immunology== 
Clinical immunology is the study of its shit [[disease]]s caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.

The diseases caused by disorders of the immune system fall into two broad categories: [[immunodeficiency]], in which parts of the immune system fail to provide an adequate response (examples include [[chronic granulomatous disease]]), and [[autoimmunity]], in which the immune system attacks its own host's body (examples include [[systemic lupus erythematosus]], [[rheumatoid arthritis]], [[Hashimoto's disease]] and [[myasthenia gravis]]). Other immune system disorders include different [[hypersensitivity|hypersensitivities]], in which the system responds inappropriately to harmless compounds ([[asthma]] and other [[allergy|allergies]]) or responds too intensely.

The most well-known disease that affects the immune system itself is [[Acquired Immunodeficiency Syndrome|AIDS]], caused by [[HIV]]. AIDS is an immunodeficiency characterized by the lack of CD4+ ("helper") [[T cells]] and [[macrophages]], which are destroyed by HIV.

Clinical immunologists also study ways to prevent [[transplant rejection]], in which the immune system attempts to destroy [[allograft]]s or [[xenograft]]s.

==Immunotherapy==
:''See main article [[Immunotherapy]]''

The use of immune system components to treat a disease or disorder is known as immunotherapy. Immunotherapy is most commonly used in the context of the treatment of [[cancer]]s together with [[chemotherapy]] ([[Medication|drug]]s) and [[radiotherapy]] ([[electromagnetic radiation|radiation]]). However, immunotherapy is also often used in the immunosuppressed (such as [[HIV]] patients) and people suffering from other immune deficiencies or autoimmune diseases.

==Diagnostic immunology==
:''See main article [[Diagnostic immunology]]''
The specificity of the bond between antibody and antigen has made it an excellent tool in the detection of substances in a variety of diagnostic techniques. Antibodies specific for a desired [[antigen]] can be conjugated with a radiolabel, fluorescent label, or color-forming enzyme and are used as a "probe" to detect it.

==Evolutionary immunology==
Study of the immune system in extant and [[extinction|extinct]] species is capable of giving us a key understanding of the [[evolution]] of species and the immune system.

A development of complexity of the immune system can be seen from simple phagocytotic protection of single celled organisms, to circulating antimicrobial peptides in insects to lymphoid organs in vertebrates. Of course, like much of evolutionary observation, these physical properties are often seen from the [[anthropocentric]] aspect. It should be recognized that every organism living today has an immune system absolutely capable of protecting it from most forms of harm; those organisms that did not adapt their immune systems to external threats are no longer around to be observed.

[[Insect]]s and other [[arthropod]]s, while not possessing true adaptive immunity, show highly evolved systems of innate immunity, and are additionally protected from external injury (and exposure to pathogens) by their [[chitin]]ous shells.

==See also==
* [[Autoimmunity]]
* [[List of immunologists]]
* [[History of immunology]]
* [[Serology]]
* [[Immunodeficiency]]
* [[Medical technologist]]
* [[Osteoimmunology]]

== References ==
* [http://en.wikibooks.org/wiki/Immunology Wikibooks Immunology Textbook]
* Goldsby RA, Kindt TK, Osborne BA and Kuby J (2003) '''Immunology''', 5th Edition, W.H. Freeman and Company, New York, New York, ISBN 0-7167-4947-5

== External links ==
{{WVD}}
* [http://www.dayofimmunology.org/ April the 29th - the annual Day of Immunology]
* [[Annual Review of Immunology]] ([http://arjournals.annualreviews.org/loi/immunol journal home])
* [http://www.biomedcentral.com/bmcimmunol/ BMC: Immunology]- [[BioMed Central]]:Immunology is an [[open access journal]] publishing original peer-reviewed research articles.
* [http://www.fleming.gr Biomedical Sciences Research Center "Alexander Fleming" Institute of Immunology]
* [http://www.brt-labs.com/ BRT-Burleson Research Technologies] Tests the effects of pharmaceuticals in the developmental stage on the immune system.
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=imm.TOC&depth=2 Janeway's Immunobiology textbook] Searchable free online version at the [[National Center for Biotechnology Information]]
* [http://www.mugen-noe.org/ MUGEN NoE] murine models for immunological disease
* [[Nature Reviews Immunology]] ([http://www.nature.com/nri/index.html journal home])
* [http://www.immport.org The Immunology Database and Analysis Portal] - an NIAID-funded database resource of reference and experiment data covering the entire immunology domain
* [http://medweb2.unige.ch/immunologie/ Transplantation Immunology] Interesting web site made by the faculty of medicine of the University of Geneva dealing with the immunological issues linked with the transplantation of materials genetically different between donor and recipient (hematopoietical stem cells, organs or the transfusion of blood).
* [http://media.med.sc.edu/microbiology2007/ Online lectures in immunology] University of South Carolina
* [http://www.aaaai.org/ American Academy of Allergy, Asthma & Immunology] Medical specialty organization

{{Medicine}}
{{Immune system}}
[[Category:Immunology| ]]
[[Category:Subjects taught in medical school]]

{{Link FA|de}}

[[af:Immunologie]]
[[ar:علم المناعة]]
[[bs:Imunologija i imunohematologija]]
[[bg:Имунология]]
[[ca:Immunologia]]
[[cs:Imunologie]]
[[da:Immunologi]]
[[de:Immunologie]]
[[et:Immunoloogia]]
[[es:Inmunología]]
[[eo:Imunologio]]
[[eu:Immunologia]]
[[fa:ایمنی‌شناسی]]
[[fr:Immunologie]]
[[gl:Inmunoloxía]]
[[ko:면역학]]
[[hr:Imunologija]]
[[id:Imunologi]]
[[it:Immunologia]]
[[he:אימונולוגיה]]
[[lb:Immunologie]]
[[lt:Imunologija]]
[[hu:Immunológia]]
[[ms:Immunologi]]
[[nl:Immunologie]]
[[ja:免疫学]]
[[no:Immunologi]]
[[pl:Immunologia]]
[[pt:Imunologia]]
[[ro:Imunologie]]
[[ru:Иммунология]]
[[sq:Imunologjia]]
[[simple:Immunology]]
[[sk:Imunológia]]
[[sl:Imunologija]]
[[sr:Имунологија]]
[[sh:Imunologija]]
[[fi:Immunologia]]
[[sv:Immunologi]]
[[th:วิทยาภูมิคุ้มกัน]]
[[vi:Miễn dịch học]]
[[tr:İmmünoloji]]
[[uk:Імунологія]]
[[ur:مناعیات]]
[[zh:免疫学]]

Immunology basics

2009-02-13T11:21:26Z

59.167.126.223: /* Classical immunology */

'''Immunology''' is a broad branch of [[biomedical science|biomedical]] [[science]] that covers the study of all aspects of the [[immune system]] in all [[organism]]s. It deals with, among other things, the [[physiology|physiological]] functioning of the immune system in states of both health and disease; malfunctions of the immune system in immunological disorders ([[autoimmune diseases]], [[hypersensitivity|hypersensitivities]], [[immune deficiency]], [[transplant rejection]]); the physical, chemical and physiological characteristics of the components of the immune system [[in vitro]], [[in situ]], and [[in vivo]]. Immunology has applications in several disciplines of science, and as such is further divided.

==Histological examination of the immune system==
Even before the concept of [[immunity (medical)|immunity]] (from ''immunis'', Latin for "exempt") was developed, numerous early physicians characterized organs that would later prove to be part of the immune system. The key primary lymphoid organs of the immune system are [[thymus]] and [[bone marrow]], and secondary lymphatic tissues such as [[spleen]], [[tonsil]]s, [[lymphatic system|lymph vessels]], [[lymph node]]s, [[adenoid]]s, and [[skin]]. When health conditions warrant, immune system organs including the thymus, spleen, portions of bone marrow, lymph nodes and secondary lymphatic tissues can be [[surgery|surgically]] excised for examination while patients are still alive.

Many components of the immune system are actually [[cell (biology)|cell]]ular in nature and not associated with any specific organ but rather are embedded or circulating in various [[tissue (anatomy)|tissues]] located throughout the body.

==Classical immunology==

Classical immunology ties in with the fields of [[epidemiology]] and [[medicine]]. It studies the relationship between the body systems, [[pathogen]]s, and immunity. The earliest written mention of immunity can be traced back to the [[Pandemic|plague]] of [[Athens]] in 430 BCE. [[Thucydides]] noted that people who had recovered from a previous bout of the disease could [[nurse]] the sick without contracting the illness a second time. Many other ancient societies have references to this phenomenon, but it was not until the 19th and 20th centuries before the concept developed into scientific theory.

The study of the molecular and cellular components that comprise the immune system, including their function and interaction, is the central science of immunology. The immune system has been divided into a more primitive [[innate immunity|innate immune system]], and [[adaptive immunity|acquired or adaptive immune system]] of vertebrates, the latter of which is further divided into [[humoral immunity|humoral]] and [[cell-mediated immunity|cellular components]].

The humoral (antibody) response is defined as the interaction between [[antibody|antibodies]] and [[antigen]]s. Antibodies are specific proteins released from a certain class of immune cells (B lymphocytes). Antigens are defined as anything that elicits generation of antibodies, hence they are '''Anti'''body '''Gen'''erators. Immunology itself rests on an understanding of the properties of these two biological entities. However, equally important is the cellular response, which can not only kill infected cells in its own right, but is also crucial in controlling the antibody response. Put simply, both systems are highly interdependent.

In the 21st century, immunology has broadened its horizons with much research being performed in the more specialized niches of immunology. This includes the immunological function of cells, organs and systems not normally associated with the immune system, as well as the function of the immune fucken bitch system outside classical models of immunity.

==Clinical immunology== 
Clinical immunology is the study of [[disease]]s caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.

The diseases caused by disorders of the immune system fall into two broad categories: [[immunodeficiency]], in which parts of the immune system fail to provide an adequate response (examples include [[chronic granulomatous disease]]), and [[autoimmunity]], in which the immune system attacks its own host's body (examples include [[systemic lupus erythematosus]], [[rheumatoid arthritis]], [[Hashimoto's disease]] and [[myasthenia gravis]]). Other immune system disorders include different [[hypersensitivity|hypersensitivities]], in which the system responds inappropriately to harmless compounds ([[asthma]] and other [[allergy|allergies]]) or responds too intensely.

The most well-known disease that affects the immune system itself is [[Acquired Immunodeficiency Syndrome|AIDS]], caused by [[HIV]]. AIDS is an immunodeficiency characterized by the lack of CD4+ ("helper") [[T cells]] and [[macrophages]], which are destroyed by HIV.

Clinical immunologists also study ways to prevent [[transplant rejection]], in which the immune system attempts to destroy [[allograft]]s or [[xenograft]]s.

==Immunotherapy==
:''See main article [[Immunotherapy]]''

The use of immune system components to treat a disease or disorder is known as immunotherapy. Immunotherapy is most commonly used in the context of the treatment of [[cancer]]s together with [[chemotherapy]] ([[Medication|drug]]s) and [[radiotherapy]] ([[electromagnetic radiation|radiation]]). However, immunotherapy is also often used in the immunosuppressed (such as [[HIV]] patients) and people suffering from other immune deficiencies or autoimmune diseases.

==Diagnostic immunology==
:''See main article [[Diagnostic immunology]]''
The specificity of the bond between antibody and antigen has made it an excellent tool in the detection of substances in a variety of diagnostic techniques. Antibodies specific for a desired [[antigen]] can be conjugated with a radiolabel, fluorescent label, or color-forming enzyme and are used as a "probe" to detect it.

==Evolutionary immunology==
Study of the immune system in extant and [[extinction|extinct]] species is capable of giving us a key understanding of the [[evolution]] of species and the immune system.

A development of complexity of the immune system can be seen from simple phagocytotic protection of single celled organisms, to circulating antimicrobial peptides in insects to lymphoid organs in vertebrates. Of course, like much of evolutionary observation, these physical properties are often seen from the [[anthropocentric]] aspect. It should be recognized that every organism living today has an immune system absolutely capable of protecting it from most forms of harm; those organisms that did not adapt their immune systems to external threats are no longer around to be observed.

[[Insect]]s and other [[arthropod]]s, while not possessing true adaptive immunity, show highly evolved systems of innate immunity, and are additionally protected from external injury (and exposure to pathogens) by their [[chitin]]ous shells.

==See also==
* [[Autoimmunity]]
* [[List of immunologists]]
* [[History of immunology]]
* [[Serology]]
* [[Immunodeficiency]]
* [[Medical technologist]]
* [[Osteoimmunology]]

== References ==
* [http://en.wikibooks.org/wiki/Immunology Wikibooks Immunology Textbook]
* Goldsby RA, Kindt TK, Osborne BA and Kuby J (2003) '''Immunology''', 5th Edition, W.H. Freeman and Company, New York, New York, ISBN 0-7167-4947-5

== External links ==
{{WVD}}
* [http://www.dayofimmunology.org/ April the 29th - the annual Day of Immunology]
* [[Annual Review of Immunology]] ([http://arjournals.annualreviews.org/loi/immunol journal home])
* [http://www.biomedcentral.com/bmcimmunol/ BMC: Immunology]- [[BioMed Central]]:Immunology is an [[open access journal]] publishing original peer-reviewed research articles.
* [http://www.fleming.gr Biomedical Sciences Research Center "Alexander Fleming" Institute of Immunology]
* [http://www.brt-labs.com/ BRT-Burleson Research Technologies] Tests the effects of pharmaceuticals in the developmental stage on the immune system.
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=imm.TOC&depth=2 Janeway's Immunobiology textbook] Searchable free online version at the [[National Center for Biotechnology Information]]
* [http://www.mugen-noe.org/ MUGEN NoE] murine models for immunological disease
* [[Nature Reviews Immunology]] ([http://www.nature.com/nri/index.html journal home])
* [http://www.immport.org The Immunology Database and Analysis Portal] - an NIAID-funded database resource of reference and experiment data covering the entire immunology domain
* [http://medweb2.unige.ch/immunologie/ Transplantation Immunology] Interesting web site made by the faculty of medicine of the University of Geneva dealing with the immunological issues linked with the transplantation of materials genetically different between donor and recipient (hematopoietical stem cells, organs or the transfusion of blood).
* [http://media.med.sc.edu/microbiology2007/ Online lectures in immunology] University of South Carolina
* [http://www.aaaai.org/ American Academy of Allergy, Asthma & Immunology] Medical specialty organization

{{Medicine}}
{{Immune system}}
[[Category:Immunology| ]]
[[Category:Subjects taught in medical school]]

{{Link FA|de}}

[[af:Immunologie]]
[[ar:علم المناعة]]
[[bs:Imunologija i imunohematologija]]
[[bg:Имунология]]
[[ca:Immunologia]]
[[cs:Imunologie]]
[[da:Immunologi]]
[[de:Immunologie]]
[[et:Immunoloogia]]
[[es:Inmunología]]
[[eo:Imunologio]]
[[eu:Immunologia]]
[[fa:ایمنی‌شناسی]]
[[fr:Immunologie]]
[[gl:Inmunoloxía]]
[[ko:면역학]]
[[hr:Imunologija]]
[[id:Imunologi]]
[[it:Immunologia]]
[[he:אימונולוגיה]]
[[lb:Immunologie]]
[[lt:Imunologija]]
[[hu:Immunológia]]
[[ms:Immunologi]]
[[nl:Immunologie]]
[[ja:免疫学]]
[[no:Immunologi]]
[[pl:Immunologia]]
[[pt:Imunologia]]
[[ro:Imunologie]]
[[ru:Иммунология]]
[[sq:Imunologjia]]
[[simple:Immunology]]
[[sk:Imunológia]]
[[sl:Imunologija]]
[[sr:Имунологија]]
[[sh:Imunologija]]
[[fi:Immunologia]]
[[sv:Immunologi]]
[[th:วิทยาภูมิคุ้มกัน]]
[[vi:Miễn dịch học]]
[[tr:İmmünoloji]]
[[uk:Імунологія]]
[[ur:مناعیات]]
[[zh:免疫学]]

Archive:Utility tunnel

2007-05-02T13:04:43Z

59.167.129.45:

[[Image:Dec27_004.jpg|right|thumb|300px| A picture of a Utility tunnel taken by an [[Urban Exploration|urban explorer]] in [[Toronto]] Canada. Note the steam and electrical conduit.]]

An '''utility tunnel''' is a subterranean space for wires, conduits, pipes, and other conveyances used in the delivery of [[utilities]] with enough room for a human to enter. Modern pipes and cables need less attention than older varieties, so the construction of utility tunnels has declined of late. Modern underground utilities tend to be enclosed in pipe chases, which are (by definition) not large enough for people.

Steam pipes, in particular, tend to be housed in large tunnels for easy access by workmen. A number of university campuses have a complex network of steam pipes; student exploration thereof is referred to as [[Roof and tunnel hacking]].
==See also==

*[[Utility vault]]
*[[Steam tunnel incident]]

[[Category:Subterranea]]

PHP/Variables

2006-10-02T10:22:23Z

59.167.101.54: /* Declaration */ Minor fixes

Variables, as mentioned briefly in [[Introduction to PHP]], are significant for any programming language. They can be used to store all forms of data, and are generally required to perform multiple manipulations on data not hard-coded into a script. This lesson will introduce the basics of variables in PHP.

== Basic syntax ==
In PHP, all variables are denoted by the $ at the beginning of their identifier. They do not need to be declared; they can simply be assigned a value and used from there on. Variables name should start with a lowercase letter; this is not required but (in certain php configurations) prevents clashes with autoglobals (which will be explained later). Here is a basic example of assigning a value to a variable and printing its value onto the page:

<?php
$message = 'This is the value of the message variable.';
echo $message;
?>

== Variable conversion ==
PHP also automagically switches variable types when needed. For example, all strings (a string is a series of characters) must be enclosed in quotes (both single quotes and double quotes are supported). However, sometimes values you fetch from external sources will be strings by default but need to be treated as ints (short for integers, which are numerical values) for the purpose of a calculation. This example shows how it can be done:

<?php
$input = '42';
$thevalue = $input * pi(); // Will multiply 42 by pi to (by default) 14 decimal places.
echo $thevalue; // This should return something along the lines of 131.946891451
?>

In this instance, we are multiplying the number 42 (in a string variable) by pi to a certain number of decimal places (a float variable - you will learn about this later). Conversion can only occur when possible, however - the following will not work:

<?php
$input = '4string2';
$thevalue = $input * pi(); // Should multiply 42 by pi, but will probably post a warning or terminate the script with an error
echo $thevalue; // This should return 0 or false, not print anything or even return an error for the previous line
?>

As '4string2' is not a number, PHP will fail to convert it (in order to be multiplied by pi(), which returns a floating point value) and (most likely) return an error or post a warning (depending on PHP's configuration settings in the php.ini file).

== Variable types ==
These are the main types of variables you will be dealing with:

* ''int'' - Short for integer. Holds any integer, i.e. a whole numerical value (no decimal places - however, if an int is assigned a number with a decimal place, it will be converted to a float automatically)
* ''float'' - Abbreviation of floating point value. Holds any integer WITH a decimal place, to a certain precision (generally 32 digits)
* ''double'' - Abbreviation of double precision floating point. Same as above except with far more precision - however, a double value also takes up twice as much memory (generally 8 bytes - obviously insignificant on modern servers)
* ''string'' - Holds any array of characters, i.e. a sentence (or two). Generally has an infinite length; however, for compatibility with older servers, limit the size of strings to 32768 characters.

== Declaration ==
In a more thorough language like [[Topic:C++|C++]], a full declaration of a variable would be needed. For example, the following code in PHP:

<?php
$a = 'Stuff';
?>

Is the same as the following in [[Topic:C|C]]:

#include <stdio>
int main() {
char[6] a;
a = "Stuff";
}

Notice that C++ requires explicit variable declaration (including variable type) whereas PHP does not. However, it is good practise to declare all variables, as if they are not declared PHP defaults their value to FALSE (0, empty etc.). This is because PHP is a dynamically typed language, and as a result neither type casting nor declaration is enforced. The following is possible:

<?php
var $a;
?>

However is, essentially, a waste of a line of code - $a can be used at will in any case, declared or not.

== Referencing ==
On a sidenote, a less used feature of PHP (and, indeed, many lower level programming languages) is memory address referencing. The idea is that every variable is stored at a certain address in memory. Now, say you wanted to have a variable that always remained the same values as another, you could just store point it at the same address - any changes at that address, i.e. any change to the value of the first variable, would be reflected in the other variable (but not vice versa). Examine the following:

<?php
$a = 'Stuff';
$b = &$a; // $b is pointed to $a
$a = 'Stuff2.0'; // $b is now also 'Stuff2.0';
?>

== Learning sessions ==
None available at present.

[[Category:Computer Science]]
[[Category:Computer Programming]]
[[Category:Articles related to php]]