??????
? ??? ?? ? ????? ?????????? ???? ?? ?? ? ?????? ??????????? ? ??? ?? ????????? ???? ?? ??? ?? ? ???? ??? ???? ?? ??? ???? ?? ??? ?? ??? ????? ?? ? ??? ?????? ???????? ?? ???? ?? ? ?????? ?? ??????? ?? ? ?????? ? ???????? ??? ?? ????? ??.
??? ????? ??? ?????? ?? ?????? ???? ? ?????? ???????????? ????????? ?? ??????? ??? ??? ?? ?? ?????? ???? ?? ? ?? ????????? ???????? ?? ???? ? ???????? ????? ????? ????? ?? ?? ????????? ??? ??? ?? ?????? ? ???????? ??????? ??????? ????? ?? ??? ?????? ??????? ???? ????? ??? ????? ????.
????????
?? ???????? ? ??????? ?? ???? ? ??? ??? ???? ??. ? ??????? ? ?????????? ?????? ????? ?? ???????? ??
nosology
?? ????. ? ???????? ? ??????? ?? ? ??? ? ?????? ?? ???? ??? ??? ?????? ???? ????? ??
medicine
??. ? ??? ????? ??? ? ??????? ?? ????? ?? ??? ????? ??? ?? ?? ????? ?? ? ??? ? ??????? ??????? ?? ? ?????? ???? ???? ???? ????. ? ??? ????? ?? ?????? ?? ?? ???????? ?? ????. ???? ?? ???????? ?????? ???? ?? ?? ???? ?? ?? ? ?????? ??????? ???? ????? ??? ?? ???? ???? ???? ? ?????? ???? ?? ??? ?? ?? ?? ? ????????? ??????? ?? ??? ?? ?? ???? ?? ?????? ??????.
???????????
??? ????? ?? ?? ? ???? ? ??????? ?? ???? ??? ????? ????.
??????? ?????? ?? ???
?? ??? ???? ?? ??? ??? ?? ??? ? ?? ??? ?? ?????? ?? ???? ????? ??? ?? ?????? ??? ?? ?? ???? ???? ?? ?? ??? ?????? ?????? ?? ???? ????. ???? ??? ?? ??????? ??? ?? ?? ?
disease
??? ?? ?
syndrome
?? ???? ????? ???. ?
disease
????? ??? ?????? ?? ???? ?? ?????? ??? ?? ????? ???? ?? ?
syndrome
????? ??? ??? ?????? ?? ???? ???? ?? ?? ???? ??? ??? ?? ????? ??? ?? ??? ????? ??? ????????? ??. ?? ?? ?? ?? ??? ???? ??????? ?? ?? ?????? ???? ?? ?? ?? ???? ???? ?? ? "syndromes" ?? ???? ???? ????? ????. ? ?? ??? ???? ?? ???? ??? ????? ??????? ?? ?????? ?? ?? ?? ??? ?????? ?? ? "diseases" ?? ???? ???? ????? ????.
?? ?? ?? ??
??????
? ? ???????? ??? ???? ???? ?? ??? ??? ?? ? ????? ???? ? ???????? ????? ?? ? ?????? ?? ???? ??????? ?? ?? ??? ?? ?? ? ??? ???? ? ?????? ???? ??????? ?? ????? ???? ????? ??? ?? ???? ?? ??? ????? ?? ??? ?????? ?? ??? ?????? ??? ?? ?? ??. ?? ??? ??? ???? ? ???? ?????? ?? ?? ??? ????? ????????? ?? ?? ??? ?? ???? ????? ??? ?? ??? ?????? ??. ?? ?? ??? ?? ??? ??? ??? ?? ?? ?? ?? ???? ?? ?? ?? ?? ??? ?? ??? ???? ?????? ???? ?? ?? ??? ?? ?? ?? ??? ?? ??? ???? ????????? ?????? ??? ? ???? ?? ?????? ?? ?? ??? ?? ??? ?????? ?????? ?? ?? ? ??? ?????? ?? ?? ?? ? ????? ??? ?????? ?? ????? ??.
? ?????? ???????
Many different factors intrinsic or extrinsic to a person (or plant or animal) can cause disease. Examples of intrinsic factors are
genetic defects
or nutritional deficiencies. An environmental exposure, such as
second-hand smoke
is an example of an extrinsic factor. Many diseases result from a combination of intrinsic and extrinsic factors. For many diseases, many cause or set of causes has been identified.
There are many different factors that can cause disease. These can be broadly categorized into the following categories such as
social
,
psychological
,
chemical
, and
biological
. Some factors may fall into more than one category. Biochemical causes of disease can be considered as a
spectrum
where at one extreme disease is caused entirely by genetic factors (e.g.
CAG repeats
in the
Huntingtin protein
gene that causes
Huntington's Disease
) and at the other extreme is caused entirely by environmental factors. Environmental factors include
toxic
chemicals (e.g.
acetaldehyde
in
cigarette
smoke and
dioxins
released from the breakdown of
Agent Orange
) and infectious agents (e.g.
smallpox
virus
and
poliovirus
). In between these extremes genes (e.g.
NOD2
/
CARD15
) and environmental factors (e.g.
Gut microbiota
) interact to cause disease, as seen for example in the
inflammatory bowel disease
Crohn's Disease
(Fig 1, right).
Figure 1. The biochemical basis of disease. Some diseases, not illustrated here, also have a social and psychological basis.
Absence of the genetic or environmental factors in this case results in disease not being manifest.
Koch's postulates
can be used to determine whether a disease is caused by an infectious agent.
To determine whether a disease is caused by genetic factors, researchers study the pattern inheritance of the disease in families. This provides
qualitative
information about the disease (how it is inherited). A classic example of this method of research is inheritance of
hemophilia
in the
British Royal Family
. More recently this research has been used to identify the
Apoliprotein E
(ApoE) gene as a susceptibility gene for Alzheimer's Disease, though some forms of this gene -
ApoE2
- are associated with a lower susceptibility. To determine to what extent a disease is caused by genetic factors (
quantitative
information),
twin studies
are used.
Monozygotic twins
are genetically identical and likely share a similar environment whereas
dizygotic twins
are genetically similar and likely share a similar environment. Thus by comparing the
incidence
of disease (termed
concordance rate
) in monozygotic twins with the incidence of disease in dizygotic twins, the extent to which genes contribute to disease can be determined. Candidate disease genes can be identified using a number of methods. One is to look for
mutants
of a
model organism
(e.g. the organisms
Mus musculus
,
Drosophila melanogaster
,
Caenhorhabditis elegans
,
Brachydanio rerio
and
Xenopus tropicalis
) that have a similar
phenotype
to the disease being studied. Another approach is to look for
segregation
of genes or genetic markers (e.g.
single nucleotide polymorphism
or
expressed sequence tag
) (Fig. 2).
?????:Disease gene segregation.jpg
Figure 2. Genetic markers help locate a disease gene
A large number of SNPs spaced throughout the
genome
have been identified recently in a large project called the
HapMap
project
[?]
[?]
). The usefulness of the
HapMap
project and
SNP typing
and their relevance to society was covered in the
27 October
2005
issue of the leading international science
journal
Nature (journal)
.
A large number of genes have been identified that contribute to human disease. These are available from the US
National Library of Medicine
, which has an impressive range of biological science resources available for free online. Amongst these resources is Online
Mendelian Inheritance
in Man -
OMIM
that provides a very, very comprehensive list of all known human gene mutations associated with, and likely contributing to, disease. Each article at
OMIM
is regularly updated to include the latest scientific research. Additionally, each article provides a detailed history of the research on a given disease gene, with links to the research articles. This resource is highly valuable and is used by the world's top science researchers.
? ??????? ????????
???? ?????? ???? ?????? ???? ?? ??????? ?????? ??? ????. ???? ?????? ? ??? ????? ????? ?? ???? ???? ???????? ?? ? ???????? ???? ?? ???? ?? ??? ??? ?? ?????? ???????. ? ???? ?? ??????? ?????? ? ??? ?? ????? ? ????? ? ???? ?? ???? ? ???? ? ??? ? ???????? ? ????? ? ?????????? ? ?????? ? ?????? ? ????? ? ????? ? ???? ?? ?? ?? ?????? ???? ????? ?? ??????? ?? ???? ?? ???????.
???? ?????? ??? ? ????? ?? ????? ?????? ?? ? ??? ??????? ? ??????? ??????? ?? ????? ?? ?? ???? ?? ?? ?? ??? ?????? ???? ??? ?????? ?? ??? ?????? ? ??? ? ???? ????? ?? ??? ?? ?????? ?? ???? ?? ?? ?? ?? ???? ??????-???????????? ?? ??-??? ? ???? ??????? ? ??? ?????? ??????? ??.
? ?????? ?????? ?????
The identification of a condition as a disease, rather than as simply a variation of human structure or function, can have significant social or economic implications. The controversial recognitions as diseases of
post-traumatic stress disorder
, also known as "shell shock";
repetitive motion injury
or
repetitive stress injury
(RSI); and
Gulf War syndrome
has had a number of positive and negative effects on the financial and other responsibilities of governments, corporations and institutions towards individuals, as well as on the individuals themselves. The social implication of viewing
aging
as a disease could be profound, though this classification is not yet widespread.
A condition may be considered to be a disease in some cultures or eras but not in others.
Oppositional-defiant disorder
,
attention-deficit hyperactivity disorder
, and, increasingly,
obesity
are conditions considered to be diseases in the United States and Canada today, but were not so-considered decades ago and are not so-considered in some other countries.
Lepers
were a group of afflicted individuals who were historically shunned and the term "leper" still evokes social stigma. Fear of disease can still be a widespread social phenomena, though not all diseases evoke extreme social stigma.
A disease can also be caused by repeated high anger or stress.
??? ??? ???? ??????
??
????????
?? ? ????? ?? ?????? ????? ?? ??? ??? ?????? ???? ?? ???? ???? ?? ? ??? ????????? ? ??????? ???? ??? ???? ?? ?? ?? ?? ????????? ?? ? ????????? ???? ????? ?? ???? ??????.
? ????? ?? ?????? ????? ??? ??? ????? ?? ???????? ??? ?? ????? ????? ?? ?? ???? ??? ?? ??? ????? ?? ???? ???? ????? ???? ???? ???? ?? ??. ?? ?? ?? ?? ??? ???? ???? ?? ??? ???? ???? ?? ? ??? ????? ????? ??? ?? ???? ??? ????.
?? ?? ?????
? ?? ?? ??????? ?????
- ????
- ??????
- ?????
- ???
- ?? ?? ?? (DNA)
- ??????? ???????
- ???????????
- ??????? ????????????
- ????????? ???????
- ????????? ?????????
- ? ???? ?????
???
?????? ????
- ↑
McVean G, Spencer CC, Chaix R (2005). "Perspectives on human genetic variation from the hapmap project".
PLoS Genet
.
1
(4): e54.
PMID
16254603
.
????? CS1: ????? ??????: ????????? ????? (
link
)
This review is free of charge
- ↑
Skelding K.A., Gerhard GS, Simari RD, Holmes DR Jr (2007). "The effect of HapMap on cardiovascular research and clinical practice".
Nat Clin Pract Cardiovasc Med
.
4
(3): 136?142.
PMID
17330125
.
????? CS1: ????? ??????: ????????? ????? (
link
)