What is leukemia? - Danilo Allegra and Dania Puggioni

Kaj je levkemija? - Danilo Allegra in Dania Puggioni

1,087,335 views

2015-04-30 ・ TED-Ed


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What is leukemia? - Danilo Allegra and Dania Puggioni

Kaj je levkemija? - Danilo Allegra in Dania Puggioni

1,087,335 views ・ 2015-04-30

TED-Ed


Za predvajanje videoposnetka dvakrat kliknite na spodnje angleške podnapise.

Translator: Nika Kotnik Reviewer: Matej Divjak
00:06
Despite advances in medicine,
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Kljub napredku v medicini,
00:09
cancer remains one of the most frightening diagnoses patients can receive.
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ostaja rak ena najbolj strašljivih diagnoz, ki jih lahko prejme pacient.
00:14
What makes it so difficult to cure is that it's not one illness,
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Težko ga je ozdraviti, ker ni ena bolezen,
00:18
but a family of over 100 diseases occurring in different types of cells.
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ampak družina več kot 100 bolezni, ki se pojavijo v različnih tipih celic.
00:23
And one type of cancer has the unfortunate distinction
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In ena vrsta raka se pomembno razlikuje
00:26
of afflicting children more than any other type.
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v tem, da prizadene otroke bolj kot katerakoli druga vrsta.
00:29
This is leukemia,
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To je levkemija,
00:31
a cancer that begins in stem cells found in the bone marrow.
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rak, ki se začne v izvornih celicah kostnega mozga.
00:35
A stem cell is a bit like an infant,
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Izvorna celica je na nek način kot dojenček,
00:38
undeveloped but possessing great potential.
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nerazvita, a z velikim potencialom.
00:41
Many stem cells specialize and become cells of organs,
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Veliko izvornih celic se specializira, in postanejo celice organov,
00:44
like the liver, brain and heart.
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kot so jetra, možgani in srce.
00:47
But in some tissues,
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A v nekaterih tkivih,
00:49
they can continue to divide into new stem cells throughout development,
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se lahko še naprej delijo v nove izvorne celice skozi razvoj
00:52
and into adulthood in order to frequently generate new cells
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in v odraslost, da lahko nastajajo nove celice,
00:57
and keep up with the body's needs.
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ki dohajajo potrebe telesa.
00:59
One example is the bone marrow,
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En primer je kostni mozeg,
01:01
where stem cells differentiate into many types of blood cells.
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kjer se izvorne celice diferencirajo v veliko različnih vrst krvnih celic.
01:05
That includes red blood cells,
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To vključuje rdeče krvničke,
01:07
which carry oxygen from the lungs to all tissues,
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ki prenašajo kisik od pljuč k tkivom,
01:10
platelets, which help stop bleeding by sticking to damaged blood vessels,
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trombociti, ki pomagajo ustaviti krvavitev z lepljenjem na poškodovane žile,
01:14
and white blood cells,
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in bele krvničke,
01:16
which patrol the body, destroying potentially harmful invaders.
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ki varujejo telo z uničevanjem potencialno nevarnih vsiljivcev.
01:20
Every once in a while,
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Vsake toliko časa,
01:21
something goes wrong during a stem cell's specialization process
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gre pri procesu specializacije izvorne celice nekaj narobe
01:25
and harmful mutations occur in the cell's DNA.
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in pride do škodljivih mutacij v celični DNA.
01:28
Cells with compromised DNA are supposed to self-destruct,
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Celice s poškodovano DNA naj bi se samouničile,
01:32
but some damaged cells ignore this order,
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a nekatere poškodovane celice ignorirajo ta ukaz,
01:34
replicating uncontrollably, even as they lose their original function.
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se množijo nenadzorovano, tudi ko izgubijo svojo prvotno vlogo.
01:39
These are what we know as cancer cells.
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Te so znane kot rakaste celice.
01:42
It is not yet clear why leukemia is the most common childhood cancer,
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Ni še čisto jasno, zakaj je levkemija najbolj pogost otroški rak,
01:46
but one contributing factor may be
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a eden izmed vzrokov je lahko,
01:48
that leukemias are often caused by just one or two DNA modifications,
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da levkemije pogosto povzroča le ena ali dve DNK spremembi,
01:53
while most cancers require many of them,
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medtem ko jih večina rakov zahteva več,
01:56
allowing leukemias to arise faster than other types of cancer.
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kar dovoli levkemijam, da nastanejo hitreje kot druge vrst rakov.
02:00
Moreover, some DNA alterations can occur in white blood cells
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Nekatere DNK spremembe lahko nastanejo v belih krvničkah
02:04
during fetal development,
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med fetalnim razvojem,
02:06
further increasing the risk of early leukemia.
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kar še bolj poveča tveganje zgodnje levkemije.
02:09
But though it affects more children than any other cancer,
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A čeprav prizadene več otrok kot katerakoli druga vrsta raka,
02:12
adults constitute the majority of leukemia patients overall.
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odrasli predstavljajo večino pacientov z levkemijo.
02:16
Once leukemia strikes, the damaged cells reproduce in the blood and the bone marrow
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Ko levkemija udari, se poškodovane celice množijo v krvi in kostnem mozgu,
02:21
until they take up all available space and resources.
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dokler ne zavzamejo vsega razpoložljivega prostora in virov.
02:24
When the bone marrow can no longer produce
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Ko kostni mozeg ne more več proizvajati
02:26
the required amount of functional cells,
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potrebne količine delujočih celic,
02:28
the blood becomes depleted.
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kri postane pomanjkljiva.
02:30
The lack of red blood cells
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Pomanjkanje rdečih krvničk pomeni, da mišice ne dobijo dovolj kisika,
02:32
means that muscles don't get enough oxygen,
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02:34
the reduced number of platelets is not sufficient to repair wounds,
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zmanjšano število trombocitov ni zadosti za popravilo rane
02:38
and the dearth of functional white blood cells impairs the immune system,
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in pomanjkanje funkcionalnih belih krvničk poškoduje imunski sistem,
02:42
increasing the risk of infections.
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kar poveča tveganje za infekcije.
02:45
To restore the normal function of the blood,
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Da bi obnovili normalno funkcijo krvi,
02:47
leukemic cells have to be eliminated.
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je treba odstraniti levkemične celice.
02:49
But because leukemias are not solid tumors,
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Zato ker levkemije niso solidni tumorji,
02:52
they can't be removed surgically.
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jih ne moremo odstraniti kirurško.
02:54
Instead, the cells are killed inside the body using various treatments
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Namesto tega, celice ubijemo znotraj telesa z različnimi zdravljenji,
02:58
that include chemotherapy,
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med katerimi je tudi kemoterapija,
03:00
a combination of drugs that destroys quickly multiplying cells.
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kombinacija zdravil, ki uničuje hitro množeče se celice.
03:04
Unfortunately, this has the side effect of killing healthy cells,
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Na žalost ima to stranski učinek ubijanja zdravih celic,
03:07
such as those found in hair follicles or intestines.
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kot so tiste v lasnih foliklih ali črevesju.
03:11
And in some cases, the dosage required is so high
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In v nekaterih primerih so potrebni odmerki tako veliki,
03:14
that it kills all cells in the bone marrow,
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da ubijejo vse celice v kostnem mozgu,
03:16
including stem cells.
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tudi izvorne celice.
03:19
When this happens, the body is no longer able to create new blood cells on its own.
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Ko se to zgodi, telo ne more več samo proizvajati novih krvnih celic.
03:24
Fortunately, outside help can come in the form of stem cells
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Na srečo, lahko pride pomoč od zunaj v obliki izvornih celic
03:28
from the bone marrow of a donor.
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iz kostnega mozga darovalca.
03:30
Once transplanted into the patient,
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Ko so enkrat presajene v pacienta,
03:32
they rapidly repopulate the bone marrow and the blood.
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se hitro namnožijo v kostnem mozgu in v krvi.
03:35
However, bone marrow transplants are a complicated process
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A presaditev kostnega mozga je zapleten proces,
03:38
requiring antigen compatibility between the donor and recipient
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ki zahteva ujemanje antigenov med darovalcem in prejemnikom,
03:43
to keep the transplanted cells from from attacking the patient's own cells
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da presajene celice ne bi napadle pacientovih lastnih celic
03:46
as foreign bodies.
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kot tuja telesa.
03:48
Unlike with blood transplants,
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Za razliko od transfuzij krvi,
03:49
there are thousands of HLA types,
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je tu na tisoče HLA tipov
03:51
and even siblings and close relatives may not have compatible bone marrow.
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in celo bratje in sestre ter sorodniki morda nimajo ujemajočega kostnega mozga.
03:56
If this is the case, the search is expanded to a database
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V tem primeru se iskanje razširi na bazo podatkov,
04:00
containing the genetic makeup of millions of voluntary bone marrow donors.
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ki vsebuje genetske strukture milijone prostovoljnih darovalcev kostnega mozga.
04:05
The more potential donors there are,
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Več kot je potencialnih darovalcev,
04:07
the more patients lives can be saved through successful transplants.
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več pacientov lahko rešimo z uspešno presaditvijo.
04:11
Leukemia may be a frightening disease, but there is strength and hope in numbers.
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Levkemija je morda strašljiva bolezen, a tu je moč in upanje v množini.
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