Fwd from Tuan V Nguyen: Kho'c ddi em, kho'c nu+~a ddi em

["Hoa Nguyen" <thanhhuy@email.msn.com>]

Cha`o ca'c ba'c,
Xin chuye^?n dde^'n ca'c ba'c ba`i vie^'t cu?a mo^.t "nha` khoa ho.c" ve^`
"nu+o+'c ma('t" (ddu+o+.c nha^'n ma.nh la` cu?a phu. nu+~) ddi  tu+` ca'c
ta'c pha^?m va(n chu+o+ng la~ng ma.n hay nhie^`u ki.ch ti'nh   dde^'n
nhu+~ng kha?o cu+'u nghie^m chi?nh cu?a y ho.c, ta^m ly' ho.c. Xin mo+`i
ca'c ba'c cho the^m y' kie^'n.
Pha^`n to^i tuy la` ngu+o+`i ddu+a tin xin cu~ng co' nha^.n xe't rie^ ng la`
ba'c Tua^'n V Nguyen tuy co' no'i dde^'n ta'c du.ng cu?a nu+o+'c ma('t
ddo^'i vo+'i ngu+o+`i kha'c, co' the^? la` ngoa.i cuo^.c, nhu+ ga^y xo^'n
xang, la`m cho lo`ng me^`m nhu~n ra... nhu+ng kho^ng no'i dde^'n ca'i cho^~
ma` tho+ ca cu~ng thu+o+`ng  no'i . Ddo' la` co' khi nu+o+'c ma('t (co^'
nhie^n la` cu?a phu. nu+~) la.i tro^ng dde.p nhu+ nhu+~ng ha.t ngo.c : gio.t
cha^u la~ cha~... Nhu+~ng do`ng nu+o+'c ma('t do ddo' co' the^? go+.i hu+'ng
cho nhu+~ng do`ng tho+ kho^ng nha^'t thie^'t la` pha?i xo't xa (kho^ng
bie^'t la` co' tuye^.t ta'c hay kho^ng). Xin nho+` ba'c Hoa`ng Linh da^~n
chu+'ng du`m va`i ca^u tho+ (hay lo+`i ha't).
N. Ho`a

Hi ca'c ba'c,
Lu'c to^i mo+'i sang U'c ddi.nh cu+ va`o na(m 1982, o^ng
Malcolm Fraser - lu'c ba^'y gio+` la` ddu+o+ng kim thu? tu+o+'ng -
bi. tha^'t cu+?.  O^ng ta le^n ti vi vu+`a kho'c [ra nu+o+'c ma('t
dda`ng hoa`ng] vu+`a than mo^.t ca^u ma` sau na`y tha`nh ma^?u
qua?ng ca'o cu?a nhie^`u co^ng ty, "Life isn't meant to be easy."
(Ta^'t nhie^n, lu'c ddo' thi` to^i cha(?ng hie^?u ca^u ddo' co'
nghi~a la` gi` ca?.)  Tuy nhie^n, hi`nh a?nh cu?a mo^.t vi.
nguye^n thu? quo^'c gia kho'c tre^n ti vi qua? la` qua' mo+'i la.
ddo^'i vo+'i to^i, va` lu'c ddo' to^i nga.c nhie^n la('m.  Tu+`
ddo', to^i dda~ co' chu? ta^m ti`m hie^?u ta.i sao mo^.t "ngu+o+`i
hu`ng" nhu+ the^' ma` la.i ro+i nu+o+'c ma('t.
To^i vo^'n thi'ch ddo.c nhu+~ng gi` co' lie^n quan to+'i ta^m
ly' - y ho.c.  Tha`nh ra, ca'ch dda^y va`i tua^`n, khi ddu+o+.c ho?i
co' muo^'n la`m "tro.ng ta`i" cho mo^.t ba`i ba'o co' tu+.a dde^` la`
"Human tears and psycho-physiological therapeutic values,"  to^i
kho^ng the^? na`o tu+` cho^'i ddu+o+.c.  Qua vie^.c la`m na`y, to^i
mo+'i bie^'t ddu+o+.c kho'c va` nu+o+'c ma('t la` mo^.t dde^` ta`i
nghie^n cu+'u kha' qui mo^ trong gio+'i chuye^n ve^` ta^m ly' ho.c
va` di~ nhie^n la` gio+'i nha~n khoa\.  Nhu+ng theo to^i, ca'c o^ng
ba` ta^m ly' ho.c co' nhie^`u y' tu+o+?ng ha^'p da^~n, hay va` la.
ho+n ca'c o^ng ba` nha~n khoa\.  Va? la.i, nhu+~ng gi` gio+'i ta^m
ly' ho.c no'i co' ve? ga^`n gu~i va` ti`nh ca?m ho+n gio+'i la`m
khoa ho.c thua^`n tu'y.  Ddo.c xong nhu+~ng ba`i nghie^n cu+'u ve^`
kho'c va` nu+o+'c ma('t, to^i co' y' ddi.nh to'm go.n va`i y' chi'nh
dde^? nho+', va` ba`i ta?n ma.n na`y la` ca'i to'm lu+o+.c ddo'.
No'i dde^'n kho'c la` pha?i dde^` ca^.p dde^'n sa?n pha^?m
cu?a no', tu+'c la` nu+o+'c ma('t.  Nhu+ng ca^`n pha?i  pha^n
bie^.t hai loa.i nu+o+'c ma('t ma` to^i ta.m dda(.t te^n la`
"tra^`n le^." va` "ca?m le^.."  Tra^`n le^. la` loa.i nu+o+'c
ma('t tie^'t ra do bu.i ba(.m hay ca'c vi va^.t la`m kho' chi.u
ma('t (tie^'ng Anh go.i la` reflective tears).  Ca?m le^. la`
loa.i nu+o+'c ma('t tie^'t ra do ta'c ddo^.ng bo+?i ca?m ti'nh
(emotional tears).  Gio+'i nha~n khoa thu+o+`ng nghie^n cu+'u
tra^`n le^., trong khi ddo' ca?m le^. la` ddo^'i tu+o+.ng
nghie^n cu+'u cu?a gio+'i ta^m ly' ho.c.  Trong ba`i na`y, to^i
chi? ba`n ve^` ca?m le^..
Nhu+ng no'i nu+o+'c ma('t la` dde^` ta`i cu?a hai
gio+'i khoa ho.c tre^n thi` cu~ng kho^ng ha(?n ddu'ng.  Dda~ tu+`
la^u, nu+o+'c ma('t la` mo^.t ddo^'i tu+o+.ng va` tha^.m chi' mo^.t
co^ng cu. cu?a ca'c nghe^. si~.  Thu+.c va^.y, du`ng nu+o+'c ma('t
dde^? the^m ma('m the^m muo^'i va`o va(n chu+o+ng la` mo^.t bie^.t
ta`i cu?a ca'c va(n si~.  Ha^`u nhu+ trong ba^'t cu+' cuo^'n tie^?u
thuye^'t na`o, nha` va(n luo^n luo^n cho mo^.t nha^n va^.t
(thu+o+`ng la` nu+~) kho'c dde^? la`m cho ca^u chuye^.n the^m la^m
ly bi dda't.  Muo^'n cho ca^u chuye^.n ta(ng ti'nh ca?i lu+o+ng,
ta'c gia? co`n the^m va`o ca'i mo^i tru+o+`ng chung quanh cho u
sa^`u chu't, cha(?ng ha.n nhu+ cho nha^n va^.t ddo' pha?i kho'c
trong mo^.t dde^m mu+a gio' ba~o bu`ng (kie^?u "mo^.t dde^m vu+`a
gio' la.i vu+`a mu+a"), va`o mu`a thu, la`m nhu+ tro+`i dda^'t
cu~ng tho^'ng kho^? vo+'i no^~i nie^`m cu?a nha^n va^.t.  Thi si~
co`n mo^.ng mo+ ho+n ca'c nha` va(n nhie^`u, ho. vi' von [va` phong
phu' ho'a] nu+o+'c ma('t ba(`ng ddu? thu+' my~ tu+` cao sang, dde.p
dde~ dde^? cho ngu+o+`i ddo.c ca?m tha^'y kho'c va` nu+o+'c ma('t
kho^ng ha(?n la` bie^?u hie^.n cu?a buo^`n kho^?, ma` la` mo^.t
bie^?u tu+o+.ng la~ng ma.n, la` mo^.t phu+o+ng tie^.n gia?i to?a
nhu+~ng bu+'c xu'c cu?a ta^m ho^`n.  Nhu+ng nhie^`u khi chu+~ nghi~a
kho^ng co' ta'c ddo^.ng ma.nh me~ ba(`ng hi`nh a?nh.  Tha`nh ra,
dde^? cho bu+'c ho.a co' ca'i ti'nh "my~ ca?m" mo^.t chu't, ma^'y
anh chi. ho.a si~ ta be`n que.t cho na`ng (thu+o+`ng la` ga^`y go`
mo^.t ca'ch be^.nh hoa.n) mo^.t gio.t le^. hay la`m cho ma('t na`ng
nga^'n le^..  Ngu+o+`i xem tranh cu~ng tha^'y i't nhie^`u xo^'n xang.
Dde^? sinh ddo^.ng ho'a nhu+~ng bu+'c ho.a na`y, ca'c nha` dda.o
die^~n phim ta^.n du.ng nu+o+'c ma('t co`n ho+n ca'c o^ng ba` ho.a
si~ dde^? la`m cho ta'c pha^?m cu?a ho. ga^`n gu~i vo+'i qua^`n
chu'ng ho+n.  To^i dda~ chu+'ng kie^'n nhie^`u kha'n gia?, nha^'t
la` pha'i nu+~, kho'c su+o+'t mu+o+'t theo die^~n vie^n khi xem
nhu+~ng phim ti`nh ca?m nhu+ Cuo^'n Theo Chie^`u Gio' (Gone with
the wind) va` The Thorn Bird.
Co`n trong nha.c thi` o^i tho^i co' vo^ so^' nhu+~ng ba`i
no'i ve^` kho'c va` nu+o+'c ma('t.  Tu+` ddo+n gia?n "Nu+o+'c ma('t
ro+i", o^ng Pha.m Duy co`n ta? "Nu+o+'c ma('t mu`a thu" (la.i mu`a
thu); co' le~ vi` "thu+o+ng qua' Vie^.t Nam" nhu+ o^ng Pha.m The^'
My~, ne^n o^ng Tri.nh Co^ng So+n vie^'t ba`i "Nu+o+'c ma('t cho
que^ hu+o+ng"; o^ng Tu+` Co^ng Phu.ng cu~ng dde^? la.i cho ddo+`i
nhu+~ng "Gio.t le^. cho nga`n sau"; o^ng Ddu+'c Huy thi` nho+'
nha` dde^'n no^~i pha?i "Kho'c mo^.t gio`ng so^ng" khi xa que^,
xa Sa`i Go`n, v.v.  Ke^? kho^ng he^'t ddu+o+.c.  Nhu+ng trong
mo^.t ba`i nha.c xu+a la('m ro^`i [ma` to^i dda~ que^n te^n] co'
ddoa.n:
Kho'c ddi em, kho'c nu+~a ddi em
Kho'c dde^? ro^`i que^n mo^.t cuo^.c ti`nh buo^`n.
(Dda.i kha'i nhu+ the^'.  Ba'c na`o (anh Dung FL) nho+' lo+`i va`
tu+.a, xin la`m o+n giu'p to^i.)  Lu'c ddo', to^i nga.c nhie^n la('m,
va` nghi~ la` o^ng nha.c si~ na`y tha^.t la` ky`, dda~ kho^ng chi.u
vo^~ ve^` "na`ng" ddang kho'c ma` co`n ba?o la` cu+' kho'c, kho'c
nu+~a ddi\.  Nhu+ng sau na`y lo+'n le^n va` co' di.p ho.c ho?i va`i
ddie^`u ve^` nu+o+'c ma('t to^i mo+'i tha^'y lo+`i nha.c tre^n dda^y
cu~ng co' ly' la('m.  Kho'c co' gia' tri. tri. lie^.u ta^m sinh ly',
chu+' kho^ng ha(?n chi? dde^? vo+i no^~i buo^`n hay tha^'t ti`nh.
Ddo^'i vo+'i tre? em, trong khi chu+a no'i ddu+o+.c, kho'c
luo^n luo^n la` mo^.t phu+o+ng tie^.n lie^n la.c va` tho^ng tin
co' ta'c ddo^.ng ma.nh me~ nha^'t.  Cha me. na`o ma` cha(?ng pha?i
kho^'n ddo^'n, lo cha.y co' co+` mo^~i khi nghe con mi`nh kho'c.
Ddo^'i vo+'i phu. nu+~, nu+o+'c ma('t va^~n la` mo^.t vu~ khi' vu+`a
ba?o ve^. mi`nh vu+`a co' ti'nh thuye^'t phu.c gio+'i dda`n o^ng
cu+.c ky` co^ng hie^.u.  Dda^'ng tru+o+.ng phu na`o ma` cha(?ng xie^u
lo`ng, va` co' khi co`n o^m tay na`ng qui` go^'i nhu+ tha^`n da^n
tru+o+'c co^ng chu'a mo^~i khi my~ nha^n ro+i le^..  Ma`, thu+.c
va^.y, ddo^'i Dda`n o^ng co' quye^`n the^', ngay ca? ca'c anh hu`ng
ha?o ha'n he't ra lu+?a, mu+?a ra kho'i, co' tra'i tim sa('t dda' co+~
na`o ddi nu+~a, cu~ng pha?i cuo^'i dda^`u tru+o+'c nu+o+'c ma('t cu?a
dda`n ba` phu. nu+~, cho du` la` nu+o+'c ma('t cu?a ke? thu`!  Nhie^`u
ca^u truye^.n co^? ti'ch li.ch su+? dda~ cho tha^'y nu+o+'c ma('t phu.
nu+~ co' the^? la`m dda?o ddie^n tha`nh tri` nhu+ cho+i.
Ve^` kho'c, xa~ ho^.i Ddo^ng Ta^y no'i chung co' "tha`nh
kie^'n" vo+'i dda`n o^ng con trai, va` ca?m ti`nh vo+'i gio+'i to'c
da`i .  Ca'i kho'c cu?a dda`n ba` con ga'i thu+o+`ng ddu+o+.c dde^`
ca^.p to+'i ba(`ng nhu+~ng ngo^n tu+` co' ti'nh hoa my~, tho^ng
ca?m, nhe. nha`ng nhu+ "nho?ng nhe?o", "nu~ng ni.u", "de^~ thu+o+ng",
"to^.i nghie^.p", v.v.  Nhu+ng dda`n o^ng con trai ma` ro+i le^.
thi` la.i mang nhu+~ng nha~n hie^.u co' ti'nh ca'ch che^ bai, mi?a
mai nhu+ "mi't u+o+'t", "ye^'u lo`ng", "ti'nh dda`n ba` con ga'i" ...
la`m nhu+ kho'c la` mo^.t dda(.c ti'nh cu?a gio+'i nu+~ kho^ng
ba(`ng!  Thu+.c ra, dda`n o^ng cu~ng thi?nh thoa?ng kho'c nhu+ mu+a,
nhu+ng co`n ra^'t i't.  To^i cho ra(`ng ca'i tha`nh kie^'n na`y dda~
cu+o+'p ddi ca'i nguo^`n an u?i lo+'n nha^'t cu?a dda`n o^ng con
trai, va` bie^'t dda^u cu~ng la` mo^.t trong nhu+~ng nguye^n nha^n
la`m cho ho., vo^'n ddu+o+.c coi la` pha'i ma.nh, che^'t so+'m ho+n
pha'i nu+~, luo^n ddu+o+.c coi la` pha'i ye^'u.
Ai cu~ng bie^'t kho'c la` mo^.t dda(.c ti'nh cu?a con ngu+o+`i.
Thu+.c ra, kho'c la` mo^.t trong nhu+~ng dda(.c ddie^?m la`m cho con
ngu+o+`i kha'c vo+'i thu' va^.t vo^'n kho^ng bie^'t kho'c.  Nhu+ng ca^u
ho?i dda^`u tie^n ma` to^i nghi~ ai cu~ng muo^'n ddu+o+.c tra? lo+`i la`
ta.i sao ngu+o+`i ta kho'c, va` ca'i gi` trong co+ the^? con ngu+o+`i
sa?n xua^'t ra nu+o+'c ma('t.  Ca'c nha` ta^m ly' ho.c gia?i thi'ch
ra(`ng mo^~i khi bi. ki'ch thi'ch bo+?i no^~i sa^`u kho^?, buo^`n na~n,
cha'n chu+o+`ng, tuye^.t vo.ng, gia^.n do^~i, hay no^~i vui mu+`ng,
ha^n hoan cu+.c ddo^., qua' kha? na(ng chi.u ddu+.ng cu?a co+ na(ng,
co+ the^? con ngu+o+`i be`n dda'p u+'ng vo+'i nhu+~ng ti`nh the^' ca(ng
tha(?ng na`y ba(`ng ca'ch gia?i thoa't sinh lu+.c (energy).  Kho'c la`
mo^.t hi`nh thu+'c gia?i thoa't na`y.  Nguye^~n Bi'nh cha(?ng tu+`ng
vie^'t "DDe^m qua na`ng dda~ che^'t ro^`i; nghe.n nga`o to^i kho'c ...
Qua? to^i ye^u na`ng" la` gi`?!  Mo^.t gia?i thi'ch kha'c co' ve?
tru+`u tu+o+.ng ho+n ra(`ng khi he^. tho^'ng ha(`ng ddi.nh no^.i mo^i
(homeostasis) trong co+ the^? bi. ma^'t ca^n ba(`ng do xu'c ddo^.ng,
va` trong lu'c qua' ddo^. na`y, co+ na(ng kho^ng dda'p u+'ng ki.p
tho+`i ba(`ng lo+`i no'i hay suy nghi~, kho'c la`m cho he^. tho^'ng
na`y ca^n ba(`ng la.i.
Qua' tri`nh kho'c cha?y nu+o+'c ma('t (tie^'ng Anh go.i la`
lacrimation) cu~ng ra^'t u+ la` ly' thu'.  He^. tha^`n kinh chi pho^'i
qua' tri`nh cha?y nu+o+'c ma('t.  Nhu+ ai cu~ng bie^'t, tha^`n kinh
so. cu?a con ngu+o+`i co' 12 ddo^i tha^`n kinh pha't xua^'t tu+` na~o
(ddo^i so^' I kie^?m soa't khu+'u gia'c; II thi. gia'c; III va^.n
ddo^.ng nha~n; IV ca?m ddo^.ng; V sinh ba; VI va^.n nha~n;  VII ma(.t;
VIII so. na~o; IX thie^.t ha^`u; X phe^' vi.; XI tu?y so^'ng; va` XII
ha. thie^.t).  Ddo^i da^y so^' V va` VII la` bo^. ma'y ddie^`u khie^?n
lu+u lu+o+.ng va` tho+`i gian kho'c cu?a con ngu+o+`i.  So+.i tha^`n
kinh (nerve fibre) cu?a ddo^i da^y tha^`n kinh so^' VII ddu+o+.c ca^'u
ta.o tu+` nha^n le^. (lacrimal nucleus).  Do ddo', khi ddu+o+.c
"le^.nh" tu+` he^. tha^`n kinh, cu`ng mo^.t lu'c, da^y tha^`n kinh
so^' VII lie^`n sa?n xua^'t nu+o+'c ma('t, va` da^y so^' V la`m ra
le^.nh tie^'p cho ca'c co+ ba('p tre^n khuo^n ma(.t va^.n ddo^.ng
la`m thay ddo^?i mo^.t ca'ch ra^'t u+ la` nhanh cho'ng va` the^ tha?m.
Sau khi tuye^'n le^. tie^'t ra nu+o+'c ma('t; nu+o+'c ma('t cha?y ddi
qua ca'c lo^~ nho? (ddie^?m le^.) o+? go'c ma('t phi'a trong va`o hai
o^'ng le^..  Tu+` ddo', nu+o+'c ma('t se~ cha?y va`o xoang mu~i qua
tu'i le^. (lacrimal) va` o^'ng mu~i le^. (nasolacrimal duct).  Va`
cuo^'i cu`ng la` ... kho'c.
Tie^'ng Vie^.t mi`nh co' tha`nh ngu+~ "nu+o+'c ma('t ca' sa^'u"
dde^? chi? nhu+~ng ke? lo`ng da. thie^'u tha`nh tha^.t.  Nhu+ng to^i
thi` la.i chu' y' ca'i hie^.n tu+o+.ng la. la` con ca' sa^'u, sau khi
nuo^'t chu+?ng con mo^`i, kho'e ma('t no' la.i tuo^n cha?y nu+o+'c
ma('t.  No' kho'c cho so^' pha^.n con mo^`i kho^ng may ma('n hay la`
sung su+o+'ng vi` dda~ no bu.ng?  Chu+a ai bie^'t ddu+o+.c ly' do
sinh ho.c dda(`ng sau ca'i hie^.n tu+o+.ng ky` la. na`y, nhu+ng co'
nghie^n cu+'u cho tha^'y qua' tri`nh "kho'c" cu?a ca' sa^'u kha'c
vo+'i con ngu+o+`i.  Theo mo^.t nghie^n cu+'u duy nha^'t co^ng bo^'
ca'ch dda^y 27 na(m thi` nu+o+'c ma('t ca' sa^'u la` do ki'ch thi'ch
tu+` nu+o+'c da~i (saliva), chu+' kho^ng pha?i do ki'ch thi'ch cu?a
ca?m ti'nh (emotion).  Nhu+ng nu+o+'c ma('t ca' sa^'u thu+o+`ng la`
nu+o+'c ma('t "ddo+n phu+o+ng", tu+'c la` chi? chu? ye^'u "kho'c"
co' mo^.t ma('t. Ngoa`i ra, ca'i kha'c dda'ng ke^? kha'c la` nu+o+'c
ma('t ca' sa^'u ddu+o+.c ddie^`u khie^?n bo+?i hai ddo^i da^y tha^`n
kinh so^' VII va` so^' IX.  Tuy nhie^n, cu~ng nhu+ con ngu+o+`i,
tru+o+'c khi kho'c, ca' sa^'u cu~ng bi. da^y tha^`n kinh so^' V
la`m thay ddo^?i ne't ma(.t.
Ngu+o+`i ta thu+o+`ng hay nghi~ ra(`ng pha'i nu+~ kho'c
nhie^`u ho+n pha'i nam, nhu+ng y' nghi~ na`y kho^ng hoa`n toa`n
ddu'ng vo+'i thu+.c te^', vi` no' tu`y thuo^.c va`o ddo^. tuo^?i.
Theo mo^.t nghie^n cu+'u na(m 1972, o+? ddo^. tuo^?i co`n bu' su+~a,
tre? em nam kho'c nhie^`u ho+n tre? em nu+~, va` ddo^.ng co+ kho'c
cu~ng kha'c nhau.  Trong ddo^. tuo^?i na`y, tre? em nam kho'c
thu+o+`ng do ca?m tha^'y kho^ng an toa`n, so+. se^.t, trong khi ddo'
ddo^.ng co+ la`m cho tre? em nu+~ kho'c la` ddau ddo+'n co+ the^?.
Nhu+ng khi o+? ddo^. tuo^?i trung va` dda.i ho.c thi` ca'c na`ng
kho'c nhie^`u ho+n, la^u ho+n va` cu+o+`ng ddo^. ma.nh ho+n ca'c
cha`ng to+'i 3 la^`n.  Khi ve^` gia`, phu. nu+~ cu~ng kho'c nhie^`u
va` la^u ho+n dda`n o^ng, nhu+ng cu+o+`ng ddo^. thi` kho^ng kha'c
nhau bao nhie^u.  Dde^? gia?i thi'ch cho su+. kha'c bie^.t na`y, ca'c
nha` ta^m sinh ly' ho.c ddo ddo^. oestradiol va` so sa'nh vo+'i so^'
la^`n kho'c va` dung lu+o+.ng nu+o+'c ma('t.  Ho. ti`m ra ra(`ng
ddo^. tu+o+ng quan giu+~a oestradiol va` dung lu+o+.ng nu+o+'c ma('t
cao ho+n giu+~a oestradiol va` so^' la^`n kho'c.  No'i ca'ch kha'c,
ca'c na`ng co' nhie^`u hormone nu+~ na`y kho'c nhie^`u ho+n va`
mo^~i la^`n kho'c, nu+o+'c ma('t cu~ng nhie^`u ho+n, ca'c na`ng co'
i't oestradiol.  Nhu+ va^.y, o+? mu+'c ddo^. la^m sa`ng va` ta^m ly',
oestrogen co' the^? chi pho^'i dde^'n kho'c.  The^' thi` ca^u ho?i
ddu+o+.c dda(.t ra la` trong nu+o+'c ma('t co' gi`, co' oestrogen
kho^ng?
Trong Truye^.n Kie^`u, cu. Nguye^~n Du co' nha('c dde^'n
"kho'c" i't nha^'t la` 12 la^`n, nhu+ng "nu+o+'c ma('t" va` "le^."
chi? 7 la^`n.  Trong ca'c ca^u co' nhu+~ng chu+~ na`y, to^i dde^?
y' nha^'t ca^u:
Tha^?n tho+` lu'c ti?nh lu'c me^,
Ma'u theo nu+o+'c ma('t ho^`n li`a chie^m bao\.
ma` to^i cho la` kha' chi'nh xa'c ve^` sinh ly' cu?a nu+o+'c ma('t.
Ne^'u hie^?u "ma'u" la` ta^.p ho+.p hormones, enzymes va` hoa' cha^'t
thi` cu. Nguye^~n cu~ng kha' ddu'ng.  Ma(.c du` va^.y, to^i va^~n
nghi~ cu. Nguye^~n vo^ ti`nh vie^'t ca^u "Ma'u theo nu+o+'c ma('t",
chu+' cha(?ng bie^'t ra(`ng no' co' y' tu+o+?ng khoa ho.c khoa hie^'t
gi` dda^u.

Ai cu~ng bie^'t trong nu+o+'c ma('t co' chu+'a lysozyme, mo^.t
enzymes cu~ng ddu+o+.c tha^'y trong nu+o+'c mie^'ng va` tru+'ng ga`.
Nhu+ng ga^`n dda^y, theo pha^n ti'ch cu?a ca'c nha` nghie^n cu+'u y
khoa, nu+o+'c ma('t co' va`i enzymes va` nhie^`u tha`nh pha^`n kha'c
nu+~a.  Trong ca'c enzymes, nu+o+'c ma('t co' chu+'a peroxidase va`
amylase.  Trong ca'c proteins, nu+o+'c ma('t co' immunoglobin A,
lactoferrin, va` albumin.  Nu+o+'c cu~ng co' chu+'a nhu+~ng khoa'ng
sa?n nhu+ calcium va` magnesium.  Quan tro.ng ho+n la` hormones;
nu+o+'c ma('t co' kha' nhie^`u: IL-1 alpha (khoa?ng 11 pg/ml), IL-1
beta (13 pg/ml), IL-6 (226 pg/ml), IL-8 (731 pg/ml).  Nhu+ng ddie^`u
ly' thu' la` tha`nh cha^'t ho'a cha^'t trong "tra^`n le^." kha'c
vo+'i tha`nh cha^'t ho'a cha^'t trong "ca?m le^.".  Trong ca?m le^.,
tu+'c nu+o+'c ma('t kho'c vi` ca?m ddo^.ng, co' so^' lu+o+.ng proteins
cao ho+n "tra^`n le^." (nu+o+'c ma('t do bu.i ba(.m la`m ngu+'a ma('t
ga^y ra) to+'i 24%.  Nhu+ng trong tra^`n le^. thi` kho^ng tha^'y co'
hormones IL-1 beta, ma` co' ra^'t i't ca'c hormones kha'c nhu+ IL-1
alpha (9.3 pg/ml), IL-6 (12 pg/ml) va` IL-8 (276 pg/ml.)
Nhu+~ng ho'a cha^'t na`y co' a?nh hu+o+?ng gi` dde^'m ta^m
sinh ly'?  Lysozyme la` mo^.t loa.i "dao" (enzyme) co' kha? na(ng
pha' vo+~ bu+'c tu+o+`ng te^' ba`o va` tie^u die^.t vi khua^?n.
Co`n Lactoferrin thi` co' nhie^.m vu. nga(n ngu+`a kho^ng cho vi
khua^?n ta(ng tru+o+?ng va` pho`ng cho^'ng nhie^~m tru`ng.  Albumin,
mo^.t protein tho^ng du.ng va` co' nhie^`u nhie^.m vu. kha'c nhau,
trong ddo' co' chu+'c na(ng kie^?m soa't ddie^`u tie^'t nu+o+'c,
chuye^n cho+? ca'c cha^'t bo^? va`o te^' ba`o va` cho+? ca'c cha^'t
tha?y ra kho?i te^' ba`o.  Pha^`n ddo^ng ca'c hormones interleukin
(tu+'c IL) co' chu+'c na(ng chi'nh trong vie^.c pho`ng cho^'ng
pho?ng (inflammation).  Nhu+ng ga^`n dda^y, mo^.t nho'm nghie^n
cu+'u y khoa o+? tru+o+`ng Penn State dda~ pha^n ti'ch la.i khoa?ng
10 hormones thuo^.c nho'm IL va` ho. ke^'t lua^.n ra(`ng nhu+~ng
hormones na`y cu~ng la` nhu+~ng "markers" cho su+. xu'c ddo^.ng
ca(ng tha(?ng (emotional stress) va` ma^`m mo^'ng cu?a nhie^`u
be^.nh ta^.t kha'c.
Ne^'u thuye^'t tre^n dda^y ddu'ng thi` no'i mo^.t ca'ch kha'c,
trong khi kho'c, co+ the^? ta tu+. dda`o tha?i nhu+~ng ho'a cha^'t
phie^`n muo^.n!  Ma` thu+.c va^.y, theo ca'c nha` ta^m ly' ho.c, ve^`
ma(.t ta^m ly', sau khi kho'c, ngu+o+`i ta ca?m tha^'y thoa?i ma'i
ho+n va` co' na(ng lu+.c ho+n dde^? ddo^'i pho' vo+'i nhu+~ng ca(ng
tha(?ng dda~ la`m cho ngu+o+`i ta kho'c.  Co`n ve^` hie^.u qua? sinh
ly', kho'c la`m gia?m nhi.p tim, gia?m mu+'c ddo^. tie^u hao oxygen,
va` gia?m su+. ca(ng tha(?ng cu?a co+ ba('p.  Tha`nh ra, kho'c co'
hie^.u qua? he^'t su+'c thie^'t thu+.c la` ddem la.i su+. bi`nh
thu+o+`ng ho'a cu?a ta^m sinh ly'.  Trong thu+.c te^', nga`y xu+a
trong y ho.c co^? truye^`n, nu+o+'c ma('t ddu+o+.c coi la` mo^.t
loa.i popular anaesthetic hay la` mo^.t loa.i thuo^'c ga^y me^ da^n
da~.  Co' le~ nha^.n ra gia' tri. tri. lie^.u na`y, ne^n trong
nhu+~ng na(m dda^`u the^' ky? na`y, gio+'i y ta' thu+o+`ng khuye^'n
khi'ch kho'c mo^~i khi ddu+o+ng dda^`u vo+'i nhu+~ng ca(n be^.nh
nga(.t nghe`o hay ca^`n gia?i pha^?u.
Nu+o+'c ma('t co`n co' the^? la` lie^`u thuo^'c chu+~a nhu+~ng
ve^'t thu+o+ng ngoa.i nu+~a.  Ho+n 50 na(m ve^` tru+o+'c, co' ngu+o+`i
dda~ chu+'ng minh su+. lie^n quan giu+~a kho'c va` to^'c ddo^.
recovery la`nh be^.nh; ngu+o+`i hay kho'c co' tho+`i gian la`nh
be^.nh thu+o+`ng nhanh ho+n ngu+o+`i kho^ng hay kho'c.  Hie^.u qua?
na`y cu~ng ddu+o+.c nha^.n trong ca'c chu' chuo^.c.  Trong mo^.t thi'
nghie^.m ddu+o+.c co^ng bo^' tre^n to+` Neuroscience Letters, mo^.t
nho'm nghie^n cu+'u be^n U'c dda~ pha't hie^.n ra nu+o+'c ma('t co`n
la` mo^.t phu+o+ng thuo^'c chu+~a nhu+~ng ve^'t thu+o+ng.  Ho. ca('t
mo^.t ve^'t nho? tre^n da mo^.t nho'm chuo^.t; sau ddo' trong so^'
pha^n nu+?a nho'm chuo^.t na`y, ho. nho? va`o ma('t chu'ng mo^.t
cha^'t ki'ch thi'ch la`m cho chu'ng kho'c ra nu+o+'c ma('t, trong
khi pha^n nu+?a nho'm kia kho^ng ddu+o+.c ki'ch thi'ch.  Ke^'t qua?
cho tha^'y ve^'t thu+o+ng cu?a ca'c chu' chuo^.t "mi't u+o+'t"
ddu+o+.c la`nh mau ho+n ca'c chu' chuo^.t kho^ng kho'c to+'i 12
nga`y.  Nho'm nghie^n cu+'u na`y be`n thu+? nghie^.m mo^.t gia?
thuye^'t dda?o ngu+o+.c: ho. cho cha^'t ki'ch thi'ch dde^? la`m cho
ca'c chu' chuo^.t kho'c he^'t nu+o+'c ma('t, sau ddo' la`m cho ho.
bi. chu't thu+o+ng ngoa`i da\.  Ke^'t qua? hoa`n toa`n ngu+o+.c la.i,
tu+'c la` ve^'t thu+o+ng de^~ bi. nhie^~m tru`ng.  Ho. suy lua^.n
ra(`ng trong nu+o+'c ma('t co' mo^.t hormone "huye^`n bi'" na`o
ddo' co' ta'c du.ng tri. lie^.u ca'c ve^'t thu+o+ng ngoa`i da\.
Nhu+ va^.y, kho'c ra^'t co' lo+.i cho su+'c kho?e.  Va` ne^'u
thuye^'t na`y ddu'ng thi` nhu+~ng ai kho^ng kho'c hay la`m bo^. nga(n
gio`ng nu+o+'c ma('t pha?i co' nhie^`u "va^'n dde^`".  Qua? va^.y,
theo nghie^n cu+'u la^m sa`ng trong tha^.p nie^n 70s, nhu+~ng ngu+o+`i
kho^ng kho'c co' nguy co+ bi. nhu+~ng be^.nh nhu+ loe't (ulcers),
vie^m ke^'t tra`ng (colitis), nhu+'c dda^`u (migraine headaches),
va` nhu+~ng be^.nh co' ti'nh psychosomatic (ta^m tha^`n co+ the^?)
cao ho+n nhu+~ng ngu+o+`i hay kho'c.  Ve^` ma(.t ta^m ly', ngu+o+`i
kho^ng kho'c cu~ng thu+o+`ng ga(.p tro+? nga.i khi ddo^'i pho' vo+'i
ca'c ti`nh huo^'ng ca(ng tha(?ng.  Nhu+~ng quan sa't na`y cu~ng phu`
ho+.p vo+'i nhie^`u nghie^n cu+'u cho tha^'y nhu+~ng phu. nu+~ so^'
kie^`m ha~m la.i su+. gia^.n ho+`n co' ty? le^. bi. be^.nh tim cao
ho+n nhu+~ng phu. nu+~ cu`ng tuo^?i nhu+ng chi.u tho^? lo^. ra mo^.t
ca'ch xa^y du+.ng.  Mo^.t gia? thuye^'t dda'ng tin ca^.y dde^? gia?i
thi'ch cho hie^.n tu+o+.ng na`y la` khi ngu+o+`i ta na(`m trong mo^.t
mo^i tru+o+`ng ga^y ca^'n, ca(ng tha(?ng, va` trong khi chu+a hay
kho^ng ho'a gia?i ddu+o+.c, trung ta^m tha^`n kinh lie^n quan to+'i
ca?m ti'nh tu+` tu+` bi. "hu+ ho?ng".  Va` khi ca'i trung ta^m na`y
bi. ho?ng, no' be`n gu+?i ddi nhu+~ng ti'n hie^.u sai la^`m cho ca'c
co+ quan va^.n ha`nh ddie^`u tie^'t trong co+ the^?, va` ga^y ra
disorders tu+'c la` be^.nh ta^.t.
Trong tho+`i dda.i nga`y nay o+? ca'c nu+o+'c phu+o+ng Ta^y,
nhu+~ng no+i ma` nha` ai na^'y o+? va` cu+?a ddo'ng ki'n mi't, chu'ng
ta so^'ng trong mo^.t mo^i tru+o+`ng tu+o+ng ddo^'i co^ la^.p va`
thie^'u ca'i ma` to^i go.i la` "human interaction", tu+'c la` su+.
co' qua co' la.i, ti`nh ha`ng xo'm.   Ma(.t kha'c, trong mo^~i con
ngu+o+`i bi`nh thu+o+`ng (kho^ng pha?i sie^u nha^n - superman) dde^`u
co' mo^.t mu+'c ddo^. gio+'i ha.n trong su+. chi.u ddu+.ng nhu+~ng
gi` con ngu+o+`i co' the^? ca?m va` nha^.n.  Ddi qua' hay co^'
ga('ng ddi qua' mu+'c ddo^. gio+'i ha.n tu+'c la` ddo^`ng nghi~a
vo+'i tu+. chuo^'c la^'y ddau kho^?.  Do ddo', thie^'u su+. "co'
qua co' la.i" kho^ng nhu+~ng da^~n dde^'n ti`nh tra.ng dde` ne'n,
be^' mo^n to?a ca?ng ve^` ti`nh ca?m ma` co`n ga^y ra be^.nh ta^.t.
Cha`, nghe co' ve? trie^'t ly' hue^` vo^'n qua', pha?i kho^ng ca'c
ba'c?   Nhu+ng ca'i ddie^?m ma` to^i muo^'n no'i to+'i qua ca^u
chuye^.n kho'c va` nu+o+'c ma('t na`y la` du+o+`ng nhu+ the^'
gio+'i y khoa chi'nh tho^'ng dda~ va` ddang ta^.p trung qua'
nhie^`u na(ng lu+.c va`o vie^.c nghie^n cu+'u ca'i "soma" hay
co+ the^?, ma` bo? qua mo^.t pha^`n kha'c cu~ng kho^ng ke'm pha^`n
quan tro.ng la` ca'i "psycho" hay ta^m tha^`n cu?a con ngu+o+`i.
Tha`nh thu+?, ngu+o+.c la.i vo+'i nhu+~ng quan nie^.m co^?
xu+a o+? A' Cha^u ta cho nu+o+'c ma('t la` bie^?u hie^.n cu?a su+.
ye^'u dduo^'i, nga`y nay nu+o+'c ma('t ddu+o+.c xem co' nhie^`u
co^ng du.ng he^'t su+'c thu+.c tie^?n va` thie^'t thu+.c.  Va^.y
thi`, mo^~i khi tha^'t ti`nh, co' chuye^.n buo^`n, hay ddau
ddo+'n [ca? ve^` ta^m tha^`n la^~n the^? xa'c] qua' su+'c chi.u
ddu+.ng thi` ca'c ba'c ddu+`ng nghe lo+`i ba`i nha.c "Ddu+`ng
kho'c nghe em", ma` cu+' kho'c, kho'c thoa?i ma'i.  Va` ne^'u
"ngu+o+`i ti`nh tre^n ddo^`i co? non" cu?a ca'c ba'c co' ddie^`u
gi` ddo' ca^`n pha?i kho'c, thi` nha^n danh su+'c kho?e va` ti`nh
thu+o+ng nha^n loa.i, ca'c ba'c cu+' tha?n nhie^n no'i:
Kho'c ddi em, kho'c nu+~a ddi em ...  :-)
=====
Tuan V Nguyen
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