Document nmoN6a1bXO7mBaz3NeQwLYx98

\ Juna 26* 1937 Dr* Kenneth B* Bi&ckfan Sarjara Medical School Child ranfs Hospi t a l 500 Longwood Avenue Boston# Mesa* Dear D octor Blackfan* X as complying with the fu rth er request in your le t t e r of June 22nd by sending you herew ith a rep rin t of Cholak*s a r t i c l e d escrib in g h is sp ectro g ra p h ic method o f lea d a n a ly s is * We are in the process of preparing an a r t ic le fo r p ub lication which w i l l d e sc r ib e the d e t a i l s o f the D lt h i2on?, method o f a n a ly s is which we use* As t o the methods o f c o l le c t in g sam ples# w hare had a l l s t a i n l e s s s t e e l n eed les manufactured fo r us b y the Max Wocher and Son Company o f C in cin n a ti* I t i s on ly n e c e ssa r y t o s p e c ify th at the n eed le be made e n t i r e l y o f s t a i n l e s s s t e e l# and th a t the hub which i s commonly u sed In th e ordinary needle should be com pletely elim inated* This requires a s p e c ia l method o f fa b r ic a tio n but one which i s not d i f f i c u l t * O bviously th e se n eed le s are somewhat more expensive than the standard brand* In o b ta in in g blood samples* we prepare pyrex t e s t tubes in to which blood and s p in a l f l u i d can be drawn* 'Sics are washed c a r e f u lly with cleaning solu tion# rinsed repeatedly with d is t ille d water* and then r in s e d a t l e a s t th ree tim es more w ith d i s t i l l e d w ater*trip le d i s t i l l e d from eith e r a pyrsx , or a s i l i c a s t i l l * p referably the la tte r * These tubes i aro allow ed to drain# stoppered w ith a clean cork which has never been used before# and covered w ith a clean f i l t e r paper which i s h eld in p la c e by a rubber band* The blood sample i s taken d ir e c t ly fresa th e v ein in t o the tube by means o f a s p e c ia l need and u s u a lly w ithout a syringe* {I o ccasion ally take samples in the laboratory making us of a pyrax sy rin g e which has been s t e r i l i s e d by b o ilin g in d is t ille d water a fte r which i t i s rin sed three tim es with t r ip le d i s t i l l e d water# as p reviou sly mentioned* In gener.1# however# I p r efer to l e t the blood run d ir e c t ly through the n eed le in to the tube*) When we have samples o b tain ed by o th er debtors# we provide both the blood tube and the n eed le* The l a t t e r I s clean ed aa p r e v io u sly d escrib ed # put in to a c le a n pyrex tube# 0020100  2* # Kenneth D. Blackfan stoppered w ith co tto n and s te r iliz e d in the autoclave so th a t I t is ready fo r use w ithout any fu rth e r attem pt a t s b e r llis a tio n . A fte r ta k in g th e sample th e blood tube is sto p p ered , the f i l t e r paper replaced c a re fu lly and the tube is kept in an u p rig h t p o sitio n , i f p o ssib le, so as to av o id c o n ta c t w ith th e c o r k . (We h a v e h ad a number of samples se n t to us through the m ail in which t h i s l a t t e r p r e c a u tio n co u ld n o t b e o b s e rv e d , and we have had no d i f f i c u l t i e s . However, th e re is the p o s s ib ility of s l i g h t e r r o r in t h a t th e serum m ig h t b e a b so rb e d to some s lig h t ex ten t in to the stopper* S u b s ta n tia lly th e same te c h n iq u e is observed in the ease of sp in al f lu id , the needles being p re p a re d and s t e r i l i s e d i n advance and th e f l u i d b e in g with drawn in to th e tub p rep ared as in the case o f th e b lo o d tubes* ` ' ' " A-.. . . A: In g e n e ra l, where i t is f e a s ib le , we o b ta in a s p o t sam ple o f u r in e a t th e same tim e th e b lo o d sample i s taken* A sm all pyrex b o ttle i s prepared in e x a c tly th e same manner as th e b lo o d tub and th e s u b je c t I s asked to void ap proxim ately 100 cc of urin d ir e c tly in to th e c o n ta in e r, a f te r which i t is stoppered w ith i t s g lass stopper which is h e ld in p la c e by a f i l t e r paper covered se c u re ly by a r u b b e r b an d . We have b ee n a b le to o b ta in sam p les i n t h i s fa s h io n even when th e y have had to be m ailed to us from seme d i s t a n c e . In g e n e r a l th e r e s u l t s a r e s a t i s f a c t o r y although, obviously, b e tte r re s u lts can be obtained in the la b o ra to ry * The g r e a t d i f f i c u l t y in c o n n e ctio n w ith u rin e samples is th a t i t Is alm ost im possible to Impress people w ith the n e c e ssity of having the sample voided d ir e c tly in to the container* Ordinary h o sp ita l equipment, if used as an in term ed iate c o n ta in e r, w ill so contam inate th e sample as to ren d er i t u tte r ly u s e le s s , and m islead in g . Consequently in o u r work here a t th e G eneral H o sp ita l and the C hildrens H o s p ita l, we have i n s i s t e d t h a t th e i n t e r n e s o b ta in th e sam ples them selves and make s u r e t h a t th e y a re c o lle c te d p rec ise ly according to in stru ctio n s* In general there is approxim ately a ten to one r e la tio n s h ip 'in th e c o n c e n tra tio n of le a d in the b lo o d as com pared w ith th e u r i n e . T hat i s to s a y , th e con c e n tr a tio n in th e blood ex p ressed in term s o f 100 grams is ap p ro x im ately th e same as the c o n c e n tra tio n in th e u r in e expressed in terms of a lite r # Obviously th is re la tio n sh ip ' does n o t h o ld to o c l o s e ly i f i f we a r e a b le to o b ta in a blood sam ple and a sm all u r in e sam ple on a p a t i e n t a t th e sane tim e, and i f these samples check so as to have approxi m a te ly th e same p h y s io lo g ic s i g n i f i c a n c e , we f e e l t h a t in a l l  'Bp . K enneth B la e k fa a p ro b a b ility n e ith e r sample has been se rio u s ly contam inated in uhe p ro c e s s o f c o lle c tio n * I f th e sam ples do n o t a g r e e , we f e e l d isp o s e d to i n s i s t upon th e c o l l e c t i o n o f a d d i tio n a l sa m p le s, and w ith somewhat g r e a t e r p re c a u tio n s * lio ra o v e r we do n o t a tte m p t to draw r e f in e d co n c lu sio n s from b o rd e rlin e c a ses* The le a d c o n te n t o f b o th b lo o d and u r in e n ay v a ry from time to tim e to such an e x te n t th a t rep ea ted o b servations may be n e c e s s a ry in o r d e r to g iv e a c e r t a i n s ig n if ic a n c e * In our ex p erience sp o t samples o f u rin e taken a t d if f e r e n t tim es of th e day and on d if f e r e n t days a r e s u b je c t to f a i r l y w ide v a r ia tio n * C o n seq u en tly we do not lik e to draw too stro n g co n clu sio n s from a s in g le sp o t sample- .w here i t i s f e a s i b l e , wc t r y to o b ta in a sam ple w hich w i l l r e p r e s e n t th e u r in a r y o u tp u t o ver a p e rio d of L to 12. i X'W <U!*i n such a sam ple th e h o u r fcc h o u r v a r i s. x on w i l l be Ironed o u t and we h ave reaso n , t o b e l ie v e t h a t in su ch a sole we a r e d e a lin g w ith an av e ra g e s e c r e to r y c o n d itio n . .A le a d content- in th e u r in e o f one te n th , of a m illig ra m or more p er l i t e r is obviously s ig n if ic a n t of a ccm paratively r e c e n t ex p o su re to l e a d , and- i f the. q u a n t ity i s in eo ess of two*tenths o f a m illig ra m p er l i t e r , we f e e l c e r t a i n t h a t v;o are d ealin g w ith s ig n if ic a n t lo a d c lo s u r e * Hot a l l persona w ith t h i s l e v e l of le a d e x c r e tio n show symptoms* A ver; la r g e p ro p o rtio n o f persons : i t h symptoms show le v e ls of th is o rd er of magnitude* . You w i l l n o te t h a t X am i n c lin e d to- p i t much g r e a te r f a i t h in the- a n a ly ti c a l r e s u lt s f r a n more than one source than in a s in g le sample* I t i s f o r th a t reaso n th a t I lik e to have a sample of u rin e and a sample of blood obtained s u b s ta n tia lly sisrultanbotisly^ i f th is is possible* X tr u s t I have not Indulged in a n y - - re p e titio n o f my fo rm e r rem arks to y o u , b u t I want to be q u ite c le a r , a s to my p o in t of view and th e re a s o n s f o r i t . C ordially yours. RAEsi s ~Robert A* i\ebLO0,"M.D* K f 0020102