Document N2OEjoREgDOgmpJOGnKNN3Gyg

% Juan 26, 1957 Dr, Keaneth D* Blaokfan Harvard Medical School iCh ild r en 1 H osp ital 500 Longwood Avenue Boston , Mass# Dear Doctor Blaokfan 1 Z an comp lyin g with the fu r t h e r r eq u est in your le t t e r of June 22nd by sending you h erewith a r e p r in t of Cholak** a r t ic le d escr ib in g h is sp ectr ogr ap h la method of lead a n a lys is * We ar e in the process of preparing an a r t ic le fo r p u blication Which w ill d escr ib e the d e t a ils of the "Dlth iaon e8 method o f a n a lys is which we use* As to the methods o f Co lle ct in g sam ples, wa have bad a l l s t a in le s s s t e e l n eed les m anufactured fo r us b y the Max Wocher and Son Company o f Cin cin n a t i, I t is on ly n ecessa r y t o s p e cify {that the n eed le be made e n t ir e ly of s t a in le s s s t e e l, and t h a t th e hub which is commonly u sed in the ord in ary n eedle should be com p letely elim in ated * This r eq u ir es a s p e cia l method of fa b r ica t io n but one which is not d iffic u lt * Obviou sly th ese n eed les ar e somewhat more expen sive than the standard brand* In ob tain in g blood sam ples, we prep are pyrex t e s t tubes in t o which blood and s p in a l flu id can be drawn* These ar e washed c a r e fu lly with clean in g so lu t io n , rin sed r ep eated ly with d is t ille d wa ter , and then r in sed a t le a s t th ree time more with d i s t i lle d w a t e r ,t r ip le d i s t i lle d from e it h e r a pyrex > or a s i l l o a s t i l l , p r e fe r a b ly the la t t e r * These tubes 2 are allowed to d r a in , stoppered with a d e a n cork which has never been used b efo r e, and covered with a clean f i l t e r pape| > which i s h eld In p la ce by a rubber band* The blood sim ple is taken d ir e c t ly from th e vein in t o th e tube by means o f a s p e cia l need and u s u a lly with ou t a syr in ge* (1 o cca sio n a lly take samples in the la b or a tor y making u se o f e p yr ex syr in ge which h as been s t e r ilis e d by b o ilin g in d i s t i lle d water a ft e r which i t I s r in se d three times with t r ip le d is t ille d water, as p r eviou sly mentioned* In gen e r a l, however, X p r efer to le t the blood run d lr e o t ly through the n eed le In to the tube*} When we have sample^ obtain ed b y oth er d o ct or s, we p r ovid e bbth the blood tube and the n eed le* The la t t e r i s clean ed ap p r eviou sly d escr ib ed , put in t o a clea n pyrex tu be, OPZIZM Dr. Ken neth D. B ls ckfa n stoppered with cotton and s t e r iliz e d In the au toclave so th at i t la ready fo r use without any fu r th er attempt a t s t e r iliz a t io n . Aft e r takin g the ample, the blood tube Is stoppered, the f i l t e r paper replaced ca r e fu lly and the tube la kept In an u p righ t p o sit io n , i f p o ssib le, so os to avoid oon taot with the co r k . (We have had a number of samples sen t to us through the m all In which t h is la t t e r p recau tion could n ot be observed , and we have had no d i ffi c u l t i e s However, th er e I s the p o s s ib ilit y o f s lig h t e r r o r in t h a t the serum might be absorbed t o some sligh t extent Into the stopper* Su b s t a n t ia lly the same tech n ique is observed In the ease o f sp in a l flu id , the n eedles bein g prepared and s t e r iliz e d in advance and the flu id bein g with * " awn In to th e tu be prepared as In the case o f the b lood bes. In ge n e r a l, where I t is fe a s ib le , we obtain a sp ot sample o f u r in e a t the same time the blood Sample I s taken . A sm all p yr ex b o t t le i s prepared In e xa ct ly t/ the same manner as the blood tube and th e s u b ject I s asked to void app roxim ately 100 cc of u r in e d ir e c t ly in t o th e con ta in er , a ft e r which I t Is stoppered with i t s gla ss stopper itch Is h eld in p la ce by a f i l t e r paper covered secu r e ly a rubber band. We have been able to obtain samples in t tis fa s h io n even when th ey have had to be m ailed to us >m same d is t a n ce . In gen er a l the Resu lts a r e s a t is fa ct o r y a lth ou gh , o b vio u sly, b e t t e r r e s u lt s can be obtain ed In the la b o r a t o r y, The gr e a t d i ffi c u lt y la con n ection with u r in e samples is t h a t i t I s alm ost Im possible to impress p eople .th the n e ce s s it y of h avin g the sample voided d ir e c t ly ito t&e co n t a in e r , Ordin ary h o s p it a l equipment, i f used an In term ediate co n t a in er , w ill so contaminate the sample to r en d er i t u t t e r ly u s e le s s , and m islea d in g. Consequently our work here a t the Gen eral H osp it a l and the Ch ild r en s H o sp it a l, we have in s is t e d t h a t the in t er n es obtain the samples them selves and make su r e t h a t th ey are co lle ct e d e o ie o ly.a ccor d in g:t o . in s t r u ct io n s . . Xtt gen er a l th er e i s approxim ately s ten to one r ela t io n sh lp M n the con cen tr ation o f lea d In the blood as compared with th e u r in e , That I s to s a y, the con* cen t r a t i on in t h e blood expressed in terms o f 100 grams is approxim ately th e same as the con cen tr ation in the u r ih e expressed in term? o f a l i t e r . Obviously th in r ela t io n sh ip dobs n ot h old too c lo s e ly i f I f we a r e able t o obtain a bipod sample and a sm all u r in e sample on a p a t ie n t a t same t im e, and i f th ese samples check so sa to have ap p r oxi m ately th e same p h ysiologic s ig n ifica n ce , we fe e l th at in a l l Dr. Ke nne th Bl a o kf a n u r o'ct iolllt y n eit h er sample has been s e r io u s ly contaminated in she p r ocess of co lle ct io n * I f th e samples do n ot a gr ee, ' v fe e l d isp osed to I n s is t upon the co lle ct io n o f a d d it ion a l sam ples, and wit h somewhat gr e a t e r precaution s# Moreover we do n ot attem pt t o draw r e fin e d con clu sion s from b or d er lin e cases* Ehe lea d con ten t o f both blood and u r in e may var y from time to time to such an ext en t th a t r ep eated obser vation s may be n ecessar y in order t o give a ce r t a in s ign ifica n ce * In our exp er ien ce spot samples o f u r in e taken a t d iffe r e n t times o f the day and on d iffe r e n t days ar e s u b ject t o f a i r l y wide va r ia t io n * Consequently we do not lik e t o draw too str on g con clu sion s from a s in gle spot sampleWhere I t is fe a s ib le , we t r y t o ob ta in a sample which \ w ill r ep r esen t th e u r in a r y output over a period of !{B to 72 h ou r s. In such a sample the hour to hour va r ia t io n s w ill be Ironed ou t and we have reason t o b e lie ve th at In such a sample ne a r e d ea lin g with an average secr e t o r y con d it ion . A lea d con ten t in th e u r in e of one ten th of & m illigr am or more p er l i t e r Is ob viou sly s ig n ific a n t o f a com p aratively r ecen t exposure t o le a d , and I f the q u a n tity Is In ecess of twcHotenths o f a m illigr a m per l i t e r , we fe e l ce r t a in t h a t we are d ea lin g with s ig n ific a n t leAd OJp o aure. Not a l l person s with t h is le v e l of lea d excr et ion show symptoms* A ver y la r ge proportion of persons with symptoms show le ve ls of t h is order o f magnitude* you w ill n ote t h a t I am in clin e d to put much gr e a t e r fa i t h iu the a n a lyt ica l r e s u lt s from more than one source than in a s in gle sample* I t is fo r t h a t reason th at X lik e to have a sample o f u r in e and a sample of blood obtain ed s u b s t a n t ia lly sim u lta n eou sly, it t h is i s p o ssib le X t r u s t X have not Indulged in . any r e p e t it io n o f my form er remarks to you , but X want to be q u it e c le a r as to my p oin t of view and the reason s fo r I t , Cordially you rs. KAKjls Robert A. Kehoe, M.D*