Document Zno9Bx56yBg95redrwaB6LKpO

iO, 1570 OJ caused by a dire.: stimou-tir.;: fc acid conipr^'sbJc to hat observed m \ \ volunteers* Tin's oiicct irn aK ;>c for the increased lcd in *! uei:*H?iD<: fed tn patients receiving deep X-ray 'rt.*;incnt they are given folic a^ui.'* "Whether the gastrointestinal div:i.r';>..u v-~ are mediated through a similar csm-ral path'-sav or resuited from ?. direct effect on the gut remains conjectural. But it is ot interest that Uk acid seen.s to he concen trated in saliva.: *a fact which may explain the bad or bitter taste complained of tn some of our volunteers. V/c thunk Or. GerutJ Cur/.:'.. oi ih t l;wi;u{c ot N^urotoi;s, f3/ thscusMnj; with us the j w s m Mc roii- of lot;. m .vrebrji- amine metabolism; Miss Catherine Duncan, of she M R.C. SutisticxI Research and SetvjiCN I 'm*. tor .utvicc on vacisnca! aspects; ami Mr. N j o lh o n Smith for help in gathering data. Requests for reprints vh.voM be adduced to R. K. RfftKENilES I . H u n te r. R . !'r*.e*. J.. M jtth e * > . O . M . t t5V, it. 066 2 W.uvr. A. H . 15. 1. 7. /.. Pot* !9ot, 14. m . 3. H u m e r .S M .H .u i.. M K . K.s\. t ; I \ l ) /V /> ; <>i/ 19Si,3. m . 4. if.. I 5 . t 5 I'm ri.i:rv..*ov.VK *1 JU*iS *f ! I ..H - peutn.'**. r ic,,s s. o,ii.ru:tn. t Tne Me* bU^tu Sarrn.a>. p vs* Cxf*fd. 1^* . V v 'J h rl. H t . n - v . K r A W t . I t i xt lift), i, 351. 7. I h-t-urH. 1 * i . httu^e. I VX\. 1 L. fir. mir.: 7 . *. * R<' '. . IJ.!*. I H . r Iwr;. t. ic h > V '!' M V. * linj. .! il.cn** *' p . t*5 f.-njr*r I**? t o C!rur.*ri'). l ft: M. -b* %:. p. Sxx `m .t J . iv^yJ II. H. Nv'! it I..*,. *.v/- - r . i . j i t j ic#>0. <s. 1 17. 12 Vc.'u. t>. <* '*.%. M J i* J 1 1^6V in 13. H<rivet. V /..i:ck-. . R. /.;>; |<J6!, 20 1* 1> N.-jT-usu. T . 1.1v.f VI . L'iTiittcnJ. S. e. . iQM . 239, 2*iU*. ts K-iufrrjn. S n TVs [.n/niw' 'hliJ hv 1' I) il.vei.lt Irviy K M>rKj.*r. . voj \:u p *?i \c* Wrfc, 196? *#*. ('./s. f; M., Ar;miror., } l! , <*iin\bcr<j, il .7 *:. 106#. IVMJ. 17. Reyn.'IJs, K H fi'j-.r, IVt)*. St. 197. IK t>n5r.. C A 4 m . } !*J \ ./ I v i n . 2J2, J57. 19 .V.*tk*ar.cn. T . Mikii*. h / iys", t, HIS. FNZVMF: IN H in iT /O N IJY LK AD ' UXDHU NOUMAL URBAN CONDITIONS S. Hi:r n-b !:!;g ]. N i k k a n f .n Institute 0/ Oecuf ju-.-'u! / letilth. IIetj' tn:^r.inl/utit / , Helsinki 29, Finland . _ A d ose neirative cofrdation was found lictwcen the concentration of lead in 'blood and the activitv of erythrocyte 5-ainir.ol.TeiiliRic acid dehydrortenase m 20 healthy individuals, never exposed occupationally to lead.The results indicate that present levels ol environmental contamination with lead can produce a measurable biochemical alteration tn man. ISTRPinCIlOX Ur/m is absorbed into the human organism by respiratory and digestive routes and is distributed to organs and tissues hv the bloodstream.* Metabolism is com plex--some lead being excreted and some deposited; the rest forms a mctabo'ically active poo! reiieetci' by the blood-.cvel o f leas'd As a result of growing industrial use and the introduction o f alky! lead compound-, as petrol ashhtives, exposure to lead is substantially above " * the background of absorption tto m iood and dim king-water, fipideinio'ogiea! and experiment;*! data point to a logarithmic correlation between the concentration of least in the ol sspv.ed individual:, ot popish':o.-.s,'* 5uf;gest that, it. .t-.an. lead c?.n accumulate as a resull increasing r / . ironmi-ntal coac&niirnticn. Any cflect o f the absorbed lead ori .oth will 'depend o;i the degree o f accumulation. T he generally aceertid " sa fe" upper limit for the concentration of Iced in the blood o f persons exposed industrially i- some 70-flf) up. per 1W) m l.,'-- and mean values 'or occupationally unexposed populittions are usually between 15 and 25 ig. per 100 m l.1-'.14 'I'hcsc levels are considered by most workers to be without any biological effects. - Inhibition of ham synthesis is one manifestation of lead toxicity; and measurements of intermediate products o f this metabolic chain-- c.g., coproporphvrin and rt-aminolcevulinic acid f.x.i. O in urine-- have long been used as quantitative tests of the response of the organism to surplus lead,3 " and have thus formed one basis for the evaluation o f what is harmful anJ what is not.- The finding that erythrocyte A.t .A. .Ii lv drogenasc aetivit v is specifically inhibited by lead has provided a n o s . specific, and sensitive method for the detection ot earb. V.<d effect.'` 1' We has e used this !r> ' ->c i< measurable bio.u.jv d effects due to present levels of urban < sp-^ore to lead .an hi found in man. MA riHtAL ANl) .V` ! t.. 'S Wood-lead levels and erwhrocytc a .i. a delivdtogcnasc activity store measured t:i lb iujlihv n.vdcai vudenfs fin males. Ip Icmalest with no p:cs m .t previous occu pational exposure to the metal. The concentration of fe.id ill whole bfK'd was measured alter wet .is.ung usim; a dithizonc method." The standard dcviatii:) oi iluplieate incasurcincnts was I d yg. per 1U0 nil. A Mind control of the lead estimation gave the to'hmir.g result (the concentration in the blank sample recorded as 9 ug. per 100 ml.); ut- r<* t'W tn!. Aff-nutoi IS 12 50 V) 100 i.<: A.I..A. dchyiirogciasc w j s nu*75ur*:J *ro:-; tV.*^h hcpjfinjseil whole blood according to IvopAigtn'ioN nicthod.lr 'The results were corrected or ivc-rontocri: v.iiu.v nad the onxv- matic activity v.vs calculated the U-nnub: !00d .< l?-5 r.A0` A0;.hicmatixnr ( A# and A arc the absorbencies at 6^ and 0 minutes, respectively, and 12-5 is the dilution, correction. f> 1 0 15 7 . 0 7 U 3 0 M 000-LEAG ( /j 3 per ! 0 0 /.!.) 35 R e l a t i o n bct*.vcf> b!Dc3lc.'tJ s-tid a f l i v i i y r.f e r y t h r o c y t e A L A . iichy<lro* c in c o f 20 p erv o n * n # v er m u;*..t:lo!ts!!v e x p o se d to leaej. . K& 0006209 j" ' ! Vy - t#iV ifi */ THE LANCI. S, JANUARY IO, 197; RESULTS There was a strong negative correlation between the concentration of lead in the blood ar.d the logarithm of a .i a . dehydrogenase activity (see figure): v 2 3 0 7 OOlRcqr -0 -8 3 . T h e remits indicate that an inhibition o f A.L.A. dehydrogenase that is proportional to the concentration of lead m the blood can be shown even-for people representing " normal " urban exposure to lead. There is no lead level on the repression line below which it can he stated that no inhibition occurs. We later extended ou- observations to M2 workers, representitig various degrees of occupational exposure, with h!;\.d-!cad values ranging from 11 to 9} y,;. per 100 mi. The regression line was almost identical. y 2;271 OOl.Sv.r - 0 9 0 . These observations confirm the results presented above and clearly show the interrelationship between the concent! at ion o ' lead in the blood and the activity o f A.I..A. dehydrogenase. D ISC ISSIO N So far as we know, there have been no earner reports indicating that present environmental . mtarninauon v.ith lead has any biological eileer . on man. Our finding tv an example of how the border between " eifcst " and " n o effect" can be shifted by the introduction of more sensitive methods. Indeed, inhibition of A.r .a. dehydrogenase \<a lound ct such low lead concentra,:ons that one ina, ask whether there is any lead dose small enough to have n o elfect at all: The same may be true for "ther poisons; but a lack of sensitive method . for measuring toju'c eiVectx leaves this question open. T h e effect of environmental contamination with lead on health has been subject to'speculation ' ' ' The finding that a .i..a . dehydroston.ise is partly inhibited in the " norma! " ui'oan population cannot be considered as p.roof of an effect on the health, since its significance is unknown as yet, but it demonstrates that even the comparatively low exposure to lead, prevailing today, interferes with metabolism. This--imerfercncc- mety*or_r.-i?.y. nou-he.,harmful. Without taking any stand point on this question, it mav be assumed from the Goldsmith-! fester regression'' that this and other possible elfects will become mote pronounced if contamination becomes heavier in the future. * iht- iv a j tn.-.lyscs. Requests for reprint should be eddressed to S. It. REtT.tSNCKS 1. K ch o c, n . A. Ar e n i t n a . H. ' i h, 2. IttN i:, K. A. i i l i . p. 2J5. X S to p p i. <* y . a cu f'. AUJ. J <. I*s.:tcivon, CZ. C . A r c h i c*:\ ir. ,5. S c l i r o - d f r ,, H . A T i p t o n , 1. . ,C O a n i i l j o n , !. R e p o r t for 1S-4, C, 232 .HMcin i*n c A V 7 il't'n S e t . Pu b ! t, IT-Vi* ,i;. 0idsrr*r.h . ] R . ICcater, A. i>. H u h !:n,*:, A T>'i c f r <} Hot. ,IO. I*frrut<T, i ) U i ' j i i ' u ' t , Ar<K, 4Kir. l i i t h . 3. I I - I)c Uruin, A SieJ. /.ut oro, 1 IZ. r. n . i h j . k c 6. s: , ,13. K Vs' jcix, <) . Yz::o .14. K ee r.sn . M: G iMvrs. D. Il .i*>J. / / . < Iv6t. 15. li s i c y , T . Ar./,; 4'n ir. }tii I 32 (. 1?, 3J ' I. Am DISSECTING- MICROSCOPY OP RUOTAI. M U C O SA S im m y Ba s k ) . s. t '<t.u D. G. Bo h n s 1. N M a r k s Cauroiiitr-rimi! I'm!, (irrv.v V /.'.'-po.,.' >jh11-r 1a.vrv, and Departh -it ol Mt.iun.o. Cm:, / ape Town, ( -ip' ! Souih A'. ie.: S u m m a ry finder :he dissecting m u m seope the n o ; '. i.il a p p e a r a n c e o f t h e tes t.it m u c o s a is a honeycom b p a i v i ol n u n s forine.I a vasciilai n e t w o r k . U n d e r >h i.iu - ii.di:. p i u p r e s u m a b l y c r y p t s o f I . i d 'c r k u u n *i .am. " o \l) (!; c c c m r e ! t h e s e u n i t s . I h o . n e niilaa:: p a r. : n i k m : !y d i s t u r b e d i n b i o p s y s p e c i m e n s :;rrco:i;t : \ j Ji-vfr.b w i : t . u ^ c r ; u i \ * e c o li t is , a n d in m a n s .*>*> n o p its c a n be .ecu.. ' 1ST KOIM'CI l u x . liti dissvctine-m uToscnpe .ippc.u anscs >t the n o r m a l a n d a b n o r m . i! c ju n a l m u c - - i a u " d ! kn,<v. n, a n d i h e fin d in g s arc ot c o n s id e r a b le cal i.' in ' he d i a g n o s i s oi s: i i li - h n w e i d i s e a s e . T o o u r know led g e , this ic. b.nisgic has not been used to investigate he large-bow*; in u n sa . VC e d e s c r i b e l u r e disse* ting- mi roscojx- a p p e a r a n c e s ol t h e :i--i n:-i: r i s t a i .am-, o .a a n d t h e c h a n g e s found in ulccr.vu c . o h m s , M A1 i I '. I \ \ S D M I I Do o s - h iltv r c * lj :.-i-iO;-.. xpe.m iens \\e :e !a,..T a! r o v 'iiu* sigm oidoscope a ' h is; 5 , r tueu r troni ili a: ai svigy. p o u r o f these w e n 'on u.ur'.jp, d in; ecaln.u -oi: 'I lie speci m en was m'.mcii. .'.il' p 'j c e d m i p e r n d o l i i n n i j i i i i : . ; Ibrmaim, examined u j.i'ii! de.as, ag.1 photography,: w iilun 15 m inutes. W u l m j o . t.i mir.i - the sp.eimen ii' U.-' . :>eamc wh.ue and f, . i - n g it iisvis'ss : --r cxaminjtio:-, to th.s m e th o d . . M S' Is .Vo m i i .;/ R ,: h i ! : T h e s t i i k i n g leni a . s a ii-gv.". onth " pattern of tlic m u c t 'sai stirta c e 1 . .. b uni; ' . ! the lionevcornb' is f o r t n e d b v a ru te. a r,". , t i ; ' a : n . ' . w r k o f vesvels w hic lr r n e r g e w n b e . u h f t l . c r ut Ha. l o r u . r s n f t h unii p r o d u c iti* : a u n i f o r m j r . d t e g i d a - .i- Ini*, t u r e fig. 1). Ai * \ .is \ * t . . *1 \ X ' - \ * *i ; \-.. */ -1^.< * I i t V / y ' ( ' *l-.s . r-/ * * -b" ' * . s. . VV s * .. * /' . ^ ' . f' . v c. >1 - <- < 2 * *t fi V 1^ ' rK ' "r c: V* r\ *i * . i/ a fc - l i;. | - N?.rrcv. w x v u l t i r c h r . n n c l s i v ** rr.vcofp-J v*t i i r *. " K rJu-tJ nm ... eo i. . -efs;e '. ' s ' Axv*