CURItE:jIS IN MODERN BIOLOGY 1 (1967) 204-213. NORTB-HOL’ANB I-UBLlsHlKG COMPANY. AMSTERDAM

I. 1NTROlXJCTlON

The number 01 blomedtcll cxperlmsnts uelng radtuieotoptc tracer* te growing. The destgn of many of tbeae e%per*ments LS b.%xrn!ng more in- volved, whhh often meane that not c&y the mum- her of calcutatlone on the dam from each ran- pie, but ateo the complexity d tbeee calcula- tions, is inerenslog. For exemplo, it the resulta es.2 *1e to neverat parnmeters actIns slmultane- ouely, then th,z c&lcuIntlons may tnvolvs m&Ix ooera!ions. Ia certabl cnsee. eoectrat ‘eumr- redolu1lon” may Lead to La&e Tram&me (Inow, 1684). To ae~tet wltb thls tncreeelng work tad, comPutere can g&c he‘P to the tuvce- tlgatar urw isotqac tlilcere ‘by prothctng prompt. accu-ate and extenrlvo calcutatlone (l‘undberg and Moore, 1666).

Two recent develapm~~ls are of spectral tn- tereat to the blologtst. Th, first La the ;~~,,ear- am20 of time-sharing uom~utsrs (Moore, loo?: Edwards. 1966: Lindgren, i968; Scherr, lB8S) with remotely located Lnprt-output devlcee. The second Is the elmplUicr,tlon end lncreeaed,wa- bll,ly of languages (Htlsenrath at al., 19dd; Ke- meny and Kurtt, ICKIS), eo Le time, effort and prcgnmmlne: experience required ‘:o vrlte, ‘debug’ and uee programs Is markedly de- CratlZCA

Th5.s ommer describes work In thie kboretorv tn whlck. liese methods were wed to PgeW WI& experimenta Involred with tranepx’t acroee h.u- man erythrocyte membrenes. Tbede eqMmente

uttltid radioteotapes to measure amounts of an amtno aotd Instde and CutaIde red blwQ cells. A model which simulated the eystem gutded tbe eatcetatton from these data to the analysts of tranepart ktnettcs.

2. METHOW

Conventionally, computers are wed to per- form many calculations in a ‘b&h prooosrtngnp’ fashion. Batch processing produces resolte from

data by mean i of the scheme illustrated In fig. 1. The nrwrar.. written in a mzw and unusuatlv

that da& be in a &escrikd for&t. This is not acbteved by revlstw the prlnted clrcult IWO- grammlng board k&h lican be done by dther kbuk of equipmeut (Blume, prlwte communlca- tlon). The loUowing Is the method used Ln this laboratory to operate upon the radioassay data

A Ita Of instruct10ns Is WrItten to accept the tape w orlgtnalty punched and from it to create a secrmd twe. cm which the format of the data 1s _ otwgd, as required, by the program comptler. Thk second tape becomes the data Input to an- other t~ogram. from which a table of calculated reetdts LB obtained. Pig. 2 18 a chart which shows the flow of InfOrmatIon from data tc. results, 88 asslsted by the time-#baring co.nputer system. The ~roa’am Is &XVII 1.1 table 2 which oar- _ _ formed the calcuhtlons that convert timdand owt data to net count rates and lhetr asawtated

205

uncertalntks. scale tgp1cal remits gtrm ocunt nta rtth cmntlne error8 ammar in tRble 5.

_wnt rate, the moat efficient dktrtlmtlon d cauntkg time betwssn wnpk and backgmmd, the mtntmum detoctab1e ammmt Of actlvlty tnvm L certatn bac&tround and ksel cd uocertatnty de- nlred, and the relstlse error of the count rat.. Such cllculatlars may be needed for data from

SAMPLE TIME, hE.U NUkBEK hIN. “PA ***t**tt*********c***

16 50 ~0375.4 17 50 10708.4 18 50 10657.3

2s 50 952.44 26 5” 135.62 e: 50 ,E9.L8 Pr‘ SO IYR.92 es 5O 205.42

. . . . . . . Shk~!_E . . . . .I.. . . . . . . . . . . . . . . . . . . . .

RED GREEN GREEN RED CPM/ EHi,“R CPR BRRBR GREEN CPM

*********rr**d***************************** .,‘i,49* 1 8104.94 c -,P3371 I 3-69097 .,3841e 1 eR59.28 c .518373 I 3.74515 .I38967 1 28b4.82 C -51877B 3 3.7331 .13861? 1 2905.64 C .5,4221 3 3.70978

..‘111965 3 200.38 c 1.9%l4 3 4.75317 t.04376 I 26.08 E 5.42772 I 5.2OO15 ,*C157R9 I e/r.42 c 5.60917 3 5.30191 .Fi6797H , IIR.8 c 4.0@98 3 S.,lbK .e;5618 , 40.26 f 4;36852 1 5.10233

T:,ble 5 The table of rerults mmducerl b:’ the ,nmg-ram shown in table d.

PAHROJ 17:::; CEIK 03/22/67

EXPERIWNT ND,............EXPFRl~ENT~R, .-.........DATE..r.,.....~...,

I&KKBBIK RFFPkENCE...-- . . . . . SAMPLE.--,.-..- ..+.-. - . . . . . . e e,... a= 20 C= 29% u= XII E= 1476O G= IRL.49, Ii= 5 ,= X21.594

35OREM+ EETUEEN SAWLE AND bACHGfiOUND = SO,? <E/25, 36QREM+ H = NIlMEtER OF STANDAPD DEVIUTIGNS AT :!klCH THE CIC>FIOENCF 37OREHr LEVEL IS SET L S”II ‘E/R + H/G) SOREM? L = v#iNlMU~ 0lzfLCTnmG UCTlV1TY = 3*9PR~2s/sGl 3wREMr m = RLLATIVE Ci?“NTING EkRDR 5 [K*SDh‘E/G + 25/5”,,/(F-2:,, 41DR&w THlRU SET 0F CALCULATED RESUL’IS r45RiQw N = GREEN CBUNTS/IXCHTE = 1oa*nm 41 OREM* 0 3 NET GREEN C0,,NTS/)IINUTE : N - 25 415REMs 25 1s 7HE BACKGRBUND TN THL GrrE&N CHANNF3 BOREM* P = GREEN CGWPING ERRBR z SW <loO&D/R> &?SREML I? - CGUNTING ERRBR 0F SAMPLE = SL’H<PW + 1112) 430REMM* FGURTH GET GF CALCULATFD LESULTS 405REf.W S -- HGST EFFIClENFDISTRIBUT~UN OF TINE = SOi=‘tN125> 440REM* 7 - NUMBER BF STANDARD DFVIATlhNS = SOHCN/B + H,G> 44511EM* U = RELATlW CLUNtlNG ERRBR = ~f+S~l~~N/B+R5/40~~/0 h94PRPRINT”TABLE OF R~SULTS+++PWGRA~: MKRD3” s95isam 496PfifNt”EXPER11ENT NG . . . . . . . . . . . ..EXPPRlRLNTER............DATG....~...V 4WPH 1 NT 49GPRINT”UGHKEJ00~ HEFEHENCEm.e....... SAMPLE.............................” 900 DIN AClGO>r GCIOOJ, C(lrlOl, DCIOO> 505 FGR # = I T0 100 510 READ A. 6, C. D 520 RE~+CAk,CULATl0N 0F FtRGT SE, 0F RESULTS %30 540

LETET=FiO_OE*CIB - 25

550 L!iT 6 = SQR <lOO+‘;CG> 560 LET H = SOR (25 * SO/501 570 LET I:- SOR tGtG + Hl2> %‘0K~t-*~XCUlAi1&4 PF SCCQND SBT bF RESULTS 600 LET J = SOR IE125> 610 LET K = SGRCE/B + H/B> 620 LET L m 3*SoR (25/50> 630 LET N I CK*SGRCE/B * 25/SO>J/CE - 25) &35liEfi* THIRD SET 0F CALC9LRTT.D RESULTS 640 LET N = ha0 + D/B 645 LET 0 = N - G5 650 LET I’ = SGR (100 * D/B> 655 LLT R - SOR cP*P + HIP> &ORMcFGURTH SET GF CALCULATED RESULTS MS LET S - SGR (NIG5) 610 LET T = GOR (N/B + H/G> $75 LET u = tT*SORtN/B + R5/SO>W(N-25> too PRINT ‘%~s~fA, “Gr”Gc “C=*‘C, “Ds”D, 710 PRINT “6r’~E, -F=-F, “G.“G, ‘9,x”“. “I-“, 720 PRINT “.In*l.J, “K=“K, “Ld’L, “M=“M P5 PRINT “Ne”N, “0-“0, “P-“PI “RI”R 730 PRINT “S=“S, “Tn”T, “Us” U 740 PRINT TM NEXT A

3. EQIJWMENT

Connmmly, scalera dlsplay data from counts by ilfumtnated numbers. A record of the data Is probced either by band, adding machine, printer or typewrtter unit, which ia auxiliary to the scaler. Some manufachrrers sell magnetic tape or tape-p.rforating devices which operate with, or instead of, a printer. A fk?~er tape perforator was added to the scalers tn tbls laboratory. The tape punch was recalved with D printed circuit tid which coded the data In IBM binary-coded deeimPl form, and this was the code of choke tn the %itfal we of D computnr. The paper tape wae converted to cards, and these WBIB processed In batches at a com@~ center. A second printed circuit board wa8 made to code the data in ASCfl (Amerlaan Standards Commlrtee on Information

Excher!!?! S-level code. Paper tape thus perlo- rated \“a6 acceptable to the teletype. The re- mote console was a model 33 teietyle machine with a dataphone set. A c~~ecfmn is made with a computer located elsewhere by dlalirq a tele- phone connection and using common class D ckannel.

At the computer center, transmission Is re- ceived by a Datanet 30 computer, in which there is a buffer (small magnetic ewe memorr) for each actlve “ser. The Datalet 30 controls a GE 235 computer. in which most of the cdcula- t,o,,s are done, and the magnetic dle.2 files on

wblch the user’~ programs are etored.

4. RESULTS OF COMPUTER METHODS

In a typical experinxst, the kinetics of trane-

ato R.McmRE

port of 14C-@yctne through the membranes of form in which the calculated results are printed. human erythrocytes was measured Sertal Barn- Headtnge for theform are printed first. The time ptes ‘I both tbs incubation medium and of the and count data are converted to counts per min, cells were taken and prepared for radioassay by the 96% conftdence limit for each result is liquid acintilbtttcm spectrometry. printed and the disintegrations per min are eal-

Table 6 show6 the form in which data are cuted. Ftg. 3 ts L plot of the results. It shows printed an the addii machtne whtch receives count rate h the first channel “ersw sample data from the scalers. The tape shows sets of 4 numwr. The minimum value, incremental axis numbers: sample, time (in hundredths of a mtn- division. ad tbz ma%inmm value of the v&able ute) zkn’ which the sample v/a8 assayed, the are printed at the top of the graph for each axts. counts acwnulated in the first channel and the The teletype plots potnts which are shown ean- cwnta Ln the iecond channel. Table 7 shows the neetal Table 8 ~howu a eatcutation for a one-

TablL? 7 Fimt o,,eratton upon data ,form 0, results,.

FaBGRAmlPAKL”7 TflBu.14 - RCFBRMATSED DATA AND RC.wLTS

FXPERINENT N(I~.....EXPCR,RENTE~..........DATA...~....~.

~.~.~~~.~~;;~~;~~.“““““““““““........................~.~

5060 10 153 153 I 5070 DATA 52 I 415631 110322 e.4*027 5080 DATA 53 10 159 116 r903409 5090 DATA 53 416530 5,lw DASA 0 : 0

,.,I;;:‘; 2p.4E9t6

. . . . . . . . ..~.........L..............................................

: 3 4

5

:

: 10

.5

.5

.3

.S ‘. 5 .5 .5 ;s .5 .5 .5 .S .5 .5 .5 .5

.5 -5 .5

0 .5 1 1.5 e 2-5

8 8.5 9

212 R.bmoRE

como*r4ment w&m. The increment b the am&t of trncir In the compartment with each tncrement cd ttme. the amlalnt in tbe cornpart-

data are graphed I” I$. 4. Table 0 nhows tbc urlntaut for a cxlcti!lm of

a two-compartment bystem, and fig. 5 le the graph of the ammmt of radtotsatope in each corn- partment “Crbus ttme.

5. RESULTS OF BlOLO‘XCAL EXPERWf.NTS

The problem to whkh tbta system was ap>Hed concerns Ihe traaport of amloo acti a‘rols membrane8 of human erythrocytee. TYP system hw assl&ed the btolo@st at several pobrts ill ‘& cDllrse oi llts work. The design 01 oxpar1menta .a, nadsted by Uw prlntwt ohovn in table 5. The m.,st efflclent dletrltutlon of camtlne time behveen sam~lea and back~ramd vae ctilrted The count rite and errors-were prtnted (table 3) and graphed (it& 3) t,) permit the dstecttm of er- rors h techilqur pkxnptly so that &pkrte ~nmples c&d be NO to check d&ant data The rewlts wsorb then tnterlwted In terms of com- partmentPL anatysls, and Y tunwer rates be- tween compPrtments were derived wg. 5).

The abo”C utustrattms tndtcate tlm stsps LI a pro&~&are In whtch P quantltatIve tnuaport mod- el vu) po8tuMed. A parttcular expsrlmsnt PPI batened to gather data t%lev~t for such P mod- et. After the data were cotlected ttiw ‘“era re-

nwtber it WPI know that M 1n9t%ntf1catltly amat amwnt of labolad amino acid vu tn the c.,, ,t xaY> time. KnowtIq the amount In the e.u

at I&r times and lawring the radioassays of the SUpernatFud and cell, values for the entrAwe4 medtum were pdS”rn6d tram 5-1032 tn 3.1 tncre- mmts. The catc”L~tlolu ga.e 7.8% tnpped s”- permtant for the cmdltlars of our sedlmmta- ttm This t8 conel~teot with values tn the tItera- ture fur thta quntlty.

Table 8 and *lg. 4 &al with P stmltar mode1 vhtch Is covered with the toss of SICr-tabeM erytbrocytea ,rom the circutat*on oi P pattent From tbu apertmental chta the loss rate ta cb- tatned (loss II) aseared to bc of first order and alpmentiat In tbll3 case).

lhoso a&n ln tabli 3. They have a rilattvely ftxed prwnm. the ccat cl calcutatton 11 hfabud

Table 10 summarizes the chief advantages and disadvantages of each mode of calculation

1. coNcLualoNa

Results can be interpreted in a broad conee~- W s&%x!, which is guiding the design of the safes o* es~erb~ents being run. The general time-shubxz comtmter has the capacity to ac- cept the ri&oassiy results, and to u&them in the ealeulations for the kIhysical. chemical. or bioluglcll) theory which guides the eX!Ierlm&. It can also prmt the rcwlt~ almost immediately Y tablw of numbers, painr plots, or both. Thls permits greatly simplified use and interpretation of the data In such enwlments. Further, the dpta can be calculated tn dUerent ways, the re- ~llts compared, and the program easily changed as the experfmentaf deedgil is altered.

TIM appltcatim of ttme-shufng computatfon to the red&Ion of radicasuay data has been de- scribed, together with Its ~advantages and Hmlta- tlow. Tlw fncrea6urlngly v/We avaulbillty of time- *lag ~ystcms suggesta the cons1dsrab1e h- hre we of tlda medium for the assistance of the investf@or usfng radfohatopes. Thla laboratory lms coupled the output d D rdfatlon detector to the fnput of the computer system and created P

series of proqans which accept the paper tape, refornat it, and we the madltted paper tape in programs which caleufnte tables of results and plot graphs of the values. The system has the advantage of power, flexibility and speed.