Development of a solid phase separation system for radioimmunoassay

Symposium Abstracts

After- r e d u c t i o n t o

lithium

l I C - m e t h a n o l , which

is

This precursor

is

Hydrocyanic acid, catalytic

aluminium

277

methanolate~

the

t r a n s f o r m e d t o l i e - m e t h y l i o d i d e by

labelled reaction

CO2 on

farms

by

successive

PzI4"

used t o e y n t h e s i z e ~ I C - m e t h y l t h y m i d i n e . labelled with

r e a c t i o n s COz N z i/H - >

carbon-ll,

is

CH4 Pt/NHs

>HCN.

prepared This

is

the

two

precursor

of

llC-urea . l e F - f l u o r a d e o x y g l u c a s e (FDG). used for cerebral and myocardial studies, is s y n t h e s i z e d by a F u c l e o p h i l i c r e a c t i o n u s i n g a n h y d r o u s f l u o r i d e obtained by 18 r e a c t i o n o f p r o t o n s an O - e n r i c h e d water'. T h i s i s o t o p e , i n t h e same chemical form~ i s used f a r t h e s y n t h e s i s o f I S F - f l u o r a e t h y l s p i p e r a n e , a l i g a n d ~ar b e t a adrenergic systems. i ~ N - n i t rogen, obtained by bombardment o-F n a t u r a l waterby p r o t o n s , is principally used i n t h e s y n t h e s i s o f ammonia by r e d u c t i o n o f NOX formed d u r i n g irradiation with Devarda's a l l o y . T h i s m o l e c u l e can a l s o be directly formed by irradiation of water with addition of gaseous hydrogen fallowed by p u r i f i c a t i o n on a c a t i o n i c r e s i n . Oxygen-15, produced not only by irradiation of natural nitrogen with deuterons b u t a l s o b y p r o t o n s an n a t u r a l o x y g e n or e n r i c h e d n i t r o g e n - 1 5 , c a n b e u s e d to l a b e l d i f f e r e n t s i m p l e m a l e c u l e s such as carbon monoxide, carbon oxide, m o l e c u l a r a;¢ygen and w a t e r . A l l t h e s e s y n t h e s i s a r e c o n t r o l l e d by a pragammable automated system 135U, which a l s o pet-farms t h e f i l l i n g and e m p t y i n g o f t h e t a r g e t .

81matic

A c o m p l e t e l y automated r a d i a c h e m i c a l p r o c e s s g i v e s h i g h s y n t h e t i c y i e l d s with goad repraducibility and c o n f l a b i 1 ity. Human intervention is greatly m i n i m i z e d t o r-educe t h e d o s e o f i o n i z i n g r a d i a t i o n d e l i v e r e d t o t h e c h e m i s t s .

68°

DEVELOPNENT

OF A .~,OLID PHASE SEPARATION SY~'TEH FOR

RADIOINNUNOASSAY BALDOMERO

DELGADO, GUILLERMINA FERRQ, FERNANDO ZAMBRANO, CONSUELO LAVALLEY AND JUDITH LEZAMA

Departamento de Materlales Radiactivos Apartado Postal I~-I027 11081, ~ica, D.F., MEXICO

-

ININ

I n eadiaimmunaassay ( R I A ) , a s a l l d phase i s used to separate the antigenic (Ag) ~ r a c t i o n banded t o an a n t i b o d y (Ab) from t h a t n o t bonded, w i t h one o f t h e r e a g e n t s r e m a i n i n g in t h e s o l i d m a t r i x . This procedure avoids centrifuging, thus simplifying the RIA. The development o f a chemical method to cover the internal surface of p e l y p r a p y l e n e or p o l y s t y r e n e tubes w i t h a n t i b o d i e s is described. The method i s based an p o l y m e r i z a t i o n i n a b a s i c medium (pH 9 . 5 ) o f a 2.5% g l u t a r a l d e h y d e s o l u t i o n which i s a b l e t o u n l t e , c a v a l e n t l y , t h e purified antibodies. The a n t i b o d i e s were p u r i f i e d by p r e c i p i t a t i o n w i t h ammonium s u l f a t e and ueed in 1 : 1 0 and 1:100 d i l u t i o n . The b a n d i n g o f the antibodies to the tubes is proven by means ~ f an i m m u n o l o g i c a l r e a c t i o n between t h e a n t i b o d i e s and a l a b e l l e d a n t i g e n ( 1 2 - I - T 4 , A g ~ , whose a c t i v i t y was 6 0 , 0 0 0 t o 20~000 cpm, w i t h i n c u b a t i o n f a r 24 h o u r s a t 4 - & - C . The maximum b o n d i n g ( A g * , A b ) was 80-90% which decreased w h e n mare d i l u t e a n t i b o d y s o l u t i o n s were u~ed. The bonding was 10% w h e n u n p u r i ~ l e d antibodies were used. The labelled antlgen banded to an antibody (Ag@-Ab) was d i s p l a c e d by nan-labelled antigen. T h i s d i s p l a c e m e n t i n c r e a s e d as more u n l a b e l l e d antigen was added i n a manner s i m i l a r t o t h a t seen i n RIA. The r e s u l t s

show t h e f e a s i b i l i t y

of

this

technique for

use i n RIA.

However,

278

Symposium Abstracts

it is n e c e s s a r y to develop a method of quality control with the a c h i e v i n g u n i f o r m i t y i n t h e q u a n t i t y o f a n t i b o d y in each t u b e .

6g.

INCIDENCE

OF

E.

CONGENITAL HYPOTHYROIDISM BORDERING ZONES

MANZANARES

A,

AND

V.

IN

BADILLO

ZACATECAS

ob]ective

of

AND

A.

Universidad Aut6noma de Zacatecas Centro Regional de Estudios Nucleates Apartado Postal 495 98000 Zacatecas, Zac., MEXICO.

Congenital hypothyroidism is an endocrinal disease characterized p r e d o m i n a n t e l y by mental r e t a r d a t i o n which can be b o r d e r l i n e o r p r o f o u n d . In g e n e r a l , t h e d i s e a s e i s d i a g n o s e a b l e o n l y when t h e c h i l d p r e s e n t s symptoms of some t y p e o f pschomotor r e t a r d a t i o n which a i d s i n t h e d i a g n o s i s , a l t h o u g h the future of the patient is u n c e r t a i n . With the installation of the Radioimmunoassay (R.I.A.) Laboratory and with development o f n e o n a t a l T.S.H., a new h o r i z o n for timely diagnosis o p p o r t u n e t r e a t m e n t was opened f o r newborns and s m a l l i n f a n t s .

the and

Five hundred newborns were studied with ages ranging from 48 hours to 90 days. The study consisted of obtaining a blood sample by heel puncture, which was deposited on a filter paper for later processing by radioimmunoassay. The ob]ectlve was to show the utility of this R.I.A. technique and to obtain an indication of the infir~ed which could be treated in a n i n t e g r a l manner by the clinic and the laboratory and counting on the participation of oediatricians, clinical psychologist~ rehabilitation specialists and~ obviodsly, the R.I.A. laboratory personnel. The previously cited parameters congenital hypothyroidism in bordering regions. The present sampled.

70.

paper

will serve the different

is a p r e l i m i n a r y

GEOGRAPHIC

DISTRIBUTION

to indicate the incidence zones oS the state and

communication

OF

THYROID

E. MANZANARES A, V. BADILLO A.

since

DISEASE

AND

more

IN

patients

ZACATECAS

will

of its

be

STATE

V.M. HERNANDEZ D.

U n i v e r s i d a d Autonoma de Zacatecas Centro Regional de Estudios Nucleares Apartado Postal 495 98000 Zacatecas, Zac., MEXICO.

In Z a c a t e c a s State, patients with thyroid disease predominate over the other endocrine pathologies. The radioimmunoassay Laboratory of the Regional Center for Nuclear Studies has the most ample sampling of the different regions of the state since it f u n c t i o n s as a reference center which attends patients from different institutions of the Health Sector. The distribution of thyroid disease by geographic region within the State is presented, making the distinction between hyperthyroid and hypothyroid patients. A statistical relationship is o b t a i n e d to indicate the zones with higher incidence. Statistics about hormones will be euthyroldlsm.

patients who presented,

came to the laboratory for comparing hypothyroidism,

evaluation of thyroid hyperthyroidism and