8io 
Chaparro  in  Dysentery. 
f  Am.  Jour.  Pharm. 
*-    December,  1919. 
more  than  the  normal  amount  of  thyroxin  to  the  animal  organism 
there  is  a  distinct  lag  in  the  absorption  of  the  compound  by  the 
tissues,  and  there  is  a  rapid  return  to  the  normal  content  if  adminis- 
tration is  stopped.  The  chemical  reactions  which  are  brought  into 
play  by  the  administration  of  thyroxin  are  probably  not  different 
from  the  fundamental  chemical  reactions  occurring  in  its  absence. 
As  a  catalyst  it  merely  increases  the  rate  at  which  these  fundamental 
reactions  are  carried  out.  The  thyroid  apparatus  apparently  has 
been  added  to  the  animal  organism  in  order  to  permit  a  greater 
range  of  flexibility  of  energy  output. 
F.  Ransom  (Lancet,  1919,  2,  433 ;  Sept.  6)  reviews  the  literature 
on  the  relation  of  iodine  to  the  thyroid  gland,  referring  inter  alia  to 
Kendall's  investigations.  He  concludes  that  there  is  considerable 
probability  that  the  active  principle  of  the  thyroid  gland  is  a  break- 
down product  of  protein,  which  may  be,  but  is  not,  necessarily 
iodized.  Iodine  appears  to  have  no  direct  effect  on  the  activity  of 
the  internal  secretion,  and  yet  when  that  activity  is  diminished  it  can 
often  be  restored  by  administration  of  iodides.  This  action  is  due  to 
two  facts:  (1)  iodine  is  specifically  absorbed  by  the  gland;  (2)  the 
iodine  in  the  gland  in  saturating  the  unsaturated  fatty  acids  of  the 
blood-supply  favours  the  autolysis  by  which  the  active  principle  of 
the  gland  is  produced.  The  efficacy  of  iodides  in  tertiary  syphilis 
may  be  explained  on  these  lines,  and  it  is  anticipated  that  tertiary 
syphilis  may  be  successfully  treated  with  thyroid  extract. 
CHAPARRO  IN  DYSENTERY:   ISOLATION  OF  ACTIVE 
PRINCIPLE.1 
A  decoction  of  Chaparro  amargosa  (Castela  Nicholsoni)  was 
recommended  by  Nixon  some  years  ago  for  amoebic  dysentery  (see 
Prescriber,  1914,  pp.  225,  284;  1916,  p.  118).  Chaparro,  or  bitter 
bush,  is  a  shrub  which  grows  in  Texas  and  Mexico.  The  entire 
plant  is  used,  6  to  8  ounces  of  the  decoction  being  given  by  the 
mouth  half  an  hour  before  each  meal.  Rectal  enemata  of  from 
500  to  2,000  Cc.  are  also  given  twice  daily,  these  being  retained  as 
long  as  possible.  A  fluid  extract  is  prepared,  the  dose  of  which  is 
60  to  180  minims.  Its  use  has  been  reported  in  cases  where  emetine 
has  failed. 
1  From  The  Prescriber,  October,  1919. 
