2 4 ~
Medical Research Society
73. USE O F KRYPTON-8lm FOR MEASURING REGIONAL LUNG FUNCTION IN CHILDREN
G. CIOFEITA,M. SILVERMAN
and J. M. B. HUGHES
Deparfmenf of Medicine, Department of Paediafrics and Neonatal Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London
Images recorded on a gamma-camera during the continuous
inhalation of the radioactive gas krypton-8lm (half-life 13 s) are
clinically useful in showing the presence or absence of uneven
regional ventilation in adults with pulmonary disease (Fazio &
Jones, 1975, British Medical Journal, iii, 673). The use of
krypton-8 Im in children offers several advantages over previous
techniques. No co-operation is required; 'the radiation dose is
similar to a routine chest X-ray; the technique is easy to perform
and non-invasive. .Because of the high ventilation per unit
alveolar volume (V,/V,) in infants and young children, the
images obtained during continuous inhalation of krypton-8lm
will tend to reflect the distribution of lung volume rather than
ventilation despite the rapid physical decay of the isotope. It is
possible to overcome this by measuring the wash-out phase, in
addition to recording steady-state images. From the washout
specific ventilation of the well-ventilated compartments (V,/V,,)
can be calculated in absolute units (1 min-l I-I) in four lung
regions (upper and lower on each side). The relative distribution
of alveolar ventilation ( VA)and the well-ventilated volume ( V,,)
can also be assessed.
Krypton-Slm, dissolved in 5% glucose solution, was also
infused at a rate of 6-10 ml/min into a forearm vein to measure
the distribution of pulmonary blood flow. The wash-out of the
infused krypton after the steady-state image gives information
about the mismatching of blood flow and alveolar ventilation in
different lung regions.
Compared with adult values (0.5-3.0 I min-l I-I), regional
VA/V,, was high (3.5-10.6), especially in a 4 weeks old infant
who had a chylothorax (20 I min-l I-'). Regional defects on the
steady-state inhalation image, in the presence of a normal distribution of V,/V,,,, was found in some patients, implying loss of
effectively ventilated volume in these lung regions.
75. PLASMA PREDNISOLONE CONCENTRATIONS
AND ADRENOCORTICAL RESPONSIVENESS AFTER
ADMINISTRATION O F PREDNISOLONE 21-PHOSPHATE AS A RETENTION ENEMA IN COLITIS
D. A. H. LEE, V. H. T. JAMES,M. TAYLOR
and J. G. WALKEH
Departments of Chemical Pathology and Gasrroenterology, St
Mary's Hospirol, London
Although prednisolone 2 I-phosphate, administered as a retention cnema, is widely used in the treatment of idiopathic
ulcerative colitis, the amount of prednisolone absorbed has been
disputed. By using a sensitive radioimmunoassay for prednisolone, we have compared oral and rectal absorption and
examined adrenocortical suppression after prolonged rectal
therapy.
Four patients with untreated active distal colitis, four with
disease recently treated by rectal prednisolone, and two healthy
volunteer subjects each received a 20 mg retention enema, and
serial blood samples were assayed for prednisolone and cortisol.
Eight of the subjects were given 250 jig of synacthen at the end
of the study. Nine healthy volunteers were given a weight-related
dose of prednisolone orally (0.3 mg/kg body weight, mean 20
mg). and serial blood samples assayed for prednisolone.
) the time
Peak plasma prednisolone concentration ( C m a Xand
to reach peak level (T,,,, ) were similar in all subjects who
received a retention enema, and were independent of disease
activity or duration of previous steroid therapy. However, the
C,,,,, and the total amount of prednisolone absorbed, were significantly lower, and the T,,,, were significantly later than that
seen in the subjects who received oral prednisolone. Plasma
cortisol concentration was depressed in all the patients who were
given a retention enema, but the response to synacthen was
normal or only slightly impaired.
Significant amounts of prednisolone are absorbed rectally and
it is possible that part of its therapeutic elTect is due to systemic
action. Adrenocortical suppression, however, is less than that
caused by oral administration of a similar dose of prednisolone,
although this may be related to a difference in the pattern of
absorption, rather than to the total amount absorbed.
76.THE NATURE O F SERUM IRON IN PRIMARY
HAEMOCHROMATOSIS
R. G. BATEY,P. LAICHUNGFONGand SHEILASHERLOCK
74. THE INHALING HABITS O F PIPE AND CIGAR
SMOKERS
J. A. McM. TURNER*,
R. W. S I L L Eand
~ M. W. MCNICOL
'Deparfment of Medicine, Middlesex Hospital, and Cardiothoracic Department, Cenfral Middlesex Hospital, London
It has now been well established that primary pipe and cigar
smokers have only slightly greater mortality rates than nonsmokers (Doll & Peto, 1976, British Medical Journal, ii, 1525).
It is known that ex-cigarette smokers, who change to cigars, do
inhale (Cowie, Sillett & Ball, 1973, Lancet, 1033) but it is
thought that these primary pipe and cigar smokers do not inhale
but may absorb nicotine via the buccal mucosa. We have
studied a group of primary pipe and cigar smokers and a group
of ex-cigarette smokers whilst smoking pipes and cigars. We
used carboxyhaemoglobin (COHb) concentrations as an indicator of inhalation and measured plasma nicotine levels to
estimate nicotine absorption.
In the primary pipe and cigar smokers the mean pre-smoking
COHb levels were low (0.8% and 1.2%) and increased to a
maximum of 1.1% during cigar smoking and 1.3% during pipe
smoking. In the ex-cigarette smokers, however, the pre-smoking
COHb levels were higher (2.9% and 4.05%) and increased to
9.6% after cigar smoking and 8.3% after pipe smoking. The
plasma nicotine levels after smoking and method of nicotine
absorption were discussed.
Deparlmenf of Medicine, Royal Free Hospital, London
Hepatic iron uptake has been shown to be abnormally high in
untreated and treated haemochromatotic patients (Fawwaz,
Winchell & Pollycove, 1967, Blood, 30, 417; Batey, Pettit,
Nicholas, Sherlock & Hoffbrand, 1977, Clinical Science and
Molecular Medicine, 53, 1 8 ~ ) The
.
causative mechanism is
unknown in either group. Recent studies have demonstrated that
serum iron exists in two forms in transfusional siderosis
(Hershko & Rachmilewitz, 1975, In: Proteins of Iron Storage
and Transport in Biochemistry and Medicine, Ed. Crichton,
R. R., Amsterdam). The existence of a non-transferrin-associated
(NTA) serum iron fraction in primary haemochromatosis could
explain the development of tissue siderosis. We have therefore
studied the nature of the serum iron compartment in untreated
and treated haemochromatotic patients and compared the
results with control, iron-deficient and liver-disease patients.
Total serum iron and transferrin iron saturation were measured
by standard techniques. NTA iron was quantified by using
a modification of the method of Hershko & Rachmilewitz
(1975). Serum (5 ml) from each patient was incubated overnight with 0.076 jig of s9Fe in the presence of excess citrate.
Duplicate aliquots (1 ml) of labelled serum were eluted from
separate DEAE-Sephadex columns (2 ml) with Tris (0.175
mol/l)/NaCI (0.15 mol/l) buffer, pH 8.5. NTA iron remained
on the column and is expressed as a percentage of total serum
sYFe.Eluted S9Fewas demonstrated to be transferrin bound by
polyacrylamide-gel electrophoresis.