26~
Medical Research Society
i t s effect on c a r d i a c vagal t o n e is unclear.
W e investigated mean heart r a t e a n d indices o f
heart r a t e variability i n 24 p a t i e n t s after
subarachnoid haemorrhage a n d 32 age-matched
normal subjects.
Patients w e r e excluded if
t h e y had p r e v i o u s cardiovascular disease, w e r e
receiving beta-adrenergic antagonists o r
required mechanical ventilation; fifteen (63%)
h a d a normal c o n s c i o u s level w i t h no m o t o r
deficit. Efferent sympathetic activity, as
reflected i n plasma noradrenaline
concentration, was increased in patients (mean
[SE] v a l u e 4 3 1 [77], range 182-1,556 p g / m l ,
n=18; mean v a l u e i n normal supine a d u l t s 1 8 7
[13]. range 120-240 p g / m l , n=10; pt0.01).
However, patients showed evidence o f enhanced
c a r d i a c vagal tone, w i t h a lower m e a n heart
rate and g r e a t e r standard deviation of t h e R-R
interval t h a n c o n t r o l s (mean R-R interval 1007
[371 vs. 909 (271 ms: standard deviation of RR interval 71 [9] vs. 39 [3] ma; b o t h pt0.01).
Spectral a n a l y s i s o f R-R interval variability
showed that t h e power o f t h e h i g h frequency
component, a measure o f vagally-mediated
respiratory s i n u s arrhythmia, w a s five-fold
greater in patients t h a n in c o n t r o l s ( 2 , 5 8 9
[953] vs. 5 1 9 1901 ms; pt0.01).
T h e s e results
challenge t h e notion o f a reciprocal relation
between vagal a n d sympathetic inputs t o t h e
s i n u s node and indicate that after
subarachnoid haemorrhage both may be
increased.
M#) BYDROCBN SULPBIDB PRODUCTION BY COLONIC SULPBATBREDUCING BACTERIA: A LUMINAL TOXIN IN ULCERATIVE
COLITIS?
MCL PITCEBR. BR BBATl'Y, GR GIBSON and JB CUBWINGS*
m c Dunn Clinical Nutrition Centre, Bills Road,
Cambridge C B ~2D8, England
Reducing sulphur compounds within the colonic 1-n
are
highly toxic, causing inhibition of butyrate oxidation,
the preferred metabolic f u e l , vithin colonacytes. A
major source of hydrogen sulphide is from the reduction
of sulphate by sulphate-reducing bacteria (SRB) and it
has been postulated that these micro-organism may be
important in the pathogenesis of ulcerative colitis (UC)
and similar diseases in anlmls.
Anaerobic faecal slurries were prepared from 29 UC
patients (20 active, 9 remismioa) and 10 healthy
controls. SRB were enumerated by the agar shake dilution
method, sulphate-reduction rates measured by the
Jorgensen method, sulphide by the mthylene blue method
and sulphate by anion exchange chromatography with
conductivity detection. Results were statistically
ansensod by analynis of variance.
The incidence of SRB carriage in the active and
remission UC g r o u p was 95% and 55% respectively with
mean loglo counts/g (SE) of 8.15 (0.7) and 5.02 (1.6)
(p-0.041). ~ l lcontrols harboured SRB with mean loglo
counts of 7.9 (0.7) but these were not significantly
different from the UC patients ( ~ 0 . 6 1 ) . Hean sulphatereduction rates nmol/g/h (SB) in the UC groups were not
significantly different from controls (0.13 (2.5)) as
were median faecal sulphides w l / g (SB) (0.24 (0.08)).
Hean free faecal gulphate )Imol/g (SB) in the UC patients
(1.38 (0.25)) was higher than in controls (0.58 (0.16))
(piO.055) and the ratio of free/total faecal sulphate
was higher in the UC group (0.75 (0.09)) than controls
(0.36 (0.09)) (p-0.009).
M89 FERROUS IRON UPTAKE BY ISOLATED H U M A N
DUOWP CODDARD, K COUPLAND, JA SMITH, and RC LONG
It is concluded that SRB are more prevalent in
active rather than quiescent UC although their
activities do not appear to differ from controls. The
higher ratios of free/total faecal sulphate in uc
patients may reflect the decreased incorporation ot
sulphate into mucin in thin dinease.
Sulphate
availability is of crucial importance to the oxidative
growth of SRB and it is surmised that the resultant
luminal production of sulphide could trigger colonic
inflammation in individuals with genetically acquired
defects in aulphide detoxification.
Medlcal Research Unit, City Hospital, Nottlngham
NCS 1PB. England
The mechanism and control of non-haem iron uptake
by mammalian Intestine remains poorly understood.
Studies In h u m a n d u o d e n u m have been llmlted to
whole subject experiments, membranes from operative
procedures a n d whole duodenal biopsies. T h e latter
has Implicated t h e existence of a saturable mechanism
In man. However whole biopsies represent a complex
cell populatlon a n d require correcting factors for
Intercellular space t o be applied. We describe a new
method for t h e assay of radio-ferrous iron uptake by
endoscopic biopsy derived free living Isolated human
enterocytes. initial characterisation of thls system
showed that Iron (11) uptake was sharply temperature
( p e a k at 37°C) and pH (optimum 7.3) dependant.
Ferrous iron was inltlally taken u p rapidly at 37°C
before a n exponential fall off In rate. T h e inltlal rclte o f
Iron uptake Increased from 32 pmol/pgDNA/min at
S0pM to 67pmol/pgDNA/min a t 2 0 0 p M . with
saturation. T h e rate of uptake was higher with cells
isolated from iron deficient subjects (serum ferritin
less than lOpg/i), being 55 pmol/pgDNA/min at SOpM
( ~ 4 . 0 7and
) IOlpmoVpgDNA/min a t 200pM ( ~ 4 . I1 ).
Zinc a n d Cobalt competitively lnhlbitcd uptake ( I < : ~
ato
50pM Iron was 75pM and 1200pM respectively).
'l'hese lnltlal results a r e consistent with a saturahlc
p r o tcln m e d i a tcd t r a n s r n e m b r a n c t r a n s p o r t
mwhanlsm for t h e uptake of f e r m u s Iron into human
entenxyes a n d form the basis of on-going studles.
M9I SKELETAL MUSCLE PROTEIN SYNTHESIS IN VlVO IN
RESrONSE TO ETHANOL: REFRACTORY RESWNSE DESIITE
HIGH BLOOD ALCOHOL LEVELS.
Matthew E. Rklly', Jaspaul S. Marway and Victor R. f " .
'Department of Clinical Biochemistry, King's College School of
Medicine and Dentistry, London SE5 9PJ. 'Tissue Pathology Unit,
The Roehampton Institute. London, SWl5 3SN.
Alcohol-induced muscle disorders arc extremely common and in the
chronic form, afFect up to two thirds of ethanol mi~~scrs.The
precise biochemical mechanisms responsible for the disorder are
unknown. We hypothesised that e~hanolwould have M immediate
effect on protein synthesis, cspadly when patbphysiological levels
were achieved. To t u t this hypothesis w e examined the scquarc of
events that occurs in response t o a single bolus of ahanol (75
mmol/ltg, i.p.) in comparison with sham injected controis
(isovolumctric 0.15 moVl NKI. i.p.). Fractional rata of protein
synthesis (defined as the percmtlge of t i w e protein m e d each
day. i e.. k,. Vdday) w n mtasud with a -lf
dose of lritiated
phenylalaninc. The rcsuhs showed that at 20 minutes (0.33 hours)
after bolus injection the blood c~hanollevels were 448 2 44 mg/dl (all
data expressed as mean 2 S.E.M.. n4-6). This dropped steadily
throughout the following 24 hours, and levels at 1, 2.5. 6 and 24
hourswerc376+26mg/dl,291 +24mg/dl. 184t 16mg/dlandOO
mddl. respectively Thc skeletal muscle k, value in control rats. i.e..
a~Ohours.was12.81+0.69O/dday.At0.33, 1.2.5.6.24hwmks
Medical Research Society
values were 12.44 f. 0.85 Ydday (PM.05); 9.70 f 0.22 Vdday
(P<O.OOI), 1007 2 0.14 Ydday (P<O.OI); R 50 2 0.47 Ydday
(P<OOOl) and 460 f: 0.36 Vdday (P<O.OOI), respectively (all P
values refer t o differences from control rats at time 0). A 24 hour
pair-feeding regime allowed us 10 isolate the effects of treatmentinduced anorexia. Compared t o the pair-fed group, the 24 hour
ethanol-treated rats still showed a 50?! decrease in fractional protein
synthesis (P<O.OOl). We conclude that ethanol p r - s e does not
initially inhibit skeletal muscle protein synthesis despite the high
circulating ethanol concentration, and a depression in protein
synthesis occurs at 24 hours in the absence of circulating ethanol
M n EPIDERMAL GROWTH FACTOR FAMILY, TGF-p AND PS2
EXPRESSION IN COLORECTAL ADENOCARCINOMA AND
SURROUNDING MUCOSA
L CHEN. CF JOHNSTON, RGP WATSON and KD BUCHANAN
Dcpanmcnt of Medicine. Thc Quccn-s University of Belfasc.
Grosvenor Road. Belfast. €3712 6BJ. N Ireland
AIM: To determine if the colorectal m u m of individuals wilh ColorCaal
adenocarcinoma is characterivd the prcrnce ofspecific growth facton.
METHODS: 25 patients with ~ o n x l a adcnocarcinoma
l
were studied. Tissuc
was taken from the centre of each turnour. the adjaccnt non-neoplastic mand the mucosa distant from the tumour at the limit of the rcscctcd specimen.
Samples were put into unbuITcred formalin and wax-embcddd Samples were
also SMP Crolrn and cryostat scrtions were processed with post fixing in acetone.
Sections wcre immunoslaincd by the ABC method for EGF. EGFR ( used in
frozen ti= only ), F4 ( specifically rcwgnising the intraallular domain of
EGFX, used in pamin tissue ), cerbB-2. crrbB-3. TGF-p and pS2.
RESULTS: ( I ) lmmunoreactivity for EGF was present in 9 (36%) samples of
wloreaal adenocarcinoma and became progressively wealter with distance from
the tumour in the * normal " muwsa. (2) Smng positivity for EGFR antibody (
frozen tissues ) was shown in all adenocarcinomas (IWA). and similarly in the
adjaant and distant mucosa. (3) Expression of F4 was found in 19 (76%)
adcnocarcinomas. and similar or slightly weaker staining was also found in the
adjacent and distant mucosa. (4) In 19 (76%) adenocdrcinomas.cxpmion of
cerbB-2 was positive becoming progressively weaker in the adjacent and distant
niucosa. (5) Positivity for cerbs-3 was observed in 18 (72%) adenocarcinomas
again generally bccoming weakcr with distancc from the tumour. Only 2 out of
7 cer6B-3 negative cars were also negative for cerhB-2. (6) In 12 (48%) thc
distant and adjacent muwsa displayed dificrential c x p m i o n of TGF-p within
cpithelial cells. with those in the superficial mucosa showing cnhanad
immunoreaclivity wmpared to cells in the proliferative conipanment. Only 3 of
12 cases were associated with p6sitire staining in the adcnocarcinomas. (7)
Positive stainiiig for pS2 was sccn in 12 (48%) adcnocarcinomas. and also in the
adjaccnt and distant mucosa. pS2 staining was observed more commonly in
right-sidcd than in len- sided adcnocarciimmas @< 0.05) No significant
rclalionshiD was found belwccn immunostainine- reactions and the denme
- Of
tumour dikerentintion and patient's scx.
CONCLUSIONS: Eoidcrnlnl ero\rth lactor familv. TGF-I3 and DSZ arc detatcd
in many colorcctal tukours ai;d surrounding niu&ra. Thfsc growth factors may
inllucncc and uprcgulatc thc prolifcration and dificrcnliation of colorcclal
carcinoma mlls. Thc pattern of EGFR esprcssion wppons the thwry that
h.ypcrprolifcralion occurs throughout thc whole mwosa as D field change in
patients with colorcctal tuinoiirs. cerhB-2 and cerbB-3 proteins Seem more
abundant in tirniour cclls than in "normal"distant epithelial cells in coloratum.
This could suggest a possiblc role in immunolocation and t3rgcted therapy. The
paltcrn of TCF-p csprcssion r n i y support that reduced responsiveness to thc
inhibitoiy cficcts of TGF-(1 may be a n important event in thc loss of growth
control in colormel carcinogcncsis. Comparison with normal controls is now
nccded to clarifv if any groath factor pattern is specific for thc mucosa of
piticnts with cdlorcctai tuiiiour if this is thc case. il n u y provide funher
inforni;itioii in tuniour pithogciicsis wid a po~siblc iiiark Tor the clinical
dctcction and scrccniiig ofcolormal tumoui~
M93 A E R O B I C A N D A N A E R O B I C A T P S Y N T H E S I S IN
E X E R C I S I N G M U S C L E OF PATIENTS W I T H CI-1RONIC
R E N A L FAILURE (CRF)
C H THOMPSON,A IRISH, GJ KEMP. B RAJAGOPALAN, P
'STYLES,DJ TAYLOR and GK RADDA
MRC Biochemical and Clinical Magnetic Resonance Unit. Oxford
Radcliffe Hospital. Oxford. U.K.. OX3 9DU
Fatigue in C R F m a y b; partly due t o metabolic defects in
skeletal muscle unrelated t o a n y reduction in haemoglobin
(Hb). W e used 31P magnetic resonance spectroscopy t o study
bioenergetics in gastrocnemius in CRF during exercise until
fatigue and subsequent recovery. Dialysed patients w e r e
compared with controls and with undialysed patients with
27P
C h a n g e s in pH and t h e phosphocreatine (PCr)
c o n c e n t r a t i o n a l l o w e d m e a s u r e m e n t o f t h e effective
mitochondrial capacity (Qmax) (calculated f r o m t h e PCr
recovery rate) and the rates of glycogenolytic (L)and oxidative
(Q) A T P s y n t h e s i s d u r i n g exercise. N e a r infra-red
SuectroscoDv esttmated the end e xercise
Measurement
Dialysed
U n d i a l y d e
Mean (S.E.M.)
(Crulinim > 200)
n=13
n=5
n=33
[Hbl
(gldl) 10.2(0.4)
10.8(1.0)
3 min exercise
L
(mWmin)
X(2)1*
l(0.5)
31)
Q .(niM/min)
14(2j*
1W)
21(2)
Duration
(min) S(l)i*
10(2)
W1)
Qmnx (mM/min)
30(3)t*
49(9)
49(3)
t p<0.05 cf undialysed; * p<0.05 cf control.
After exercise, dialysed patients h a v e reduced muscle reoxygenation rate as well a s reduced muscle blood flow. They
show a significant rcdttction in effective mitochondrial capacity
resulting in a compensatory increase in glycogenolytic ATP
synthesis. T h e s e bioenergetic abnormalities did not correlate
with e x e r c i s e d u c t t i o n or w i t h creatinine, [ H b ] or reoxygenation half-tinie. Compared t o controls, there was no
metabolic abnormality in undialysed patients despite similar
[ H b ] t o t h e diulysed patients.
Exercise duration w a s
significantly reduced in dialysed patients but there is n o simple
metabolic cause for this.
CRF.
M94 ASYMPTOMATIC RESTENOSIS A m E R CORONARY
ANGIOPLASTY: AN UNCOMMON OCCURRENCE
R K AGGARWAL, R S MORE. t J BALL, M J BRACK and
A H GERSHLICK
DEPARTMENT OF CARDIOLOGY, UNIVERSITY OF LEICESTER
& tTHE CARDIOTHORACIC CENTRE, LIVERPOOL.
Many symptom free patients undergo investigation following coronary
angioplasty (PTCA) because of suspected restenoss, consuming a
considerable amount of medical time and resources. To investigate
whether patients with asymptomatic angiographic restenosis ( d e h e d
as >50% net luminal diameter loss) after PTCA remain symptom fiee
at follow up, we reviewed the records of 339 patients entered into a
randomised trial of subcutaneous heparin m restenosis prevention after
PTCA. Early (< 4 months) angiographic follow up was available for
299 patients (88.2%). Restmosis of one or more of the dilated
vessels was present in 138 patients (46%) and 41 (27.7%) of these
were symptom t?ee without medical therapy at the time of
angiography. There were 29 men and 12 women, median age 56 years
(range 35-70). Nmeteen patients had single vessel disease and 20
(49%) a history of previous myocardial infarction.
At median follow up of 9 months (range 6-36), only 4 of the 41
patients (9.75%) remained asymptomatic without need for
revascularisation or medical therapy. A further 9 (21%) were
.symptom hee only with drug therapy or following a second
revascularisation procedure. S h e e n patients (39%) reported grade I
angina and 12 (30%) grade I1 angina. Ten of the 4 I patients (24.4%)
undenvent revascularisation either by repeat PTCA (n=7) or coronary
artery bypass surgery (n=3). Thirty two patients (78%) were taking I
or more antianginal drugs.
Conclusion: the majority (>90%) of patients with asymptomatic early
angiographic restenosis following PTCA d k e l o p a recurrence of
symptoms at follow up necessitating reintroduction of medical therapy
or a revascularisation procedure. Symptom recurrence should thus be
used as the primary guiding factor it1 determining the need for repeat
iiivcstigation following coronary angioplasty.