1138
SiR,—I
was
disturbed
to
CHANGE IN ELECTROPHORETIC MOBILITY OF ERYTHROCYTES
read Mr
Holliday and Professor 309) on delay in diagnosis and
AFTER ADDITION OF LINOLEIC ACID
Hardcastle’s article (Feb. 10, p. treatment in symptomatic colorectal carcinoma because I found the methods used either badly reported or plainly inadequate to the study of delays in the receiving of medical care. Patients were "interviewed after admission"-by whom?, with a standard format?, were interviews done at night on confused elderly patients?, and what happened to patients too sick to be interviewed?, such as some of the 42 admitted as emer-
gencies ? The only data seem to have been the referral latter of the general practitioner and the patient’s recall of events seven to nine months previously. Was any attempt made to validate the data by scrutiny of G.P. records? Could it be that a tendency to attribute "blame" for delay in diagnosis on G.P.s results in a subconscious unwillingness to go into the community, speak with G.P.s, and use records that are available? I suggest that greater collaboration in the design of such studies would improve their scientific value. Department of Community Medicine, Faculty of Medicine, Khon Kaen University,
SHAH EBRAHIM
Khon Kaen, Thailand
(L.A.)
* p « 0 - 001 for 65 M.S. patients versus 32controls.
diagnosis of M.S. are being evaluated. The simplified Field test especially attractive since it involved the electrophoresis of red blood-cells, the major area of interest of one of us (G.V.F.S.) for over twenty years. We were sceptical about the test--especially since no one could explain why the electrophoretic mobility of red bloodcells from M.S. patients should fall when arachidonic or linoleic acid are added to the suspending medium-and we decided to do the studies blind. Four investigators, using four separate Rank cylindrical electrophoresis apparatuses3 in two different
was
institutions, took part. While these studies ***Dr Ebrahim’s letter has been shown to Mr Holliday and Professor Hardcastle who provide the following extra information from their survey.-ED. L.
SIR,-The interviews
all done
person (H. H.) a pilot study of following proforma, 40 unreported cases. The interviews were done in pleasant surroundings on the wards, and lasted just over 30 min. Those patients who were severely ill on admission were usually questioned after resuscitation or postoperatively when their condition had suitably improved. Assessment of the duration of symptoms followed close questioning in an attempt to pinpoint the onset. We did not feel that accuracy on this point could have been improved by looking at the general practitioner’s records-indeed the duration of symptoms tended to vary from those given in the G.P.’s letter. Only the date of referral was recorded from this letter. The patient was asked to describe how many times he or she visited the family doctor with those particular symptoms and this did not seem to cause any difficulty. We did not validate this figure by examining G.P. records, and would accept that this might have improved the accuracy of our results. We are not attempting to place the blame with the family doctor, merely to record the facts. Working in hospital allows us to acknowledge that a considerable amount of filtering and selection of patients has gone on before we are asked to make a diagnosis, and indeed we suggest that, particularly for colonic carcinoma, the diagnosis may be difficult. This department is at present engaged in a project of early detection in the community with one of the local health centres, and results of this study will be made available later. a
standard
Department of Surgery, General Hospital, Nottingham NG1 6HA
were
by
one
modified after
H. W. HOLLIDAY J. D. HARDCASTLE
SIMPLIFIED RED-CELL ELECTROPHORETIC MOBILITY TEST FOR MULTIPLE SCLEROSIS
SIR,-We have been able to confirm the test for multiple sclerosis (M.S.) described by Field et aLI,2 One of us (R.L.S.) has a very large group of M.S. patients under his care. Diagnosis of M.S. is very difficult at the beginning of the disease process and often several years elapse before a definitive diagnosis can be made. As a consequence many methods for the early
were under way three groups4-6 reported that they could not confirm the simplified Field test, and this led us to examine the reasons why this might be and to explore the mechanisms underlying the redcell electrophoretic mobility test. In view of the greater instability of arachidonic acid we re-’ stricted our studies to linoleic acid. mt.s. patients, both participants and non-participants in the Swank’ low-fat diet, were selected to cover different grades of neurological disability with both active and inactive disease. For comparison controls and some cases of other neurological diseases (O.N.D.) were selected. The method of Field et awl. was used with the following exceptions : analytical particle electrophoresis was done with a cylindrical chamber electrophoresis apparatus equipped with silver/ silver-chloride electrodes3,s following the general procedure described by Seaman,9 and the blood was defibrinated by allowing1 it to clot, the red cells being gently teased out and washed. Our results on 65 clinically confirmed M.S. patients show no false-negatives and a mean decrease of 7-0±2.5% (S.D.) in redcell electrophoretic mobility on addition of linoleic acid. The criterion for a positive result was a mobility decrease of In four additional cases with minimal neurological >3.0%. findings the decreases in electrophoretic mobility of the patients’ red cells upon addition of linoleic acid fell within the decrease in mobility). range for normal controls (i.e.,
SiR,—I
was
disturbed
to
CHANGE IN ELECTROPHORETIC MOBILITY OF ERYTHROCYTES
read Mr
Holliday and Professor 309) on delay in diagnosis and
AFTER ADDITION OF LINOLEIC ACID
Hardcastle’s article (Feb. 10, p. treatment in symptomatic colorectal carcinoma because I found the methods used either badly reported or plainly inadequate to the study of delays in the receiving of medical care. Patients were "interviewed after admission"-by whom?, with a standard format?, were interviews done at night on confused elderly patients?, and what happened to patients too sick to be interviewed?, such as some of the 42 admitted as emer-
gencies ? The only data seem to have been the referral latter of the general practitioner and the patient’s recall of events seven to nine months previously. Was any attempt made to validate the data by scrutiny of G.P. records? Could it be that a tendency to attribute "blame" for delay in diagnosis on G.P.s results in a subconscious unwillingness to go into the community, speak with G.P.s, and use records that are available? I suggest that greater collaboration in the design of such studies would improve their scientific value. Department of Community Medicine, Faculty of Medicine, Khon Kaen University,
SHAH EBRAHIM
Khon Kaen, Thailand
(L.A.)
* p « 0 - 001 for 65 M.S. patients versus 32controls.
diagnosis of M.S. are being evaluated. The simplified Field test especially attractive since it involved the electrophoresis of red blood-cells, the major area of interest of one of us (G.V.F.S.) for over twenty years. We were sceptical about the test--especially since no one could explain why the electrophoretic mobility of red bloodcells from M.S. patients should fall when arachidonic or linoleic acid are added to the suspending medium-and we decided to do the studies blind. Four investigators, using four separate Rank cylindrical electrophoresis apparatuses3 in two different
was
institutions, took part. While these studies ***Dr Ebrahim’s letter has been shown to Mr Holliday and Professor Hardcastle who provide the following extra information from their survey.-ED. L.
SIR,-The interviews
all done
person (H. H.) a pilot study of following proforma, 40 unreported cases. The interviews were done in pleasant surroundings on the wards, and lasted just over 30 min. Those patients who were severely ill on admission were usually questioned after resuscitation or postoperatively when their condition had suitably improved. Assessment of the duration of symptoms followed close questioning in an attempt to pinpoint the onset. We did not feel that accuracy on this point could have been improved by looking at the general practitioner’s records-indeed the duration of symptoms tended to vary from those given in the G.P.’s letter. Only the date of referral was recorded from this letter. The patient was asked to describe how many times he or she visited the family doctor with those particular symptoms and this did not seem to cause any difficulty. We did not validate this figure by examining G.P. records, and would accept that this might have improved the accuracy of our results. We are not attempting to place the blame with the family doctor, merely to record the facts. Working in hospital allows us to acknowledge that a considerable amount of filtering and selection of patients has gone on before we are asked to make a diagnosis, and indeed we suggest that, particularly for colonic carcinoma, the diagnosis may be difficult. This department is at present engaged in a project of early detection in the community with one of the local health centres, and results of this study will be made available later. a
standard
Department of Surgery, General Hospital, Nottingham NG1 6HA
were
by
one
modified after
H. W. HOLLIDAY J. D. HARDCASTLE
SIMPLIFIED RED-CELL ELECTROPHORETIC MOBILITY TEST FOR MULTIPLE SCLEROSIS
SIR,-We have been able to confirm the test for multiple sclerosis (M.S.) described by Field et aLI,2 One of us (R.L.S.) has a very large group of M.S. patients under his care. Diagnosis of M.S. is very difficult at the beginning of the disease process and often several years elapse before a definitive diagnosis can be made. As a consequence many methods for the early
were under way three groups4-6 reported that they could not confirm the simplified Field test, and this led us to examine the reasons why this might be and to explore the mechanisms underlying the redcell electrophoretic mobility test. In view of the greater instability of arachidonic acid we re-’ stricted our studies to linoleic acid. mt.s. patients, both participants and non-participants in the Swank’ low-fat diet, were selected to cover different grades of neurological disability with both active and inactive disease. For comparison controls and some cases of other neurological diseases (O.N.D.) were selected. The method of Field et awl. was used with the following exceptions : analytical particle electrophoresis was done with a cylindrical chamber electrophoresis apparatus equipped with silver/ silver-chloride electrodes3,s following the general procedure described by Seaman,9 and the blood was defibrinated by allowing1 it to clot, the red cells being gently teased out and washed. Our results on 65 clinically confirmed M.S. patients show no false-negatives and a mean decrease of 7-0±2.5% (S.D.) in redcell electrophoretic mobility on addition of linoleic acid. The criterion for a positive result was a mobility decrease of In four additional cases with minimal neurological >3.0%. findings the decreases in electrophoretic mobility of the patients’ red cells upon addition of linoleic acid fell within the decrease in mobility). range for normal controls (i.e.,
