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FLUOROSCOPIC EXAMINATION OF THE CHEST
504 fewer dysenteric and more non-specific cases of enterocolitis. Œsophageal varices (9%), carcinoma of the stomach (8%), carcinoma of the rectum and pelvic
probably
colon (6%), idiopathic ulcerative colitis (5-5%), diverticulitis of the colon (4%), and uraemic colitis (3%) came next in frequency. Intussusception was the cause of only 1-4%, and there were no examples of blood diseases. Lesions of the small intestine, which formed only 2% of this series, are rare in most people’s experience, though from time to time Meckel’s diverticulum, Crohn’s disease, mesenteric thrombosis, and tumours of the small bowel do cause bleeding without much other evidence of their true nature. The causes of small intestinal bleeding have lately been reviewed by Hodes and Edeiken.3 Tests for occult blood in the stools have fallen into disrepute in some quarters, but their results may be valuable if they are interpreted critically. Bleeding gums and piles, and meat in the food, may give positive reactions, and constipation may cause false negative results. When using the benzidine test a meat-free diet for at least two days is essential, and the stools must always be examined for meat fibres. The test should be done on at least three separate occasions. Hoerr and colleagues5 favour a modification of the guaiac test, easily performed in the consulting-room. This is not sensitive enough to be affected by meat and can therefore be done on outpatients, provided they are not taking iron. While are that reactions claim unreliable, negative positive they guaiac reactions denote significant organic bleeding in a high proportion of cases. The test is simple : .
A smear of faeces (from a fingerstall) is placed on a filter paper, and one or two drops each of guaiac solution, glacial acetic acid, and hydrogen peroxide, in that order, are placed near the faeces. If a blue or dark green colour appears within 30 seconds the result is positive. Dunphy6 reports 2 cases of resectable carcinoma of the
small intestine which had produced positive guaiac reactions but could not be demonstrated by routine radiology. In each case a Miller-Abbott tube was passed until a level was reached from which the aspirated samples contained occult blood. That part of the bowel was then filled selectively with barium through the tube, and the lesion was demonstrated radiologically. This rather if it will trouble worth the extra test will be complex locate even an occasional growth of the small gut at a curable stage. PENETRATION OF OVUM BY SPERM IN VITRO EARLY in 1948 Menkin and Rockannounced that they had obtained fertilisation and cleavage of human ova removed from ovaries by dissection in vitro under aerobic conditions. They had made the attempt 138 times and had obtained cleavage in 4 ova. -This caused a stir in the popular press ; but more sober observers were not so readily convinced, and Rock himself admitted that parthenogenesis could not entirely be ruled out. After working on the subject for several years, Moricard and Bossu 8 report that their attempts to obtain fertilisation and cleavage of rabbit ova under aerobic conditions, as described- by Menkin and Rock, were invariably negative in 60 cases ; the spermatozoa never succeeded in penetrating the membrana pellucida. But, when rabbit spermatozoa and ova were brought together under relatively anaerobic conditions in the presence of tubular epithelium and seminal plasma, penetration occurred every time in 8 cases. By cutting serial sections they have observed and demonstrated the very earliest stages in the process of fertilisation. They believe that their technique will be applicable to human spermatozoa 3. Hodes, P. J., Edeiken, J. Ibid, p. 1284. 4. Necheles, H. Ibid, p. 1217. 5. Hoerr, S. O., Bliss, W. R.. Kauffmann, J. Ibid, p. 1213. 6. Dunphy, J. E. Ibid, p. 1217. 7. Menkin, M., Rock, J. Amer. J. Obstet. Gynec. 1948, 55, 440. 8. Moricard, R., Bossu, J. Bull. Acad. Méd. Paris, 1949, 133, 659.
and ova, and, if so, this will mark a definite step forward in the struggle to unravel the complex physiology of mammalian ova, spermatozoa, and tubular epithelium. FLUOROSCOPIC EXAMINATION OF THE CHEST " IN the early days of radiography screening was used freely in diagnosis ; but as films became easier to take it dropped into the background. It is so pleasant and convenient to be able to back one’s opinion with a permanent record that the temptation to ask for a film is very strong, both for the physician and the radiologist. However, things have reached such a pass that our X-ray departments are congested by the amount of work pouring into them, and our task is how to think of ways of lightening the load. Dr. Stephen Hall and Dr. William Tattersall, on another page, advocate a return to a much wider use of fluoroscopy. Not only would this save time and money, but it would also, they suggest, give information which could not readily be obtained in other ways. Thus it is possible by changing the tilt of the patient’s body, and by making him bend, breathe deeply, or pant, to estimate the depth of various shadows, and to avoid some common pitfalls of diagnosis from the film. Fluoroscopy, they say, differs from inspection of the film in the same way that cinephotography differs from still photography ; and they have found that the information it gives tallies well with that to be expected of the fixed film. Fluoroscopy has its drawbacks however, one of them being that radiologists, like other people, differ in their powers of dark adaptation. Hall and Tattersall suggest the use of dark glasses to enable the radiologist to go on working while his visual purple is collecting ; and evidently they are themselves both capable of good adaptation. But, as Mr. Cecil Ashwin, M.s.R., has pointed out,l in a review of prevailing opinion on the value of fluoroscopy in tuberculosis case-finding, " the ability of an individual to see in the dark depends on many factors such as temperament, physiological condition and vitamin intake : further, this function can vary from day to day." This variability probably accounts for the large body of opinion he is able’to report against the value of fluoroHe quotes Garland, who put the percentage scopy. error in the detection of tuberculosis with this method (as compared with radiography) between 13 and 35 ; Fellows and Ordway, from a study of 2500 cases, agreed with this figure, and Voigtlander, from another 2500 cases, concluded that in 32% the diagnosis by fluoroscopy "
was
error
either incorrect or insufficient. Schaare found an of 18% in fluoroscopic findings ; while Edward
and Ehrlich, after reviewing mass surveys of 100,000 people, decided that the drawbacks of fluoroscopy outweighed the advantages. Ashwin quotes other opinions of the same kind, but sets them against an equally weighty set of favourable reports. It seems that if fluoroscopy is to be widely used we need some method of testing the accuracy of the observer. A test of visual adaptation in darkness has been devised by Chantraine and Cramer, which consists, Ashwin says, in enumerating, from a fixed distance, lead numbers of various sizes mounted on a standard fluorescent screen. Of 30 doctors tested in this way, only 6 were " good," 10 were " medium " and 14 were " poor." Two-thirds of them needed more than ten minutes to attain minimum dark adaptation. Ashwin suggests that patients should be sieved first by mass radiography ; and that suspected cases should then be fluoroscoped by a capable observer, and a spot film taken of any suspicious area. This would enable the preliminary sifting to be done in the absence of the radiologist, and would make a full-size film necessary only in exceptional cases. Hall and Tattersall believe that screening alone can safely be used to exclude tuberculous lesions and will thus save many films which are
at
present wasted. 1. Med. Lab.
Progress, 1949, 10, 141.
probably
colon (6%), idiopathic ulcerative colitis (5-5%), diverticulitis of the colon (4%), and uraemic colitis (3%) came next in frequency. Intussusception was the cause of only 1-4%, and there were no examples of blood diseases. Lesions of the small intestine, which formed only 2% of this series, are rare in most people’s experience, though from time to time Meckel’s diverticulum, Crohn’s disease, mesenteric thrombosis, and tumours of the small bowel do cause bleeding without much other evidence of their true nature. The causes of small intestinal bleeding have lately been reviewed by Hodes and Edeiken.3 Tests for occult blood in the stools have fallen into disrepute in some quarters, but their results may be valuable if they are interpreted critically. Bleeding gums and piles, and meat in the food, may give positive reactions, and constipation may cause false negative results. When using the benzidine test a meat-free diet for at least two days is essential, and the stools must always be examined for meat fibres. The test should be done on at least three separate occasions. Hoerr and colleagues5 favour a modification of the guaiac test, easily performed in the consulting-room. This is not sensitive enough to be affected by meat and can therefore be done on outpatients, provided they are not taking iron. While are that reactions claim unreliable, negative positive they guaiac reactions denote significant organic bleeding in a high proportion of cases. The test is simple : .
A smear of faeces (from a fingerstall) is placed on a filter paper, and one or two drops each of guaiac solution, glacial acetic acid, and hydrogen peroxide, in that order, are placed near the faeces. If a blue or dark green colour appears within 30 seconds the result is positive. Dunphy6 reports 2 cases of resectable carcinoma of the
small intestine which had produced positive guaiac reactions but could not be demonstrated by routine radiology. In each case a Miller-Abbott tube was passed until a level was reached from which the aspirated samples contained occult blood. That part of the bowel was then filled selectively with barium through the tube, and the lesion was demonstrated radiologically. This rather if it will trouble worth the extra test will be complex locate even an occasional growth of the small gut at a curable stage. PENETRATION OF OVUM BY SPERM IN VITRO EARLY in 1948 Menkin and Rockannounced that they had obtained fertilisation and cleavage of human ova removed from ovaries by dissection in vitro under aerobic conditions. They had made the attempt 138 times and had obtained cleavage in 4 ova. -This caused a stir in the popular press ; but more sober observers were not so readily convinced, and Rock himself admitted that parthenogenesis could not entirely be ruled out. After working on the subject for several years, Moricard and Bossu 8 report that their attempts to obtain fertilisation and cleavage of rabbit ova under aerobic conditions, as described- by Menkin and Rock, were invariably negative in 60 cases ; the spermatozoa never succeeded in penetrating the membrana pellucida. But, when rabbit spermatozoa and ova were brought together under relatively anaerobic conditions in the presence of tubular epithelium and seminal plasma, penetration occurred every time in 8 cases. By cutting serial sections they have observed and demonstrated the very earliest stages in the process of fertilisation. They believe that their technique will be applicable to human spermatozoa 3. Hodes, P. J., Edeiken, J. Ibid, p. 1284. 4. Necheles, H. Ibid, p. 1217. 5. Hoerr, S. O., Bliss, W. R.. Kauffmann, J. Ibid, p. 1213. 6. Dunphy, J. E. Ibid, p. 1217. 7. Menkin, M., Rock, J. Amer. J. Obstet. Gynec. 1948, 55, 440. 8. Moricard, R., Bossu, J. Bull. Acad. Méd. Paris, 1949, 133, 659.
and ova, and, if so, this will mark a definite step forward in the struggle to unravel the complex physiology of mammalian ova, spermatozoa, and tubular epithelium. FLUOROSCOPIC EXAMINATION OF THE CHEST " IN the early days of radiography screening was used freely in diagnosis ; but as films became easier to take it dropped into the background. It is so pleasant and convenient to be able to back one’s opinion with a permanent record that the temptation to ask for a film is very strong, both for the physician and the radiologist. However, things have reached such a pass that our X-ray departments are congested by the amount of work pouring into them, and our task is how to think of ways of lightening the load. Dr. Stephen Hall and Dr. William Tattersall, on another page, advocate a return to a much wider use of fluoroscopy. Not only would this save time and money, but it would also, they suggest, give information which could not readily be obtained in other ways. Thus it is possible by changing the tilt of the patient’s body, and by making him bend, breathe deeply, or pant, to estimate the depth of various shadows, and to avoid some common pitfalls of diagnosis from the film. Fluoroscopy, they say, differs from inspection of the film in the same way that cinephotography differs from still photography ; and they have found that the information it gives tallies well with that to be expected of the fixed film. Fluoroscopy has its drawbacks however, one of them being that radiologists, like other people, differ in their powers of dark adaptation. Hall and Tattersall suggest the use of dark glasses to enable the radiologist to go on working while his visual purple is collecting ; and evidently they are themselves both capable of good adaptation. But, as Mr. Cecil Ashwin, M.s.R., has pointed out,l in a review of prevailing opinion on the value of fluoroscopy in tuberculosis case-finding, " the ability of an individual to see in the dark depends on many factors such as temperament, physiological condition and vitamin intake : further, this function can vary from day to day." This variability probably accounts for the large body of opinion he is able’to report against the value of fluoroHe quotes Garland, who put the percentage scopy. error in the detection of tuberculosis with this method (as compared with radiography) between 13 and 35 ; Fellows and Ordway, from a study of 2500 cases, agreed with this figure, and Voigtlander, from another 2500 cases, concluded that in 32% the diagnosis by fluoroscopy "
was
error
either incorrect or insufficient. Schaare found an of 18% in fluoroscopic findings ; while Edward
and Ehrlich, after reviewing mass surveys of 100,000 people, decided that the drawbacks of fluoroscopy outweighed the advantages. Ashwin quotes other opinions of the same kind, but sets them against an equally weighty set of favourable reports. It seems that if fluoroscopy is to be widely used we need some method of testing the accuracy of the observer. A test of visual adaptation in darkness has been devised by Chantraine and Cramer, which consists, Ashwin says, in enumerating, from a fixed distance, lead numbers of various sizes mounted on a standard fluorescent screen. Of 30 doctors tested in this way, only 6 were " good," 10 were " medium " and 14 were " poor." Two-thirds of them needed more than ten minutes to attain minimum dark adaptation. Ashwin suggests that patients should be sieved first by mass radiography ; and that suspected cases should then be fluoroscoped by a capable observer, and a spot film taken of any suspicious area. This would enable the preliminary sifting to be done in the absence of the radiologist, and would make a full-size film necessary only in exceptional cases. Hall and Tattersall believe that screening alone can safely be used to exclude tuberculous lesions and will thus save many films which are
at
present wasted. 1. Med. Lab.
Progress, 1949, 10, 141.