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MEASURING RESIDUAL URINE
665 do cannot yet be recognised before picking. When tested 30 °C some of the colonies are inhibited on both nutrient agar and methicillin agar, some grow well on both media, and others show true methicillin sensitivity. The populaThe tions are apparently heterogeneous and unstable. colonies shown in fig. 1 were from a plate which was one of a batch yielding the drug-dependent variant. The inhibition of growth on nutrient agar at 30 °C is apparently only bacteriostatic, for inhibited growth such as that shown in fig. 2A, when transferred to 43 °C, yields confluent culture within 12 hours. A great deal more exploratory work is necessary before more systematic studies can be designed and carried out. The present findings do little more than expose some new areas for research on staphylococcal metabolism and its interaction with penicillins and cephalosporins. The interesting feature of these findings is the hitherto unreported role of these drugs to act under some conditions as stimulants rather than inhibitors of staphylococcal growth. at
Addendum.-Broth cultures of penicillinase-negative variants of two strains of methicillin-resistant Staph. aureus have now been examined and shown to yield colonies which have the same features as described here and in addition are stimulated by benzylpenicillin. Department of Microbiology, Royal Perth Hospital,
Perth, Western Australia 6000. Department of Microbiology, University of Western Australia, Nedlands, Western Australia 6009.
D. I. ANNEAR. W. B. GRUBB.
MEASURING RESIDUAL URINE
SIR,-Dr Bailey and his colleagues (March 3, p. 486) describe a technique for the measurement of residual urine involving the injection of a radioactive solution We into the bladder through a suprapubic catheter. have used this method during the past 5 years as part of an investigation of bladder-urethral function in incontinent
patients.1 The isotope commonly used in the measurement of residual urine is iodinel31.’* When using the suprapubic injection method, we found that better results could be obtained by using the short-lived isotope technetium-99m. The lower radiation dose from this isotope allows a larger activity to be administered, resulting in better resolution. To avoid errors due to diffusion of the isotope into the bladder wall, the technetium was tagged to human serumalbumin using the method of Gwyther and Field.’ For this investigation the patient was seated on a specially designed micturition chair. After the isotope had been instilled into the bladder, the activity in the bladder region before, during, and after micturition was measured by a scintillation counter which was placed at a distance of 60 cm. from the patient to minimise the effects of patient movement. During micturition the radioactive urine was collected in a lead-shielded vessel. By connecting the suprapubic catheter to a strain-gauge pressure transducer it was possible to record the variation of intravesical pressure during voiding. By electronic differentiation of the isotope clearance curve the urine flow-rate was obtained as a function of time. 1.
2. 3. 4. 5. 6. 7.
Rowan, D., Millar, W. T., Alexander, S. Bio-Med. Engng, 1972, 7, 304. Mulrow, P. J., Huvos, A., Buchanan, D. L. J. Lab. clin. Med. 1961, 57, 109. Rosenthal, L. Radiology, 1963, 80, 454. Shand, D. G., MacKenzie, J. C., Cattell, W. R., Cato, J. Br. J. Urol. 1968, 40, 196. Strauss, B. S., Blaufox, M. D. J. nucl. Med. 1970, 11, 81. Winter, C. C. J. Urol. 1964, 91, 103. Gwyther, M. M., Field, E. O. Int. J. appl. Rad. Isotopes, 1966, 17, 485.
We agree with Dr Bailey and his colleagues that this method of measuring residual urine volume is more accurate than catheter aspiration. Department of Clinical Physics and Bio-Engineering, Western Regional Hospital Board,
D. ROWAN W. T. MILLAR.
Glasgow G4 9LF. University Department of Surgery, Royal Infirmary, Glasgow G4 OSF.
S. ALEXANDER.
CORONARY EMBOLISM
SIR,-Coronary embolism was described by Virchow in 1856. Since then it has been reported clinically and from post-mortem studies, and in 1958 Wenger and Bauer,! reviewing the literature, found about 60 well-documented The most common cases and several necropsy studies. cause was bacterial endocarditis, and others included rheumatic heart-disease, left atrial myxoma, and myocardial infarction. The vessel most commonly involved was the left coronary artery. A high proportion of cases occur in patients under 40.2 We have lately diagnosed coronary embolism in a 29-year-old woman. She was admitted with central chest pain, which had come on while walking. This radiated to her left arm and back and was associated with dizziness and vomiting. In the past, she had had rheumatic fever and was being followed up at another hospital. Exercise tolerance was normal. On examination, she looked fit. Her pulse was regular, with blood-pressure 130/70 mm. Hg, and the apex beat was displaced laterally with a heaving impulse. The first sound was loud in the mitral area. She had an ejection systolic murmur at the left sternal edge well radiated into the neck and a blowing systolic murmur audible from apex to axilla. At the left sternal edge an immediate diastolic murmur was noted, and there was an opening snap and a mid-diastolic murmur in the mitral area. There was no evidence of heart-failure, and all other systems were within normal limits. The following day she developed a fever and evidence of left lower-lobe consolidation. She was treated with ampicillin and eventually discharged. A month later she was admitted again with malaise, palpitation, fever, and crushing central chest pain radiating into the back. This pain was exacerbated by exercise and breathing. There was no history of upper respiratory-tract infection or
arthralgia. On examination, there
Pulse-rate was 72 was little change. There was no lymphadenopathy, splenomegaly, or rash. Her urine showed 1 + of protein and contained 100 pus cells per c.mm. Blood-cultures were negative. Full blood-count and erythrocyte sedimentation-rate were within normal limits. At this time the lactic dehydrogenase was 103 and serumglutamic-oxaloacetic acid was 14 international spectrophotometric units. Results which had returned late, however, since her first admission showed levels of 720 and 63, respectively. An electrocardiogram showed evidence of anterolateral and inferior infarction. She was started on anticoagulants and was well 2 months later.
per minute.
This patient had a long history of rheumatic heartdisease involving aortic and mitral valves-a diagnosis based on clinical signs only. She had a history of central chest pain compatible with ischsemic heart-disease and developed abnormal levels of cardiac enzymes before her electrocardiographic abnormalities. In view of the background of aortic valvular disease, the simultaneous occurrence of two separate areas of infarction, and her normal lipoprotein profile it was thought that coronary embolism was a likely cause. It was thought unlikely that this had been associated with bacterial endocarditis. We thank Dr P.
Harvey for
St. Stephen’s Hospital, London SW10. 1. 2.
his
help. FERGUS MADDEN GEORGE MEREDITH. FERGUS MADDEN
Wenger, N. K., Bauer, S. Am. J. Med. 1958, 25, 549. Shrader, E. L., Bawell, M. B., Moragues, V. Circulation, 1956, 14, 1159.
Addendum.-Broth cultures of penicillinase-negative variants of two strains of methicillin-resistant Staph. aureus have now been examined and shown to yield colonies which have the same features as described here and in addition are stimulated by benzylpenicillin. Department of Microbiology, Royal Perth Hospital,
Perth, Western Australia 6000. Department of Microbiology, University of Western Australia, Nedlands, Western Australia 6009.
D. I. ANNEAR. W. B. GRUBB.
MEASURING RESIDUAL URINE
SIR,-Dr Bailey and his colleagues (March 3, p. 486) describe a technique for the measurement of residual urine involving the injection of a radioactive solution We into the bladder through a suprapubic catheter. have used this method during the past 5 years as part of an investigation of bladder-urethral function in incontinent
patients.1 The isotope commonly used in the measurement of residual urine is iodinel31.’* When using the suprapubic injection method, we found that better results could be obtained by using the short-lived isotope technetium-99m. The lower radiation dose from this isotope allows a larger activity to be administered, resulting in better resolution. To avoid errors due to diffusion of the isotope into the bladder wall, the technetium was tagged to human serumalbumin using the method of Gwyther and Field.’ For this investigation the patient was seated on a specially designed micturition chair. After the isotope had been instilled into the bladder, the activity in the bladder region before, during, and after micturition was measured by a scintillation counter which was placed at a distance of 60 cm. from the patient to minimise the effects of patient movement. During micturition the radioactive urine was collected in a lead-shielded vessel. By connecting the suprapubic catheter to a strain-gauge pressure transducer it was possible to record the variation of intravesical pressure during voiding. By electronic differentiation of the isotope clearance curve the urine flow-rate was obtained as a function of time. 1.
2. 3. 4. 5. 6. 7.
Rowan, D., Millar, W. T., Alexander, S. Bio-Med. Engng, 1972, 7, 304. Mulrow, P. J., Huvos, A., Buchanan, D. L. J. Lab. clin. Med. 1961, 57, 109. Rosenthal, L. Radiology, 1963, 80, 454. Shand, D. G., MacKenzie, J. C., Cattell, W. R., Cato, J. Br. J. Urol. 1968, 40, 196. Strauss, B. S., Blaufox, M. D. J. nucl. Med. 1970, 11, 81. Winter, C. C. J. Urol. 1964, 91, 103. Gwyther, M. M., Field, E. O. Int. J. appl. Rad. Isotopes, 1966, 17, 485.
We agree with Dr Bailey and his colleagues that this method of measuring residual urine volume is more accurate than catheter aspiration. Department of Clinical Physics and Bio-Engineering, Western Regional Hospital Board,
D. ROWAN W. T. MILLAR.
Glasgow G4 9LF. University Department of Surgery, Royal Infirmary, Glasgow G4 OSF.
S. ALEXANDER.
CORONARY EMBOLISM
SIR,-Coronary embolism was described by Virchow in 1856. Since then it has been reported clinically and from post-mortem studies, and in 1958 Wenger and Bauer,! reviewing the literature, found about 60 well-documented The most common cases and several necropsy studies. cause was bacterial endocarditis, and others included rheumatic heart-disease, left atrial myxoma, and myocardial infarction. The vessel most commonly involved was the left coronary artery. A high proportion of cases occur in patients under 40.2 We have lately diagnosed coronary embolism in a 29-year-old woman. She was admitted with central chest pain, which had come on while walking. This radiated to her left arm and back and was associated with dizziness and vomiting. In the past, she had had rheumatic fever and was being followed up at another hospital. Exercise tolerance was normal. On examination, she looked fit. Her pulse was regular, with blood-pressure 130/70 mm. Hg, and the apex beat was displaced laterally with a heaving impulse. The first sound was loud in the mitral area. She had an ejection systolic murmur at the left sternal edge well radiated into the neck and a blowing systolic murmur audible from apex to axilla. At the left sternal edge an immediate diastolic murmur was noted, and there was an opening snap and a mid-diastolic murmur in the mitral area. There was no evidence of heart-failure, and all other systems were within normal limits. The following day she developed a fever and evidence of left lower-lobe consolidation. She was treated with ampicillin and eventually discharged. A month later she was admitted again with malaise, palpitation, fever, and crushing central chest pain radiating into the back. This pain was exacerbated by exercise and breathing. There was no history of upper respiratory-tract infection or
arthralgia. On examination, there
Pulse-rate was 72 was little change. There was no lymphadenopathy, splenomegaly, or rash. Her urine showed 1 + of protein and contained 100 pus cells per c.mm. Blood-cultures were negative. Full blood-count and erythrocyte sedimentation-rate were within normal limits. At this time the lactic dehydrogenase was 103 and serumglutamic-oxaloacetic acid was 14 international spectrophotometric units. Results which had returned late, however, since her first admission showed levels of 720 and 63, respectively. An electrocardiogram showed evidence of anterolateral and inferior infarction. She was started on anticoagulants and was well 2 months later.
per minute.
This patient had a long history of rheumatic heartdisease involving aortic and mitral valves-a diagnosis based on clinical signs only. She had a history of central chest pain compatible with ischsemic heart-disease and developed abnormal levels of cardiac enzymes before her electrocardiographic abnormalities. In view of the background of aortic valvular disease, the simultaneous occurrence of two separate areas of infarction, and her normal lipoprotein profile it was thought that coronary embolism was a likely cause. It was thought unlikely that this had been associated with bacterial endocarditis. We thank Dr P.
Harvey for
St. Stephen’s Hospital, London SW10. 1. 2.
his
help. FERGUS MADDEN GEORGE MEREDITH. FERGUS MADDEN
Wenger, N. K., Bauer, S. Am. J. Med. 1958, 25, 549. Shrader, E. L., Bawell, M. B., Moragues, V. Circulation, 1956, 14, 1159.