Spontaneous remission and relapse in adult T cell lymphoma/leukaemia associated with HTLV-I.
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Biomedical subjects
Publications and source records attributed to C D Sheldon.
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Pressure gradients estimated by Doppler echocardiography were compared with values obtained at cardiac catheterisation in 31 children (aged seven days to 16 years, mean 2 years 7 months) with pulmonary infundibular stenosis including 16 with tetralogy of Fallot. Various parasternal and subcostal positions were explored to obtain the maximum velocity of blood flow and the obstructive gradient was calculated from the modified Bernoulli formula. The gradient across the obstruction could be measured directly at the time of catheterisation in only 21 patients. The correlation coefficient for the Doppler and total measured gradients was r = 0.90 for catheter entry and r = 0.77 for catheter withdrawal. Doppler ultrasound, by measuring the total gradient from the right ventricle to the pulmonary artery, provides a non-invasive assessment of the severity of pulmonary stenosis, and in those with infundibular obstruction allowance need not be made for possible energy losses caused by the elongated obstruction or the presence of narrowing at more than one level.
Doppler echocardiographic estimation of pressure gradient has been compared to that measured at cardiac catheterisation in 37 children, 6 weeks to 15 years of age, with suspected pulmonary valve stenosis or a pulmonary artery band. Various parasternal and subcostal positions were explored to obtain the maximum velocity of blood flow and the valve gradient was calculated from the modified Bernoulli formula. The Doppler study was performed at the time of catheterisation in 19, the maximum velocity being measured during catheter withdrawal in 7, immediately after withdrawal in 7, and while simultaneous right ventricular and pulmonary arterial pressures were measured in 5. Five other patients were studied within 24 hours of catheterisation and the other 13 within 6 months. Comparison of Doppler and catheterisation gradients showed a close correlation, this being particularly good where simultaneous right ventricular and pulmonary arterial pressures were measured. Doppler now provides an accurate non-invasive measurement of the severity of pulmonary valve stenosis and the adequacy of a pulmonary artery band.
Continuous wave Doppler echocardiography was used to study 41 adults with clinically suspected aortic stenosis undergoing cardiac catheterisation. Non-invasive assessment of the severity of stenosis was made before catheterisation using electrocardiograms, chest radiographs, and cross sectional echocardiography in addition to clinical examination and assessment modified, where appropriate, by the result of the Doppler examination. Catheterisation gradients were obtained in 33 patients and correlated well with those obtained by Doppler examination particularly when simultaneous recordings were obtained. All patients with surgically significant stenoses were identified by non-invasive assessment including Doppler examination and overestimation was not found in any patient with a less than significant stenosis. Thus surgery can be recommended in patients with aortic stenosis without the need for previous cardiac catheterisation.
One hundred and ninety-five consecutive referrals to the vascular laboratory for carotid artery investigation have been studied. Carotid bruits were assessed by the referring clinician and documented. All patients underwent bilateral imaging and spectrum analysis of the extra-cranial carotid vessels using a pulsed Doppler ultrasound technique. Eighty-two were further assessed by X-ray contrast angiography. Of 390 internal carotids examined by ultrasound, 65 exhibited intraluminal turbulence of which 49 (75 per cent) had a bruit. In 62 (56 per cent) of 111 internal carotids in the series which were said to have a bruit on clinical examination, no turbulence was found; in 15 instances the external carotid vessel was shown as the true source of turbulence and in the remainder the bruits may have been transmitted from the heart. One hundred and fifty-six vessels were assessed by X-ray and 55 shown to have significant stenosis; 38 (69 per cent) of these exhibited a bruit. Bruit was often absent at high degrees of stenosis and in occluded vessels. Although a carotid bruit is often a marker of internal carotid intraluminal turbulence and stenosis, this is by no means always so. Cervical bruit may also be due to a diseased external carotid or to sounds transmitted from a more proximal source. Conversely, absence of bruit is a feature not only of normal vessels but of many arteries which are stenosed (especially if this is of high degree) or occluded.
One hundred carotid arteries in 53 patients suffering from transient cerebral ischaemia or amaurosis fugax have been studied prospectively. Internal carotid arteries were assessed by a six-channel pulsed Doppler imaging system combined with Doppler spectrum analysis and the findings compared with those obtained by X-ray contrast arteriography. Stenosis (greater than 25% diameter reduction) was correctly diagnosed by ultrasonography with a sensitivity of 93% and a specificity of 96%. Occlusion was correctly diagnosed with a sensitivity of 92% and a specificity of 97%. The ability to recognize arterial stenosis and occlusion with this noninvasive system suggests that it has a major part to play in screening patients with suspected carotid artery disease.
Femoral artery pressure contour can be measured directly by percutaneous needle puncture and may be a useful indicator of proximal vessel stenosis. Pressure waveform in 53 limbs was compared with radiological appearance of the aorto-iliac segment. Forty-one limbs were graded angiographically as normal and 12 as stenosed. Pressure contour was studied at rest and after intra-arterial injection of papaverine. The following parameters were examined: 1. systolic pressure at rest 2. systolic pressure after papaverine 3. per cent reduction of systolic pressure after papaverine 4. pulse pressure at rest 5. pulse pressure after papaverine 6. per cent reduction in pulse pressure after papaverine 7. maximal gradient (dp/dt) at rest 8. maximal gradient after papaverine: p less than 0.001 (Figure 5b) 9. (formula; see text) A significant difference between the angiographic normal and stenotic groups was found in the values of all parameters. p less than 0.001 for 1 to 8 inclusive; p less than 0.05 for 9. Good discrimination between groups was achieved only by 3, 6 and 8. Three produced the best discrimination: systolic pressure reduction after papaverine greater than or equal to 14 per cent indicating stenosis (1 in 12 false negative) and less than 14 per cent indicating no stenosis (no false positive).
Ultrasonic imaging using a six-channel pulsed Doppler system combined with Doppler spectral analysis of 65 carotid bifurcations has been studied in a prospective clinical trial. The results were compared with X-ray contrast angiography. An overall sensitivity in excess of 90 per cent was achieved using the ultrasound technique, with a specificity of 89 per cent in the detection of significant stenosis or occlusion of the internal carotid artery. The ability to recognise significant arterial stenosis with a non-invasive system suggests that it has a major part to play in screening patients with suspected carotid artery disease.
To establish a histological standard against which surgical biopsy material could be compared, the degree of mesothelial proliferation was studied in 100 unselected necropsies. A minor degree of mesothelial hyperplasia was identified in 10 cases, usually close to areas of fibrous adhesions. Pleural plaques were present in 33 patients but there was no evidence of associated mesothelial proliferation. No mesothelial changes were noted in patients with empyema or pleural metastases. These findings indicated that the degree of mesothelial hyperplasia in common disorders of the pleura is relatively slight. Significant mesothelial proliferation in needle biopsies should therefore be viewed with considerable suspicion and, where clinically appropriate, be followed by further investigation.
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We examined the internal jugular veins in three groups of patients who had undergone (1) a functional neck dissection and radiotherapy, (2) a functional neck dissection alone, or (3) radiotherapy alone, using a noninvasive color Doppler ultrasound scan. The internal jugular veins were ultrasonically bilaterally normal in 18% of patients who had undergone a functional neck dissection and radiotherapy, in 88% of patients who had undergone a functional neck dissection alone, and in 57% of patients who had undergone radiotherapy alone. The combination of a functional neck dissection and radiotherapy significantly affected the internal jugular vein when compared with a functional neck dissection alone.
In a clinical study, 78 carotid bifurcations were examined by pulsed Doppler ultrasonography and X-ray arteriography. Maximum Doppler frequencies greater than or equal to 3 kHz diagnosed stenoses of greater than or equal to 25% diameter reduction with a sensitivity of 73% and specificity of 79%. A quantitative analysis of the degree of spectral broadening was obtained from the ratio of the maximum to mean frequency at peak systole and improved the sensitivity and specificity to 90% and 98% respectively. All vessels greater than 40% stenosis were correctly classified as stenosed and all less than 20% stenosis were classified as normal.
Only 55% of common carotid arteries bifurcate in the neck at the classically described level of C3 vertebra or C3/4 interspace. Others bifurcate as high as C2/3 interspace or as low as C5/6. Eighty-five percent of bifurcations occur at the same height as that on the contralateral side. Even if asymmetry occurs, it is not greater in magnitude than the height of one cervical vertebra. Atheroma does not appear to be associated with any particular bifurcation position. Abnormally curved or kinked morphology of the extracranial internal carotid occurs in 6% of angiograms. This feature also has no specific association with atheroma.
In twelve patients, the fluid resistance across the origin of the profunda femoris artery was assessed by flow and pressure recordings, before reconstructive profundaplasty was performed. There was a considerable range of resistance values obtained and in the eight patients having repeat flow and pressure recordings following the reconstruction in only five patients was there a reduction in the fluid resistance. This suggests that not all atheromatous plaques at the profunda femoris origin produce a blood flow disturbance to warrant profundaplasty, and may explain the variable results reported following this operation.