Usefulness of the diagnostic total body scan in differentiated thyroid cancer.
Explore the source record for details and available documents.
Follow-Up Studies↗
Biomedical subjects
S A Doi
Publications and source records attributed to S A Doi.
Ablation of the thyroid remnant and 131I dose in differentiated thyroid cancer.
AIMS: To compare the efficacy of remnant ablation following a single low dose (specific activity of 131I administered, 1074-1110 MBq) vs. a single high dose (mostly 2775-3700 MBq) of 131I in patients with differentiated thyroid cancer and to determine whether or not the extent of surgery influences outcome. METHODS: Nineteen studies have reported the results of low dose 131I ablation. Of these, 11 met our criteria for a comparative analysis. Two additional cohorts of ours were added and these were analysed in two groups based on the extent of surgery (near-total [NT; Woodhouse1] vs. sub-total [ST; Woodhouse2]). There were 518 low dose and 449 high dose patients in all. RESULTS: The average failure of a single low dose was 46 +/- 28% (SD). Meta-analysis revealed a statistically significant advantage for a single high over a single low dose and a pooled reduction in relative risk of failure of the high dose of about 27% (P < 0.01). From this we estimate that for every seven patients treated one more would be ablated given a high rather than a low dose (assuming a low dose failure risk of 50%). Also, a significantly greater proportion of patients are ablated after a single high or low dose, if they underwent near-total as opposed to sub-total thyroidectomy (summary relative risk (RR) 1.4; P < 0.05). CONCLUSION: High dose 131I is more efficient than low dose for remnant ablation particularly after less than total thyroidectomy. Results suggest that patients with differentiated thyroid cancer should routinely have a total thyroidectomy followed by high dose 131I (2775-3700MBq) for ablation of the remnant.
Cohort Studies↗
Cryptococcosis at the University Hospital, Kuala Lumpur.
We review our experience with 27 cases of pulmonary and meningeal cryptococcosis at the University Hospital, (Kuala Lumpar, Malaysia) where this is the most common cause of adult meningitis in patients without debilitating illnesses. Of the 27 cases analysed, six presented primarily with pulmonary symptomatology which usually were mainly cough, chest pain and low grade fever. The rest presented with primarily central nervous system (CNS) symptomatology of which headaches and fever were the most consistent symptoms although a third of these patients also had pulmonary lesions noted on chest radiographs. Treatment in all cases was with amphotericin B and 5-fluorocytosine and usually till a total cumulative dose of 1.5 g of amphotericin had been reached (an average of 10 weeks). Primary pulmonary presentations, if symptomatic, were treated as per CNS cryptococcosis due to the high likelihood of CNS dissemination. Incidental pulmonary cryptococcoma found on routine chest radiographs were confirmed by biopsy under ultrasound or fluoroscopy guidance and booked for surgical resection. Death usually occurred early in patients who presented late. Once patients responded to therapy, mortality was usually avoided. The only cause of morbidity in survivors was visual impairment or blindness, and this was attributed mainly to intracranial hypertension with residual deficits determined by the measures taken to lower intracranial pressures. Our experience suggests that: (i) symptomatic patients should have combination therapy with 5-fluorocytosine and amphotericin B till at least a cumulative dose of 1.5 g amphotericin B is reached irrespective of whether they have primary CNS or pulmonary symptomatology; (ii) non-symptomatic pulmonary cryptococcoma could be treated primarily by surgical resection; (iii) visual failure or papilloedema should be treated aggressively; and (iv) prognosis is good with adequate therapy and early presentation.
Adolescent↗
Radiation-induced pericardial disease: a case report.
A typical case of chronic pericardial effusion resulting in cardiac tamponade is presented. A pericardiocentesis was done for diagnosis and drainage, followed by a pleuro-pericardial window as definitive therapy. The minimal cumulative dose expected to produce pericardial disease is about 4000 rads, and the disease usually manifests within 12 months of such radiation exposure, as in this patient. It is concluded that for symptomatic pericardial effusions, available evidence justifies a subtotal pericardiectomy, a window procedure being reserved to tide over ill patients as in this patient. No strong evidence exists for the efficacy of steroid therapy; such therapy is reserved for asymptomatic mild effusions, which may also resolve spontaneously.
Adult↗
Pharmacodynamic optimization of warfarin therapy.
Pharmacokinetic-pharmacodynamic information regarding warfarin is used to produce a predictive model based on the idea that pharmacodynamic variability is more important than pharmacokinetic variability in the overall dose-response variability to warfarin. A modification of the maximum effect model is tested on a group of patients initiating oral anticoagulation with warfarin. Results indicate that the model can account for at least half of the total variation in maintenance doses observed (sample coefficient of determination, 0.53) and offer the physician a framework for dose requirements at the onset of therapy. The basic prediction equation is as follows: Maintenance dose = (11/international normalized ratio)-1, with a coefficient of correlation of 0.73 (95% confidence limits, 0.46-0.88). Application of this model may improve on the traditional empiric approach to warfarin dose adjustment.
Dose-Response Relationship, Drug↗
Herpes gestationis: one of the rare skin lesions in pregnancy.
Herpes gestationis is a rare disease in pregnancy. A 35-year-old G3P2 presented during her third trimester with erythematous pruritic papular eruptions. Direct immunofluorescence of a skin biopsy confirmed the diagnosis of herpes gestationis. The patient responded well to predniosolone treatment.
Adult↗
Results of long-term follow-up after compensated fixed-dose therapy for thyrotoxicosis.
To evaluate the effects of simple compensated fixed-dose iodine-131 therapy for thyrotoxicosis, the long-term results for 74 patients treated with a fixed dose of iodine-131 ranging from 5 to 12 mCi (185 to 444 MBq) were evaluated in the first 2 years of a trial. The dose selected was loosely based on the gross size of the thyroid gland. Routine antithyroid drug therapy was given for a minimum of 3 months after iodine-131 therapy. The mean (+/- SD) duration of follow-up was 74.5 +/- 42 months. The results indicated that roughly 25% of patients treated in this way will become hypothyroid after 5 years and that 85% are cured (need no further therapy during the follow-up period) using a single dose of iodine-131. Of those cured using a single iodine-131 dose, 81% were no longer receiving drugs after 6 months and 85% after 1 year. Such a regimen seems currently to be among the best available where prolonged periods of medication-free euthyroidism after therapy are sought.
Female↗
Digoxin therapeutics: straightening out the facts.
This article is essentially a review of the pharmacokinetic rationale behind digoxin therapeutics. It covers the various approaches to digoxin therapeutics including the therapeutic endpoint and the use of plasma concentrations of digoxin, the various problems involved in dosage design (particularly pharmacokinetic variability), prescribing aids (and their total impact on the variability in plasma concentrations achieved), and finally, the alternative use of blood-level data to separate and identify the variation in absorption-disposition from the variation in the relationship of plasma concentration to effect. On the basis of available data, it is concluded that by both turning to prescribing aids that have been formulated from clinical data gathered under more nearly ideal conditions and selecting the dosage to give a target concentration based on single measurements of serum digoxin concentrations, may not result in much improvement over fixed or intuitive dosing as far as achieving a predetermined target level is concerned. The probable causes for this lack of precision are explored, and finally an optimum approach to digoxin therapeutics is defined.
Animals↗
Visual perception--a hypothesis.
Based on the results of after-image experiments, it can be concluded that the retinal perception of image position is linked to head position information, since this affects after-image positioning. Why actual perception of object position is not affected is hypothesised as a resetting of the retinal horizon, from information received on head position. Tilting of the after-image is thus explained as superimposition of the former image on a reset (tilted) horizon (axis).
Afterimage↗
Pharmacodynamic optimization of warfarin therapy II.
A pharmacodynamic (E(max)) model for optimizing warfarin initiation had previously been reported. This study assessed the validity of this model, adjusted further for age in both the initial cohort and another cohort distinct from that used for the formulation of the model. Thirty-one patients undergoing oral anticoagulation for mainly cardiac indications were recruited from Kuala Lumpur. Thirty-four patients undergoing oral anticoagulation for deep vein thrombosis were recruited from Cambridge. They were studied for their anticoagulant response to the initiation of warfarin. The former were intuitively dosed after a 2-day loading of 10 mg warfarin/d. The latter all were commenced on warfarin via a standard 4-day induction protocol of Fennerty et al that allows early estimation of the required maintenance dose. The actual maintenance doses in both cohorts were compared with their predicted doses on the initiation of therapy that was calculated both from this model and from the induction protocol of Fennerty et al. The third day's international normalized ratio and age combination was additive in terms of their influence on the maintenance dose. The predictive model in both cohorts returned similar results and explained at least two thirds of the interindividual variability in warfarin maintenance dose requirements, whereas the induction protocol of Fennerty et al explained only one third of this interindividual variability. Use of this model in the form of the included nomogram should be able to decrease both the occurrence of either under- or overanticoagulation as well as the time taken to initiate treatment and decide the correct maintenance dose during the initiation of oral anticoagulation with warfarin in hospitals. A prospective evaluation of the nomogram is recommended.
Administration, Oral↗
Digoxin in clinical practice: sorting out the facts.
The aim of this review is to sort out from the huge amount of facts related to digoxin in the literature those pertinent to current clinical practice. Seven aspects of digoxin are discussed: its mechanism of action, therapeutic controversy, clinical efficacy, avoidance of toxicity, manifestations of toxicity, indications, and its use in coronary artery disease.
Atrial Fibrillation↗