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At least 289 records · Page 16Linked to original sources
PubMed2000

High-density lipoproteins from human alcoholics exhibit impaired reverse cholesterol transport function.

We have previously shown that chronic alcohol consumption leads to inhibition of sialylation of apolipoprotein E (apo E) that results in its impaired binding to high-density lipoprotein (HDL) molecule. Because apo E plays a major role in reverse cholesterol transport (RCT), we speculated that ethanol-mediated formation of HDL molecules without apo E may affect the RCT process. Therefore, we have investigated whether the RCT function of HDL is affected in chronic alcoholics with or without liver disease compared with nondrinkers. HDL was isolated from fasting plasma of normal subjects, n = 9 (nondrinkers), chronic alcoholics, n = 8 (ALC), and chronic alcoholics with liver disease, n = 6 (ALD). A portion of HDL sample from each subject was evaluated for its cholesterol efflux capacity from [3H]cholesterol oleate preloaded mouse macrophages. The remaining portion of each HDL sample was labeled with [3H]cholesterol oleate and evaluated for its ability to deliver cholesterol to the liver using HepG2 cells in culture. Cholesterol efflux capacity of HDLs was decreased by 83% (P < .0002) in alcoholics without liver disease and by 84% (P < .0006) in alcoholics with liver disease compared with the HDLs from nondrinkers. The capacities of HDLs to deliver cholesterol to the liver were decreased by 54% (P < .005) in alcoholics without liver disease and by 64% (P < .005) in alcoholics with liver disease compared with the HDLs from nondrinkers. The fact that further complications by liver disease in alcoholic subjects did not significantly exacerbate the extent of impairment in RCT function of HDL suggest that alcohol per se is responsible for its deleterious effects on RCT. Significantly, plasma HDL apo E concentration relative to that of apo A1 (apo E/apo A1 ratio) was also decreased by 31% to 32% (P < .0005) in alcoholics without or with liver disease compared with nondrinkers. It is therefore concluded that chronic alcohol consumption adversely affects the RCT function of HDL by altering its association with apo E due to ethanol-induced desialylation of apo E.

Adult↗
PubMed2003

Survival and prognostic factors of patients with unresectable glioblastoma multiforme.

The aim of this study was to assess survival and prognostic factors of 98 consecutive patients with unresectable glioblastoma multiforme (GBM) after stereotactic biopsy. Patients were diagnosed between 1993 and 1998, and the treatment modality subsequent to stereotactic biopsy was determined by the year of diagnosis. Before 1995, patients did not receive further specific therapy after stereotactic biopsy (n=36). In 1996, patients were administered radiotherapy starting within 6 weeks after stereotactic biopsy (n=24). From 1997 to 1998, patients received combined radio-/chemotherapy (RCT; CCNU orally) starting within 2 weeks after stereotactic biopsy (n=38). Patients' age ranged from 21 to 84 (median 64) years and their median Karnofsky performance score 2 weeks after stereotactic biopsy was 80 (range 60-100). Survival and prognostic factors were analyzed with respect to administered treatment modalities (without specific therapy versus radiotherapy versus combined RCT), with respect to age (>or or=or<80), tumor location (frontal, parieto-temporal, central, occipital) and tumor size (>or 5 cm) by the Kaplan-Meier method, by log-rank test and multivariate Cox regression analysis. Post-biopsy treatment modality was the strongest predictor for survival. Median (range) survival was 9 (3-47) weeks in those without specific therapy, 13 (5-54) weeks in patients receiving radiotherapy and 31 (11-101) weeks in patients receiving combined RCT (p<or=0.001). Age<or=50 years (p<or=0.05) in addition to tumor size in multivariate Cox analysis were found to be of significant influence onto survival, too. Combined RCT could be performed on a complete outpatient basis. Toxicity consisted of mild asymptomatic thrombocytopenia. We conclude that the administration of combined RCT within a minimum interval after stereotactic biopsy yielded a significant increase in survival. Patients' acceptance was excellent. These results encourage us to treat even patients with unresectable GBM with combined RCT.

Adult↗
PubMed2006

Will the dilemma of evidence-based surgery ever be resolved?

Exponents of evidence-based medicine do not undermine the importance of clinical expertise and skills, but they emphasize that decision-making in medicine should be based on the best available evidence derived from the systematic analysis of observations made in an objective, unbiased and a reproducible fashion. The randomized controlled trial (RCT) is the most scientifically rigorous means of hypothesis testing in epidemiology. Discrepancies between established surgical and other interventions and best available evidence are common. These can be in the form of significant delay in adopting a new intervention despite strong supportive evidence, adopting an intervention before supportive evidence becomes available for reasons of novelty or pear pressure and the lack of supportive evidence for many established common practices. This is compounded further by the paucity of good quality evidence for most surgical procedures. This is arguably because of the inherent difficulties in conducting surgical RCT. The practical, ethical and financial ramifications are complex and the nature of surgical disease often compromise the chances of success or completion of RCT. Carrying out surgical RCT may have more implications on the clinician's authority, autonomy and income and their results are more likely to be influenced by his/her expertise and competence than medical RCT. Furthermore, the success of surgical RCT is often jeopardized by very low recruitment rates. The aim of this study is to discuss the dilemma of producing evidence in surgery.

Evidence-Based Medicine↗
PubMed2006

Hypothermia pediatric head injury trial: the value of a pretrial clinical evaluation phase.

BACKGROUND: The utility of a pretrial clinical evaluation or run-in phase prior to conducting trials of complex interventions such as hypothermia therapy following severe traumatic brain injury in children and adolescents has not been established. METHODS: The primary objective of this study was to prospectively evaluate the ability of investigators to adhere to the clinical protocols of care including the cooling and rewarming procedures as well as management guidelines in patients with severe traumatic brain injury (Glasgow Coma Scale<or=8) treated with 24 h of hypothermia therapy. A secondary objective was to evaluate the ability of study research assistants to complete the study case report form using a procedures manual. The study was conducted at 18 sites in Canada, the United Kingdom and France prior to proceeding to a randomized controlled trial (RCT). After 2 patients were enrolled at each center, an independent clinical evaluation committee examined the process of care and the completeness of data collection. Centers were permitted to enroll patients in the RCT once they met pre-established adherence criteria. RESULTS: Seventeen of the 18 centers completed the pretrial clinical evaluation phase demonstrating compliance with study procedures and proceeded to an RCT of hypothermia therapy. One center enrolled only 1 patient in the pretrial clinical evaluation phase due to small numbers of patients with traumatic brain injury, and therefore, did not proceed to the RCT. Three centers were required to enroll more than 2 patients in the pretrial clinical evaluation phase prior to proceeding to the RCT because of problems with adherence to the clinical protocols at two centers and the training of new study personnel at another center. Of the 39 patients enrolled during the pretrial clinical evaluation phase, 8 (20.5%) died and 22 (62.9%) had a good outcome defined as normal, mild or moderate disability assessed using the Pediatric Cerebral Performance Category score at 6 months following injury. DISCUSSION: The pretrial clinical evaluation phase was useful to ensure compliance with complex hypothermia therapy and consensus-based clinical management guidelines of care successfully implemented across 17 of 18 centers. This study maneuver allowed us to complete a subsequent RCT in 225 children following severe traumatic brain injury.

Algorithms↗
PubMed1991

Clinical usefulness of n-of-1 randomized controlled trials in patients with nonreversible chronic airflow limitation.

To determine if n-of-1 randomized controlled trials (n-of-1 RCT) are useful in the care of patients with nonreversible chronic airflow limitation (CAL). Individual trials had a double-blind, randomized, multiple crossover design. Patients with CAL were recruited from several respirology practices. For each individual trial the main outcome measure was a symptom questionnaire; peak flow measurements were used as a secondary measure. Physicians' plans of management (before and after trials) and confidence in the plans were determined. The proportion of trials that provided a definite clinical or statistical answer was established. Patients were followed, and long-term adherence to decisions based on n-of-1 RCT was examined. A total of 26 n-of-1 RCT in patients with CAL were attempted; 18 of these (69%) were completed. After 17 (94%) of the completed trials clinicians expressed a high degree of confidence in their management plans, confidence that was not, in any case, present before the trial. After 8 n-of-1 RCT (44% of all completed, or 31% of all trials) clinicians decided to stop the drug, which would otherwise have been continued indefinitely. In all 17 of the clinically definite n-of-1 RCT, the management decision that followed the trial was still being adhered to 40 months (on average) after completion of the trial. The results support the feasibility and usefulness of n-of-1 RCT in respirology practice.

Double-Blind Method↗
PubMed2006

A systematic review and economic model of the clinical and cost-effectiveness of immunosuppressive therapy for renal transplantation in children.

OBJECTIVES: To review the clinical and cost-effectiveness of basiliximab, daclizumab, tacrolimus, mycophenolate mofetil (MMF), mycophenolate sodium (MPS) and sirolimus as possible immunosuppressive therapies for renal transplantation in children. DATA SOURCES: Electronic databases were searched up to November 2004. REVIEW METHODS: Data from selected studies were extracted and quality assessed. An economic model [Birmingham Sensitivity Analysis paediatrics (BSAp)] was produced based on an adaptation of a model previously developed for the assessment of the cost-effectiveness of immunosuppressants in adults following renal transplant. RESULTS: For the addition of basiliximab, one unpublished paediatric randomised control trial (RCT), reported that the addition of basiliximab to tacrolimus-based triple therapy (BTAS) failed to significantly improve 6-month biopsy-proven acute rejection (BPAR), graft function, graft loss and all-cause mortality. No significant difference between groups was seen in 6-month or 1-year or longer graft loss, all-cause mortality and side-effects. In a meta-analysis of adult RCTs, the addition of basiliximab to a ciclosporin, azathioprine and steroid regimen (CAS) significantly reduced short-term BPAR. There was no significant difference in short- or long-term graft loss, all-cause mortality or side-effects. One adult RCT was included for the addition of daclizumab to CAS, which reported reduced 1-year BPAR, although no difference between groups was seen in either 1- or 3-year graft loss, all-cause mortality and side-effects. For tacrolimus versus ciclosporin, one unpublished paediatric RCT found that a regimen of tacrolimus, azathioprine and a steroid (TAS) reduced 6-month BPAR and improved graft function [glomerular filtration rate (GFR)] compared with CAS. This improvement in BPAR with tacrolimus was as shown in the meta-analysis of adult RCTs. There was evidence, particularly in children, that in comparison with ciclosporin, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. The total level of withdrawal in children was reduced in children receiving tacrolimus. Adult RCTs showed an increase in post-transplant diabetes mellitus with tacrolimus. For MMF versus azathioprine, a meta-analysis of adult RCTs showed MMF [regimen of ciclosporin, MMF and a steroid (CMS)] to reduce 1-year BPAR compared with azathioprine (CAS). There was evidence, particularly in children, that in comparison with azathioprine, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. There was an increase in the level of cytomegalovirus infection with MMF, although the overall level of withdrawal due to adverse events was not different to that of azathioprine-treated adults. No study comparing MPS with azathioprine (CAS) was identified. In an adult RCT comparing MMF with MPS, there was no significant difference between groups in 1-year efficacy or side-effects. One unpublished paediatric RCT assessed the addition of sirolimus to CAS. BPAR, graft loss and all-cause mortality were not reported. In two adult RCTs, compared with azathioprine, sirolimus reduced 1-year BPAR, reduced graft function (as assessed by an increased serum creatinine) and increased the level of hyperlipidaemia. No significant differences were seen in other efficacy and side-effect outcomes. On an adult RCT comparing sirolimus with ciclosporin, there were no significant differences between groups in 1-year efficacy or side-effects with the exception of an increased level of hyperlipidaemia with sirolimus substitution. Both the assessment group and drug companies assessed the cost-effectiveness of the newer renal immunosuppressants currently licensed in children using an adaptation (BSAp) of the Birmingham Sensitivity Analysis (BSA) model. This model is based on a 10-year extrapolation of 1-year BPAR results sourced from paediatric RCTs or adult RCTs (where paediatric RCTs were not available). The addition of basiliximab and that of daclizumab to CAS was found to increase quality-adjusted life-years (QALYs) and decreased overall costs, a finding that was robust to sensitivity analyses. The incremental cost-effectiveness ratio (ICER) of replacing ciclosporin with tacrolimus was highly sensitive to the selection of the hazard ratio for graft loss from acute rejection, dialysis costs and the incorporation (or not) of side-effects. The ICERs for tacrolimus versus ciclosporin ranged from about 46,000 pounds/QALY to about 146,000 pounds/QALY. Although sensitive to varying the hazard ratio for graft loss with acute rejection, the ICER for replacing azathioprine with MMF remained in excess of 55,000 pounds/QALY. CONCLUSIONS: In general, compared with a regimen of ciclosporin, azathioprine and steroid, the newer immunosuppressive agents consistently reduced the incidence of short-term biopsy-proven acute rejection. However, evidence of the impact on side-effects, long-term graft loss, compliance and overall health-related quality of life is limited. Cost-effectiveness was estimated based on the relationship between short-term acute rejection levels from RCTs and long-term graft loss. Both the addition of daclizumab and that of basiliximab were found to be dominant strategies, that is, regarding cost savings and increased QALYs. The incremental cost-effectiveness of tacrolimus relative to ciclosporin was highly sensitive to key model parameter values and therefore may well be a cost-effective strategy. The incremental cost-effectiveness of MMF compared with azathioprine, although also sensitive to model parameter, was unattractive. There is a particular need for RCTs to assess the use of MMF, MPS and daclizumab for renal transplantation in children where no such evidence currently exists. Future comparative studies need to report not only on the impact of the newer immunosuppressants on short- and long-term clinical outcomes but also on side-effects, compliance, healthcare resource, costs and health-related quality of life.

Child↗
PubMed2001

Oral administration of recombinant cholera toxin subunit B inhibits IL-12-mediated murine experimental (trinitrobenzene sulfonic acid) colitis.

Trinitrobenzene sulfonic acid (TNBS)-induced colitis is an IL-12-driven, Th1 T cell-mediated colitis that resembles human Crohn's disease. In the present study, we showed initially that the oral administration of recombinant subunit B of cholera toxin (rCT-B) at the time of TNBS-induced colitis by intrarectal TNBS instillation inhibits the development of colitis or, at later time when TNBS-induced colitis is well established, brings about resolution of the colitis. Dose-response studies showed that a majority of mice (68%) treated with rCT-B at a dose of 100 microg (times four daily doses) exhibited complete inhibition of the development of colitis, whereas a minority (30%) treated with rCT-B at a dose of 10 microg (times four daily doses) exhibited complete inhibition; in both cases, however, the remaining mice exhibited some reduction in the severity of inflammation. In further studies, we showed that rCT-B administration is accompanied by prevention/reversal of increased IFN-gamma secretion (the hallmark of a Th1 response) without at the same time causing an increase in IL-4 secretion. This decreased IFN-gamma secretion was not associated with the up-regulation of the secretion of counterregulatory cytokines (IL-10 or TGF-beta), but was associated with a marked inhibition of IL-12 secretion, i.e., the secretion of the cytokine driving the Th1 response. Finally, we showed that rCT-B administration results in increased apoptosis of lamina propria cells, an effect previously shown to be indicative of IL-12 deprivation. From these studies, rCT-B emerges as a powerful inhibitor of Th1 T cell-driven inflammation that can conceivably be applied to the treatment of Crohn's disease.

Administration, Oral↗
PubMed2001

Evaluating severity and status in rheumatoid arthritis.

There is general agreement regarding the most appropriate examinations and methods to use to evaluate change in status in randomized controlled trials (RCT). However, no guidelines exist to aid in determining and evaluating actual status rather than change in status, particularly when applied to individual patients with rheumatoid arthritis (RA). In addition, methods appropriate for clinical trials may not be useful in evaluating individual patients because of time constraints. This report reviews current methods of evaluation and develops modified methods, based on data bank research that will be useful in clinical practice and in the evaluation of RCT and observational studies. Using data from longitudinal observational data banks, further reduction in the number of joints examined is evaluated to reconcile the time constraints of clinical practice with the need to maintain reliability and validity. Percentile methods to determine severity status are applied to the variables used in RCT and extended further to observational studies and routine clinical practice. Shortened joint counts, based on modifications of the Ritchie method, are identified that allow for examination of groups of 18 (clinical-18) and 16 (clinical-16) joints, the clinical-16 omitting the metatarsophalangeal joints. Using percentile charts, actual severity valuations are given to the variables evaluated in the clinic as well as in RCT. Disease activity status of clinic patients can be determined quantitatively thus allowing clinicians further insight into the status and prognosis of their patients. By quantifying disease activity severity, clinicians and 3rd party payers can better evaluate the appropriateness of and response to disease modifying antirheumatic drugs and biologic therapies. Further, RCT can be evaluated as to severity status of patients participating, and the generalizability of RCT can be better evaluated.

Arthritis, Rheumatoid↗
PubMed2002

Wound management after colon injury: open or closed? A prospective randomized trial.

It is unknown whether leaving the skin wound open to heal by secondary intention is associated with a lower rate of wound infections compared with primary skin-wound closure after operations for colon injuries. From June 1998 to December 2000 at our Level I academic trauma center 48 patients entered into a randomized controlled trial (RCT) and were randomized to have their skin wound primarily closed (CLOSED-RCT) or left open (OPEN-RCT). At the same time patients not included in the RCT were followed prospectively. At the discretion of the surgeon their skin wounds were managed by primary closure (CLOSED-nonRCT) or were left open (OPEN-nonRCT). Univariate and multivariate analysis was done to identify independent risk factors of wound infection, wound dehiscence, and necrotizing soft tissue infection. Wound infection developed in 65 per cent of CLOSED-RCT and 36 per cent of OPEN-RCT patients (P = 0.04) and wound dehiscence in 31 per cent and 14 per cent respectively (P = 0.18). No remarkable differences were noted in any other variable including length of hospital stay. Wound infection developed in 29 per cent of CLOSED-nonRCT and 15 per cent of OPEN-nonRCT patients (P = 0.46). There were three independent risk factors of wound infection: primary wound closure [odds ratio (OR) = 5.5, 95% confidence interval (CI) = 1.8-19.4], colectomy (OR = 3.4, 95% CI = 1.2-10.4), and intraabdominal infection (OR = 5.3, 95% CI = 1.3-24.2). There were two independent risk factors for wound dehiscence and/or necrotizing soft tissue infection: wound infection (OR = 20.9, 95% CI = 4.9-152.3) and intra-abdominal infection (OR = 19.3, 95% CI = 4.0-146.9). Primary closure of the wound almost doubles the rate of wound infection compared with leaving the wound open in operations for colon injuries. Primary wound closure is a risk factor for wound infection and wound infection is a risk factor for wound dehiscence or necrotizing soft tissue infection. Because of the complexity of evaluating the real clinical significance of superficial wound infection larger studies on trauma patients are required.

Adult↗
PubMedDate not supplied

Two-year outcomes of primary molar ferric sulfate pulpotomy and root canal therapy.

PURPOSE: The objective of this outcome study was to compare ferric sulfate pulpotomy (FS) and primary tooth root canal therapy (RCT) on cariously exposed vital pulps of primary molars. METHODS: A total of 291 molars were treated in 130 children--182 molars received FS and 109 received RCT by random selection. RESULTS: At 2-year reassessment, 116 molars (73 FS, 43 RCT) were available for clinical and radiographic examination. There was no clinical evidence of pathosis in 96% of FS and 98% of RCT molars. Two independent pediatric dentists evaluated periapical radiographs of the treated molars. Molars were classified into 1 of 4 outcomes: (1) N--normal treated molar, (2) H--nonpathologic radiographic change present, (3) P(O)--pathologic change present, follow-up in 6 months, and (4) P(X)--pathologic change present, extract immediately. Survival analysis was applied. A good level of agreement between raters was found for molars with outcome P(X) (kappa=0.745). Intrarater reliability was good for molars with outcome P(X) (kappa=0.710). Significantly greater numbers of FS than RCT molars were rated P(X) at the 2-year recall (chi2=5.8; P=.02). No significant difference in survival between the 2 types of vital pulp treatments was detected in log rank tests (P=.22). CONCLUSIONS: Outcomes for FS were poorer than RCT outcomes at 2 years; however, at 2 years, the survival rates were not statistically different.

Chi-Square Distribution↗
PubMedDate not supplied

Long-term outcomes of primary molar ferric sulfate pulpotomy and root canal therapy.

PURPOSE: The purpose of this study was to compare long-term outcomes of ferric sulfate pulpotomy (FS) and primary tooth root canal therapy (RCT) in vital pulps of deciduous molars exposed to caries lesions. METHODS: A total of 291 molars were treated in 130 children. One hundred and eighty-two molars received FS and 109 received RCT by random selection. RESULTS: At 3-year re-assessment, 29 molars (15 FS, 14 RCT) were available for clinical and radiographic examination. Two independent pediatric dentists evaluated periapical radiographs of the treated molars. Molars were classified 1 of 4 outcomes: (1) N = normal treated molar; (2) H = nonpathologic radiographic change present; (3) P(o) = pathologic change present, follow-up in 6 months; (4) P(x) = pathologic change present extract immediately. Survival analysis was applied. A good level of agreement between raters was found for molars with outcome P(x) (K = 0.79). No difference in radiographic outcomes was demonstrated 3 years after treatment (chi2 = 1.4). Survival analysis demonstrated a 3-year survival probability of 0.62 for FS-treated molars and 0.92 for RCT molars. Survival of RCT molars was significantly greater than for FS molars (Wilcoxon: P = .01; log-rank: P = .02). CONCLUSIONS: RCT-treated molars demonstrated significantly greater survival than FS-treated molars 3 years after treatment.

Child, Preschool↗
PubMed2005

[Clinical analysis of 1 423 cases of root canal therapy].

OBJECTIVE: To evaluate the clinical quality of root canal therapy (RCT) in West China Dental Hospital of Sichuan University. METHODS: 1 423 RCT teeth were finished from Mar. 2001 to Feb. 2002 in West China Dental Hospital. Root canal filling quality and treatment period of these teeth were evaluated. 695 teeth of the total were revisited 2 years later and 2-year success rate were evaluated. RESULTS: The ratios of adequate filling, underfilling, and overfilling were 79.97%, 14.62% and 5.41%, receptively. Full canal RCT ratio of molar was 89.44%. Average RCT treatment period was 2.8 weeks. 2-year success rate of RCT was 94.39%. CONCLUSION: Clinical RCT level of West China Dental Hospital was satisfactory from 2001 to 2002.

Adult↗
PubMed2006

Pennsaid therapy for osteoarthritis of the knee: a systematic review and metaanalysis of randomized controlled trials.

OBJECTIVE: To systematically review published randomized controlled trials (RCT) evaluating a new topical diclofenac solution (Pennsaid) in patients with osteoarthritis (OA) of the knee. METHODS: RCT were identified by searching electronic data sources as well as by contact with the manufacturer of Pennsaid. Details of study demographics, methodology, quality, and outcomes were analyzed. A metaanalysis evaluating the efficacy and safety of Pennsaid in OA of the knee was performed. RESULTS: Four RCT were analyzed in this systematic review (3 published reports and one published abstract). Mean trial duration was 8.5 weeks. Generally, these RCT were of excellent quality. The mean Jadad quality score was 4.5 out of 5. Many indicators of high quality in a RCT were found in these RCT, including adequate descriptions of the methods used for randomization, blinding, and allocation concealment. In comparison to a vehicle control placebo (VCP), the standardized mean differences (SMD) for the WOMAC pain, stiffness, and physical function subscales, as well as for patient global assessment, were all statistically significant in favor of Pennsaid, with SMD ranging from 0.30 to 0.39. Pennsaid was as safe as VCP, with the only exception that it was more likely to result in minor skin dryness at the site of application (relative risk 1.7). In a 12 week equivalence trial that used the WOMAC subscales to compare treatment response, Pennsaid was as effective as oral diclofenac, but was much better tolerated. CONCLUSION: Pennsaid is an effective topical NSAID in patients with OA of the knee. Apart from minor localized skin reactions, Pennsaid was as safe as VCP. It is not known whether the favorable results of Pennsaid can be extrapolated to other topical NSAID preparations. Pennsaid deserves further consideration when the existing treatment guidelines for OA of the knee are updated.

Administration, Topical↗
PubMedDate not supplied

[The role of beta-blockers in the preventive treatment of rupture of esophageal varices].

beta-blockers, mainly propranolol, have dramatically modified the treatment of portal hypertension. It has been demonstrated that it was possible to decrease portal pressure over a long period and to modify the natural history of gastrointestinal bleeding in cirrhosis. The prevention of first bleeding, or primary prophylaxis, should be distinguished from prevention of rebleeding, or secondary prevention, as these two situations pertain to different events. Concerning primary prophylaxis, at least five randomized controlled trials, (RCT), comparing beta-blockers and placebo, have been published. All the results are homogenous and their meta-analysis suggests that the incidence of first bleeding is significantly decreased but not that of death rate. Results of studies comparing propranolol and sclerotherapy are also available but we know that the results of more than 15 RCT testing sclerotherapy are debated. In secondary prevention, there are more than 10 RCT comparing beta-blockers versus placebo. Results of these RCT are heterogeneous. Meta-analysis suggests that the incidence of rebleeding is significantly decreased but not that of death rate. The results of 5 RCT comparing propranolol versus sclerotherapy are available. Whatever the trial, there was no significant differences between these two treatments. However, meta-analysis suggests that the bleeding incidence is decreased by sclerotherapy but this does not reach statistical significance. Finally, there are RCT with combined treatments: it seems that sclerotherapy plus propranolol is superior to sclerotherapy alone; however this result should be confirmed. In conclusion beta-blockers seem to bring about real changes in the prevention of digestive bleeding in cirrhosis. Their contribution is particularly appreciable in primary prevention of cirrhotic patients with large oesophageal varices.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1978

[Retinal circulation time in diabetic retinopathy treated with photocoagulation (author's transl)].

A preliminary report is given on studies of the retinal circulation in diabetic retinopathy before and after photocoagulation treatment. The local retinal circulation time RCT of selected retinal areas was calculated by means of a fluorescein long-term infusion technique. In 7 eyes with diabetic retinopathy (DR) the mean RCT was significantly higher (2.0 +/- 0.58 sec. range 1.27-2.6) than in 15 control eyes (1.11 +/- 0.34 sec, range 0.50-1.82, Niesel 1976). Assuming an increase of blood flow in DR (L'Esperance 1971, Kohner 1975) the increase of RCT by a factor 2 would imply an increase of the vascular volume by a factor hardly less than 3 indicating the marked impairment of retinal hemodynamics in DR. After photocoagulation, the mean RCT was significantly shortened only in eyes with preoperative RCT values above 2 sec. The reduction of local RCT correlated with the extent of treated retinal areas. The cross-sectional area of the retinal veins measured near the optic disc was generally reduced independently of the extent of coagulation treatment. Taking also the obvious postoperative reduction of the total retinal vascular volume into account, photocoagulation resulted in a marked decrease of blood flow not only in extensively treated but also in areas with little coagulation effects. In DR the disturbed retinal circulation in general tends to normalize following extensive photocoagulation.

Blood Volume↗
PubMed1981

[Basic studies on radionuclide computed tomography using a rotating chair (author's transl)].

Radionuclide Computed Tomography (RCT) was studied from the technical standpoint of view. In this study, a gamma camera (Ohio Nuclear sigma 410S) and a rotating chair designed by one of us were used. The computer used was Scintipac 1200 (32 kW memories and 2.4 MB X 2 disk memories). A cylindrical phantom having a diameter of 20 cm was also designed by us into which various-sized tubes could be inserted for resolution study. The phantom was set on the chair, the center of which was 20 cm off from the surface of the detector. The chair was rotated manually 10 degrees, and finally 36 digital images in the form of 64 X 64 elements were obtained, covering an entire circumference. RCT images were displayed in the form of 128 X 128 elements on a X-ray film through a Microdot Imager. At first, the phantom was filled with 99mTc solution and the uniformity of the RCT image on it was checked using several formulae for count rate correction to find out which one of the formulae was best fitted. For the reconstruction of the RCT image, "filtered back projection" was used. Then, we found that, as far as out phantom study was concerned, simple geometrical mean on the data from the two opposing directions was found the best for the count rate corrections, which was exclusively used thereafter. The fluctuation on the uniform source was found to be approximately 15%. For the resolution study, hot tubes having diameters of 1.0, 2.0, 3.0, and 4.0 cm and cold tubes of 1.5, 2.4, 3.5, and 4.7 cm were inserted into the phantom. As for the hot tubes, all the tubes were depicted on the RCT image whereas 2.4 cm was the smallest depicted for the cold tubes. FWHM was checked with a fine line source in the phantom and was found to be 2.0 cm regardless to its depth. The Alderson liver phantom was also used to detect defects in the air and it was found both balls having diameters of 2.7 and 3.7 cm could be depicted on the RCT image. Now we are evaluating clinical usefulness of this technique on the liver. The results will be published in the near future.

Evaluation Studies as Topic↗
PubMed1995

Fibrin polymerization defect in HIV-infected patients--evidence for a critical role of albumin in the prolongation of thrombin and reptilase clotting times.

Thrombin clotting time (TCT) and reptilase clotting time (RCT) were found significantly prolonged in a series of 72 HIV-infected patients drawn for routine coagulation testing. Both TCT and RCT were highly significantly correlated with albumin (r = -0.64, and r = -0.73 respectively, p < 0.0001). TCT and RCT were significantly higher (p < 0.0001) in a series of 30 other HIV-infected patients selected on their albumin level below 30.0 g/l (group 1) than in 30 HIV-infected patients with albumin level above 40.0 g/l or in 30 HIV-negative controls; the two latter groups were not different. In vitro supplementation of plasma from group 1 patients with purified human albumin up to 45.0 g/l (final concentration) lead to a dramatic shortening effect on both TCT and RCT, which reached normal values. The TCT and RCT of the purified fibrinogen solutions (2.0 g/l final concentration) were not different in the three groups, and normal polymerization curves were obtained in all cases. This further ruled out the presence of any dysfibrinogenemia in the plasma from group 1 patients. Using purified proteins, highly significant correlations were demonstrated between the albumin concentration and the prolongations of both TCT and RCT, which were of the same magnitude order than those found in the patients plasma. These results suggest that hypoalbuminemia is responsible for the acquired fibrin polymerization defect reported in HIV-infected patients. The pathophysiological defect reported in HIV-infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1977

Radionuclide emission computed tomography of the head with 99mTc and a scintillation camera.

To investigate the potential application of radionuclide computed tomography (RCT) to nuclear medicine imaging using 99mTc, a tomographic system using a lightweight scintillation camera for brain imaging was constructed, and lesion contrast with RCT and conventional scintigraphy were compared. The detector revolves once around the patient's head at constant angular velocity, requiring approximately 20 min. Nine sections are reconstructed from the data, using either a Fourier transform or a filtered back-projection algorithm. In a phantom simulating the radionuclide distribution observed during brain imaging, quantitative lesion contrast was far superior in the RCT images. In a series of 25 patients with intracranial lesions, the average RCT lesion contrast was superior to that of standard scintigraphy by a factor of more than 2. An RCT image of an experimentally infarcted dog's heart, taken after the injection of 99mTc-MAA into the left atrium, also showed excellent correspondence to the gross anatomic defect. Although problems of photon absorption may occur in imaging larger body areas, RCT imaging in this feasibility study produced surprisingly good results that warrant further investigation of the technique.

Aged↗