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Biomedical subjects

R Dick

Publications and source records attributed to R Dick.

At least 37 records · Page 2Linked to original sources
PubMed1994

Incidence, risk factors, management, and outcome of portal vein abnormalities at orthotopic liver transplantation.

Portal vein thrombosis is often considered a contraindication to orthotopic liver transplantation. We have analyzed the incidence, risk factors, management and outcome of patients with portal vein thrombosis undergoing orthotopic liver transplantation. During the period from October 1988 to October 1992 140 grafts were performed on 132 patients. Fourteen had portal vein thrombosis with either partial (n = 7) or complete (n = 7) occlusion of the portal vein at surgery. Portal vein thrombosis was more common in patients with autoimmune chronic active hepatitis (3/5 vs. 11/127, chi 2 = 13.3, P < 0.001), cryptogenic cirrhosis (4/12 vs. 10/120, chi 2 = 7.2, P < 0.01), or those with tumors (6/22 vs. 10/110, chi 2 = 5.7, P < 0.05). In 13 of the 14 portal inflow was reestablished by flushing, balloon thrombectomy, or passage of a graduated dilator. In one patient complete fibrous obliteration necessitated a portal vein to right gastroepiploic vein anastomosis. On follow-up there have been 6 deaths in this group (6/14 = 43%) from recurrent cancer (n = 1), sepsis (n = 4), and cardiac and renal failure (n = 1). Four of these 6 patients had confirmation of PV patency on imaging. The remaining 8 patients are alive and well (median follow-up 37 months, range 6-53 months). Post-transplant portal vein thrombosis occurred in 3 of the 14 patients (21%) with a portal vein abnormality at surgery and in two of the 118 patients with a normal portal vein (3/14 vs. 2/118, chi 2 = 8.5, P < 0.01). Four of the 5 cases were successfully treated by surgical thrombectomy.

Adolescent↗
PubMed1994

Low-dose intra-arterial thrombolysis in the treatment of phlegmasia caerulea dolens.

Three patients with phlegmasia caerulea dolens treated successfully by low-dose intra-arterial thrombolysis are presented. In all patients a rapid improvement was observed and amputation avoided. The risk of pulmonary embolus was reduced by the use of a retrievable vena cava filter in one patient and thrombolytic therapy in the presence of a previously inserted cava filter in the other two.

Adult↗
PubMed1994

Emergency transjugular intrahepatic portasystemic stent shunting as salvage treatment for uncontrolled variceal bleeding.

Creation of a transjugular intrahepatic portasystemic stent shunt (TIPSS) was used as a rescue treatment for patients with variceal bleeding refractory to standard medical and endoscopic treatment. Over a 2-year period 242 episodes of variceal bleeding were treated and emergency shunting was performed on 20 patients with uncontrolled bleeding (Pugh grade A, one; B, seven; C, 12). The procedure was technically successful and controlled bleeding in all patients. Six patients had early rebleeding within 5 days, and further shunting was required in two. Two had late rebleeding related to shunt occlusion and had a further TIPSS procedure followed by portacaval shunting. Twelve patients died within 40 days from liver failure and sepsis, and there were two late deaths after 2 and 6 months, unrelated to bleeding. TIPSS insertion is an effective therapeutic option in patients with acute variceal bleeding refractory to medical and endoscopic treatment. However, despite control of bleeding in this group, the hospital mortality rate was high, reflecting the severity of the underlying liver disease.

Adult↗
PubMed1994

Review article: the transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of portal hypertension.

The transjugular intrahepatic portosystemic shunt (TIPS) is a non-surgical intrahepatic shunt connecting the hepatic and portal veins. The shunt can be inserted successfully in more than 90% of patients and it effectively decompresses the portal venous circulation. Serious complications, such as intraperitoneal bleeding, occur but they are uncommon. The role of TIPS in the treatment of portal hypertension is currently being evaluated. There are few controlled data available to compare TIPS with established treatment such as drugs, injection sclerotherapy, endoscopic banding or shunt surgery. TIPS has also been used to treat ascites, the Budd-Chiari syndrome and cirrhotic hydrothorax. Concerns over the long-term patency and the true incidence of encephalopathy following TIPS raise doubts about its long-term efficacy. Controlled trials are required to demonstrate the cost-effectiveness of TIPS for individual indications before it is widely adopted. TIPS may find its most immediate application in the emergency treatment of active variceal haemorrhage refractory to standard medical and endoscopic therapy, as there is no satisfactory treatment currently available for this high-risk group. TIPS may also have a role in patients awaiting liver transplantation who bleed from varices. Long-term patency should not be an issue in this patient group and portal decompression may reduce blood transfusion requirements during transplant surgery.

Clinical Trials as Topic↗
PubMed1994

Rim calcification in primary liver cell carcinoma mimicking hydatid disease.

The case described is of a primary liver cell carcinoma (PLCC), which was initially misdiagnosed as hepatic hydatid disease. The computed tomographic appearances of hepatic hydatid disease are often characteristic although not specific. When supported by the clinical findings, however, they will probably not be confused with other liver masses. In this case the presence of peripheral rim calcification, commonly seen in hydatid disease but which has not been previously noted in PLCC, lead to an erroneous diagnosis.

Calcinosis↗
PubMed1994

Selective radionuclide localisation in primary liver tumours (pilot study).

The therapeutic potential of 131I-Lipiodol was investigated in 8 patients with cholangiocarcinoma (CCA) and 15 patients with hepatocellular carcinoma (HCC). Patients received one or two doses of 131I-Lipiodol via hepatic arterial injection. The mean total administered activity was 668 (SD 325) MBq in CCA and 953 (SD 477) MBq in HCC. One patient with CCA retained 131I-Lipiodol. The cumulative radiation dose was 9.6 Gy to tumour, 6.4 Gy to liver and 1.5 Gy to lung. The patient remained asymptomatic with no evidence of tumour 30 months from the start of treatment, whereas the remaining 7 patients exhibited tumour progression. The mean survival in CCA was 11.6 (SD 14.5) months. All 15 patients with HCC retained 131I with tumour: liver ratios of up to 30:1. The mean cumulative radiation dose was 34.7 (SD 32.4) Gy to tumour, 3.3 (SD 1.5) Gy to liver and 4.4 (SD 2.3) Gy to lung. The mean dose per administered activity was 3.8 (SD 4.1) cGy/MBq. Partial response (reduction in tumour size > 50%) was observed in 6 patients (40%). The mean survival was 7.1 (SD 6.0) months. 131I-Lipiodol can deliver highly selective internal irradiation to foci of HCC with evidence of objective response and may be the treatment of choice for patients with cirrhosis and a small tumour.

Adult↗
PubMed1994

The radiology of sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. The role of radiology is not only to support the clinical diagnosis but also as an adjunct to monitor the course and progression of the disease. The cornerstone of radiological assessment is the plain radiograph, however newer imaging methods are producing more information in relation to the anatomical distribution and pathophysiology which may ultimately have a profound effect on the management of this protean disease.

Female↗
PubMed1993

Peptide-induced changes in class I heavy chains alter allorecognition.

Class I molecules of the MHC are intimately involved in the development and function of CD8+ T cells. Small peptides, derived from endogenous proteins, bind within the Ag binding groove created by the beta-pleated sheets and alpha-helices of the alpha 1 and alpha 2 domains of the class I molecule. This peptide-MHC complex has been shown to influence allorecognition by CD8+ T cells. However, the precise role of peptide in alloantigen recognition remains unclear. We have previously shown that conformational changes induced in the class I molecules can be identified as specific alterations in serologic epitopes. These results suggested that alloreactive T cells may detect structural changes in MHC based on the nature of the peptide binding to the class I protein. Here, we have shown that, in at least some instances, alloreactivity may not depend on the recognition of a precise self-peptide but on an epitope on the class I molecule influenced by the peptide. The nature of specific peptides expressed by class I-bearing cells may, therefore, have a dramatic effect on T cell development, self-tolerance, and alloreactivity.

Amino Acid Sequence↗
PubMed1993

Superior mesenteric artery blood flow in man measured with intra-arterial Doppler catheters: effect of octreotide.

Changes in splanchnic blood flow are important in the pathogenesis of portal hypertension, but research in this area is hampered by the difficulty in measuring splanchnic arterial blood flow in man. We therefore investigated the use of intra-arterial Doppler catheters in measuring superior mesenteric artery blood flow in man and assessed the effect of intravenous octreotide on superior mesenteric artery blood flow in a placebo-controlled double-blind study. Nine experiments were performed in a flow model using vessels with internal diameters of 6.5, 4.5 and 3.0 mm, with flow rates ranging from 50 to 700 ml/min. In this model the catheters gave instantaneous, reproducible measurements of blood flow in vessels of 6.5 mm internal diameter with a mean error ranging from +5.3% to +36.4%, compared to electromagnetic flowmetry, but were less accurate in smaller vessels. When used in patients, the catheters provided stable, reproducible measurements of superior mesenteric blood flow, in 16 out of 20 patients studied. In a double-blind placebo-controlled study, including 12 subjects, superior mesenteric artery blood flow was significantly reduced in patients receiving octreotide. We suggest that measurement of splanchnic arterial blood flow using intra-arterial Doppler catheters may be a useful additional investigation in the assessment of splanchnic vascular pathophysiology and pharmacology in man.

Adenoma↗
PubMed1993

A comparison of transjugular and plugged-percutaneous liver biopsy in patients with impaired coagulation.

Patients with liver disease frequently have impaired blood coagulation. The optimal method for liver biopsy in this situation is not established. To investigate this issue we randomised 117 patients with impaired blood coagulation, in whom liver biopsy was required, to receive either transjugular or plugged-percutaneous biopsy. Seventeen patients were excluded prior to biopsy and a protocol biopsy was performed in 100 patients (44 transjugular, 56 plugged-percutaneous). Liver tissue was obtained in 97 (42 transjugular, 55 plugged-percutaneous). Plugged-percutaneous liver biopsy was quicker and easier than transjugular liver biopsy and the biopsies obtained were significantly larger (12 +/- 5 mm vs. 6 +/- 4 mm; p < 0.001). However, 2 of 56 (3.5%) patients who received plugged-percutaneous biopsy had haemorrhage which required transfusion, while none of the 44 patients who received transjugular biopsy had haemorrhage (not significant). Both methods of liver biopsy were associated with a high success rate and a low incidence of complications. Plugged-percutaneous liver biopsy provides larger biopsies but may be associated with an increased risk of haemorrhage.

Biopsy↗
PubMed1993

Does a vegetarian diet control Wilson's disease?

The literature indicates that copper (Cu) is less bioavailable from a vegetarian as compared to mixed diet. Further, several groups, including ours, find rather marginal average Cu intake in the typical American diet. For example, our data indicate that Wilson's disease patients on a typical American diet ingest only about 25% more Cu than is required. This suggests that a vegetarian diet, if it reduced bioavailability by about 25% or more, would be an adequate maintenance therapy for Wilson's disease. Observations in two of our patients, who were on lactovegetarian diets by choice, and who were almost totally noncompliant with anti-Cu therapy, support this view. These observations suggest that vegetarian diets may be a management tool for Wilson's disease. They also further emphasize the marginal Cu intake in American diets, and suggest that some seemingly healthy people, particularly vegetarians, may be at risk for mild Cu deficiency.

Acetates↗
PubMed1993

Trends in antimicrobial utilization at a tertiary teaching hospital during a 15-year period (1978-1992).

BACKGROUND: Antimicrobials are a major part of hospital pharmacy budgets and must be considered in resource planning and spending projections. Logically, trends in antimicrobial usage should be linked to trends in resistant pathogens. OBJECTIVE: To examine long-term trends in antimicrobial use over a 15-year period (1978 to 1992) and contrast them with changes in pathogens causing nosocomial bacteremia. SETTING: A 900-bed, tertiary care teaching hospital. METHODS: Pharmacy records were reviewed to identify parenteral antimicrobial agents administered to adult inpatients. Results were expressed in average daily adult doses per 1,000 patient days. RESULTS: Chloramphenicol use decreased, while use of penicillin G, antistaphylococcal penicillins, first-generation cephalosporins, and aminoglycosides remained relatively stable. In contrast, there was a sharp increase in the use of second- and third-generation cephalosporins (7-fold and 6.5-fold increase, respectively), vancomycin (161-fold increase), metronidazole (32-fold increase) and amphotericin B (35-fold increase). The proportion of nosocomial bacteremias due to methicillin-resistant gram-positive bacteria rose, but gentamicin resistance in gram-negatives remained at low levels. During the past 14 years, the percentage of patients receiving at least one parenteral antimicrobial rose from 23% to 44%. Among patients receiving antimicrobials, the average number of different agents used per patient increased from 1.8 to 2.1. CONCLUSIONS: If newer agents were available, use of older agents usually declined. If newer alternatives were not available, use of older agents rose sharply. The increased use of antimicrobials in adults was related to the expanded proportion of patients receiving these agents.

Adult↗
PubMed1993

Societal norms and risk-taking behaviour: inter-cultural comparisons of casualties and alcohol consumption.

Inter-cultural comparisons point to associations among aggregate rates of consumption and certain alcohol-related complications, particularly chronic effects, such as liver cirrhosis mortality. Accidental, poisoning and violent incidents are not considered to have as strong an association with societal drinking patterns, since situational, environmental and interactional features contributing to the incident are likely to play a strong role relative to the volume of alcohol consumed. This paper compares annual alcohol consumption rates and male and female mortality rates for liver cirrhosis and 12 main accidental/violent causes of death for Canada, Finland, France, the Netherlands, Switzerland, and the US between 1965 and 1987. Using filtering techniques to account for autocorrelation, conservative measures of association were developed. The results indicate that while statistically significant correlations were evident with regard to liver cirrhosis and suicide in some jurisdictions, in most instances the comparisons were not significant. Further work is suggested with regard to the following: utilizing more refined approaches to examine the covariations of casualties and alcohol consumption, and studies combining aggregate level investigations with those focusing at the group or interactional level--in particular those specifying and examining societal norms and risk-taking at the group and sub-population levels.

Accidents↗