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Biomedical subjects

A van Breda

Publications and source records attributed to A van Breda.

At least 19 recordsLinked to original sources
PubMed2000

Detection and quantitation of human cytomegalovirus DNA in faeces.

The development and performance of a robust and sensitive PCR assay are described for the detection and quantitation of human cytomegalovirus DNA in human faecal specimens. In this assay, CMV DNA was purified by an optimised DNA extraction protocol together with internal control DNA that monitored both DNA extraction efficiency and PCR efficiency. The lower detection limit of the assay was reached at about 100 CMV particles per ml of (25-50%) faecal suspension. CMV DNA could be quantitated in the range of about 300-100000 molecules per ml of faecal suspension. CMV DNA loads obtained in clinical faeces specimens suggest that the assay can be used to monitor the efficacy of antiviral treatment. Reconstruction experiments that monitored the efficiency of DNA extraction of a preliminary DNA extraction protocol, showed low DNA yields for 9% of the specimens (n = 78). In all cases, low DNA extraction efficiency seemed to be due to a component present in faeces that prevented DNA binding to silica particles, presumably by competitive binding. Choosing the right ratio of silica particles to faeces specimen solved this problem. Similarly, reconstruction experiments showed that the strong PCR inhibition that was observed in 8% of the specimens could effectively be relieved by the inclusion of alpha-casein in the PCR mixtures.

Adult↗
PubMed1993

Angioplasty, bypass surgery, and amputation for lower extremity peripheral arterial disease in Maryland: a closer look.

Tunis and colleagues attempted to assess the effect of peripheral angioplasty in a large population with descriptive epidemiologic methods. Their study suffered from a vague statement of purpose, inappropriate and inadequate outcome measures, undetermined differences in prevalence of peripheral vascular disease and prevalence of risk factors for bypass/amputation in 1989 versus 1979, no differentiation between levels of amputation or between primary and secondary amputation, lack of a unique ICD-9-CM code indicating angioplasty for peripheral vascular disease of the lower extremities, lack of unique patient identifiers, a mistaken perception of the adoption of angioplasty as "widespread" in Maryland, and the assumption of uniform coding accuracy throughout the period of study. We conclude that the study design of Tunis et al was inadequate to determine the beneficial effects of angioplasty or bypass surgery in the treatment of peripheral vascular disease. Moreover, the conclusion by Coffman (2) that "invasive procedures are indicated only for the severely ischemic limb" is completely unsupported by the study data. Physicians should not attempt to apply the results of the study by Tunis et al to individual case situations. It should be further appreciated that the study findings do not provide an adequate basis for policy-making decisions. It is clear that important clinical questions concerning the roles of angioplasty, bypass, and amputation should be answered with more definitive studies.

Algorithms↗
PubMed1992

Current status and extended applications of intravascular stents.

The introduction of several novel techniques and mechanical devices to interventional radiology has expanded the range of therapies for a variety of medical disorders. Intravascular metallic stents have received widespread acclaim and may possess the most potential of all the newest devices available to the interventionist. The addition of metallic stents to the percutaneous therapeutic arsenal provides the interventionist with a device that can resist the elastic recoil of a stenotic vessel or support a newly created vascular tract. Peripheral artery metallic stent placement holds great promise for the treatment of selected patients; other applications of stents, including transjugular intrahepatic portosystemic stent shunts are likely to have a great impact in patient management. We review the techniques, appropriate indications, and recent clinical results of vascular stents for percutaneous intervention and therapy.

Angiography↗
PubMed1991

Relative cost-effectiveness of urokinase versus streptokinase in the treatment of peripheral vascular disease.

A retrospective case control study of 271 patients with peripheral arterial occlusion (PAO) who were treated with urokinase (UK) or streptokinase (SK) at two clinical centers, Alexandria Hospital and the Cleveland Clinic, was performed. The primary objective was to evaluate the relative cost-effectiveness of thrombolytic therapy with SK or UK in the treatment of PAO. A secondary objective was to identify factors to which any major differences in cost-effectiveness between these two agents could be attributed. All available patients hospitalized at the two centers for PAO who underwent treatment with UK or SK from 1979 to 1987 were included. Therapeutic success was defined as complete clot lysis or partial clot lysis judged to be of clinical benefit by the attending physician, with no major bleeding or other serious complication such as renal insufficiency or death. Success rates with UK were higher than those with SK at both centers. The advantage with UK could not be explained by baseline patient characteristics. A cost-effectiveness ratio--dollars expended on medical care for up to 2 days after infusion per therapeutic success--was calculated for each of the treatments. Overall, at Alexandria Hospital, $10,700 was expended per therapeutic success with UK therapy compared with $14,500 for successful SK therapy. At the Cleveland Clinic, differences were more pronounced, with $15,000 expended per therapeutic success for UK treatment and $46,400 per success for SK treatment. Support for preference of UK therapy is provided by the consistency of results in favor of UK cost-effectiveness for subgroups of patients that were determined according to site of occlusion and type of therapy following lysis. The cost-effectiveness of UK was not dependent on the definition of patient costs associated with PAO.

Aged↗
PubMed1990

Percutaneous placement of a hepatic vein stent in the treatment of Budd-Chiari syndrome.

The authors describe the first reported use, to their knowledge, of an intravascular stent to relieve hepatic vein stenosis causing the Budd-Chiari syndrome. A patient with severe stenosis of the left hepatic vein is described. Multiple balloon angioplasty procedures were performed over a period of several months and provided only transient relief of symptoms. As an alternative to surgical management, an intravascular stent was placed, with complete resolution of symptoms. Intravascular stent placement may play an important role in treatment of the Budd-Chiari syndrome.

Budd-Chiari Syndrome↗
PubMed1989

Blue toe syndrome: treatment with percutaneous atherectomy.

"Blue toe syndrome" refers to digital ischemia of the foot in the presence of palpable or Doppler audible pedal pulses. This clinical syndrome is caused by microembolization to small vessels from a proximal source. The use of percutaneous transluminal atherectomy is described in the treatment of embologenic superficial femoral artery lesions in seven patients. All seven had prompt healing of the ischemic toes, and none required surgical revascularization or amputation. One patient developed a recurrent stenosis at the atherectomy site and had a second episode of digital ischemia, which was treated by means of atherectomy with a larger device. Histologic study of atherectomy specimens suggests that emboli arise from adherent fibrinoplatelet aggregates or thrombus and less often from cholesterol-rich atheromatous plaque. Although either percutaneous transluminal angioplasty or atherectomy can be used to treat the underlying stenosis, percutaneous atherectomy offers the advantage of nonsurgical removal of embologenic material and provides material for histologic study. Percutaneous atherectomy is an effective method of treating embologenic superficial femoral stenoses in patients with ipsilateral blue toe syndrome.

Adult↗
PubMed1989

Vena caval filter splaying: potential complication of use of the titanium Greenfield filter.

Significant structural and mechanical differences exist between the titanium and stainless steel versions of the Greenfield filter (GF). The titanium GF has a longer leg length (49 mm vs 43 mm), a greater span (38.5 mm vs 28.0 mm), and a larger hook angle (41 degrees vs 23.5 degrees). In vitro tests demonstrated approximately sevenfold greater filter length shortening (a measure of filter splaying) for the titanium GF in response to a given applied load. These differences resulted in marked filter splaying and inferior vena cava (IVC) perforation in three patients in whom a titanium GF had been inserted. The aorta was penetrated by a filter leg in one patient, and abdominal or back pain was present in all three patients. In vitro tests involving thrombosis within a latex balloon revealed that the titanium GF, but not the stainless steel GF, remained splayed even in the face of clot retraction. Design modifications, possibly using shorter, thicker filter legs and using reduced hook angles, should be made in the titanium GF to decrease the risk of filter splaying and IVC perforation before widespread use of this device.

Adult↗
PubMed1989

Type 3 procollagen peptide in bronchoalveolar lavage fluid. Poor indicator of course and prognosis in sarcoidosis.

To investigate the role of bronchoalveolar lavage type 3 procollagen peptide as a prognostic indicator in sarcoidosis, we measured type 3 procollagen N-terminal peptide levels in lavage fluids from 84 sarcoidosis patients and monitored disease progress in these patients for a period of 12 months. Lavage procollagen peptide levels were significantly elevated in sarcoidosis patients compared to control subjects (p less than 0.001). No association was observed between lavage type 3 procollagen peptide and disease severity, as assessed by lung function tests. Follow-up monitoring of patients failed to demonstrate any relationship between subsequent functional deterioration and initial lavage type 3 procollagen peptide. These results suggest that elevated lavage type 3 procollagen peptide concentrations in sarcoidosis may reflect increased type 3 collagen synthesis associated with the inflammatory process rather than signal an early event in the development of chronic disease.

Adult↗
PubMed1989

Laser angioplasty.

The current status of the use of lasers in the treatment of vascular disease, including the mechanism of laser angioplasty, is reviewed. The current clinical experience with various laser systems is discussed. Potential modifications of laser devices to improve their clinical utility are examined.

Angioplasty, Balloon↗
PubMed1988

Altered immunological reactivity in alveolar macrophages from patients with sarcoidosis.

Lung macrophages may play an important role in the pathogenesis of pulmonary sarcoidosis. In this study, the ability of pulmonary macrophages and blood monocytes from sarcoidosis patients, normal controls and disease controls to provide the accessory signal necessary for the concanavalin A-induced activation of normal blood T cells was examined. Blood monocytes from all groups supplied a significantly greater accessory signal than lung macrophages. The accessory capacity of lavage macrophages from sarcoidosis patients varied over a wide range and correlations were sought between these values and other parameters of disease activity. Whilst there was no correlation with clinical parameters, accessory function of alveolar macrophages correlated significantly with the percentage of T helper cells in bronchoalveolar lavage (BAL) fluid (p less than 0.05) and, more closely, with the T helper:T suppressor ratio in BAL fluid (p less than 0.01). This interrelationship between macrophage activity and the T cell infiltrate favours the probability that both cell types participate in the sarcoid disease process and raises the possibility that T cells of both helper and suppressor phenotypes contribute to the pathogenesis.

Adult↗
PubMed1987

Use of digital subtraction angiography for evaluation of vascular access for hemodialysis.

We used digital subtraction angiography (DSA) with conventional methods of contrast injection to evaluate 13 failing vascular accesses in 12 patients undergoing hemodialysis. DSA results were confirmed in all cases by surgical findings and/or clinical follow-up. The DSA technique is extremely flexible and rapid and requires the injection of only small amounts of dilute contrast with much less patient discomfort. DSA is an excellent alternative to film screen angiography for the evaluation of vascular access complications.

Angiography↗
PubMed1987

Urokinase versus streptokinase in local thrombolysis.

In a retrospective analysis, the efficacy of lysis, the degree of systemic thrombolytic effect, and the rate of complications during local thrombolytic therapy with either streptokinase (SK) or urokinase (UK) were compared in 47 patients. There were 24 infusions of each agent; one patient in the UK group received two infusions. The overall efficacy of lysis was better in the UK-treated group (80% vs. 63%). The UK group had a lower frequency of systemic thrombolytic effect and of bleeding complications. SK antibody titers were measured in all patients who received infusions. Patients with high titers who were treated with SK responded poorly (20% lysis); patients with low titers responded at a rate equal to that of UK-treated patients. Three patients with high titers of SK antibodies did not respond to SK, but subsequent successful lysis did occur with UK. In conclusion, UK is believed to be preferable to SK for local thrombolytic therapy due to increased efficacy of lysis and decreased rate of systemic fibrinolytic effect and bleeding complications.

Antibodies↗
PubMed1985

Impassable urethral strictures: percutaneous transvesical catheterization and balloon dilatation.

Urethral strictures that are impassable in retrograde fashion present a special problem to the urologist because they cannot be managed by standard dilatation techniques or direct-vision internal urethrotomy. Open urethroplasty is usually required. We describe a technique to catheterize the urethra in an antegrade fashion and dilate the strictures. Our study involved six patients with impassable urethral strictures that were successfully traversed and dilated. Percutaneous transvesical antegrade catheterization and balloon dilatation are beneficial for patients with bladder outlet obstruction.

Aged↗
PubMed1984

Low-dose direct fibrinolysis in peripheral vascular disease.

One hundred thirty patients underwent low-dose, catheter-directed fibrinolytic therapy for arterial and graft occlusions present for various periods of time. In 65 consecutive patients the therapeutic parameters were identical, and a careful hematologic evaluation was performed. In the subsequent 65 patients, varying doses of fibrinolytic agents were employed. Fibrinolytic therapy was found to be beneficial in a diverse group of clinical situations and in patients whose occlusions had occurred at varying lengths of time. Early study demonstrated that effective fibrinolysis can be achieved at approximately one-twentieth of the systemic level and that systemic effects could be avoided in all patients during 24-hour infusions and in many patients infused up to 96 hours. Bleeding complications occurred only in patients in whom concomitant heparinization was employed, and this was thought to be the causative factor. Therapeutic success and avoiding complications are strongly dependent on close monitoring of patients and joint decision making by the vascular surgeon and radiologist.

Arterial Occlusive Diseases↗
PubMed1984

Gastric bleeding: therapy with intraarterial vasopressin and transcatheter embolization.

Angiographic therapy to control gastric bleeding was attempted in 200 patients. One hundred ninety-four patients were treated with intraarterial vasopressin and 17 of them were also treated with transcatheter embolization. Six patients underwent primary embolization, and an additional six received intravenous vasopressin. The initial rate of bleeding control in all patients angiographically treated was 73%. When embolization was used in some of the patients who did not respond to vasopressin, the overall control rate increased to 79%. Recurrent bleeding occurred in 18%. When angiographic therapy was attempted again in the patients with recurrent hemorrhage, the bleeding was stopped in 36%. Major complications occurred in 6.5% and minor in 17.5%. Of the patients with bleeding that was angiographically controlled, 73% survived and 27% died of associated clinical conditions. Among the failures of angiographic therapy, 48% died during the same hospital admission. Intraarterial infusions of vasopressin or transcatheter embolization are useful for the control of gastric bleeding.

Adolescent↗
PubMed1984

Local thrombolysis in the treatment of arterial graft occlusions.

Nineteen patients with 20 occluded arterial bypass grafts were treated with local infusion of streptokinase. Grafts treated included four aortofemoral graft limbs, 14 femoropopliteal or femorotibial grafts, one axillofemoral graft, and one transpubic femorofemoral graft. Complete lysis of thrombus was possible in 12 patients, partial lysis in five patients, and no lysis in two patients. Thrombolytic therapy was thought to be beneficial in the management of 14 patients. In two of these 14 only thrombolysis was required to restore and maintain graft patency, and in an additional two patients angioplasty was performed after thrombolytic therapy with no subsequent therapy necessary. In three patients who were initially poor operative risks, surgery could be postponed. Thrombolysis revealed the probable cause of thrombosis in 12 patients. Complications included four bleeding episodes, two of which were significant. There were no significant embolic complications. Unsuccessful thrombolytic therapy did not result in worsening of ischemia in any patient. Local infusion of thrombolytic agents is a useful adjunct in the management of occluded bypass grafts.

Adult↗
PubMed1983

Transcatheter vessel occlusion: angiographic results versus clinical success.

A review was made of 219 transcatheter vessel occlusion procedures performed over a ten-year period for control of hemorrhage, tumor palliation, or blood supply redistribution prior to intra-arterial chemotherapy. Complete angiographic success was obtained in 85% of the procedures, with partial success in 8%; complete clinical success was achieved in 53% of patients, with partial success in 23%. The most satisfactory clinical results were obtained with hemorrhagic gastritis and pelvic trauma. Embolizations for duodenal ulcer hemorrhage and transhepatic variceal occlusion were the least clinically successful, although isobutyl-cyanoacrylate appeared to be a significant improvement in angiographic therapy for duodenal ulcer. The overall complication rate was 13%, with one third of the complications clinically silent. These results indicate that transcatheter vessel occlusion is a relatively safe and effective method for control of hemorrhage or tumor infarction.

Abdomen↗