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Biomedical subjects

J Vermylen

Publications and source records attributed to J Vermylen.

At least 181 records · Page 10Linked to original sources

Intra-arterial injection of papaverine in the decision of balloon dilatation of the iliac arteries.

In patients with low degree stenoses of the iliofemoral arteries, a discrepancy can occur between the clinical complaints and the severity of the angiographic lesions. Intra-arterial injection of 20 mg of papaverine by mimicking the need for augmented blood supply during exercise will help to objectify the clinical importance of a stenosis. Therefore, it will be of help in the decision of balloon dilatation of low-degree lesions.

Catheterization↗

Campylobacter fetus subspecies fetus infection of an abdominal aneurysm.

We report a case of aneurysm of the abdominal aorta with spontaneous rupture in a 64-year-old man with emphysema and chronic alcoholism. Campylobacter fetus subspecies fetus was repeatedly recovered from the blood and from specimens of the excised aneurysm. The patient died in spite of early diagnosis, intravenous erythromycin and surgical intervention. The bacteriology and epidemiology of campylobacteriosis in man is briefly discussed and eight other published cases of aneurysm, infected with the same organism, are tabulated. C. fetus ssp. fetus should be added to the list of bacteria having a tropism for vascular endothelium.

Aorta, Abdominal↗

Thrombosis in particular organ veins.

Renal vein thrombosis in early infancy is a complication of dehydration and prolonged hypotension. The onset is usually acute and the most common clinical signs are uni- or bilateral frank masses, hematuria, proteinuria and thrombocytopenia. In most cases, with conservative management, the late outcome is favorable. In the adult, renal vein thrombosis is often a silent complication of the nephrotic syndrome, the hypercoagulability of which may be an important factor in the pathogenesis of the thrombosis. Clinically, the presentation of a sudden complete occlusion is that of severe abdominal and lumbar pain with hematuria and loss of function of the kidney that suffers hemorrhagic infarction. Physical examination often reveals an enlarged kidney. With gradual occlusion, renal function is preserved. The initial diagnostic approach is with ultrasound studies and computed tomography; definitive diagnosis is established by renal venography or by selective renal arteriography. In general, a conservative approach including the use of anticoagulant treatment is preferred to surgical intervention. Priapism is a persistent painful penile erection due to ischemic or non-ischemic causes; therapeutic intracavernosal injection of papaverine is becoming the most common cause. In early and mild stages, aspiration of blood from the corpora cavernosa supplemented with intracavernosal irrigation with alpha-stimulating agents is the procedure of first choice; in late and severe ischemia, a shunt procedure may become necessary. Hepatic vein thrombosis occurs in association with a number of conditions considered predisposing factors including the use of oral contraceptives. The clinical picture may be that of an acute illness with abdominal pain, hepatomegaly, ascites and hepatic failure as well as early death. More often, the onset is insidious with slowly developing ascites and wasting. For the diagnosis, hepatic scintigraphy may be helpful but, at present, ultrasonography, computed tomography and magnetic resonance scanning are procedures of choice. There is, as yet, no adequate treatment. A fatal outcome may be prevented by surgical decompression of the congested liver and, in recent years, liver transplantation has been employed. Portal vein thrombosis, in children, is usually considered a complication of umbilical sepsis or a result of a congenital abnormality of the portal vein. In adults, the most frequent causes are hepatic cirrhosis and neoplasia. Clinically, there may be a sudden appearance of ascites with resolution in a symptom-free interval until the onset of other features of portal hypertension occur. Currently, ultrasound real-time imaging supplemented with Doppler capability, computed tomography and magnetic resonance scanning provide the necessary diagnostic information. Variceal hemorrhage is often the first major complication requiring treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Budd-Chiari Syndrome↗

The platelet insulin receptor: detection, partial characterization, and search for a function.

A direct demonstration and partial characterization of the insulin receptor on human platelets was obtained by immunoprecipitation with a monoclonal antibody against the human insulin receptor. Two subunits were detected, one with a MW of 95 KD, which dose-dependently was phosphorylated upon challenge of the platelets with insulin and another with a MW of 69 KD that does not become phosphorylated. Retention on wheat germ agglutinin indicates that at least part of the receptor protein is glycosylated. In a search for cellular effects provoked by insulin on platelets, no changes could be detected in cAMP formation or degradation, inositol phosphate formation or phosphorylation of proteins other than the receptor itself.

Adenylyl Cyclases↗

Heparin plus dipyridamole in childhood hemolytic-uremic syndrome: a prospective, randomized study.

From 1976 to 1985, a total of 58 infants and children with the hemolytic-uremic syndrome were randomly assigned to treatment either with heparin and dipyridamole or with supportive management only. In the treatment group, two patients died in the early weeks of the disease. Analysis of clinical and laboratory data showed no significant difference between either group of patients as to the evolution of their illness except for a significantly higher incidence of anuria and a significantly faster recovery from hypertension in the treated group. Renal biopsy studies showed no differences between the two groups in terms of incidence and severity of the histologic lesions. The long-term data on blood pressure and creatinine clearance values in the survivors were similar in both groups. This study indicates that treatment with heparin and dipyridamole has no benefit over symptomatic therapy alone in the typical form of childhood hemolytic-uremic syndrome.

Adolescent↗

Effectiveness and tolerability of CV-3988, a selective PAF antagonist, after intravenous administration to man.

1. The efficacy and tolerability of CV-3988, a selective PAF antagonist with structural analogies with PAF, were studied after intravenous infusion in man. 2. The compound, in doses from 750 to 2,000 micrograms kg-1, significantly reduced platelet sensitivity for PAF. The threshold aggregating concentration (TAC) of PAF, expressed in % of the mean predosing value, increased in a dose dependent manner reaching 356 +/- 162% of the basal TAC at the end and 266 +/- 123% of the basal TAC 4 h after infusion of the highest dose. The TAC of PAF returned to the basal value within 24 h after the end of the infusion. 3. CV-3988 did not cause major side effects nor changes in blood pressure, pulse and respiratory rate. However, small but clinically insignificant changes in plasma haemoglobin and serum haptoglobin were seen at the end and 4 h after the end of the infusion, indicating a slight haemolysis. 4. Our results indicate that, when adequate infusion volumes and infusion rates are used, CV-3988 can safely be administered to man and should be useful in elucidating the role of PAF in disease.

Adult↗

Congenital macrothrombocytopenia, leucocyte inclusions, deafness and proteinuria: functional and electron microscopic observations on platelets and megakaryocytes.

We report a patient with a variant of Alport's syndrome: macrothrombocytopenia, leucocyte inclusions, deafness and proteinuria. Ultrastructural studies revealed giant spheroid platelets with a high density of organelles and a disorganized microtubular system. In addition, Fechtner inclusions were observed in neutrophils of the patient and her mother. In platelet rich plasma platelets aggregated normally for the low platelet number, although no shape change was visible. Platelet studies in whole blood using impedance aggregometry gave supernormal aggregation curves; this is not in agreement with the abnormally long bleeding time, showing the limited usefulness of this technique in patients with such large platelets. The megakaryocytes (MK) showed two different distribution patterns of the demarcation membrane system (DMS), which may explain the production of few large platelets. The formation of platelets occurred by fragmentation of the granular zone of the MKs, which seemed to be followed by expulsion of platelets through openings of the peripheral zone. The involvement of cytoskeletal structures in the organization of the DMS and the expulsion of platelets is discussed.

Adult↗

Adenylate cyclase activation determines the effect of thromboxane synthase inhibitors on platelet aggregation in vitro. Comparison of platelets from responders and nonresponders.

The effect of five thromboxane-synthase inhibitors (UK-37248, UK-38485, UK-34787, CGS-13080 and OKY-1581) on arachidonic acid-induced platelet aggregation has been studied in vitro on platelets from 30 different healthy volunteers. The sensitivity of their platelets to adenylate cyclase stimulators or to dibutyryl cyclic AMP has been evaluated contemporarily. In 4 of the 30 volunteers tested no inhibition of platelet aggregation was obtained with any of the five thromboxane synthase inhibitors: these subjects were defined nonresponders; in 13 volunteers inhibition was observed with all the five drugs (responders). Significantly higher amounts of prostaglandin (PG)D2, prostacyclin and adenosine were required to suppress arachidonic acid-induced aggregation of platelets from nonresponders in vitro. No differences were instead observed between responders and nonresponders concerning platelet sensitivity to forskolin or dibutyryl cyclic AMP. The cyclic AMP rise obtained with exogenous prostacyclin was lower in platelets from nonresponders than in those from responders. PGE2 added in vitro to platelets from nonresponders exerted always a proaggregatory effect whereas this PG was antiaggregatory in most of the nonresponders. PGE2 blunted the antiaggregatory activity of PGD2 and limited the cyclic AMP increase induced by PGD2 in all the subjects tested. These data indicate that the unequal functional response of platelets from different subjects to thromboxane synthase inhibition depends essentially on adenylate cyclase function: a relative insensitivity of this enzyme to activating stimuli and the accumulation of substances (PGE2, PG endoperoxides, etc.) reducing the activity of adenylate cyclase may lead to continued platelet activation in some subjects despite the suppression of the synthesis of thromboxane A2.

Adenylyl Cyclases↗

Thrombo-embolic complication after streptokinase therapy of pulmonary emboli.

A 58-year old patient is reported who developed an ischaemic cerebrovascular accident 22 hours after successful thrombolysis with streptokinase for life-threatening pulmonary emboli. Despite effective thrombolysis, the plasma fibrinogen level rose during streptokinase administration and reached extremely high values 72 hours later. The mechanism of this unusual early and extreme rise of fibrinogen levels is unclear but it probably played a role in the pathogenesis of the cerebrovascular accident.

Coronary Artery Bypass↗

Percutaneous transluminal angioplasty of the subclavian artery: early and late results.

Percutaneous transluminal angioplasty of 23 subclavian arteries was attempted in 22 patients. Dilatation was successful in 3 of 4 right subclavian artery stenoses and 18 of 19 left subclavian artery stenoses. The primary clinical indication was posterior fossa ischemia in 11 patients, upper limb ischemia in 14 and both symptoms in 6. In 2 patients, dilatation of an asymptomatic high-degree left subclavian artery stenosis was performed before coronary artery bypass surgery using the internal mammary artery. Eighteen patients on follow-up over 6-60 months (mean 25 months) are free of symptoms with equivalent systolic blood pressures in both arms. Three patients showed relapse of the stenosis after 8, 12, and 15 months; one was successfully treated with a second dilatation. Complications consisted of an occlusion at the left axillary artery puncture site and a distal embolus to a finger artery. Percutaneous transluminal angioplasty appears safe and efficient therapy for subclavian artery stenoses with excellent short- and long-term results.

Aged↗

Local thrombolysis in femoropopliteal occlusion: early and late results.

The early and late results of local thrombolysis with low-dose streptokinase followed by balloon dilatation in 64 patients with an occluded femoropopliteal artery are reviewed. The primary success rate was 77% for the native arteries; it was higher (80%) for short (less than 10 cm) as compared with long occlusion (40%) and for patients with claudication as compared with those with advanced ischemia (89% versus 48%). Eleven complications were observed in 10 patients, most frequently a local hematoma at the puncture site. Ascending thrombosis and absence of lysis or incomplete lysis were the main reasons for failure. The cumulative patency rate after 1 and 2 years follow-up was 87% and 82%, respectively.

Angioplasty, Balloon↗