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Biomedical subjects

C Vermylen

Publications and source records attributed to C Vermylen.

At least 91 records · Page 5Linked to original sources
PubMed1986

A variant of the congenital dyserythropoietic anaemia type II with structural abnormalities in the granulocytic series.

Typical features of congenital dyserythropoietic anaemia (CDA) were found in a 13-year-old girl admitted for chronic recurrent multifocal osteomyelitis. The findings on light microscopy were in agreement with those described in CDA type II, whereas on electron microscopy, the ultrastructure findings were compatible with both types I and II. The acidified serum lysis test (Ham test) performed with eight normal sera was negative. The patient's red blood cells showed an increased agglutinability with anti-i antibodies. Morphological changes were also shown in the mature neutrophilic granulocyte suggesting that the primary disorder exists already in the multipotent stem cell.

Adolescent↗
PubMed1986

Transfer factor therapy in multiple sclerosis: a three-year prospective double-blind clinical trial.

One hundred five patients with MS were divided into three groups matched for age, sex, and disability, and treated with either placebo, transfer factor prepared from leukocytes of random donors, or transfer factor from leukocytes of family members living with the patients. There were no differences in the three treatment groups for changes in disability, activities of daily living, or evoked potentials. Eighteen months of transfer factor therapy had no effect on gamma-interferon production or natural killer cell activities.

Activities of Daily Living↗
PubMed1985

Sjögren's syndrome in a child.

Sjögren's syndrome is a relatively uncommon condition in the paediatric age group. The youngest child reported thus far was a 5-year-old girl. This article reports the case of a 2-year-old girl admitted for recurrent infections of the respiratory tract with diffuse pulmonary interstitial infiltrations and a progressive swelling of the parotid glands. The clinical features and the results of laboratory investigations, including parotid and hepatic biopsies, chest X-rays and sialography helped to establish the diagnosis of Sjögren's syndrome. Clinical, immunological and genetic characteristics of Sjögren's syndrome are reviewed.

Biopsy↗
PubMed1985

Immunoglobulin G antibodies to lymphadenopathy-associated virus in differently treated French and Belgian hemophiliacs.

Immunoglobulin G antibodies to lymphadenopathy-associated virus have been detected in two groups of French hemophiliacs and in one group of Belgian hemophiliacs, whose mode of treatment differed. Seropositivity was more frequent (58.9%) in patients heavily transfused with blood products of French and foreign origin than in less frequently transfused persons (10.3%). The Belgian group, treated only with local products, showed the lowest frequency of seropositivity (3.4%). In healthy French controls, 1 of 330 had antibody to the virus. The results indicate transmission of lymphadenopathy-associated virus via blood-derived products.

Antibodies, Viral↗
PubMed1984

Immunological alterations in haemophiliacs treated with lyophilized Factor VIII cryoprecipitate from volunteer donors.

We studied immune function in Belgian haemophiliacs treated with Factor VIII from volunteer donors. No patient had clinical evidence of immune deficiency. We found a decrease in T-helper cells (p less than 0.0005), in the ratio of T-helper over T-cytotoxic/suppressor cells (1.72 +/- 0.47 versus 2.24 +/- 0.82 in controls, p less than 0.005) and in lymphocyte responsiveness to mitogens (p less than 0.05). These findings could not be linked to the amount of F VIII received over the last year, the time since last F VIII administration, circulating immune complexes (54% positive patients, 7% positive controls, p less than 0.005), increased ALT levels, antibodies to cytomegalo -virus (85% of the patients, 45% of the controls, p less than 0.005), antibodies to Epstein-Barr virus, nor to the presence of HLA-DR 5 which was found in 56% of the haemophiliacs (20% of the overall Belgian population, p less than 0.005). Either F VIII induces long lasting immunological alterations unrelated to AIDS, or haemophilia is itself associated with such changes.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Effect of lymphoplasmapheresis on clinical indices and T cell subsets in rheumatoid arthritis. A double-blind controlled study.

The effects of lymphoplasmapheresis on immunologic indices, including T cell subsets, and on clinical parameters of rheumatoid arthritis were evaluated in a controlled double-blind trial. Twenty patients were randomized to receive either 6 lymphoplasmapheresis sessions or a seemingly identical control procedure over a 3-week period. Lymphoplasmapheresis produced significant reduction in serum levels of total lymphocytes, erythrocyte sedimentation rate, C-reactive protein, and IgG. These serologic measures returned to baseline 5 weeks after lymphoplasmapheresis. No change in the imbalance of T cell subsets (increased helper/suppressor ratio) was observed. No changes in the serologic measures, except IgA, were observed in the control group. An improvement in some of the clinical parameters was observed in both the lymphoplasmapheresis and control groups. A rebound above baseline values for several parameters was observed in both the lymphoplasmapheresis and the sham apheresis groups.

Adult↗
PubMed1983

The wandering spleen.

The article presents two cases of wandering spleen in the pediatric age group. Both patients were admitted for abdominal pain. In one, the onset was sudden and, on physical examination, a mass was felt in the left hypochondrium. In the other, it was the second episode and a firm mid-abdominal mass was found. The wandering spleen is a specific clinical syndrome which should be taken into account when an abdominal tumor is found. Ultrasonography and isotopic scan are very useful diagnostic tools The wandering spleen is caused by the absence of the splenorenal ligament which allows increased mobility of the splenic hilum. Both children underwent a splenectomy and made an uneventful recovery.

Abdominal Neoplasms↗
PubMed1983

Interferon production and natural killer (NK) activity in leukocyte cultures from multiple sclerosis patients.

Peripheral blood leukocyte (PBL) cultures from only 37% of MS patients produced detectable HuIFN-gamma in response to ConA as opposed to 85% of the cultures derived from normal blood donors. However, the yields in patient-derived cultures that were responsive, were not lower than those in cultures from controls. Production of HuIFN-alpha after stimulation with Sendai virus was not aberrant in cells taken from MS patients. The difference in HuIFN-gamma response rate between MS and normal donor-derived cells was more pronounced when DR2+ carriers were compared amongst each other than when DR2-k carriers were compared. Among the MS patients, the failure of PBLs to produce HuIFN-gamma in response to ConA was not correlated with age, sex, disease duration and type of disease. However, positive correlations were found with current disability indices and past disease progression rates. Unstimulated NK-activities of MS patient-derived PBLs were not different from those of normal donor-derived cells. the degree of augmentation of the activity by stimulation with ConA and interferon-alpha was also normal. Within the MS patients group, but not in the control group, there was a trend for DR2+ carriers to have lower spontaneous and stimulated NK-activities than DR2- individuals.

Adult↗
PubMed1982

Activation of natural cytotoxicity of human peripheral blood mononuclear cells by interferon: a kinetic study and comparison of different interferon types.

Overnight incubation of human peripheral blood mononuclear (PBMN) cells with leucocyte interferon (leucocyte IFN) resulted in a 2-5-fold increase in natural cytotoxicity (NC) against the erythroleukaemic cell line K562. Fibroblast IFN, purified to homogeneity by zinc-chelate chromatography, stimulated NC to the same extent, while partially purified immune IFN was about twice as active. Upon gel filtration of immune IFN, NC stimulating and antiviral activity co-eluted. Treatment of PBMN cells with ammonium chloride buffer (AmCl) abrogated NC nearly completely. Incubation of AmCl-treated cells with leucocyte IFN resulted in a partial regeneration of NC. Kinetic studies revealed that this regeneration required only short exposure to IFN followed by a longer incubation period. The data are interpreted as indicating that in the process of NC activation IFN mainly acts as a trigger for precursor cells to mature into cells with NC.

Ammonium Chloride↗
PubMed1981

Interferon induced in human leukocytes by concanavalin A: isolation and characterization of gamma- and beta-type components.

Interferon (IFN) was induced in suspensions of fresh human leukocytes by incubation with concanavalin A (Con A). The crude supernatant was concentrated and partially purified by adsorption to silicic acid and elution with an ethylene glycol (EG)-containing buffer. Th EG eluate was shown to contain two antivirally active components (tentatively called 22K), separable from each other by gel filtration. The 45K component was strictly species specific, relatively sensitive to acid (pH 2) and poorly neutralized by anti-human IFN-beta (HuIFN-beta) antibody. In all probability, it predominantly contained (a) molecular variant(s) of human gamma-type IFN (HuIFN-gamma ). The 22K component was acid resistant and serologically indistinguishable from HuIFN-beta prepared from fibroblasts. However, in contrast to the latter, it had little activity on bovine kidney cells and no activity on human HEp-2 and monkey Vero cells. A preparation with the same properties was obtained by substituting glycine buffer (pH 2) for EG in the elution of Con A-induced IFN from silicic acid. This IFN failed to adsorb to a zinc chelate column, while HuIFN-beta from fibroblasts can easily be purified by affinity chromatography on this type of column. It was concluded that the Con A-induced IFN contained an acid-resistant component of apparent molecular weight 22000 serologically related to classical HuIFN-beta but differing by certain physicochemical and biological criteria.

Animals↗
PubMed1980

Interferon induced in human leukocytes by mitogens: production, partial purification and characterization.

Interferon was induced in leukocyte suspensions from human buffy coats by exposure to phytohemagglutinin P, concanavalin A (Con A) and staphylococcal enterotoxin A, under a variety of cell culture conditions. Con A was found to rapidly (within 12 h) induce high yields of antiviral activity (1.5 units/1000 cells). Lesser yields were obtained with the other two mitogens studied. The interferon was partially purified to a spec. act. around 10(5.3) units/mg protein, by batch adsorption on controlled-pore glass (CPG) beads and desorption by ethylene glycol. This material was characterized as containing mainly gamma-type interferon. Specifically on gel filtration, a fraction of 45000 daltons was obtained which could account for virtually all antiviral activity present in the starting material. Furthermore, the ethylene glycol-eluted antiviral activity was acid-labile, serologically distinct from alpha and beta-type interferon and strictly species-specific (no activity detectable on any of the available cell species sensitive to alpha and beta-type interferon). The crude culture supernatant also contained some antiviral activity which resembled beta-type interferon in that it adsorbed to CPG, could be desorbed by pH 2 buffer, was acid-resistant and could be neutralized by a specific anti-fibroblast interferon antiserum. The CPG/ethylene glycol-purified gamma-type interefron preparation was found to inhibit the growth of certain lymphoblastoid cells (Daudi and Molt-4). It also potentiated natural killer activity of fresh donor lymphocytes. In both respects, the gamma-type interferon preparation was not significantly more active than preparations of alpha and beta-interferon of similar antiviral potency.

Chemical Phenomena↗
PubMed1980

The Belgian plasmapheresis programme.

In Belgium 6000 non-remunerated donors regularly give plasma by the double plasmapheresis technique. The donation frequency is once every two weeks. Thus 75 000-80 000 liters of plasma are collected annually. This figure represents 7 500-8 000 liters of plasmapheresis plasma/10(6) inhabitants. Furthermore 5000 liters of plasma/10(6) inhabitants are recovered from whole blood (60% utilization of erythrocytes-concentrates). The 13 000 liters of plasma/10(6) inhabitants allow the country to cover all the national needs of albumin, coagulation factors and immunoglobulins. The programme is fully described and presented as a unique model of national self-sufficiency avoiding red cells wastage, and being entirely based on non-remunerated donors.

Belgium↗
PubMed1976

Massive feto-maternal hemorrhage as a cause of perinatal mortality and morbidity.

11 cases of massive feto-maternal hemorrhage (FMH) detected at the Leuven Blood Transfusion Center are described. Based on these case reports, a review is given of the various theoretical and practical problems related to this complication, e.g. the relative frequency of perinatal mortality and morbidity due to massive FMH, the causes and pathogenesis, the symptoms and diagnosis, the clinical varieties, and the pathophysiology as seen in the fetus and newborn. Finally, the indications for looking for large FMHs are described, and the therapeutic implications when this complication is discovered.

Adult↗
PubMed1975

Hepatitis-B immunoglobulin in prevention of HBs antigenaemia in haemodialysis patients.

In a double-blind study, hepatitis-B immunoglobulin significantly protected patients in a haemodialysis unit against the development of HBs antigenaemia, compared to control patients receiving normal human immunoglobulin (p less than 0-01). Injections were given at the beginning and after 6 months, and observations extended over 16 months. Analysis of antiHBc and anti-HBs antibodies suggested that neutralisation of the virus inoculum, as well as modification of infection, may be implicated in the prevention of HBs antigenaemia.

Adult↗