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Biomedical subjects

J Ingerslev

Publications and source records attributed to J Ingerslev.

At least 145 records · Page 8Linked to original sources

A case of Bernard-Soulier syndrome: study of platelet glycoprotein Ib in a kindred.

The Bernard-Soulier syndrome is characterized by low platelet counts, abnormally large (giant) platelets, and impaired or absent platelet aggregation by the inducer antibiotic ristocetin. The recent discovery of the inherited biochemical defect and the deficient synthesis of platelet glycoprotein Ib (GP-Ib), has contributed greatly to the understanding of the disease. We report a case of the Bernard-Soulier syndrome presenting with bleeding from the pharynx after adenotomy. The patient and nearest family members were studied by a novel immunoperoxidase method for quantification of platelet glycoprotein Ib using a specific monoclonal antibody (AN51).

Antibodies, Monoclonal↗

Application of an enzyme-linked immunoassay for the measurement of pregnancy zone protein (PZP) in cell culture supernatants and sera.

A simple and sensitive enzyme-linked immunosorbent assay (ELISA) measuring specifically the pregnancy zone protein (PZP) was constructed. The assay range was 2.0-500 micrograms/l. The intra-assay coefficient of variation (CV%) was 5.9% at the level of 100 micrograms/l and 3.5% at 10 micrograms/l. The imprecision between runs was 4.5% at 100 micrograms/l and 7.6% at 10 micrograms/l. Recovery of the native PZP standard added to serum-free cell culture medium was 98.1 +/- 3.7% (mean +/- SD), and recovery from serum of women in late pregnancy was 96.0 +/- 9.3%. Recovery from PZP-chymotrypsin (PZP-CT) complexes added to serum-free medium was 141 +/- 4.3%. There was no detectable cross-reactivity between the anti-human PZP antibody and human alpha 2-macroglobulin (alpha 2-M). The dose-response of two PZP standards and the PZP serum concentrations of 100 blood donors were determined. Furthermore, the serum level of PZP from 11 patients suffering from IgA myeloma was quantitated and found within the normal range when compared to serum levels of healthy blood donors of the same age and sex. Finally, supernatants from serum-free cultures of different human peripheral blood mononuclear cell (PBM) subpopulations were assayed. Neither of them were found to exhibit any detectable increase in PZP concentration during culture, but cultures of monocytes were found to produce alpha 2-M.

Blood↗

A sensitive ELISA for von Willebrand factor (vWf:Ag).

A sensitive and precise enzyme-linked immunosorbent assay for the measurement of the von Willebrand factor (new nomenclature:vWf:Ag, previous name: F VIII:RAg) of plasma and factor VIII concentrates was constructed using a microtitre plate based sandwich technique. The coating antibody extracted vWf:Ag from standard and test material. Bound fraction was detected by a F(ab')2 peroxidase conjugate of the same antibody as used for coating. The sensitivity limit of the assay was 0.004 IU/ml, at least 10 times lower than the electro-immunoassay (EIA) using the same antibody, and better than any previously reported polyclonal ELISA for vWf:Ag. Imprecision between runs was 5.1% (CV%) at the 0.50 IU/ml level. Plasma from 30 healthy people gave 1.02 +/- 0.25 IU/ml (mean +/- 1SD) in the ELISA assay and 0.99 +/- 0.30 IU/ml (mean +/- 1SD) using electro-immunoassay (EIA) with a correlation coefficient of 0.967. Two cases of homozygous recessive von Willebrand's disease revealed vWf:Ag values at or below buffer blank in all dilutions. In 18 patients with type I von Willebrand's disease, a correlation coefficient of 0.899 was found comparing ELISA and EIA. All patients with variant von Willebrand's disease tested exhibited complete dose-response congruity of patient plasma and pooled standard plasma calibrated against the 1st International Standard for Plasma F VIII. Factor VIII concentrates also behaved like normal plasma in the assay.

Enzyme-Linked Immunosorbent Assay↗

The renin-angiotensin-aldosterone system in normal 85-year-old people.

Active and total plasma renin concentration, as well as plasma angiotensin II, aldosterone and renin substrate concentrations were measured in venous blood samples from 17 normal 85-year-old people at rest. No discernible sex-related differences were seen. Active plasma renin and plasma aldosterone concentrations were significantly lower in the old people compared to a group of normal 40-year-old people. Plasma angiotensin II concentration showed no decrease with increasing age. Active plasma renin concentration constituted approximately 20% of total plasma renin concentration, with a significant correlation between the two renin moieties. The values for plasma renin substrate concentration are similar to those reported for younger age groups. The lack of standardization of methods severely hampers inter-laboratory comparisons of both active plasma renin and total plasma renin concentrations.

Adult↗

Prevalence and prognostic significance of cardiac arrhythmias detected by ambulatory electrocardiography in subjects 85 years of age.

24 hour ambulatory electrocardiography was performed in a representative group of people born in 1897. Out of 73 people included in the study, 22 were without known heart disease, 15 had definite ischaemic heart disease (IHD) and 36 symptoms of possible cardiac origin. An R-R interval in excess of 2000 ms was seen in only 3 subjects and Wenckebach A-V block in only one. One subject without a history of syncope had a nocturnal episode of complete A-V block with an escape interval of 8000 ms. The most striking difference between healthy subjects and patients with IHD was the higher number of patients with more than 1000 ventricular premature beats (VPBs) per 24 hour and ventricular couplets compared with the number of healthy subjects with such findings. At follow-up two years later 11% had died, with the highest mortality in patients with IHD (33%), and out of 8 patients with IHD who had more than 1000 VPBs per 24 hour, 4 (50%) had died compared with only one (14%) of those with less than 1000 VPBs. Our results seem to indicate that more than 1000 VPBs per 24 hour is a very unusual finding in healthy 85 year old individuals. When it occurs in very old people, it is usually in connection with IHD, and in this setting it signifies a poor prognosis.

Age Factors↗

Enzyme linked immunosorbent assay (ELISA) for the measurement of factor VIII coagulant antigen (CAg) using haemophilic antibodies.

A method for the quantitation of factor VIII clotting antigen (VIII:CAg) has been developed based on a micro enzyme linked immunosorbent assay (ELISA) principle employing antibodies from two polytransfused haemophilia A patients. Solid polystyrene support bound IgG fraction of inhibitor plasma extracted VIII:CAg from normal plasma and samples. Bound VIII:CAg was detected by peroxidase labelled F(ab')2 fragment of the IgG used for solid phase. Two assays, each based on its particular inhibitor antibody, were set up. The F VIII clotting antigen in plasma of 30 healthy persons was found identical with the two VIII:CAg assays (r=0.97) and closely correlating with clotting activity (VIII:C) (r=0.84). Serum VIII:CAg was 67% (+/-14.5%) of the corresponding plasma value. In severe haemophilia A, 17 out of 19 had VIII:CAg values less than 1 U/dl. Two patients with cross-reactive material (CRM+) were found. In some milder cases of haemophilia A, higher values of VIII:CAg than VIII:C was recorded. The sensitivity of the method was 0.08 U/dl. Inter assay coefficient of variation at the 100 U/dl level was 9.5% (CV%), at the 2 U/dl level 16.4% (CV%). Mainly due to the great stability of enzyme conjugated antibody compared to the natural decay of radioiodinated material and subsequent loss of detecting material, ELISA was found superior to immunoradiometric assay (IRMA).

Antibodies↗

Pentoxifylline does not interfere with stable coumarin anticoagulant therapy: a clinical study.

A study was undertaken to investigate the possible interaction between pentoxifylline and coumarin. Ten patients on a previously stable anticoagulant treatment were investigated twice prior to, then 13 and 27 days after initiation of treatment with 1600 mg pentoxifylline daily. Coumarin therapy was continued in unaltered dosage. Parameters recorded were: bleeding time, platelet count, platelet adhesivity, spontaneous and collagen-induced platelet aggregation, activated partial thromboplastin time, prothrombin time, prothrombin-proconvertin activity, plasminogen activator and fibrin(ogen) degradation products. Platelet aggregation studies revealed a slightly higher sensitivity to collagen in 2 patients compared to pre-treatment values and in 1 patient the tendency to spontaneous aggregation was slightly increased after treatment. No other single test result changed significantly from premedication baseline values.

4-Hydroxycoumarins↗

Insulin-gene flanking sequences, diabetes mellitus and atherosclerosis: a review.

A highly polymorphic locus flanking the human insulin gene contains two major size classes of DNA restriction fragments, which segregate in families as stable genetic elements. The L-allele, i.e. fragments with an average size of about 600 base-pairs seems to be a weak genetic marker for Type 1 (insulin-dependent) diabetes mellitus, whereas the U-allele, i.e. fragments of an average size of about 2500 base-pairs hitherto has been associated with Type 2 (non-insulin-dependent) diabetes mellitus and diabetic hypertriglyceridaemia. The most recent reports on this subject do not confirm an association between the U-allele and Type 2 diabetes. Our own studies indicate that the U-allele is a fairly strong marker for the development of atherosclerosis (relative risk for U-carriers 3.36). The putative functions of the polymorphic region in atherogenesis and the relation of this region to other genetic markers for atherosclerosis are not known.

Alleles↗