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Biomedical subjects

H E Nielsen

Publications and source records attributed to H E Nielsen.

At least 19 recordsLinked to original sources
PubMed1992

Rate-limiting components and reaction steps in complement-mediated haemolysis.

The aims of this study were to identify the rate-limiting components and reaction steps in the integrated activation sequence of the alternative (AP) and classical (CP) pathways of the complement (C) system. In an initial correlation analysis we found that the haemolysis rate in AP was correlated with the concentrations of C5 and IgM. In CP, the haemolysis rate was correlated with the concentrations of C2-C6, factors I and B, and IgM. In order to identify the rate-limiting components, we added single, purified C components and IgM to pooled, normal human serum and measured the resultant change in the haemolysis rate. We found that a large number of different components, rather than a single one, were rate-limiting in AP and CP. In reconstitution experiments we found that in CP the rate-limiting reaction steps are the activation of C4 and C2. In AP we cannot identify the rate-limiting step precisely, but can only state that it is at the C3 activation step or earlier.

Adolescent↗
PubMed1991

[Occurrence of complement defects in meningococcal disease: who should be examined?].

Congenital complement deficiency states occur very rarely. These deficiencies are associated with a high risk of meningococcal disease (MD). We suggest that the following groups of individuals with MD are examined for complement deficiencies: 1. Individuals belonging to families, in which more than one case of MD has occurred with an interval exceeding one month. 2. Individuals infected with the low-virulent meningococcal serogroups W-135, 29E, X, Y, Z. 3. Individuals with recurrent MD. Since properdin deficiency probably is the most common deficiency associated with MD it is important that the screening includes the alternative complement pathway.

Complement System Proteins↗
PubMed1991

Immunoglobulin and complement studies in children with Schönlein-Henoch Syndrome and other vasculitic diseases.

In 35 children with Schönlein-Henoch Syndrome (SHS) serum IgG, IgM, and IgA concentrations were increased in 15%, 21%, and 44% of cases, respectively. Seven children with other vasculitic syndromes (VS) had normal serum Ig concentrations. Serum concentration of IgG subclass IgG1 was increased in 72% of children with SHS and 57% with VS. In SHS this was related to the presence of arthritis, but inversely related to nephritic symptoms. Only a few children had IgG subclasses IgG2, IgG3, or IgG4 concentrations outside the normal ranges. Platelet associated Ig (PAIg) was found in 75% of children with SHS or VS. In SHS the identification of increased amounts of PAIgG was related to the presence of nephritis. The serum concentration of properdin, a component of the alternative complement system, was reduced in 21% of children with SHS. This was related to the presence of abdominal symptoms or nephritis. No cases of retinal vasculitis was observed, but 4 of 22 children with SHS had punctuate retinal haemorrhages. SHS and VS may be clinical variations of the same syndrome. The immunological aspects indicate a close relationship with autoimmune diseases.

Adolescent↗
PubMed1990

Complement and immunoglobulin studies in 15 cases of chronic meningococcemia: properdin deficiency and hypoimmunoglobulinemia.

The purpose of this study was to investigate whether patients with chronic meningococcemia have abnormalities in their humoral immune system. The alternative and classical complement system, the levels of IgA, IgG and IgM, as well as IgG subclasses were studied in 15 individuals who had recovered from chronic meningococcemia. We found one individual with complete deficiency of properdin, a component of the alternative complement pathway. In the other patients, the complement system was normal. The mean plasma IgG concentration was significantly below normal in the patient group, while the mean values of IgA, IgM and the IgG subclasses were normal. Two individuals, however, had low IgG2 and IgG4 levels. We conclude that properdin deficiency and reduced plasma IgG levels may predispose to chronic meningococcal disease, but that the majority of patients with chronic meningococcemia have a normal humoral immune system.

Adolescent↗
PubMed1989

Hereditary, complete deficiency of complement factor H associated with recurrent meningococcal disease.

Complement factor H (beta-1H globulin) is an important regulatory protein which inhibits the spontaneous complement activation via the alternative pathway. We describe a 15-year-old girl without any detectable factor H in plasma. She has had two episodes of meningococcal disease, but is otherwise completely healthy. Secondary to the factor-H deficiency, the levels of factor B, properdin, C3, and C5-C9 were strongly reduced due to spontaneous in vivo activation of the alternative complement pathway. Plasma C3dg was strongly elevated in spite of the factor-H deficiency; apparently erythrocyte CR1 substitutes for factor H in C3 degradation. Neither C3 nor complement lesions were demonstrable on her erythrocytes which did, however, show increased, spontaneous haemolysis in vitro in citrate plasma, but not in serum. The patient is a single child and her parents, who are unrelated and healthy, had half-normal levels of factor H. This reduction of factor H is sufficient to cause increased, spontaneous activation of the alternative pathway.

Antibodies, Bacterial↗
PubMed1989

Complement deficiencies in selected groups of patients with meningococcal disease.

We have examined 125 individuals who have earlier had meningococcal (mgc) disease. They belonged to one or more of the following groups: (1) 2 or more cases of mgc disease in the same family; (2) individuals with 2 episodes of mgc disease or with 1 episode of mgc disease and 1 or more episodes of purulent meningitis of another aetiology; and (3) infections with Neisseria meningitidis belonging to serogroups that are uncommon as causes of disease and presumably low-virulent (W-135, 29E, X, Y). Among these we found 15 complement (C)-deficient individuals (12%). The prevalence of C deficiency in the groups above was 7%, 41% and 19%, respectively. The first group (family cases), is very heterogeneous and may be further subdivided into 2 groups: families whose members fell ill within an interval of 30 days (in these the prevalence of C deficiency was 2%), and families in which the interval between mgc disease cases exceeded 30 days (in those the prevalence of C deficiency was 14%). We found a predominance of defects of the initiation pathways, with properdin deficiency being the most common.

Animals↗
PubMed1988

Epidemiology of Schönlein-Henoch purpura.

The purpose of this study was to determine if Schönlein-Henoch purpura represents an abnormal host response to microorganisms. Among 1,222 cases, representing all new Danish cases in children during the years 1977-84, there was no tendency for the cases to cluster; this means that the disease is not caused by a single, contagious agent. In a smaller sample of 281 children examined in detail, a higher number than expected attended day nursery or nursery school and 17% had received antibiotic treatment during the week prior to admission. The latter findings, together with the seasonal variation of the incidence and the activation of the immune apparatus in many cases, suggest that Schönlein-Henoch purpura may be triggered by infection with several different microorganisms, but there is no evidence that a single one such as the streptococcus is the major offender.

Adolescent↗
PubMed1987

Congenital properdin deficiency and meningococcal infection.

We report a family in which three males in two generations had meningococcal infections; one of them died. Hemolytic activity of the alternative complement pathway in the two survivors and in one healthy boy belonging to the family was reduced, as measured in a kinetic system. These three individuals had 10-11% of normal properdin concentration in plasma, as measured by a catching ELISA method, while the other complement components were normal. Hemolytic complement activity was normalized when purified properdin was added. The data are compatible with an X-linked mode of inheritance of properdin deficiency.

Complement Activation↗
PubMed1987

Risk factors and sib correlation in physiological neonatal jaundice.

The effect of a number of explanatory variables on the degree of physiological jaundice in mature infants was evaluated by multiple regression analysis. The sampling was designed so that comparisons could be made between siblings. We found an effect of gestational age, gender, infant nutrition, ABO incompatibility and induction of labour. Taking these factors into account we still found a highly significant correlation between the peak bilirubin levels of siblings. Whether this correlation is genetically or environmentally determined is not clear.

Bilirubin↗
PubMed1987

Meningococcal disease in congenital absence of the fifth component of complement.

We describe a family in which 2 brothers had meningococcal infection, 1 of them twice. Their parents were first degree cousins. The brothers showed a complete, isolated deficiency of C5, both antigenic and functional. The parents had half-normal values, and the data are compatible with an inherited C5 deficiency where the defect is transmitted as an autosomal codominant trait.

Adult↗
PubMed1987

Safety of osteoporosis treatment with sodium fluoride, calcium phosphate and vitamin D.

During an 8-year period, 163 consecutive patients with spinal crush fracture osteoporosis started a 5-year treatment with a combination of sodium fluoride (60 mg/day), calcium phosphate (45 mmol/day) and vitamin D2 (18,000 IU/day), and were followed in the outpatient clinic every 3 months. Fourty-three patients completed the 5-year treatment. Mean observation time was 2.8 years, totalling 460 patient-years. Fifty-one percent of the patients experienced joint-related (37%) or gastrointestinal (25%) side effects at one time or another. All side effects subsided after a median 6-week withdrawal of fluoride. Six percent of the patients withdrew from treatment due to side effects. Mean serum calcium values slightly decreased during treatment and no hypercalcemic episodes were seen. Urinary excretion of calcium did not change during treatment. No changes in renal, bone marrow or thyroid functions could be detected. The liver function might be slightly affected as indicated by minute increases in serum bilirubin and decreases in serum coagulation factors and albumin, but no other changes in liver function were observed.

Adolescent↗
PubMed1986

Metacarpal bone measurements in renal transplant recipients, in corticosteroid-treated patients with polymyalgia rheumatica and in patients with primary hyperparathyroidism.

Quantitative radiological measurements on the second left metacarpal bone were carried out in 23 patients with primary hyperparathyroidism, 22 corticosteroid-treated patients with polymyalgia rheumatica and 40 renal transplant recipients treated with prednisone and azathioprine. Women with primary hyperparathyroidism and corticosteroid-treated women showed significantly decreased mean values of metacarpal bone compared to normal controls, probably due to a higher bone resorption than formation at the endosteal surface. Bone loss was more pronounced in corticosteroid-treated women than in women with primary hyperparathyroidism, partly due to age difference. In renal transplant recipients, bone loss took place during the initial period after renal transplantation, probably due to increased endosteal bone resorption. During this period a periosteal new bone formation took place in female renal transplant recipients. The quantitative radiological measurements make it possible to determine whether bone loss is due to a higher ratio of bone resorption than of bone formation at the periosteal and/or endosteal surface.

Adrenal Cortex Hormones↗
PubMed1986

[Quantitative evaluation of the relation between bone mass of the metacarpal bone and bone mineral content of the forearm in normal persons and patients with chronic renal failure before and after kidney transplantation].

Twenty-seven healthy normal subjects, 30 non-dialyzed patients with chronic renal failure, 25 hemodialyzed patients on chronic hemodialysis, and 54 renal transplant recipients were evaluated simultaneously with regard to a correlation between the bone mineral content of the forearm and the total cortical thickness and area of the second left metacarpal bone. A significant correlation was found between bone mineral content of the forearm and the cortical bone mass of the metacarpal bone in normal subjects and in the patient groups.

Adult↗