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Biomedical subjects

J Bollerslev

Publications and source records attributed to J Bollerslev.

At least 73 records · Page 4Linked to original sources
PubMed1989

The role of carbonic anhydrase in autosomal dominant osteopetrosis.

Twenty-eight patients with two different radiological types of the autosomal dominant form of osteopetrosis, from six different kindreds, were investigated and compared with age- and sex-matched controls, in order to evaluate the role of carbonic anhydrase in this disorder. There were 15 patients with Type I and 13 with type II osteopetrosis. The concentrations of haemoglobin and bicarbonate were normal in both types and without differences between the types. The concentration of carbonic anhydrase isoenzyme II (CA II) in the erythrocytes did not differ from controls in any of the two types. It is concluded that CA II does not seem to play any pathogenetic role in these two different forms of autosomal dominant osteopetrosis.

Adolescent↗
PubMed1989

Fracture patterns in two types of autosomal-dominant osteopetrosis.

Thirty-five individuals with autosomal-dominant osteopetrosis were interviewed and radiographs were reviewed. Twenty had the radiographic Type I osteopetrosis, characterized by diffuse, symmetric osteosclerosis and pronounced sclerosis of the skull with a thickened cranial vault. Fifteen had Type II, where the most striking findings were diffuse symmetric osteosclerosis, "Rugger Jersey Spine," and endobones (bone within a bone) in the pelvis, while the cranial vault was almost unaffected. Of the 12 probands who had had a fracture, 2/20 were Type I and 10/15 were Type II. Fracture complications were also more frequent in Type II.

Adolescent↗
PubMed1988

Radiological, biochemical and hereditary evidence of two types of autosomal dominant osteopetrosis.

Review of the radiographs of 34 patients with autosomal dominant osteopetrosis revealed two distinct phenotypical types. Both were strictly family-related and exhibited progressive sclerosis with aging. Descriptive, radiogrammetric and biochemical analyses were performed. Type I showed a pronounced sclerosis of the skull with an enlarged thickness of the cranial wall. The sclerosis of the skull in Type II was most striking at the base. In Type II there was a typical "Rugger-Jersey spine," and endobones ("bone within a bone") were seen in the pelvis. The radiogrammetric investigations of the long bones did not show any difference between the two types. Compared to normal controls, there was a normal total subperiosteal width (W), but a significant enlarged cortical thickness (C) (P less than 0.01), and thus a reduced medullary cavity (M), suggesting normal bone formation and disturbed bone resorption. Serum phosphate was lower in Type I compared to Type II (P less than 0.01), and serum acid phosphatase was markedly increased in Type II (P less than 0.01), suggesting differences between the two types in bone mineral metabolism and structural functions of the osteoclasts. The two types may represent two different entities with the same mode of inheritance, and in both cases with affected bone resorption.

Adolescent↗
PubMed1988

Triiodothyronine stimulates urinary excretion of calcium and hydroxyproline in autosomal dominant osteopetrosis.

Six patients with autosomal dominant osteopetrosis were treated orally with 100 mcg. triiodothyronine (T3) daily for seven days. The effect of T3 on bone remodelling was monitored. T3 treatment increased serum T3 from day 1 to 7 (p less than 0.02) with a corresponding fall in serum T4 (p less than 0.01) and serum TSH (p less than 0.02). The levels of thyroid hormones returned to initial levels within the observation period. The renal excretion of calcium and hydroxyproline increased significantly (p less than 0.05) on day 7 and 14 respectively, while there was no significant increase in phosphate excretion. No significant changes were observed in serum calcium, phosphate, or osteocalcin during the study. The observed changes suggest that bone resorption in autosomal dominant osteopetrosis is stimulated by exogenous administration of T3.

Adult↗
PubMed1988

Serum vitamin D metabolites and nuclear uptake of (3H)-1,25-dihydroxyvitamin D3 in monocytes from patients with autosomal dominant osteopetrosis: a study of two radiological types.

The nuclear uptake of (3H)-1,25 dihydroxyvitamin D3 in freshly isolated human monocytes and the serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were investigated in 13 patients with autosomal dominant osteopetrosis and in sex- and age-matched controls. Seven patients had type I osteopetrosis characterized by diffuse, symmetrical osteosclerosis with pronounced sclerosis of the skull and increased thickness of the cranial vault. The other six patients had type II with "Rugger Jersey Spine" and "endobones" as characteristic findings. In type I osteopetrosis the serum 1,25-dihydroxyvitamin D was significantly reduced (p less than 0.05), whereas serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D receptor binding were normal. In type II osteopetrosis the serum vitamin D metabolites were normal, as was the maximal binding capacity (Bmax) of 1,25-dihydroxyvitamin D to the nuclear receptor. The dissociation constant (Kd), however, was significantly increased (p less than 0.01) indicating a modest resistance to 1,25-dihydroxyvitamin D. It is concluded that a general end-organ resistance to 1,25-dihydroxyvitamin D at the receptor level does not exist in type I osteopetrosis, but may contribute to some of the radiological and biochemical findings in type II.

Adult↗
PubMed1988

Biochemical evidence of disturbed bone metabolism and calcium homeostasis in two types of autosomal dominant osteopetrosis.

Biochemical markers of bone resorption and bone formation were measured in 14 patients with autosomal dominant osteopetrosis, and compared with age- and sex-matched controls. There were eight patients with the radiological type I characterized by diffuse, symmetrical osteosclerosis with pronounced sclerosis of the skull and enlarged thickness of the cranial vault, and six patients with type II characterized by diffuse, symmetrical osteosclerosis, "Rugger-Jersey spine" and "endobones" (bone within a bone) in the pelvis. Serum levels of alkaline phosphatase and osteocalcin in types I and II did not differ from controls indicating normal bone formation. However, a significantly decreased fasting renal excretion of phosphate and hydroxyproline in both types compared with normal controls, suggests a reduced bone resorption. Serum levels of parathyroid hormone (PTH), albumin-corrected calcium, phosphate, and acid phosphatase were normal in type I. In type II serum levels of albumin-corrected calcium and PTH were significantly increased (p less than 0.05 and p less than 0.01). The level of acid phosphatase was markedly increased in this type (p less than 0.01). These findings suggest differences between the two types in calcium homeostasis and bone metabolism, and thus corroborate the evidence that the two radiological types reflect two different disorders of bone resorption.

Adult↗
PubMed1988

Autosomal dominant osteopetrosis: an otoneurological investigation of the two radiological types.

Otoneurological examination was performed on 14 patients with autosomal dominant osteopetrosis. Eight patients had radiological type I osteopetrosis, characterized by a pronounced osteosclerosis of the skull and an enlarged thickness of the cranial vault. Six patients had type II, in which osteosclerosis is most pronounced at the base of the skull. All investigated patients except one had otoneurological manifestations, but only two of of the 14 had otoneurological complaints. Symptoms were related to radiological types. Involvement of the trigeminal nerve was seen only in type I, whereas involvement of the facial nerve was found primarily in type II. Conductive hearing loss was particularly common in type I, and may reflect a high frequency of otosclerosis. Tomography of the petrous bones showed a significant narrowing of the internal acoustic meatus in type I (p less than 0.01) when compared to normal controls, but no significant narrowing in type II.

Facial Paralysis↗
PubMed1988

Thyroid hormone resistance in blood monocyte cells and elevated serum T3 in patients with autosomal dominant osteopetrosis.

Seven patients with autosomal dominant osteopetrosis from three different families were investigated. They all had the roentgenological type I disease, characterized by universal, symmetrical osteosclerosis and enlarged thickness of the calvarium vault. Serum concentrations of thyroid hormones and the specific nuclear binding of triiodothyronine (T3) in mononuclear blood cells were studied. All patients appeared clinically euthyroid. The serum level of T3 was significantly elevated (serum T3 = 1.89 nmol/l) compared with normal age and sex-matched controls (serum T3 = 1.44 nmol/l, p less than 0.05). The specific maximal nuclear binding capacity of T3 was significantly decreased (MBC = 0.51 fmol T3/mg DNA) in these patients compared with controls (MBC = 1.8 fmol/mg DNA, p less than 0.05) whereas no difference in the equilibrium association constant (Ka) was observed. The decreased specific nuclear binding of T3 and the slightly elevated serum level of T3 might indicate a modest peripheral resistance to T3 in patients with autosomal dominant osteopetrosis type I.

Adult↗
PubMed1987

Autosomal dominant osteopetrosis (a family study).

Osteopetrosis is a rare metabolic disorder, characterized by an abnormal accumulation of bone mass probably caused by diminished bone resorption. Symptoms are directly and indirectly derived from the increased amount of bone. A family study was made, starting with a proband presenting with symptoms of trigeminal neuralgia. The pedigree indicated an autosomal dominant inheritance through three generations, comprising four affected subjects, of whom two were free of symptoms.

Genes, Dominant↗
PubMed1987

Heterogeneity of autosomal dominant osteopetrosis.

A review of the radiographs of 26 patients with autosomal dominant osteopetrosis disclosed two distinct and strictly family-related radiographic types. Both types had universal osteosclerosis. In type 1 the most striking finding was pronounced sclerosis of the cranial vault while the spine was almost unaffected. In type 2 the sclerosis of the skull was most pronounced at the base, the vertebrae always had end-plate thickening, and in the pelvis the iliac wings contained convex arcs of sclerotic bone. Age and sex distribution did not differ between the types. Autosomal dominant osteopetrosis may be a heterogeneous group of inherited bone disorders.

Adolescent↗
PubMed1987

Atrial natriuretic peptide in relation to physical exercise.

The effect of physical exercise on atrial natriuretic peptide (ANP) was studied in 10 healthy young volunteers. The subjects were exercised on a bicycle ergometry until exhaustion. Blood samples were drawn at rest, at maximal load and in the following resting period. ANP concentrations were measured by radio-immunoassay. The level of ANP rose from 6.7 +/- 0.5 at rest to 33.2 +/- 7.0 pmol/l (mean +/- SEM) (p less than 0.05) at maximal load and returned to normal after 45 min. It was not possible to demonstrate a correlation between a change in ANP concentration and changes in pulse rate, blood pressure, maximal physical load, volume of urine, the amount of urine sodium, urine potassium or urine creatinine during the exercise load.

Adult↗
PubMed1987

Osteopetrosis. A genetic and epidemiological study.

By a systemic search of osteopetrosis in the county of Funen, Denmark, the prevalence was 5.5/100,000 inhabitants. The study disclosed 33 patients of whom 32 had the mild, autosomal dominant form of osteopetrosis. Two obligate carriers, who had the genotype but were not phenotypically affected, were disclosed. There was a great variation in the clinical manifestations; 39% were asymptomatic. The age of first appearance of symptoms also varied widely (8-76 years), with a tendency to increasing symptoms with aging. The frequency of fractures was low. Plasma inorganic phosphate was low in 7% of the patients, and plasma acid phosphatase was increased in 39%.

Adolescent↗
PubMed1986

Gonadotropin and androgen levels in patients operated upon for cryptorchidism.

53 patients previously operated upon for cryptorchidism were examined seven years (range 2-18) after the operation. We measured serum levels of sex-hormone-binding-globulin (SHBG), testosterone (T), free testosterone (free T), dihydrotestosterone (DHT), 4 androstenedione (4-AD), and dehydroepiandrosteronesulphate (DHAS), and the gonadotropin luteinizing hormone (LH) and follicular hormone stimulating (FSH). Compared to normal controls, there were decreased levels of free testosterone and DHT and increased levels of SHBG and DHAS. The FSH levels were elevated and LH values low. No relationship was found between androgen and gonadotropin levels, suggesting that the normal feed-back mechanism is malfunctioning. There were no hormonal differences between patients with previous unilateral and bilateral cryptorchidism, although SHBG levels were higher in the former. We concluded that cryptorchidism is probably due to a defect in the hypothalamic-pituitary axis and not to a primary defect in the testes.

Adolescent↗