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Biomedical subjects

C H Jensen

Publications and source records attributed to C H Jensen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Quantification of the N-terminal propeptide of human procollagen type I (PINP): comparison of ELISA and RIA with respect to different molecular forms.

This paper compares the results of procollagen type I N-terminal propeptide (PINP) quantification by radioimmunoassay (RIA) and enzyme linked immunosorbent assay (ELISA). PINP in serum from a patient with uremic hyperparathyroidism was measured in RIA and ELISA to 20 micrograms l-1 and 116 micrograms l-1 and the corresponding concentrations in dialysis fluid were 94.5 micrograms l-1 and 140 micrograms l-1, respectively. PINP antigen appears in two distinct peaks following size chromatography and the two peak fractions display immunological identity and identical M(r)'s (27 kDa: SDS-PAGE). Analysis of fractions from size separated amniotic fluid, serum and dialysis fluid demonstrated that the RIA failed to measure the low molecular weight form of PINP. However, the anti-PINP supplied with the RIA-kit and the anti-PINP applied in the ELISA reacted equally well with both molecular forms of PINP when analysed in a direct ELISA. It is concluded that the major difference in the ELISA and RIA results is due to assay efficacy with respect to the low molecular weight form of PINP.

Amniotic Fluid↗
PubMed1998

Interlocking nailing of humeral shaft fractures.

: In this retrospective study 48 humeral shaft fractures in 48 patients were operated on using the Seidel interlocking nail. The length of follow-up ranged from 6 to 60 months (median, 26 months). The treatment of fractures was satisfactory with the Seidel nail, but we emphasize the importance of countersinking the tip of the nail into the humeral head to avoid impingement. In 5 of 12 patients with non-unions, the procedure failed, and we found that the distal locking seemed to be inadequate. Pathological fractures (i.e., those caused by metastatic tumors) were all efficiently treated with the Seidel nail.

Adult↗
PubMed1997

Fetal antigen 1 (FA1), a circulating member of the epidermal growth factor (EGF) superfamily: ELISA development, physiology and metabolism in relation to renal function.

We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3.2% and an average recovery of 105% in serum and 98% in urine. Comparison of FA1 in amniotic fluid, serum and urine revealed parallel titration curves, identical elution volumes following size chromatography, immunological identity and similar profiles when analysed by MALDI-MS. The reference interval for serum FA1 was 12.3-46.6 ng/ml and the levels were 10 times higher in patients with renal failure. FA1 showed no diurnal variation, no variation during the menstrual cycle and was not influenced by the acute phase reaction. In humans (n = 10) the renal clearance of FA1 was 11 ml/min and an identical high renal clearance was found in rats when expressed per 100 g body weight. In rats the initial increase in serum FA1 was 10 ng/ml/h following bilateral nephrectomy, explaining the increased serum concentrations of FA1 observed in patients with renal failure.

Acute-Phase Reaction↗
PubMed1997

Magnetic resonance imaging-determined synovial membrane and joint effusion volumes in rheumatoid arthritis and osteoarthritis: comparison with the macroscopic and microscopic appearance of the synovium.

OBJECTIVE: To evaluate the relationship between synovial membrane and joint effusion volumes determined by magnetic resonance imaging (MRI) and macroscopic and microscopic synovial pathologic findings in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: Synovial biopsies were performed, and macroscopic grades of synovitis assigned, at preselected knee sites during arthroscopy or arthrotomy in 17 knees with RA and 25 with OA. Synovial inflammation and 9 separate tissue characteristics were graded histologically. Synovial membrane and joint effusion volumes were determined by preoperative MRI, enhanced with intravenous gadopentetate dimeglumine. RESULTS: MRI-determined synovial membrane volumes were correlated with the overall histologic assessment of synovial inflammation (Spearman's sigma = 0.55, P < 0.001), with fibrin deposition, with subsynovial mononuclear and polymorphonuclear leukocyte infiltration (sigma = 0.51-0.59), and less significantly with macroscopic synovitis, vessel proliferation, and granulation tissue formation (sigma = 0.40-0.42). No correlation with synovial lining multiplication, perivascular edema, villous formation, or fibrosis was found (sigma < 0.30). CONCLUSION: MRI-determined synovial volumes are correlated with synovial inflammatory activity. Synovial volumes probably mainly reflect the mass of cell-infiltrated, vascularized subsynovial tissue, but may also be influenced by the cumulative synovial proliferative activity. MRI-determined synovial membrane and effusion volumes may be sensitive markers and/or predictors of disease activity and treatment outcome in RA.

Adult↗
PubMed1996

FA1 immunoreactivity in endocrine tumours and during development of the human fetal pancreas; negative correlation with glucagon expression.

Fetal antigen 1 (FA1) is a glycoprotein containing six epidermal growth factor (EGF)-like repeats. It is closely similar to the protein translated from the human delta-like (dlk) cDNA and probably constitutes a proteolytically processed form of dlk. dlk is homologous to the Drosophila homeotic proteins delta and notch and to the murine preadipocyte differentiation factor Pref-1. These proteins participate in determining cell fate choices during differentiation. We now report that FA1 immunoreactivity is present in a number of neuroectodermally derived tumours as well as in pancreatic endocrine tumours. A negative correlation between FA1 and glucagon immunoreactants in these tumours prompted a reexamination of FA1 immunoreactants during fetal pancreatic development. At the earliest stages of development, FA1 was expressed by most of the non-endocrine parenchymal cells and, with ensuing development, gradually disappeared from these cells and became restricted to insulin-producing beta cells. Throughout development FA1 was not detected in endocrine glucagon, somatostatin or pancreatic polypeptide cells. Moreover, developing insulin cells that coexpressed glucagon were negative for FA1. Thus, there was a negative correlation between FA1 and glucagon both in tumours and during development. These results, together with FA1/dlk's similarity with homeotic proteins, point to a role of FA1 in islet cell differentiation.

Antibodies, Monoclonal↗
PubMed1996

Procollagen type I N-terminal propeptide (PINP) as an indicator of type I collagen metabolism: ELISA development, reference interval, and hypovitaminosis D induced hyperparathyroidism.

A sandwich enzyme-linked immunosorbent assay (ELISA) for quantification of the N-terminal propeptide of human procollagen type I (PINP) utilizing purified alpha 1-chain specific rabbit antibodies is described. The ELISA measured the content of the alpha 1-chain of PINP independent of the molecular form of the molecule. A parallelism was found between amniotic fluid (calibrator), normal and patient serum, and purified PINP (alpha 1), as well as the high and low molecular weight forms of PINP (alpha 1). The concentration of PINP in the calibrator (second trimester amniotic fluid) was determined to 25 micrograms/mL and the detection limit was 62 pg/mL measured in amniotic fluid, and 41 pg/mL measured in serum. The interassay coefficients of variation were 4.6% (low control) and 5.3% (high control), and the corresponding intraassay parameters were 2.9% and 4.9%. Recovery studies revealed an accuracy between 93% and 105%. The normal range (n = 57) for PINP was 56 ng/mL (median) the 10th and 90th centiles being 30 and 82 ng/mL, respectively. Patients with hyperparathyroidism due to hypovitaminosis D had median serum level of 168 ng/mL with a 10th centile of 44 ng/mL and a 90th centile of 450 ng/mL, these values being significantly different from the normal range (p < 0.001). The PINP-ELISA was superior to commercially available assays for PICP and osteocalcin in separation between healthy controls and patients with osteomalaci.

Adult↗
PubMed1996

Biodegradable pins versus Kirschner wires in hand surgery.

We compared biodegradable pins with standard Kirschner wires in the fixation of fractures, arthrodeses and osteotomies in the hand in a prospective, randomized study. Eleven patients were allocated to the biodegradable pin group and 12 to the Kirschner wire group. Age, gender, operative procedure and postoperative treatment did not differ in the two groups. All patients were evaluated after 6 months. No differences in time to union or complication rates were found, but the number of additional operative procedures in the Kirschner wire group significantly exceeded the number needed in the biodegradable pin group.

Adult↗
PubMed1996

Further investigations of the intraosseous pressure characteristics in necrotic lunates (Kienböck's disease).

To confirm the hypothesis that venous congestion plays a role in idiopathic lunate necrosis (Kienböck's disease), intraosseous pressure in 12 normal and 12 necrotic lunates was measured. Intraosseous pressure in the capitate of 12 healthy subjects served as reference measurement. The intraosseous pressure was recorded in neutral position and 60 degrees extension of the wrist under normotensive conditions and during venous stasis. In all groups, the mean intraosseous pressure rose significantly with extension of the wrist, with the largest increase being 92.3 mmHg for necrotic lunates, followed by 40.3 mmHg for normal lunates, 6.9 mmHg for normal capitates and during venous stasis, 26.6 mmHg for necrotic lunates, 26.1 mmHg for normal lunates, and 5.9 mmHg for normal capitates. In some necrotic lunates, the intraosseous pressure during extension exceeded the arterial blood pressure, which can be explained by mechanical deformation of the bone. In neutral position, no significant differences in pressure were found between normal lunates and capitates. A significant difference was found for venous stasis and extension. The intraosseous pressure rise in the normal lunate in extension was slightly higher than the pressure found during venous stasis. The intraosseous pressure differed significantly (by 56.9 mmHg) between normal and necrotic lunates in extension. These data support the hypothesis that impairment of venous drainage plays a role in lunate necrosis and that the lunate can be considered as a venous bone at risk.

Adult↗
PubMed1995

Idiopathic avascular necrosis of the scaphoid in a child.

A 10-year-old boy presented with a one month history of pain in his right (dominant) wrist. He was treated by immobilisation for three weeks with little improvement. By 28 months later his symptoms had settled and activities were unrestricted. Radiographic examination showed unaltered fragmentation of the scaphoid and radial subluxation of the capitate. To our knowledge this is the first report of avascular necrosis of the scaphoid in a child.

Age of Onset↗
PubMed1994

Protein structure of fetal antigen 1 (FA1). A novel circulating human epidermal-growth-factor-like protein expressed in neuroendocrine tumors and its relation to the gene products of dlk and pG2.

The present paper describes the primary structure, glycosylation and tissue localization of fetal antigen 1 (FA1) isolated from second-trimester human amniotic fluid. FA1 is a single-chained, heterogeneous glycoprotein of 225-262 amino acid residues. FA1 has six well conserved epidermal-growth-factor motifs and contains up to ten O-glycosylation and N-glycosylation sites, six of which are differentially glycosylated. Alignment to the translated sequences of Mus. musculus dlk and human dlk revealed 86% and 99% identity, respectively, to a 259-amino-acid residue overlap, and this high similarity extends with minor corrections to the human adrenal-specific mRNA, pG2 as well. Immunohistochemical analysis demonstrated the presence of FA1 in 10 out of 14 lung tumors containing neuroendocrine elements, and in the placental villi where FA1 was exclusively seen in stromal cells in close contact to the vascular structure. In the pancreas, FA1 co-localized with insulin in the insulin secretory granules of the beta cells within the islets of Langerhans. Our findings suggest that FA1 is synthesized as a membrane anchored protein and released into the circulation after enzymic cleavage, and that circulating FA1 represents the post-translationally modified gene product of human dlk which, in turn, is identical to human adrenal-specific mRNA pG2.

Amino Acid Sequence↗
PubMed1993

Intraosseous pressure in Kienböck's disease.

Intraosseous pressure was measured in the lunate of 10 patients undergoing surgery for Kienböck's disease. Using the styloid process of the radius and the capitate as reference points of bone pressure, I found a stasis rather than arterial insufficiency in the lunate. This pattern was observed regardless of the stage of the disease according to Ståhl and regardless of the finding by technetium TC 99m-methylene diphosphonate scintigraphy. The significance of this finding is still unknown but questions the current concept that Kienböck's disease is caused by arterial insufficiency, because these results imply an interruption of the blood flow as a result of venous congestion.

Adult↗
PubMed1993

Studies on the isolation, structural analysis and tissue localization of fetal antigen 1 and its relation to a human adrenal-specific cDNA, pG2.

Fetal antigen 1 was purified from second trimester human amniotic fluid by immunospecific affinity chromatography followed by reversed-phase chromatography. Fetal antigen 1 is a single chain glycoprotein with a M(r) of 32-38 kDa. The amino acid composition revealed a high content of cysteines, prolines and amino acids (aa) with acidic side-chains indicating that fetal antigen 1 is a compactly folded, strongly hydrophilic molecule. The N-terminal amino acid sequence (37 aa) revealed no homology to other known protein sequences, implying that fetal antigen 1 is a 'novel' human protein. When the aa sequence was back-translated into the appropriate degenerate sequence of nucleic acids, fetal antigen 1 could be partially aligned to a 'human adrenal-specific mRNA, pG2'. The indirect immunoperoxidase technique demonstrated fetal antigen 1 in fetal hepatocytes, glandular cells of fetal pancreas and in fetal adrenal cortex, whereas fetal medullary cells were fetal antigen 1 negative. In adult specimens fetal antigen 1 was exclusively found within the beta cells of the islets of Langerhans and in the adrenals with pronounced staining in the cortex. Our observations suggest that fetal antigen 1 is encoded by the mRNA defined by the cDNA clone pG2, but definitive sequencing and expression studies of this mRNA have not been achieved.

Adrenal Glands↗
PubMed1992

Subtrochanteric fractures following osteosynthesis of femoral neck fractures with the VLC-femoral system.

Twenty-two patients with femoral neck fracture were treated with the VLC (Variable Length Cannulated)-femoral screw system. In four patients, the osteosynthesis had complications with ipsilateral subtrochanteric femoral fractures in relation to the screw holes in the lateral cortex. The problem seemed to be excessive stress on the lateral cortex during insertion of the screws. The method has been abandoned in our department.

Adult↗
PubMed1991

[The distribution effects of the Danish 800 crown rule. Preliminary results of the DIKE study. Choice of drugs and drugs used by the population].

During the period 1 July 1989 to 31 December 1990, patients had to pay the full price for subsidized medicine up to DDK 800 (66 pounds) per calendar year. The consequences for the population were examined by a representative national survey (January 1990) and for the patients by interviews at pharmacies (December 1989 and April 1990). Fourteen percent of the population had exceeded the limit of DDK 400 (33 pounds) for the second half of 1989. By the end of December 1989, 53% of patients at pharmacies had exceeded the limit. According to the national health survey (1986) 51% of the population took medicine during a period of two weeks; 58% female, 42% male. In 1990, 41% of the population had no medicine expenses. Among the other fraction 15% had expenses of DDK 200 (16 pounds) or more, monthly. Among patients at pharmacies 22-25% had expenses to that amount. More than 90% of the patients at pharmacies bought the prescribed medicine or the medicine normally used. Less than 10% asked the physician to prescribe a cheaper medicine. The new regulation on medicine reimbursement has not yet induced greater price-consciousness in the users. Whether this is possible by economic means, is an open question.

Adult↗
PubMed1991

A diagnostic problem in tuberculous dactylitis.

We report a case of tuberculous dactylitis. This rare manifestation of extra-pulmonary tuberculosis must be kept in mind in the diagnosis of a slowly-growing bone tumour. The diagnostic problems and pitfalls are discussed.

Child↗