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Biomedical subjects

H Mortensen

Publications and source records attributed to H Mortensen.

At least 19 recordsLinked to original sources
PubMed2003

Deletion of V335 from the L2 domain of the insulin receptor results in a conformationally abnormal receptor that is unable to bind insulin and causes Donohue's syndrome in a human subject.

An infant with Donohue's syndrome (leprechaunism) was found to be homozygous for an in-frame trinucleotide deletion within the insulin receptor gene resulting in the deletion of valine 335. When transiently transfected into Chinese hamster ovary cells, mutant receptor was produced in a mature form, but at significantly lower levels compared with wild-type receptor. Cell surface biotinylation experiments revealed that significant amounts of the DeltaV335 receptor were expressed on the cell surface. Despite this, cells expressing this receptor showed no significant insulin binding or ligand-induced receptor autophosphorylation. Although the DeltaV335 receptor was capable of being immunoprecipitated with antibodies directed against the beta-subunit of the receptor, the mutant receptor could not be recognized by a panel of antibodies directed against different epitopes of the alpha-subunit, suggesting that the loss of V335 results in a major conformational alteration in the receptor alpha-subunit. This would be predicted by the positioning of V335 at a critical location within a strand that provides the main rigid scaffold for the two beta-sheet faces of the L2 domain of the receptor. The severe biochemical and clinical consequences of this novel mutation, which occur despite substantial expression on the cell surface, emphasize the crucial role of the L2 domain in ligand binding by the insulin receptor.

Abnormalities, Multiple↗
PubMed2000

Dynamics of high-barrier surface reactions: laser-assisted associative desorption of N2 from Ru(0001)

We have determined the dynamics and energetics of associative desorption of N2 from Ru(0001) using both an experimental technique, laser-assisted associative desorption, and density functional calculations. These show that N2 is preferentially desorbed into very high vibrational states and that the barriers between gas phase N2 and adsorbed N atoms increase from 2 to >3 eV with increasing N coverage on the surface. This experimental technique is found to be quite insensitive to low barrier steps and defects which complicate interpretations from other methods of studying high-barrier surface reactions.

Journal Article↗
PubMed1999

A multidisciplinary memory clinic in a neurological setting: diagnostic evaluation of 400 consecutive patients.

This report describes the operation of a multidisciplinary university hospital memory clinic in a neurological setting, and the diagnostic evaluations in 400 consecutive patients referred for cognitive symptoms and possible dementia during a period of 27 months (1 September 1995-31 December 1997). The mean age of the patients was 63.6 years (range 19-97). On clinical and neuropsychological examination, 46% of the patients fulfilled DSM IV criteria for dementia, 5% had selective amnesia, and 14% had other selective cognitive deficits. The remaining patients had either no significant cognitive deficits (31%) or were not evaluable (4%). A wide range of disorders from the fields of neurology, psychiatry, neurosurgery and internal medicine were identified as the underlying etiologies for the cognitive symptoms. Potentially reversible conditions were observed in 26% of the patients, not including the 11% in whom no specific underlying disease was identified. Concomitant conditions or risk factors with a potential influence on cognitive functions were identified in 61% of the patients. Diagnostic evaluation of patients with mild to moderate cognitive symptoms and possible dementia is an integrated multidisciplinary task, which should focus on the identification of non-progressive and potentially reversible etiologies, co-morbidity, selective cognitive deficits, and rare or atypical neurological conditions, as well as on the early identification of common progressive dementia disorders.

Adult↗
PubMed1996

Isolation and characterization of porcine mannan-binding proteins of different size and ultrastructure.

The authors report on the purification and characterization of mannan- binding proteins (MBP) isolated from porcine serum. The MBPs were purified by use of PEG precipitation, affinity chromatography on mannan-Sepharose, protein A- and anti-porcine IgM-Sepharose followed by gel filtration. The MBP proteins were collagenase sensitive and showed gamma 1-gamma 2-electrophoretic mobility. The MBP designated pMBP-28 had a molecular mass of 28 kDa when analysed on SDS-PAGE under reducing conditions and eluted corresponding to a molecular mass of approximately 700 kDa on gel filtration chromatography. Electron micrographs of pMBP-28 revealed an oligomeric protein similar to rodent MBP-A and human MBP but with a predominance of penta- and hexameric molecules. Another protein designated pMBP-27 was composed of peptides of 27 kDa and had an Mr of 300-350 kDa on gel filtration chromatography. Electron microscopy of pMBP-27 showed dimer and trimer molecules; the trimers without distinct stalk regions. The N-terminal 26(pMBP-27) and 24(MBP-28) amino acid residues showed 54% and 58% identity with human MBP.pMBP-28 showed a higher degree of sequence similarity to rat and mouse MBP-A (60% identity) than to mouse and rat MBP-C (41-45% identity). Both pMBPs exhibited Ca2+-dependent binding to D-mannose immobilized on agarose but no significant binding to N-acetyl-D-glucosamine- or fucose-agarose. The results further suggested the presence of a third pMBP which copurified with pMBP-27 but this protein was not sequenced.

Amino Acid Sequence↗
PubMed1995

[Leptospirosis].

Leptospirosis is a worldwide zoonosis. When human beings are infected the clinical spectrum varies from a mild, febrile illness to severe, icteric disease with multiorgan failure and fatal outcome. The illness falls into two phases, the septicaemic and the so-called immune. The diagnosis is confirmed by culture of blood and spinal fluid during the first phase, by culture of urine during the second and by serology. It is recommended that penicillin be given as quickly as possible. Prevention is important e.g. effective rat control and individual protection such as wearing protective clothing in contaminated work areas.

Animals↗
PubMed1995

[Leptospirosis in the Ribe County 1980-1991].

Though only 4.2% of the Danish population live in Ribe County, 12 cases of leptospirosis (22% of the Danish total) were found in the county between 1980-1991. Nine cases were associated with fresh water angling or fish farming. The patients were typically young or middle-aged formerly healthy men, who suddenly became ill with acute febrile disease. Eleven patients survived, one died. Cases were most often seen in late summer and autumn. Four patients required dialysis, and these patients also had relatively high serum levels of bilirubin. Case history and simple laboratory findings are helpful in leading to the diagnosis. Three patients were admitted with the correct diagnosis, and by the third day in hospital all 12 were being treated with relevant antibiotics, eight on suspicion of leptospirosis. Three patients had positive blood cultures on day 4, 6 and 9, and nine patients had late positive serology, two of whom also belonged to the group with positive blood cultures. In two patients the diagnosis was based on clinical findings alone. For these reasons, penicillin should be commenced on clinical suspicion alone.

Adult↗
PubMed1989

[Fractionated P-bilirubins].

A diazo-based dry film technique for the estimation of different bilirubins in plasma is now available. This procedure separates bilirubins from icteric sera into three separate fractions: bilirubin (unconjugated), bilirubin-glucuronides (mono + diglucuronide) and bilirubin-albumin. In newborns with prolonged jaundice classification of hyperbilirubinemia is of importance for choice of treatment. While binding of bilirubin and bilirubin-glucuronides to albumin is non covalent, reversible, bilirubin-albumin appears to be firmly associated with albumin by covalent bonds. This causes delayed clearance of this bilirubin fraction from plasma as the half-life of albumin is approximately 18 days. Hence the substance concentration of bilirubin-albumin will decrease at a slower rate than will bilirubin and bilirubin-glucuronide, despite hepatobiliary recovery. Bilirubin-albumin may therefore prove of value in the differentiation between different clinical entities with hyperbilirubinemia.

Bilirubin↗
PubMed1989

[Fractionated P-bilirubins. Clinical use].

Development of new assays for accurate quantification of bile pigments in plasma have facilitated their clinical application. Hyperbilirubinemia and jaundice occur frequently in the neonatal period. The purpose of the present study was to determine reference intervals for bilirubins in 60 fullterm healthy infants during the first four days of life. For comparison the bilirubin fractions were analyzed in an infant with biliary atresia and six adults with hepatobiliary disorders.

Adult↗
PubMed1988

Carbohydrate and lipid metabolism of skeletal muscle in type 2 diabetic patients.

Peripheral hyperinsulinaemia is the cause of metabolic changes that might contribute to the high incidence of macrovascular disease in patients with diabetes mellitus. In order to test this hypothesis muscle biopsies from 12 Type 2 diabetic patients and 14 age and sex matched non-diabetic patients, undergoing minor surgery, were obtained. The diabetic patients had significantly elevated fasting serum insulin (0.29 +/- 0.05 vs 0.06 +/- 0.03 nmol-1) and glucose (8.3 +/- 1.5 vs 4.6 +/- 0.5 mmol-1) and HbA1 levels (8.4 +/- 0.4 vs 5.0 +/- 0.2 per cent). The fasting and 2-h postprandial C-peptide levels were 0.99 +/- 0.25 vs 0.39 +/- 0.12 and 3.12 +/- 0.75 vs 1.09 +/- 0.34 nmol/l, respectively. The diabetic patients showed a marked elevation of triglyceride in the striated muscle biopsies compared to the non-diabetic controls (290 +/- 52 vs 48 +/- 6 mumol/g wet weight, p less than 0.001). Moreover, the activities of glucose-6-phosphate dehydrogenase (0.25 +/- 0.03 vs 0.13 +/- 0.01 U/g wet weight) and malic enzyme (0.15 +/- 0.01 vs 0.05 +/- 0.01 U/g wet weight), necessary for lipid synthesis, were significantly increased (both p less than 0.001) in the diabetic patients while the glycolytic enzymes, hexokinase (0.65 +/- 0.09 vs 1.82 +/- 0.11 U/g wet weight), pyruvate kinase (7.3 +/- 0.9 vs 13.2 +/- 0.9 U/g wet weight), phosphofructokinase (1.3 +/- 0.2 vs 2.6 +/- 0.2 U/g wet weight), and alpha-glycerophosphate dehydrogenase (7.3 +/- 0.5 vs 12.5 +/- 0.7 U/g wet weight) were decreased (all p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1984

Reference intervals for urinary glucose in pregnancy.

Reference interval upper limits for glucose in urine from non-fasting pregnant women, estimated by a glucose dehydrogenase method are higher than for non-pregnant women (1.4 mmol/l) and increase with gestational age: week 10-20, 2.0 mmol/l (n = 158); week 21-30, 2.3 mmol/l (n = 124) and week 31-42, 2.7 mmol/l (n = 245). The reagent strip Tes-Tape correctly identified glucosuria above a clinical decision limit of 7 mmol/l and reacted in two-thirds of urine samples with from upper reference interval to 8 mmol/l of glucose. The reagent strip Uristix in no case gave a positive reaction.

Adolescent↗