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Biomedical subjects

J Pedersen

Publications and source records attributed to J Pedersen.

At least 127 records · Page 7Linked to original sources
PubMed1990

In vivo processing of N-terminal methionine in E. coli.

The processing of amino-terminal methionine from cytosolic proteins in E. coli has been investigated in vivo, using amino-terminal-extended human growth hormone (hGH) as a model system. Twenty different hGH-genes with the sequence Met-Xxx-Glu-Glu-hGH where Xxx denotes each of the 20 different amino acids, were constructed and expressed in E. coli. Following purification of the products, the N-terminal amino acid sequences (10 cycles) were determined. The results demonstrate that the removal of methionine is dependent on the amino acid adjacent to methionine, and that the processing is strongly correlated to the radius of gyration of this amino acid. In addition, measurement of the hGH expression level from the 20 clones demonstrated that the small difference in the amino acid extension leads to a change in the specific hGH expression rate.

Amino Acid Sequence↗
PubMed1990

[Sinusitis caused by nasotracheal intubation].

Sinusitis following nasotracheal intubation (NTI) is an almost overlooked complication. The pathogenesis is believed to be development of oedema of the nasal mucosa due to irritation by the tube in the nasal cavity. The size of the tube is probably not important, whereas the duration of intubation is of major importance. The infection is often caused by Gram-negative microorganisms. The frequency is found to be 0.3% in short term intubation (less than 5 days) and 40.4% in long term intubation (greater than 5 days). In neurosurgical patients treated with NTI sinusitis is found in 52% and 100% of the patients. In adults the indications for prolonged NTI instead of orotracheal intubation and early tracheostomy should be considered carefully. If fever or sepsis develops in patients treated with NTI, investigations for sinusitis should be included in the search for focus. When sinusitis has developed, the tube should be removed, and the patient tracheostomised. If this treatment fails, surgical drainage should be performed.

Humans↗
PubMed1990

Isolation of transferrin from porcine gastric mucosa: comparison with porcine serum transferrin.

1. An iron-binding glycoprotein has been purified to homogeneity from porcine gastric mucosa. 2. The molecular weight (80,000), amino acid composition, carbohydrate content, N-terminal amino acid sequence, tryptic map, stoichiometry of iron binding (2 mol/mol), visible absorption spectrum of the ferric complex and chromatographic behaviour of the gastric protein are all strikingly similar to the corresponding properties of porcine serum transferrin. 3. The quantity of the gastric protein (1.3 mg/g wet weight) present in the gastric mucosa suggests that it is not serum transferrin (plasma concentration 1.8 mg/ml) contaminating the tissue. 4. A role for transferrin in the uptake of dietary iron by the gastrointestinal tract is proposed.

Amino Acid Sequence↗
PubMed1990

The model Malawi.

Explore the source record for details and available documents.

Anesthesiology↗
PubMed1990

Exaggerated reaction to insect bites in patients with chronic lymphocytic leukemia. Clinical and histological findings.

We report three patients with chronic lymphocytic leukemia with unusual vesiculo-bullous skin eruptions on exposed areas which were more commonly noted in spring and summer. The lesions appeared to be due to insect bites and could be differentiated from other causes on the basis of histological, immunohistological and clinical features. There was no correlation between the occurrence of the skin eruptions, disease status and treatment modalities. Exaggerated cutaneous reaction to insect bites should be considered as a cause of vesiculo-bullous lesions in patients with chronic lymphocytic leukemia.

Adult↗
PubMed1990

Antibody-combining sites: prediction and design.

For maximum value, a predicted model of an antibody-combining site should have an accuracy approaching that of an X-ray structure (1.6-2.7 A). In addition, the method by which the combining site is modelled should make no demands on the user of a sort that require arbitrary or subjective decisions to be made during the process. We have made substantial progress towards this objective and some recent results are reviewed. In addition, we describe how the modelling protocols developed can aid in the design of novel features within the antibody-combining site. The particular design example reported here suggests an approach for the introduction of metal-binding sites to create metallo-antibodies. This type of modification may be useful in the design of immunobiosensors, the induction of catalytic activity or simply as an alternative to metal chelates in the preparation of antibodies for imaging.

Algorithms↗
PubMed1989

Crystallization and X-ray data collection on human growth hormone.

Single crystals of natural sequence human growth hormone have been grown from media containing ethanol, acetone or paraldehyde. Recombinant growth hormone in its native and desamidated form and pituitary hormone have been crystallized. A full native set of diffraction data extending to 3.5 A resolution has been obtained with synchrotron radiation for crystals of recombinant human growth hormone grown from ethanol. The identity of the material in these crystals has been established by anion-exchange chromatography.

Chromatography, Ion Exchange↗
PubMed1989

Ossification of the cricothyroid membrane following minitracheotomy.

We describe a case in which a repeat minitracheotomy (MT) could not be performed 2 months after the first. The cricothyroid membrane seemed calcified and histological examination showed scar formation with dystrophic calcification and heterotopic bone formation. Scar formation following MT may have caused these alterations making repeat access to the airway through the membrane impossible.

Carcinoma, Squamous Cell↗
PubMed1989

Comparative X-ray crystallographic evidence for a beta-bend conformation as the active structure for peptide T in T4 receptor recognition.

A sequence similarity has been found between two segments of endothiapepsin (acid proteinase, 2APE), bovine pancreatic ribonuclease A, and peptide T, a segment of the gp120 protein of human immune deficiency virus (HIV), which has been implicated in blocking viral attachment to the T4 receptor. The two similar sequences of the acid proteinase enzyme are Leu-Ile-Asp-Ser-Ser-Ala-Tyr-Thr (residues 169-176) and Tyr-Thr-Gly-Ser-Leu-Asn-Tyr-Thr (residues 175-182). Since the X-ray crystallographic structures of the acid proteinase and ribonuclease are known, it has been possible to determine whether the three-dimensional structures of the segments are similar. Portions of both the segments of acid proteinase are directly superimposable on the structure of the RNase A 19-26 segment. The fact that the three similar sequences from two completely unrelated proteins give rise to almost identical structures raises the possibility that these segments may be involved in nucleating the folding of these proteins. In addition, this provides further support for the concept that the octapeptide sequence of peptide T of HIV, which is also similar in sequence to the 19-26 sequence of RNase A, is also structurally similar to these residues, which adopt a beta-bend conformation. Furthermore, comparison of similarities and differences in the structure of these similar sequences provides an explanation for alterations in the biological activity of various truncated or substituted derivatives of peptide T and additional confirmation of the structural requirements for peptide T in T4-receptor recognition.

Animals↗
PubMed1989

An ethological approach to autism: an analysis of visual behaviour and interpersonal contact in a child versus adult interaction.

Eighteen children classified into 4 diagnostic categories were compared based on their behaviour in a child-adult interaction. The categories consist of autistic children with full syndrome, autistic children in a residual state, hyperactive children, and mentally retarded children. An ethological analysis of the interpersonal distance, the amount of physical contact, and the direction of the look/gaze was carried out to describe some behavioural aspects of infantile autism. The autistic children with full syndrome were found to be different from the other categories by a relatively close interpersonal distance, a high frequency of physical contact, and a low frequency of "look at face".

Adolescent↗
PubMed1988

Dihydroergotamine and the thromboprophylactic effect of dextran 70 in emergency hip surgery.

In a prospective randomized controlled trial treatment with a combination of dextran 70 and dihydroergotamine (DHE) was compared with the administration of dextran 70 alone as prophylaxis against postoperative thrombo-embolic complications in emergency hip surgery. Forty-five consecutive patients with a fractured hip entered the study. Twenty-one were randomized to prophylactic treatment with dextran 70 (group 1) and twenty-four patients received dextran 70 and DHE (group 2). Both regimens were initiated pre-operatively and the surgical and postoperative procedures were the same in the two groups. On the first and fourth postoperative day, Tc-plasmin scintigraphy of the lower extremities and pulmonary ventilation/perfusion scintigraphy were performed to detect any deep vein thrombosis (DVT) and/or pulmonary emboli. A total of 19 per cent of group 1 patients developed DVT and so did 25 per cent in group 2; this difference was not statistically significant. Of the detected DVT, 60 per cent were subclinical, and 7 per cent of the patients had minor pulmonary emboli, all of which were symptomless. No therapeutic difference could be demonstrated between the two regimens. A recent report claiming that adding DHE to the prophylactic administration of dextran 70 considerably reduces the incidence of postoperative DVT in emergency hip surgery is questioned.

Aged↗
PubMed1988

Minitracheotomy in the treatment of postoperative sputum retention and atelectasis.

Minitracheotomy (MT) is a new method for the treatment of sputum retention and atelectasis. Through a 1-cm incision in the cricothyroid membrane (coniotomy), a specially designed tube is placed in the trachea, allowing suction to be performed. Fifteen patients, aged 37-78 years (median 62 years), with postoperative sputum retention, atelectasis and imminent respiratory failure, were treated with suction by MT. Thirteen of the patients recovered from their respiratory problems, while two patients had to be treated with intermittent positive pressure ventilation (IPPV). During insertion, one case of external bleeding and one case of subcutaneous and mediastinal emphysema were seen, while no complications were seen during cannulation. The duration of cannulation was 4-38 days (median 10 days). Following decannulation the incisions were airtight within 1 day and healed within 3 days. Ten patients left hospital in good health and five died because of surgical complications and/or cardiovascular failure. MT seems to be effective in the treatment of sputum retention and atelectasis. Advantages over other invasive methods make it a method of first choice. The method involves few complications and is often so effective that avoidance of intubation and IPPV is possible.

Adult↗
PubMed1988

An ethological description of depression.

During the last 20 years ethological psychiatric research has developed a working method for the systematic and quantitative recording and analysis of the nonverbal behaviour of psychiatric patients in their actual hospital environment. In this study this method was used to follow changes in the behaviour pattern of 5 depressed, hospitalized patients during their entire hospital stay. Parallel to ethological recording, patients were rated according to Hamilton twice a week. The patients who were most depressed at admission showed the greatest behavioural changes; the changes were most conspicuous in the behavioural elements representing social contact and communication. One patient who obviously developed a new depression during the observation period without this being recognized by the Hamilton rating or the clinical control, seemed to have been better described by the behaviour recording. This study shows that ethological psychiatric methods are very suitable for obtaining a better basis for the observations of the staff in the ward environment.

Aged↗