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Biomedical subjects

C Hansson

Publications and source records attributed to C Hansson.

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

The effects of cadexomer iodine paste in the treatment of venous leg ulcers compared with hydrocolloid dressing and paraffin gauze dressing. Cadexomer Iodine Study Group.

BACKGROUND: The aim was to examine cadexomer iodine paste in a comparative clinical trial. METHODS: A 12-week, randomized, open, controlled, multicenter, multinational trial in patients with exudating, venous leg ulcers of cadexomer iodine paste (Iodosorb/Iodoflex), hydrocolloid dressing (Duoderm E, Granuflex E), or paraffin gauze dressing (Jelonet) was carried out. All patients used short-stretch compression bandages (Comprilan) throughout the study. The primary efficacy variable was a reduction in ulcer size (%), and the secondary end-point was the time taken to stop exudation, when the patient had completed the study according to the protocol. A total of 153 patients entered the study and were treated for 12 weeks or until cessation of exudation. RESULTS: The mean reduction in ulcer size in all patients was 62% with cadexomer iodine vs. 41% and 24% for hydrocolloid and paraffin gauze (ns). Of those treated for 12 weeks (n = 51), ulcer area reduction was 66% for cadexomer iodine and 18% for hydrocolloid (p = 0.0127). For the whole material, the rate of healing (ulcer area reduction per week) was significantly higher for cadexomer iodine than for paraffin gauze (0.64 cm2/week vs. 0.19 cm2/week, p = 0.0353). The treatment costs were similar in all groups; however, when the costs were correlated with healing over a 12-week period, cadexomer iodine paste was found to be more cost effective than hydrocolloid dressing or paraffin gauze dressing. CONCLUSIONS: This study shows that cadexomer iodine paste is an efficient, cost-effective and safe alternative to hydrocolloid dressing and paraffin gauze dressing for the treatment of venous leg ulcers.

Adult↗
PubMed1998

A clinically applicable method for determining the three major alleles at the Duffy (FY) blood group locus using polymerase chain reaction with allele-specific primers.

BACKGROUND: The clinically significant antigens of the Duffy (Fy [FY]) blood group system are expressed on the red cell form of the FY glycoprotein, a promiscuous chemokine receptor and also a receptor for malarial parasites. After the cloning of cDNA coding for FY glycoprotein, the molecular basis of the three major alleles (Fya/Fyb/Fy) has been established. Because of the mistyping of the silent Fy allele as Fyb, the error rate of current genotyping methods is high in black populations. STUDY DESIGN AND METHODS: Two hundred blood donors (European whites and African Blacks) and some amniotic DNA samples were investigated by a new allele-specific primer polymerase chain reaction technique. Sense primers corresponding to normal and GATA-1-mutated FY gene promoter region sequences were combined with antisense primers discriminating the Fya/Fyb polymorphism. RESULTS: Complete correlation between FY phenotypes and genotypes was obtained in all samples studied, although, in two whites and one black, serology showed weak Fyb expression while polymerase chain reaction indicated a Fyb allele. Gene frequencies were calculated. CONCLUSION: This simple and rapid polymerase chain reaction method was shown to detect the three common alleles at the FY locus in two representative ethnic populations. Its future use as an independent technique in red cell FY investigations and for fetal genotyping in hemolytic disease of the newborn is predicted.

Alleles↗
PubMed1997

The macrophage migration inhibitory factor MIF is a phenylpyruvate tautomerase.

A macrophage migration inhibitory factor (MIF), originally described as a product of activated lymphocytes, has been defined as a 12 kDa protein, expressed in a wide variety of tissues. Here MIF is identified as a phenylpyruvate tautomerase (EC 5.3.2.1) having p-hydroxyphenylpyruvate and phenylpyruvate as its natural substrates. The definition of MIF as an enzyme may yield insight into the mechanism of action of this proinflammatory and immunomodulating cytokine.

Amino Acids↗
PubMed1997

Extraction of mercaptobenzothiazole compounds from rubber products.

At evaluation of contact dermatitis caused by solid material, patch testing is usually performed with the material as such and with extracts of it. In this study, optimization of the extraction technique monitored by quantitative HPLC analysis of the extracted haptens is described for mercaptobenzothiazole derivatives. Several solvents with different properties are included. Acetone has traditionally been a solvent widely used for the extraction of organic haptens from solid products. However, acetone and other ketones are not inert solvents. The rubber accelerators 2-(4-morpholinyl mercapto) benzothiazole (MMBT) and N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) react with acetone, yielding 2 new compounds, which were isolated and characterised by NMR and MS. For the extraction of solid rubber products, methyl tert-butyl ether (MTBE) was found to be a more suitable solvent which is unreactive to most common haptens.

Antifungal Agents↗
PubMed1997

Concomitant contact dermatitis due to textile dyes and to colour film developers can be explained by the formation of the same hapten.

p-phenylenediamine derivatives are widely used in industry and in cosmetics, and several of them are well-known sensitizers. One group of allergenic p-phenylenediamine derivatives are used as colour film developers. Cross-reactivity between the colour film developers has been reported. In this paper, an occupational facial dermatitis due to colour film developers is described. The patient reacted to colour film developers (CD-1, CD-2, CD-3, and CD-4), but not to other p-phenylenediamine derivatives tested. He also showed allergic reactions to Disperse Blue 106 and Disperse Blue 124 and to Disperse Red 17, but not to Disperse Orange 3. The activation of the colour film developers by oxidation at physiological pH was analysed with chemical methods, and the mechanism responsible for the concomitant reactivities to the colour film developers and the disperse dyes at a molecular level is discussed.

Adult↗
PubMed1997

Interactive wound dressings. A practical guide to their use in older patients.

The properties of an ideal wound dressing do not change with the introduction of new types of wound dressing, but the range of effects on wound healing increases. The number of dressings available is enormous, and the choice between them is often bewildering. Because there is still no ideal dressing for all wound types, it is necessary to get to know a few well, and to avoid switching to new therapies solely on the basis of anecdotal reports. The adoption of novel dressings should be based on scientific evidence. At present, dressings are still chosen on the basis of local traditions and personal empirical experience, together with evidence from the few double-blind, placebo-controlled trials that have been performed. In the management of ulcers, a particular wound management plan should not be changed if the ulcer being treated is decreasing in size and the patient is comfortable. The dressing should be chosen with care. The type of chronic ulcer and its appearance, the amount of exudate and the presence or absence of pain all assist in the selection of an appropriate wound dressing product. Quality-of-life aspects are important. In the elderly, good quality of life may not necessarily require complete ulcer healing, although this is naturally desirable. Dressing changes should be minimised and the ulcer should be kept moist and the surrounding skin dry. The high cost of interactive dressings is a potential disadvantage of their use. However, if the wound can be re-dressed at longer intervals and if healing occurs more quickly, their use may be cost effective and associated with less pain and a better quality of life.

Aged↗
PubMed1997

Treatment of adolescents with Hansaplate/headgear. Influence on face in profile and on dentition.

The treatment effects of Hansaplate/headgear in the course of 1 year were analyzed. Twenty-one girls and 19 boys, 10 and 11 years old, respectively, with postnormal occlusion and an average overjet of 8 mm, made up the treatment group. Forty untreated patients with the same type of malocclusion and dentofacial morphology as the treated children, and paired and matched for sex and age, made up the controls. Measurements were obtained from cephalometric headfilms. Matched-intrapairs analysis of control versus treatment changes after 1 year of treatment was done. This showed that the treatment resulted in inhibited sagittal growth of the maxilla, increased anterior face height and a flattened soft tissue profile with a less protrusive upper lip and a less pronounced sulcus mentolabialis. The overjet decreased by 5 mm on average. Only slight retroclination of the upper incisors without extrusion and retroclination of lower incisors to the mandibular plane occurred. No significant anterior positioning of the mandible as compared with the controls was recorded in this study.

Adolescent↗
PubMed1996

Pulmonary 99mTc-human serum albumin clearance and effects of surfactant replacement after lung lavage in rabbits.

OBJECTIVE: Pulmonary clearance of technetium-labeled human serum albumin was measured in order to investigate whether the surfactant layer is a rate-limiting factor for the permeability of the alveolar-capillary membrane for 99mTc-labeled albumin. DESIGN: Prospective, randomized, controlled trial. SETTING: Research laboratory. SUBJECTS: Nineteen white New Zealand adult rabbits. INTERVENTIONS: Three groups of rabbits were studied: group 1 animals received natural surfactant after lung lavage; group 2 animals underwent lung lavage only; and group 3 animals were not lavaged and served as an untreated, healthy control group. All animals were ventilated with high pressures. MEASUREMENTS AND MAIN RESULTS: 99mTc-labeled albumin was nebulized into the inspiratory line of the breathing circuit with an air jet nebulizer. The clearance measurements were then immediately started. Gamma camera images were obtained in 1-min frames for 120 mins and stored in a 64 x 64 image matrix in a computer. In group 1 animals, surfactant restored blood gases to near normal, and all animals except one had bi-exponential clearance curves. The half-life of the fast compartment was 35.9 +/- 6.4 mins, and the half-life of the slow compartment was 847.5 +/- 143.5 mins. All group 2 animals also had bi-exponential clearance curves of the tracer (the half-lives of the fast and slow compartments were 14.6 +/- 6.7 and 459.8 +/- 167 mins, respectively). The half-lives of both the fast (p < .01) and slow (p < .01) components were significantly different between groups 1 and 2. Group 3 had a mono-exponential half-life of 580 +/- 225 mins. CONCLUSIONS: The use of 99mTc-human serum albumin as a tracer molecule is possible and feasible. The clearance of this tracer is, in part, determined by the integrity of the pulmonary surfactant system, as it is with 99mTc-diethylenetriamine pentaacetate.

Animals↗
PubMed1996

Antibodies to pneumococcal polysaccharides in human milk: lack of relationship to colonization and acute otitis media.

BACKGROUND: This study analyzed antibodies to pneumococcal polysaccharides in human milk and their effect on nasopharyngeal colonization and acute otitis media in breast-fed infants. METHODS: A total of 503 milk samples were collected from 310 mothers. Nasopharyngeal cultures were obtained from their children at 2, 6 and 10 months postpartum, and the capsular groups/types of the Streptococcus pneumoniae isolates were determined. RESULTS: Types 6A, 6B, 19A, 19F and 23F accounted for 54% of the pneumococcal isolates, but type 3 isolates were uncommon. Milk samples were analyzed for antibody activity to the common capsular polysaccharide types 6A, 19F and 23F; to the type 3 polysaccharide; to C-polysaccharide; and to phosphorylcholine (PC), a major component of the pneumococcal cell wall polysaccharide (CWPS). Anti-capsular antibody activity was low or absent in > 90% of the milk samples. In contrast anti-PC antibody activity was detected in 88% and anti-CWPS in 84% of the samples. The frequency of acute otitis media did not vary with the milk anti-capsular, anti-PC or anti-CWPS antibody activity. CONCLUSIONS: There was no reduction in nasopharyngeal carriage of S. pneumoniae among children fed milk with anti-capsular or anti-PC antibody activity, but carriage was increased in those children who received milk with anti-CWPS antibody activity. A protective role of antipolysaccharide or anti-CWPS antibodies in milk was not detected under the study conditions.

Adult↗
PubMed1995

Fusarium infection with unusual skin lesions in a patient with acute lymphocytic leukemia.

A 27-year-old woman with acute lymphocytic leukemia developed red painful skin lesions, asymmetrically distributed over the face and extremities. They gradually increased in size and number, and in the center of each lesion blisters appeared followed by central necrosis with surrounding erythema. In several lesions the central necrosis was covered with a white powder shown to be fungal mycelium. Cultures from skin lesions and blood showed a Fusarium species. The skin lesions are helpful in recognizing this deep fungal infection in an immunocompromised host.

Adult↗
PubMed1995

The microbial flora in venous leg ulcers without clinical signs of infection. Repeated culture using a validated standardised microbiological technique.

The change of ulcer size in relation to the presence of species and quantities of microorganisms was analysed in 58 patients with venous leg ulcers, all without clinical signs of infection. Microbiological samples were taken on the day of inclusion and then repeated 4 times at monthly intervals or until the ulcer had healed or was too small to be cultured from. There was growth of microorganisms in all ulcers, and the numbers were below 10(4) per mm2 of ulcer surface in all cases. No correlation was found between ulcer size change and the species and amounts of microorganisms. Sixty-nine species were isolated. Staphylococcus aureus was found in 88%, Enterococcus faecalis in 74%, Enterobacter cloacae and Peptococcus magnus in 29%, and fungi in 11% of the samples. One or more obligate anaerobe species was found in 41% of the samples and in half of the ulcers and constituted 62% of all bacterial species. The colonising ulcer flora was markedly constant over time in the individual ulcers regardless of change in size. Resident bacterial species were found in 57 of the 58 ulcers. If all samples were considered, the microorganisms were associated with not more than one fifth of the variability in healing rate, as shown by linear multiple regression analysis. The same species of microorganisms were found in ulcers that decreased (or healed) and in those that increased in size. Although an association between the microorganisms and ulcer healing could not be ruled out in this study, there seems to be no indication for routinely performed culture in the absence of clinical signs of infection in venous leg ulcers.

Aged↗
PubMed1995

Urinary excretion of melanocyte metabolites during treatment with chloroquine phosphate.

The antimalarial drug chloroquine is also used in the prevention of photodermatoses and in patients with inflammatory connective diseases. The drug binds strongly to melanin. Melanocytic activity can be studied by analysis of the urinary markers of eumelanin (6-hydroxy-5-methoxyindole-2-carboxylic acid, 6H5MI-2-C) and phaeomelanin (5-S-cysteinyl-dopa, 5-S-CD). To determine whether chloroquine interacts with this activity, we measured the urinary excretion of the two metabolites in 16 patients with either systemic or discoid lupus erythematosus, polymorphic light eruption or rheumatoid arthritis, during a period with and without treatment with chloroquine phosphate. Two control groups consisting of 7 untreated patients and 10 healthy subjects were also included in the study. During medication, there was a significant increase in 5-S-CD excretion, while the excretion of 6H5MI-2-C was not significantly affected. No significant changes in the excretion of any of the two urinary markers were found in the untreated patients, while a non-significant increase in 5-S-CD excretion was seen in the healthy controls at the follow-up.

Adult↗
PubMed1995

The effect of antiseptic solutions on microorganisms in venous leg ulcers.

The effect on the microbial ulcer flora of wet gauze dressings soaked in antiseptic solutions used for desloughing leg ulcers is not known. Quantitative cultures were therefore performed in 45 venous leg ulcers, before application and after 15 minutes' treatment with gauze dressings with four different antiseptic solutions: aluminium acetotartrate (Alsol) 1%, potassium permanganate 0.015%, acetic acid 0.25% and chloramine 0.25%. The percentage of ulcers with each type of microorganism did not differ before and after application of the antiseptic solutions. Staphylococcus aureus was found in 79% of the ulcers, gram-negative rods in 39%, S. epidermidis in 21%, Proteus spp in 21%, Pseudomonas spp in 14% and fungi in none. Potassium permanganate reduced the mean number of bacteria per ulcer from 4.4 x 10(6) to 0.9 x 10(6) (ns), chloramine from 2.7 x 10(6) to 2.2 x 10(6) (ns), Alsol from 1.2 x 10(7) to 3.5 x 10(6) (ns) and acetic acid from 6.3 x 10(6) to 2.6 x 10(5) (p = 0.007). S. aureus was reduced by acetic acid (p = 0.002), gram-negative rods by both chloramine (p = 0.03) and acetic acid (p = 0.03). The number of Pseudomonas, Proteus, S. epidermidis and Streptococcus haemolyticus group G was not reduced significantly (p > 0.05) by any of the solutions.

Acetates↗
PubMed1995

Oxidative activation of the propolis hapten isoprenyl caffeate.

The reactions of isoprenyl caffeate, the strongest allergen known to be present in propolis, with plausible functional groups of proteins were studied. The thiols glutathione and cysteine, which add to isoprenyl caffeate after having been oxidised to the corresponding quinone, served as model substances. The structure of the thiol adducts was determined by spectroscopic methods, addition being found to occur at C-2. The results support the hypothesis that the catecholic propolis hapten is a pro-hapten that forms a complete antigen after oxidation to caffeate quinone and addition to nucleophilic groups of proteins.

Allergens↗