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Biomedical subjects

M Andersson

Publications and source records attributed to M Andersson.

At least 289 records · Page 16Linked to original sources
PubMed1994

Cerebrospinal fluid in the diagnosis of multiple sclerosis: a consensus report.

The Committee of the European Concerted Action for Multiple Sclerosis (Charcot Foundation) organised five workshops to discuss CSF analytical standards in the diagnosis of multiple sclerosis. This consensus report from 12 European countries summarises the results of those workshops. It is hoped that neurologists will confer with their colleagues in clinical chemistry to arrange the best possible local practice. The most sensitive method for the detection of oligoclonal immunoglobulin bands is isoelectric focusing. The same amounts of IgG in parallel CSF and serum samples are used and oligoclonal bands are revealed with IgG specific antibody staining. All laboratories performing isoelectric focusing should check their technique at least annually using "blind" standards for the five different CSF and serum patterns. Quantitative measurements of IgG production in the CNS are less sensitive than isoelectric focusing. The preferred method for detection of blood-CSF barrier dysfunction is the albumin quotient. The CSF albumin or total protein concentrations are less satisfactory. These results must be interpreted with reference to the age of the patient and the local method of determination. Cells should be counted. The normal value is no more than 4 cells/microliters. Among evolving optional tests, measurement of the combined local synthesis of antibodies against measles, rubella, and/or varicella zoster could represent a significant advance if it offers higher specificity (not sensitivity) for identifying chronic rather than acute inflammation. Other tests that may have useful correlations with clinical indices include those for oligoclonal free light chains, IgM, IgA, or myelin basic protein concentrations.

Acute Disease↗
PubMed1994

Self-treatment using 0.25%-0.50% podophyllotoxin-ethanol solutions against penile condylomata acuminata: a placebo-controlled comparative study.

OBJECTIVE: To compare the efficacy of 0.50% and 0.25% podophyllotoxin preparations against previously untreated penile warts. DESIGN: The study was performed as a double-blind, placebo-controlled investigation on 57 males randomly allocated to one of three groups of 19 males in each, receiving either the placebo solution (70% ethanolic vehicle) or one of the two podophyllotoxin preparations for 1-2 self-treatment courses b.i.d. for three days, separated by a one-week drug-free interval. SETTING: The STD out-patient clinic of the Department of Dermatovenereology at Southern Hospital of Stockholm, Sweden. RESULT: The placebo solution merely exerted a marginal influence on the warts while a primary cure was documented in 72% (13/18) and 81% (13/16) of altogether 34 evaluable men who treated their warts with 0.25% and 0.50% podophyllotoxin, respectively. Follow-up investigation (range 5-23 weeks) was possible for 24 of 26 podophyllotoxin treated men who were primarily cured. Some degree of relapse occurred in nine of them (38%). Of these relapses, warts occurred on previously untreated sites only in three cases (33%), and in another four (44%) relapse was associated with regrowth on treated sites as well as on new sites. When analysing the debulking potential of podophyllotoxin, it appeared that 0.25% podophyllotoxin eradicated 184 of originally 217 warts (85%); the corresponding figure for 0.50% podophyllotoxin was as high as 130 of 135 lesions (96%). Side effects were generally mild-moderate and well tolerated. CONCLUSION: The results underscore the potential usefulness of low-dose podophyllotoxin preparations as first-line chemotherapy of condylomata acuminata for home-treatment. The efficacy from topical use of 0.25% podophyllotoxin detected in the study is certainly of a magnitude signifying that podophyllotoxin concentrations lower than 0.50% deserve further investigation if the drug may be incorporated into alternative vehicles such as creams or ointments.

Adolescent↗
PubMed1994

Microvascular exudative hyperresponsiveness in human coronavirus-induced common cold.

BACKGROUND: The inflammatory response of the airway microcirculation in rhinitis and asthma may be recorded as luminal entry of plasma macromolecules (mucosal exudation). This study examines the exudative responsiveness of the subepithelial microvessels in subjects with and without common cold after inoculation with coronavirus. METHODS: The airway mucosa was exposed to exudative concentrations of histamine (40 and 400 micrograms/ml) before and six days after inoculation. To assess whether mucosal penetration of a topically applied agent was altered, nasal absorption of chromium-51 labelled ethylene diamine tetraacetic acid (51Cr-EDTA, MW 372) was also examined. A nasal pool technique kept the challenge and tracer solutes in contact with the same ipsilateral mucosal surface. Concentrations of albumin in lavage fluids were measured as an index of mucosal exudation of plasma. Nasal absorption of 51Cr-EDTA was determined by the cumulated 24 hour urinary excretion of radioactivity. RESULTS: Nine subjects developed common cold after coronavirus inoculation and 10 remained healthy. Histamine produced concentration dependent mucosal exudation of plasma in all subjects before and after coronavirus inoculation. In subjects with common cold, however, the histamine-induced mucosal exudation was significantly augmented compared with the group without common cold. This exudative hyperresponsiveness is not explained by an increased baseline exudation because the lavage regimen used produced comparably low baseline exudation in both groups of subjects, nor is it explained by an increased penetration of topical histamine because the ability of the nasal mucosa to absorb 51Cr-EDTA was not significantly increased in the subjects with common cold. CONCLUSIONS: An increased proclivity of the airway subepithelial microcirculation to respond with plasma exudation develops during coronavirus-induced common cold. This specific exudative hyperresponsiveness may be a feature of inflammatory airway diseases.

Adult↗
PubMed1994

Osteoporosis in a largely self-referred population: high prevalence but low medical priority: why?

Dual photon bone density screening for osteoporosis (OP) and osteopenia of the lumbar spine was performed in 108 women aged 34-75 years of whom 91% were self-referred in a cross-sectional study. OP was present in 18.6% when defined as greater than 2 SD bone mineral density (BMD) reduction compared to young normals and in 41.6% with osteopenia (1 SD BMD reduction). Twelve percent gave an actual history of previous fractures. In those who showed reduced BMD (60%), 69.5% had a family history and 54% scalp hair loss although this was not a good prognostic sign. An Osteoporosis Risk Questionnaire was not an accurate predictor of BMD, thus bone density screening remains essential for early and accurate diagnosis. Previous oral contraceptive use appears to be protective (p = 0.004). Sex hormone replacement therapy (sHRT) taken by 20% of the postmenopausal patients had not yet provided significant protection (p = 0.15) probably due to its late introduction, short exposure and failure to optimise dose levels. Despite detailed information and questionnaires provided to their doctors, of 53 patients with OP or osteopenia 15 (28%) started sHRT without additional investigation, 19 (36%) remained untreated, while the outcome in the rest, 19 (36%), was unknown. A disturbing indifference by doctors and patients continues to the prevention and treatment of OP and low BMD, a potentially preventable and reversible condition, which signals a higher risk of future fragility fracture.

Adult↗
PubMed1994

The primary in vivo immune response to Mls-1 (Mtv-7 sag). Route of injection determines the immune response pattern.

Injection of cells expressing the retroviral superantigen Mls-1 (Mtv-7 sag) into adult Mls-1- mice induces a strong immune response including both T- and B-cell activation. This model was used for studying qualitative aspects of the immune response in normal mice with a defined antigen-presenting cell (the B cell) and without the use of adjuvant. BALB/c mice were injected locally or systemically with Mls-1-expressing spleen cells from Mls-1-congenic BALB.D2 mice. Intravenous injection led to an initially strong expansion of Mls-1-reactive V beta 6+ CD4+ cells mainly in the spleen, to a large degree explained by the trapping of reactive cells, and a rapid down-regulation of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production, consistent with the proposed tolerogenic property of B cells as antigen-presenting cells. However, these mice developed a slowly appearing but persistent B-cell response dominated by IgG1-producing cells, suggesting a shift in lymphokines produced rather than complete unresponsiveness. Subcutaneous injection into the hind footpad with the same number of cells led to a strong local response in the draining lymph node, characterized by a dramatic increase of V beta 6+ CD4+ T cells, local production of IL-2 and IFN-gamma and a strong but short-lived antibody response dominated by IgG2a-producing cells, characteristic of a T-helper type 1 (Th1) type of response. Both routes of injection led ultimately to deletion of reactive T cells and anergy, as defined by the inability to produce IL-2 upon in vitro stimulation with Mls-1. It is concluded that Mls-1 presented by B cells induces qualitatively different responses in vivo dependent on the route of injection. We propose that the different responses result from the migration of the injected cells to different micro-anatomical sites in the lymphoid tissue. Furthermore, these results suggest that B cells may function as professional antigen-presenting cells in vivo present in an appropriate environment.

Animals↗
PubMed1994

Glucocorticoids may not inhibit plasma exudation by direct vascular antipermeability effects in human airways.

In animal airways, single topical treatment with glucocorticoids produces a prompt vascular anti-permeability effect that may last for several hours. This has been considered a potentially important anti-inflammatory action in human airways. The present study, involving nine healthy subjects, examines whether nasal budesonide application affects histamine-induced mucosal exudation of plasma and plasma-derived mediators in human airways. A selected low concentration (40 micrograms.ml-1) of the vascular permeability-inducing agent histamine was kept in one of the nasal cavities for 10 min, and this challenge was repeated at 50 min intervals over 4 h. Ten minutes after the first histamine-challenge, a clinical dose of budesonide (100 micrograms) was sprayed into the same nasal cavity. Nasal lavage fluid levels of albumin and fibrinogen were measured as indices of mucosal exudation of bulk plasma, and bradykinins were analysed to indicate generation of plasma-derived mediators. The baseline levels of albumin and fibrinogen were evaluated in 24 healthy control subjects by means of a 10 min saline lavage. Histamine produced significant mucosal exudation of albumin and fibrinogen, compared to control subjects. Topical budesonide treatment did not affect the histamine-induced mucosal exudation of albumin or fibrinogen, nor did budesonide affect the mucosal output of bradykinins. The present human airway data do not support the view, based on animal findings, that airway glucocorticoids reduce mucosal exudation of plasma by direct vascular effects. We suggest that anti-exudative effects of topical glucocorticoids in airway diseases indirectly reflect the inhibition of cellular inflammatory processes by these drugs, rather than any direct effects on the airway microcirculation.

Administration, Intranasal↗
PubMed1994

[Malnutrition common in Swedish hospitals. Risk of complications and prolonged care increases].

The occurrence of malnutrition has been investigated at four hospitals and the underlaying factors evaluated. The results suggest that malnutrition is still a manifest clinical problem at Swedish hospitals, and that it is associated with an increased risk of complications and prolonged care. During hospitalisation a negative nitrogen and energy balance is observed. It is important to identify patients at risk, as the prevention of undernourishment would appear to be a more effective approach than the treatment of established malnutrition.

Activities of Daily Living↗
PubMed1994

Purification of diacylglycerol:acyltransferase from rat liver to near homogeneity.

A method to isolate a protein related to the diacylglycerol:acyltransferase (DGAT) activity in rat liver microsomes has been developed. The microsomes were treated with sodium deoxycholate (DOC; 0.1 mg/mg protein) at a concentration of 1 mM, i.e., below the critical micellar concentration (CMC), to remove luminal and loosely bound proteins. Three percent of the DGAT activity and all of the acylCoA hydrolyse activity were present in the supernatant, i.e., among the extracted loosely bound proteins. The insoluble material, recovered as a pellet, was suspended in DOC (1.6 mg/ml and mg protein in the original microsomes), and subjected to multiple, short (1-2 sec) sonications. CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate; 5 mg/ml) was then added, and the sonication was repeated. The detergent-treated microsomal membranes were filtered through a 0.22-micron filter and chromatographed on a Superose 6 column from which the DGAT activity was recovered in a high molecular mass fraction. A monoclonal antibody that reacted with this fraction was raised and used in immunoaffinity experiments. This antibody removed 93 +/- 6% (mean +/- SD, n = 4) of the DGAT activity present in solution and 44 +/- 6% (mean +/- SD, n = 5) of the applied activity could be recovered after desorption. The antibody recognized a 60 kDa protein upon Western blot of rat liver microsomal proteins as well as of the DGAT-containing fraction from the Superose 6 column. A 60 kDa protein was highly enriched in the DGAT-containing retained fraction from the immunoaffinity chromatography. This 60 kDa protein reacted with the monoclonal antibody on Western blot. In addition to the 60 kDa protein, the retained fraction from the immunoadsorber contained a 77 kDa protein. This protein did not react with the monoclonal antibody on Western blots. Neither the 60 nor the 77 kDa protein reacted with antibodies to mouse immunoglobulins or showed any unspecific reaction with immunoglobulins.

Acyltransferases↗
PubMed1994

Dentacolor as veneering material for titanium. A clinical evaluation after 51-72 months.

Fifty-one patients who had been provided with 104 Dentacolor veneered titanium copings/pontics were recalled after periods varying between 51 and 72 months. Fourty-two patients with 85 units-67 crowns and 18 pontics-attended. In this retrospective study the condition of the veneering material was rated by dentists who had performed the treatment. Seven units exhibited Dentacolor fractures and one obvious discoloration of the veneering material. These eight units correspond to a failure rate of 9.4%. The corresponding failure rate after 3 years was 7.1%.

Adult↗
PubMed1994

Primary liver tumors among Danish patients exposed to Thorotrast.

The potential carcinogenic effects of internally deposited alpha-particle-emitting nuclides, notably plutonium, in the liver in humans are unknown but are of concern in relation to exposures from the nuclear industry. However, patients injected with the radiographic contrast medium Thorotrast are chronically exposed to alpha-particle radiation from 232ThO2 in the liver. Among 1003 patients injected with Thorotrast, 584 of whom were alive 15 years after the injection and 40 at the end of follow-up, a total of 127 liver cancers were diagnosed, 45 of which were hepatocellular carcinomas, 41 cholangiocarcinomas and 33 hemangiosarcomas. The median time from injection to diagnosis was 35 years (range 18-48) and the cumulative frequency was 55.4% after 48 years. In univariate and multivariate analyses, the cumulative frequency of liver cancer was best described as a function of the estimated mean cumulative alpha-particle radiation dose to the liver 15 years ago, being independent of age, gender and volume of injected Thorotrast. This may be interpreted to mean that the liver cancer rate is not related to the dose rate and that the period from malignant transformation to diagnosis of cancer is 15 years. The risk of liver carcinogenesis induced by alpha-particle radiation, assuming 15 years from induction to diagnosis, was estimated to be 712 cases/10(4) persons per gray. This value is considerably higher than estimated earlier.

Adolescent↗
PubMed1993

Isolation of three antibacterial peptides from pig intestine: gastric inhibitory polypeptide (7-42), diazepam-binding inhibitor (32-86) and a novel factor, peptide 3910.

Two antibacterial peptides, cecropin P1 and PR-39 (39-residue proline/arginine-rich peptide), from the upper part of pig small intestine have previously been isolated and characterized. We have now continued our search for antibacterial peptides in different side fractions generated during the isolation of intestinal hormones. Starting from one such fraction and monitoring activity against Bacillus megaterium, we isolated three homogeneous peptides by three consecutive chromatographic steps. Amino acid sequence analysis in combination with mass spectrometry identified two of the peptides as gastric inhibitory polypeptide (7-42) [GIP(7-42)] and diazepam-binding inhibitor (32-86) [DBI(32-86)], derived from factors already known. However, intact GIP and DBI have hardly any antibacterial activity by themselves. The third peptide constitutes a previously unknown structure, designated as peptide 3910 from its molecular mass. All three peptides showed good activity against B. megaterium. In addition, GIP (7-42) showed some activity against Streptococcus pyogenes and an Escherichia coli mutant with a defect in its outer membrane.

Amino Acid Sequence↗
PubMed1993

Structural studies of the extracellular polysaccharide from Butyrivibrio fibrisolvens strain X6C61.

The capsular polysaccharide from Butyrivibrio fibrisolvens strain X6C61 has been investigated using NMR spectroscopy, mass spectrometry, methylation analysis, and partial acid hydrolysis as the main methods. The polysaccharide is composed of hexasaccharide repeating units having the following structure. [formula: see text] The polysaccharide also contains O-acetyl groups, of which approximately 70% are substituted to O-3 of the beta-D-Glc pA residue.

Bacterial Capsules↗
PubMed1993

Assignment of intrachain disulfide bonds in platelet-derived growth factor B-chain.

Platelet-derived growth factor (PDGF)-BB is a dimeric protein held together by two disulfide bonds involving the 2nd and 4th cysteine residues from the NH2 terminus. To localize the three intrachain disulfide bonds in PDGF, a method was devised that made it possible to cleave PDGF at specific sites. A set of PDGF derivatives in which specific amino acids were mutated to methionine residues was generated. The recombinant proteins, immunoprecipitated from metabolically labeled transfected COS cells, were then subjected to CNBr cleavage and analyzed by SDS-gel electrophoresis under nonreducing conditions. Based on whether the mutated proteins remained in one piece or fell apart after CNBr cleavage, it was possible to deduce the disulfide bond arrangement in the PDGF B-chain; one bond involves the 1st and 6th cysteine residues, another the 3rd and 7th, and the last the 5th and 8th. The latter disulfide bond was found to be dispensable for receptor binding, whereas the former two were found to be essential for the correct folding or stability of the PDGF B-chain.

Animals↗
PubMed1993

Simultaneous solubilization of high-affinity receptors for VIP and glucagon and of a low-affinity binding protein for VIP, shown to be identical to calmodulin.

Anion-exchange chromatography of solubilized pig liver cell membranes on DEAE-Sepharose gave a fraction with high affinity binding proteins for VIP and glucagon distinct from each other. Scatchard analysis indicated the presence of one binding site for VIP (Kd 1.5 +/- 0.6 nM and Bmax 1.3 +/- 0.4 pmol/mg). The order of potency for VIP-related peptides to inhibit [125I]VIP binding was: VIP > peptide histidine isoleucine amide (PHI) > rat growth hormone releasing factor (rGRF) > secretin. GTP-gamma-S inhibited [125I]VIP binding and reduced the affinity of VIP binding sites to 6.5 nM. In the same isolated fraction, [125I]glucagon binding was displaced by glucagon preferentially to oxyntomodulin, and GTP did not affect this [125I]glucagon binding. Scatchard analysis indicated the presence of one binding site for glucagon (Kd 0.08 +/- 0.03 nM and Bmax 0.31 +/- 0.01 pmol/mg). A low-affinity VIP binding protein (IC50 0.7 microM) was detected in a fraction eluting later and exhibited a peptide specificity: rGRF > VIP > VIP(10-28) > secretin > PHI. This rGRF-preferring protein (18 kDa) was purified and had a partial amino-acid sequence identical to that of calmodulin. Its [125I]VIP binding was competitively inhibited by VIP and calmidazolium in a manner similar to that for pig brain calmodulin. Thus we have co-solubilized VIP and glucagon high affinity receptors from pig liver cell membranes and separated them from VIP-binding calmodulin.

Amino Acid Sequence↗
PubMed1993

Distribution of prenyltransferases in rat tissues. Evidence for a cytosolic all-trans-geranylgeranyl diphosphate synthase.

The present study describes the presence of two different geranylgeranyl diphosphate (GGPP) synthase activities, one cytosolic and one membrane-associated, in a number of rat tissues. Both enzymes utilize farnesyl diphosphate (FPP) and isopentenyl diphosphate (IPP) as substrates, but they give rise to different products. The membrane-associated activity produces trans,trans,cis-(E,E,Z)-GGPP, involved in the biosynthesis of long-chain polyprenols. The cytosolic activity produces only the all-trans-(E,E,E) isomer of GGPP, which is utilized as substrate in cytosolic protein prenylation reactions. All-trans-GGPP synthase activity was recovered in the cytosolic fraction from all tissues investigated, but the specific activities varied. The highest specific activities were found in brain, spleen, and testis, followed by kidney and liver. The enzyme activity in rat brain cytosol was further characterized and found to exhibit a narrow pH optimum around 5.0-6.0 and to be highly stimulated by Zn2+. Maximal stimulation was attained with 1 mM Zn2+, whereas Mg2+ had no effect on the enzyme activity. The all-trans-GGPP synthase activity exhibited high affinities for its substrates, i.e. the apparent Km values for FPP and IPP were found to be 0.6 and 3.5 microM, respectively. When rats were fed mevinolin (lovastatin), FPP and all-trans-GGPP synthase activities were affected differently in certain tissues. Mevinolin treatment resulted in an increase in FPP but a decrease in all-trans-GGPP synthase activity in rat liver and kidney. In spleen mevinolin treatment caused a greater than 70% decrease in all-trans-GGPP synthase activity, while FPP synthase was almost unaffected. The presence of two different GGPP synthase activities in the cell, together with the fact that FPP and all-trans-GGPP synthesis in the cytosol are regulated independently, may be of significance in the regulation of isoprenoid biosynthesis, as well as of protein isoprenylation.

Alkyl and Aryl Transferases↗