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Biomedical subjects

M Andersson

Publications and source records attributed to M Andersson.

At least 433 records · Page 24Linked to original sources
PubMed1987

Isotachophoretic and HPLC determination of nucleotides in rat liver cell nuclei isolated by non-aqueous technique.

Rat liver whole cells and cell nuclei were prepared by a non-aqueous technique (glycerol). The nuclear preparations were of different purity as determined by RNA/DNA ratios (0.17-1.60) and accordingly were divided into 3 subgroups (mean values 0.29, 1.04 and 1.48). RNA nucleotides were separated by isotachophoresis and HPLC and calculated per mg DNA. Two of the nuclear subgroups (RNA/DNA = 1.04 and 1.48) had significantly elevated nucleotide values in relation to RNA/DNA. UDP-N-acetylhexosamine/DNA, on the contrary, was reduced in conformity with RNA in the preparations. Our findings may indicate different nucleotide concentrations in different parts of the cell.

Adenine Nucleotides↗
PubMed1987

Inhibition of the dermal immediate allergic reaction through prolonged treatment with topical glucocorticosteroids.

The effect of prolonged topical dermal glucocorticosteroid treatment on the immediate and late-phase allergic skin reaction was studied in a double-blind, randomized, placebo-controlled study. Seventeen patients with hay fever and with a positive skin test for timothy and/or birch pollen allergens were studied in a pollen-free season. Skin prick tests for these two allergens as well as a negative saline and a positive histamine control were made with a preloaded standardized prick test needle. The area of the induced wheal-and-flare reaction was measured 15 minutes after allergen application, and any induced late-phase responses were measured after 6 hours. After a baseline recording, the patients treated the volar aspect of one forearm twice daily with a cream of 0.05% clobetasol 17-propionate and the other forearm with the equivalent vehicle in a randomized, double-blind fashion. After 1 week the skin prick test was repeated on both arms. A statistically significant reduction of the allergen-induced wheal-and-flare response was found after active treatment as compared to control and pretreatment values. A reduction was also found in the histamine-induced flare but not the wheal reaction as compared to the control. A late-phase dermal reaction was found in six of the patients, and this was statistically significantly reduced by the glucocorticosteroid pretreatment. Thus, in similarity to findings in vivo on the human nose and bronchus, we found, in addition to the well-known glucocorticosteroid-induced reduction of the allergic late-phase response, an inhibition of the dermal immediate allergic reaction as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1987

Expression of an interferon-alpha gene variant in E. coli using tandemly repeated synthetic ribosomal binding sites.

A human interferon-alpha 2 gene variant was expressed in Escherichia coli under the control of the tryptophan operon promoter and of a series of synthetic partially overlapping ribosomal binding sites, which control initiation of translation. Variation in the distance between the start codon and such a set of ribosomal binding sites affected the level of interferon expression much less than previously described for single ribosomal binding sites.

Base Sequence↗
PubMed1987

A method for the analysis of a large number of specific and multispecific B cell hybridomas derived from primary immunized lymph nodes.

A previously described efficient short term immunization protocol enables analysis of the specificities of large numbers of monoclonal antibodies in murine lymph nodes. In this paper we measure the B cell responses against two highly immunogenic antigens, rat type II collagen (NRC) and chick ovalbumin (OVA), as well as against the poorly immunogenic denatured rat type II collagen (DRC). We found that relatively large numbers of specific B cell hybridomas could be produced after immunization with NRC (28%) and lower numbers with OVA (6%) and DRC (3%). However, in all immunizations there were also generated large numbers of hybridomas producing multispecific antibodies (5-15%). The multispecificity was sustained when the hybridomas were subcloned. These results show that large numbers of immunogen-reactive hybridomas can easily be obtained with the present method. They also show that different immunogens differ in their immunogenicity. The very high efficiency of native type II collagen to induce an antibody response, which is widely crossreactive with autologous type II collagen, could possibly be explained if it is assumed that the natural occurring repertoire is based on stimulation of autoantigens.

Animals↗
PubMed1987

Distribution and metabolism of N'-nitrosonornicotine in the miniature pig.

The distribution and metabolism of [5-3H]N'-nitrosonornicotine ([5-3H]NNN) was studied in three 18-day-old miniature pigs. [5-3H]NNN was administered by intracardiac administration into the right ventricle of the heart to mimic uptake by the lung. Whole body autoradiograms taken 15-220 min after treatment showed high levels of radioactivity in the mandibular and parotid salivary glands, Harder's gland, lacrimal glands, glands of the snout and respiratory part of the nasal cavity, and the melanin of the eyes and skin. Bound radioactivity was most abundant in the nasal mucosa and liver. Analysis of tissues by h.p.l.c. showed the presence of high levels of [5-3H]NNN in the mandibular glands and Harder's gland. Levels of [5-3H]NNN and its metabolites were determined in arterial and venous serum, 0.5-220 min after injection. The disappearance of [5-3H]NNN from serum was biphasic. 4-Oxo-4-(3-pyridyl) butyric acid, a metabolite of [5-3H]NNN resulting from 2'-hydroxylation, which is a suspected activation pathway, was detected 0.5 min after injection and appeared to reach a steady state 2-220 min after injection. 4-Hydroxy-4-(3-pyridyl)butyric acid, from 5'-hydroxylation of [5-3H]NNN, and norcotinine, from denitrosation, were also rapidly formed. These experiments are the first in which the appearance of NNN metabolites in blood has been measured. The ratio of 2'-hydroxylation to 5'-hydroxylation varied from 0.27 to 0.60 in arterial serum and from 0.33 to 0.49 in venous serum in the period from 2-220 min. [5-3H]NNN accumulated in the stomach contents such that its levels were greater than those in arterial or venous serum, 60 min after injection. The results of this study demonstrate that the miniature pig is a useful model for the investigation of nitrosamine metabolism and indicate some similarities and differences in metabolism and distribution compared with the rat.

Animals↗
PubMed1987

Differential pattern of oncogene and beta-actin expression in leukaemic cells from AML patients.

The presence of mRNA hybridizing to five oncogene (fos, mos, myc, sis, abl) and a beta-actin probe(s) was studied with a semiquantitative dot-blot procedure in eight AML patients. Around 10(7) leucocytes, corresponding to 1-10 ml blood, sufficed for the analysis. Each patient, regardless of the FAB group, exhibited a distinct pattern of oncogene or beta-actin expression. Especially strong signals were obtained with the beta-actin probe in two patients and with the fos probe in three patients. The findings underscore the heterogeneity of AML, either present from the first step towards malignancy or arising during the progression of the disease. The pattern of oncogene expression in leukaemic cells studied in routine blood samples may become an additional means for classification and follow-up of AML patients.

Actins↗
PubMed1987

Topical dermal anaesthesia inhibits the flare but not the weal response to allergen and histamine in the skin-prick test.

The effect of topical dermal anaesthesia on the immediate allergic skin reaction was evaluated in a double-blind, randomized, placebo-controlled study. Twenty-one patients with strictly seasonal allergic rhinitis, confirmed by a positive skin test for the respective pollen allergen, were studied in the pollen-free winter months. Skin-prick tests for one pollen allergen and histamine were performed after pre-treatment of the skin for 1 hr with an emulsion of lidocaine and prilocaine (EMLA) and the equivalent vehicle on different test sites. The skin-prick tests were made with a preloaded standardized test needle (Phazet). The area of the induced weal-and-flare reaction was measured and subsequently calculated with the help of a digitizer served by a microcomputer. The topical dermal anaesthesia induced a reduction of the flare response to histamine by 49% (P less than 0.01) and allergen by 21% (P less than 0.05). No reduction of the histamine- and allergen-induced weal response were noted. Our findings indicate that the treatment did not affect the allergen-induced release of inflammatory mediators and the vascular leakage induced by these mediators. However, this study seems to confirm earlier suggestions that the flare response is partly mediated through neural reflex activity as it was ameliorated by topical anaesthesia. Furthermore, from a clinical point of view, this study shows that it is possible to perform a valid skin test, without any associated itching and pain, if only the weal response is taken into account in the evaluation of the skin-prick test.

Adolescent↗
PubMed1987

Allergen-induced nasal hyperreactivity appears unrelated to the size of the nasal and dermal immediate allergic reaction.

It has been previously demonstrated in nasal challenge studies that there is an increased sensitivity to allergen following an initial allergen challenge. A similar feature has been demonstrated following natural allergen exposure in patients with seasonal allergic rhinitis. To further explore the characteristics of this "priming" phenomenon and its relationship to other expressions of their allergic airway disease, 28 hay fever patients with strictly seasonal disease were studied. Skin tests with the relevant pollen allergen and histamine were performed and the size of the immediate and late phase allergic reaction was determined. An initial nasal allergen challenge was followed by a rechallenge of the nose with allergen 24 h later using a lavage technique. Determinations of TAME-esterase activity, as a biochemical marker of the allergic reaction, were made in the returned lavage fluid. The number of sneezes was counted and nasal symptoms were also assessed using a scoring technique. 19 of 28 patients (67%), displayed an increased responsiveness at rechallenge with similar findings in terms of symptom scores and TAME-esterase measurements. The increase was statistically significant for the symptoms of nasal blockage, which increased from 0.7 +/- 0.1 (mean +/- SEM) to 1.1 +/- 0.2 (P less than 0.05), and nasal secretion which rose from 1.1 +/- 0.2 to 1.7 +/- 0.2 (P less than 0.01). A composite nasal symptom score which also took account of the number of sneezes, increased from 2.9 +/- 0.4 to 4.0 +/- 0.3 (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Tail stump sperm defect in Ayrshire bulls: morphogenesis of the defect.

Three cases of tail stump sperm defect have been presented in Finnish Ayrshire bulls. The semen samples of the bulls showed markedly reduced number of sperm with almost total absence of tails. Transmission and scanning electron microscopy of the testicular samples revealed the testicular origin of the defect. The anlagen of the implantation fossa, proximal and distal centrioles, connecting piece, nuclear ring, manchette and annulus were demonstrated, but the axoneme formation was completely blocked. A separate population of spermatids showed nuclear bending and was possibly destroyed by the phagocytic activity of Sertoli cells. The pedigree of the bulls supports the concept that the defect is inherited by a single recessive autosomal gene.

Animals↗
PubMed1987

Distribution of dolichol and dolichyl phosphate in human brain.

Autopsy material from deceased individuals between ages 2 and 90 was used to prepare cerebellum, pons, and other selected regions of the brain, the spinal cord, and peripheral nerves. The concentration of dolichol in these different tissues varied greatly and the increase in concentration during the life span varied between 2.5- and 21-fold. In contrast, dolichyl-phosphate (dolichyl-P) was more evenly distributed in these tissues and its concentration increased to a moderate extent only during childhood. The level of cholesterol displayed smaller regional differences and decreased about 15% between ages 35 and 90. Differences in the total phospholipid content were limited. These results demonstrate enrichment and individual regulation of various lipids in specialized regions of the human brain. The independent regulation of dolichol and dolichyl-P levels in the brain and the possible role of dolichol in the function of the aging nerve cell are also emphasized.

Adolescent↗
PubMed1987

Raised acute-phase glycoprotein and IgM levels in cord serum.

The usefulness of a combined screening for acute-phase glycoproteins and IgM level in cord sera to denote various intrauterine or delivery-associated disorders was tested in approximately 2,000 consecutive cord sera. Increased glycoprotein level, measured by sensitive and technically simple concanavalin A binding nephelometry, showed a significant association with birth injuries and abnormalities of amniotic fluid, whereas raised IgM levels were linked to maternal genitourinary infections and to cesarean sections performed because of fetal distress. The correlation between these putative risk indices was poor (r = 0.38). Both indices were connected with severe neonatal disease and/or poor outcome of the child, but since such conditions were also otherwise evident at birth, routine screening by these tests was considered unwarranted.

Acute-Phase Proteins↗
PubMed1987

Origin of the autoreactive anti-type II collagen response. I. Frequency of specific and multispecific B cells in primed murine lymph nodes.

DBA/1 mice develop systemic polyarthritis and high titres of collagen autoantibodies after immunization with type II collagen. In this study we have analysed the frequency and specificity of antibody-producing B cells in draining lymph nodes 11 days after a primary immunization with rat type II collagen. A remarkably high frequency of type II collagen-reactive hybridomas (30%, n = 71), the majority cross-reacting with autologous type II collagen, were generated. Most of the collagen-reactive hybridomas produced IgG antibodies specific for type II collagen. Many other hybridomas produced multispecific antibodies (9%): these were preferentially of the IgM class. Some of the monoclonal multispecific hybridomas produced antibodies that cross-reacted with specific epitopes on the collagen molecule. One type II collagen-reactive hybridoma also displayed rheumatoid factor activity. Different mechanisms for the generation of the high frequency of collagen reactive antibodies are discussed.

Animals↗
PubMed1987

An XXX male resulting from paternal X-Y interchange and maternal X-X nondisjunction.

A 2-year-old boy was found to have a 47,XXX karyotype. Restriction-fragment-length-polymorphism analysis showed that, of his three X chromosomes, one is of paternal and two are of maternal origin. The results of Y-DNA hybridization were reminiscent of those in XX males in two respects. First, hybridization to Southern transfers revealed the presence in this XXX male of sequences derived from the Y-chromosomal short arm. Second, in situ hybridization showed that this Y DNA was located on the tip of the X-chromosomal short arm. We conclude that this XXX male resulted from the coincidence of X-X nondisjunction during maternal meiosis and aberrant X-Y interchange either during or prior to paternal meiosis.

Child, Preschool↗
PubMed1987

Cardio-pulmonary elimination of 5-fluorouracil after bolus injection in the hepatic artery.

Theoretically, administration of 5-fluorouracil (5-FU) into the hepatic artery should improve the clinical response rate by high tumor cell extraction of the drug. However, previous studies in animals and man have also found a major extrahepatic elimination route for 5-FU. In the present study of 7 patients with primary and secondary liver cancer, we have found indications that a considerable elimination of 5-FU takes place in the cardio-pulmonary circuit. Thus, the mean AUC in the hepatic vein was 7185 mumol X min X l-1 and 3792 in a peripheral vein.

Adult↗
PubMed1986

Chromosome Y-specific DNA is transferred to the short arm of X chromosome in human XX males.

Y-chromosomal DNA is present in the genomes of most human XX males. In these cases, maleness is probably due to the presence of the Y-encoded testis-determining factor (TDF). By means of in situ hybridization of a probe (pDP105) detecting Y-specific DNA to metaphases from three XX males, it was demonstrated that the Y DNA is located on the tip of the short arm of an X chromosome. This finding supports the hypothesis that XX maleness is frequently the result of transfer of Y DNA, including TDF, to a paternally derived X chromosome.

Cells, Cultured↗