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Biomedical subjects

B Andersson

Publications and source records attributed to B Andersson.

At least 415 records · Page 23Linked to original sources
PubMed1986

Terfenadine reduces skin and conjunctival reactivity in grass pollen allergic children.

Terfenadine suspension, 30 mg b.i.d., was compared with placebo in a randomized, double-blind cross-over study in twenty-five children, 6-12 years of age, with grass pollen induced allergic rhinoconjunctivitis. The patients were treated during two 7-day periods separated by a 4-day wash-out period. Efficacy was assessed during a period without provoking pollen in the air. At the end of each treatment period, skin-prick tests were carried out in quadruplicate with three concentrations of grass pollen extracts (identical batches of Pharmalgen) and histamine HCl, 1 and 10 mg/ml, as were conjunctival provocations with the same grass pollen. The mean size of weals caused by allergen and histamine was significantly smaller after terfenadine than after placebo; in fact, terfenadine increased the tolerance to the allergen by a factor of ten. Similarly, the tolerance to conjunctival provocation was significantly increased during terfenadine treatment as compared with placebo. There was no significant difference between the treatments in scores for alertness and salivation. Seasonal symptoms were mild when the children were allowed to use terfenadine in an open follow-up study. Thus, terfenadine reduced specific as well as non-specific reactivity in grass pollen allergic children and caused few side effects.

Benzhydryl Compounds↗
PubMed1986

Effects of hay-feeding on acid/base balance, renal sodium excretion, aldosterone and vasopressin secretion in the goat.

Effects of 30 min intense hay-feeding on acid/base and sodium homeostasis were studied in semi-starved goats during hyper- and euhydration. Parallel analyses of carotid and jugular blood samples revealed that feeding induced metabolic acidosis, which to some extent was subjected to respiratory compensation. The acidosis was accompanied by renal sodium retention and urinary acidification persisting for 2-3 h. The sodium retention was succeeded by an increase in renal Na excretion above the initial level. This natriuresis was most accentuated during hyperhydration. Blood samples taken for hormone assays during euhydration revealed a 15% increase in haematocrit and a significant rise in plasma aldosterone at termination of feeding. Inhibition of the water diuresis in hyperhydrated animals, and moderate increases in renal arginine vasopressin (AVP) excretion and plasma AVP were inconsistent effects of feeding. It is concluded, that simply jugular vein blood provides reliable information on the acid/base status of goats, but that the feeding schedule has to be considered in all experiments where small ruminants are used to investigate the integrated control of acid/base and sodium homeostasis.

Acid-Base Equilibrium↗
PubMed1986

Influence of heat exposure on acid/base and fluid balance in hyperhydrated goats.

Hyperhydrated goats were exposed to an environmental temperature of 45 degrees C (relative humidity 70%) for 120 min. After 90 min, rectal temperature and respiratory frequency reached plateau levels of 40.5 degrees C and 280 respirations min-1, respectively. Measurements of arterial and venous blood acid-base parameters revealed that respiratory alkalosis had started to develop after 60 min, and had become obvious at the end of the heat exposure period. Renal compensation (evidenced by gradual increases in urinary pH and renal Na excretion) developed in parallel with the respiratory alkalosis. The heat exposure elicited a moderate, temporary inhibition of the water diuresis, but no obvious increase in the renal excretion of arginine vasopressin (antidiuretic hormone, ADH). Preliminary determinations of plasma aldosterone did not show any change during the actual heat exposure period, but a 50% temporary decrease in plasma aldosterone 30 min thereafter. The study confirms the susceptibility of goats to develop respiratory alkalosis during thermoregulatory panting, and shows that this is not to any appreciable extent diminished during hyperhydration. It can further be concluded that a heat-induced rise in body temperature to 40.5 degrees C is no powerful stimulus for vasopressin release in the hyperhydrated goat. The determinations of plasma aldosterone suggest that reduced liberation of the hormone does not contribute to the immediate renal compensation of respiratory alkalosis, but that respiratory alkalosis reaching a certain intensity inhibits aldosterone secretion.

Acid-Base Equilibrium↗
PubMed1986

Observations on normal EEG activity in different brain regions of the unrestrained swine.

This methodological and electrophysiological study was undertaken with the aim of obtaining possibilities for evaluating objectively the ethical value of using high concentration CO2 inhalation as pre-slaughter anaesthesia for swine. A technique for implantation of recording electrodes into the porcine neocortex and limbic system is described, as are results of EEG recording from these brain regions in the unrestrained animal. In addition to expected desynchronized activity in the awake animal, bilateral recordings from the frontal neocortex revealed the irregular occurrence of 'sleep spindle' during apparent non-REM sleep. The 'spindles' were sometimes unilateral, and when bilaterally simultaneous, the amplitude was often larger in one of the hemispheres. The EEG recorded from the dorsal hippocampus was characterized by theta-wave activity. The offering of food to the hungry animal, and subsequent brief feeding periods, were associated with marked accentuation of this theta activity. Recording via electrodes placed within the amygdaloid nuclear complex showed high-frequency activity irregularly interrupted by slow waves. However, if one of the 'amygdaloid' twin electrodes hit the ventral pole of the hippocampus, theta activity was dominant. Electrodes placed adjacent to the amygdaloid nuclei in the pyriform cortex exhibited a basic awake activity similar to that recorded from these nuclei. During apparent non-REM sleep, however, trains of slow waves were seen simultaneously with the appearance of 'sleep spindles' in the ipsilateral neocortex.

Amygdala↗
PubMed1986

A procedure for the analysis of S-benzyl-N-acetylcysteine and S-(o-methylbenzyl)-N-acetylcysteine in human urine.

Analytical methods for mercapturic acids, the end-products of glutathione metabolism of the industrial solvents toluene and o-xylene (i.e., S-benzyl-N-acetylcysteine and S-(o-methylbenzyl)-N-acetylcysteine), added to human urine have been developed. The sensitivity is 2 ng/microliter (R.S.D. = +/- 13%) and 1 ng/microliter (R.S.D. = +/- 6.4%) urine for S-benzyl-N-acetylcysteine and S-(o-methylbenzyl-N-acetylcysteine, respectively, when using the h.p.l.c. method. The corresponding sensitivities for the g.l.c.-mass spectrometric method are 0.5 and 0.3 ng/microliter urine, respectively.

Acetylcysteine↗
PubMed1985

The oxidation of p-phenetidine by horseradish peroxidase and prostaglandin synthase and the fate of glutathione during such oxidations.

The oxidation of p-phenetidine by horseradish peroxidase and prostaglandin synthase was investigated. The existence of a free radical intermediate formed during enzymatic oxidation was supported by a ratio of hydrogen peroxide: p-phenetidine consumed of 1:2 in the horseradish peroxidase system. Furthermore in both enzyme systems a rapid oxidation of added glutathione was observed and in the presence of the thiol there was a decreased removal of p-phenetidine. This suggests the reduction of a p-phenetidine radical by glutathione generating p-phenetidine and a thiyl radical. The latter react with oxygen and a rapid oxygen uptake was observed during enzymic oxidation in the presence of thiols. That p-phenetidine radicals were produced during horseradish peroxidase catalyzed oxidation of p-phenetidine was supported by experiments using the spin probe OXANOH. This was oxidized to its stable free radical form (OXANO.) in an enzyme- and substrate-dependent reaction and the EPR signal obtained was not decreased by SOD (80 micrograms/ml) or benzoate (10-100 mM). TLC characteristics of the products of the oxidation of p-phenetidine by both enzymes were almost identical inferring a similar mechanism of oxidation. Two of the metabolites were characterized by mass spectrometry and by comparison with reference compounds prepared by chemical oxidation. One metabolite was identified as 4,4'-diethoxyazobenzene, which further supports a radical mechanism, and the other was a p-phenetidine trimer which could exist in both oxidized and reduced forms. On the basis of these observations a mechanism for the oxidation of p-phenetidine and the fate of glutathione during such oxidations is proposed.

Aminophenols↗
PubMed1985

Defence of mucous membranes by antibodies, receptor analogues and non-specific host factors.

Most infections reach man via the mucosal membranes, and more than half of the lymphoid system is found in connection with mucosae. The major antibodies found on mucous membranes are secretory IgA, which function primarily by binding microorganisms and thereby preventing their contact with the host tissues. The optimal mode of immunization to obtain a secretory IgA response is not well defined. Repeated mucosal exposure with antigen may result in oral tolerance, with decreasing circulating antibodies but a remaining secretory IgA response. The secretory IgA response is usually short-lived and can be difficult to boost. IgM as well as IgG antibodies may add to host defence at the mucosal level, but when engaged, they usually induce inflammation in host tissues. Analogues to bacterial receptors on mucosal epithelium may be present in exocrine secretions such as human milk. During an attack on the host, it is possible that such receptor analogues may aid in the prevention of attachment of bacteria to mucous membranes used as an initial site. A number of non-specific host factors support mucosal defence. One of them is lactoferrin. Lactoferrin deficiency seems to result in recurrent bacterial infections, suggesting its importance in normal host defence.

Antibody Formation↗
PubMed1985

Novel dopamine receptor agonists and antagonists with preferential action on autoreceptors.

The enantiomers of cis-5-hydroxy-1-methyl-2-(di-n-propylamino)tetralin and its methyl ether have been synthesized. The compounds were tested for central dopamine (DA) receptor activity, by using biochemical and behavioral tests in rats. The (1R,2S)-(-) enantiomers of 1 and 2 are characterized as centrally acting DA-receptor agonists while the corresponding (1S,2R)-(+) enantiomers are characterized as centrally acting DA-receptor antagonists. Compounds (+)-1 and (+)-2 differ from classical neuroleptics in being able to increase DA synthesis rate in a wide dose range without reducing locomotor activity, suggesting a pronounced selectivity for DA autoreceptors. Also the (-) enantiomers seem to act preferentially on DA autoreceptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1985

Resolved monophenolic 2-aminotetralins and 1,2,3,4,4a,5,6,10b-octahydrobenzo[f]quinolines: structural and stereochemical considerations for centrally acting pre- and postsynaptic dopamine-receptor agonists.

A detailed structure-activity relationship is revealed for resolved, centrally acting dopamine (DA) agonists acting on both pre- and postsynaptic DA receptors. The compounds resolved are 5- and 7-hydroxy-2-(di-n-propylamino)tetralin and cis- and trans-7-hydroxy-4-n-propyl-1,2,3,4,4a,5,6,10b-octahydrobenzo [f]quinoline. By the superimposition of the structures of the more active enantiomers of these compounds with those of known dopaminergic agonists, apomorphine and ergolines, a new DA-receptor model is proposed as an outgrowth of current DA-receptor theories. One of the most important concepts of this receptor model is its emphasis on the possible positions taken by the N-substituents of dopaminergic compounds. One of these positions i sterically well defined while the other direction is sterically less critical. The model has been used to explain the lack of dopaminergic activity of some previously reported structures and also to predict properties of novel structures, including inherent chirality, which should be active at DA receptors. Hopefully, this heuristic DA-receptor model will lead to the discovery of more selective and potent pharmacological tools, which ultimately might lead to the development of therapeutic agents for treating diseases of dopaminergic function in the central nervous system.

Animals↗
PubMed1985

Treatment of recurrent genital herpes simplex infections with oral acyclovir.

A total of 113 patients with recurrent genital herpes were enrolled in a multicentre cross-over study. Two consecutive recurrences were treated with either oral acyclovir 200 mg or matching placebo five times daily for five days. Acyclovir significantly reduced the time to crusting and healing and the duration of new lesions and symptoms. Acyclovir was not found to have any clinically significant effect on the haematological or biochemical parameters measured, or to have caused adverse events and was well tolerated. Early self-initiated treatment may abort a recurrent attack of genital herpes without progression to the ulcerative or crusting stage.

Acyclovir↗
PubMed1985

Spun glass hair: two cases investigated with SEM and TEM.

Two cases of spun glass hair have been investigated with SEM and TEM. The SEM studies confirm previous findings by other authors. The TEM investigations reveal a completely normal cross section appearance. These findings stress the need for investigation of the time sequence of the keratinization process of the different layers of the inner root sheath.

Child, Preschool↗
PubMed1985

Protective factors in milk and the development of the immune system.

The neonate is immature in certain immunologic functions. The slow development of secretory immunoglobin A (IgA) seems to be compensated by selective transfer of secretory IgM into exocrine secretions on mucous membranes during the first few months of life. Secretory IgA and secretory IgM antibodies against Escherichia coli and poliovirus are already found in the neonate, possibly in response to the maternal anti-idiotypic IgG antibodies transplacentally exposing the fetus. Via such a mechanism, food antibodies could occur before direct food exposure in the infant. Human milk provides large amounts of antibodies (as a crude comparison, about 50 times the amount of antibodies given to a patient with hypogammaglobulinemia). The milk antibodies, dominated by secretory IgA, protect especially against intestinal infections. The milk also contains oligosaccharide analogues to epithelial receptors for bacteria. They, as well as a number of milk components such as lactoferrin and lysozyme, may contribute to host defense. The food antibodies in human milk may influence the infant's immune response to foreign food proteins introduced during weaning.

Animals↗
PubMed1984

Surface immunoglobulin phenotype of complement receptor-positive and complement receptor-negative B cells of normal and xid immunodeficient mice.

Single- and dual-parameter fluorescence-activated cell sorter analyses of complement receptor-positive and -negative (CR+ and CR-) splenic B cells of normal and xid immunodeficient mice were performed to determine the frequencies of surface (s) IgM+ and sIgD+ cells, as well as the quantities of sIgM and sIgD on these cells. Single parameter analysis revealed identical frequencies of sIgM+ and sIgD+ cells in the CR+ B cell population of normal mice. In contrast, the percentage of sIgM+ cells exceeded that of sIgD+ cells in the CR- normal and CR+ xid B cell population to a similar extent. CR- xid B cells showed an even greater discrepancy between sIgM+ and sIgD+ cells. Dual-parameter analysis of CR+ normal B cells showed the typical sIg phenotype of mature B cells, i.e. an intermediate density of sIgM and a high density of sIgD. The CR+ xid B cell population displayed an increase in cells with high sIgM and no-to-low sIgD and a decrease in cells with intermediate sIgM and high sIgD when compared to CR+ normal cells. CR- B cells from normal and xid immunodeficient mice were similar in that both consisted largely of a cell population with low sIgM and no-to-low sIgD. However, the CR- normal B cell population also contained cells with intermediate sIgM and high sIgD, which were lacking in the CR- xid cell population. Similar results were obtained when CR+ and CR- B cells from normal and xid mice were purified from a small resting B cell population, isolated by elutriation. This indicates that the sIg phenotype of CR- cells is not due to the presence of large cells which have lost sIgD during activation.

Animals↗
PubMed1984

Prostaglandin synthase-catalyzed metabolic activation of some aromatic amines to genotoxic products.

Cultured human fibroblasts were incubated with different aromatic amines in the presence of different activation systems and the induction of strand breaks in fibroblast DNA was studied. In the presence of ram seminal vesicle microsomes and arachidonic acid, DNA strand breaks were induced by 2-naphthylamine, 2,4-diaminotoluene and 4-methoxy-m-phenylenediamine. This effect was decreased when the prostaglandin synthase of the ram seminal vesicle microsomes was inhibited. The data suggest that metabolic activation catalyzed by prostaglandin synthase may be of importance in the formation of genotoxic products by certain urinary tract carcinogens.

Amines↗