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Biomedical subjects

K Larsson

Publications and source records attributed to K Larsson.

At least 145 records · Page 8Linked to original sources
PubMed1994

Prospective study of laboratory-animal allergy: factors predisposing to sensitization and development of allergic symptoms.

In a prospective study of laboratory technicians, selected indicators of allergy and atopy were studied in an attempt to determine predictors of laboratory-animal allergy (LAA). Laboratory technicians underwent spirometry, methacholine provocation tests, and blood sampling, and responded to a questionnaire during training and after 2 years' work. Among 38 laboratory-animal-exposed subjects, total IgE before exposure gave the best correlation (P < 0.01; Mann-Whitney U-test) to reported symptoms caused by laboratory animals (n = 8) at follow-up. The prevalence of atopy and allergic symptoms had increased in exposed technicians at follow-up, but this was also found among unexposed matched referents (n = 36 pairs). One subject in the exposed group reported asthma before exposure, compared with seven at follow-up (P < 0.05; Fisher's exact test). However, the prevalence of asthma had increased from two to six (not significant) also among unexposed technicians. There were no significant differences between the groups in any measured variable at follow-up. Among 43 subjects who later worked with laboratory animals, 21% had a positive skin prick test for common allergens, as compared with 37% among 112 without animal exposure (P = 0.06; chi2 test), suggesting selection for laboratory animal work.

Adolescent↗
PubMed1994

The psychobiology of parenting in mammals.

Parental behavior denotes a variety of genetically programmed activities in which parents help their young to survive to maturity. A highly successful research has been devoted to the psychoneuroendocrine bases of parenting in two species, rat and sheep. As a result empirical data along with conceptual formulations have been obtained which provide a model for generating hypothesis for the study of other species. This review was written to draw the attention to this research because of its enormous potential significance for problems pertaining to human infant care. It discusses the current status of research on the physiological bases of parental behavior.

Aggression↗
PubMed1994

The effect of Salinum on the symptoms of dry mouth: a pilot study.

The effect of a new saliva substitute, Salinum, was tested in 37 patients with severe symptoms of reduced salivation. The majority of the patients had suffered from hyposalivation and dry mouth for more than 8 years. The saliva substitute consisted of a water soluble extract of linseed. The physical properties of this extract are similar to those of the glycoproteins of the salivary secretions. The patients used the saliva substitute for a seven days period. Prior to the use of the extract the patients reported that the most severe symptoms of decreased salivation were a feeling of dryness in the mouth and burning sensations in the tongue, pharynx and oesophagus, The majority of the patients reported that the use of Salinum reduced the symptoms of hyposalivation. Great variation in effect occurred from patient to patient. Generally the patients with the most severe symptoms experienced the greatest relief of the symptoms when they used Salinum. Although of short duration the results of this pilot study indicate that an extract of linseeds may compensate for some aspects of the consequences of reduced salivation. Further studies are needed to elucidate the feasibility of the extract as saliva replacement.

Adult↗
PubMed1994

A cost-effectiveness study of leg ulcer treatment in primary care. Comparison of saline-gauze and hydrocolloid treatment in a prospective, randomized study.

OBJECTIVE: The majority of leg ulcer patients in Sweden are managed by primary health care personnel. To compare, in a primary care setting, the healing results and the expenses of two commonly used wound dressings for leg ulcers. DESIGN: Thirty patients with leg ulcers of venous or mixed venous/arterial aetiology were randomized to treatment with saline-soaked gauze or with the hydrocolloidal dressing [HCD: DuoDERM (ConvaTec, A Bristol-Myers Squibb Company, Princeton)]. All patients were bandaged with the same compression of low-stretch-type [Comprilan (Beiersdorf AG, Hamburg)]. SETTING: Vårdcentralen Marieberg, Primary Health Care Centre, Motala, Sweden. OUTCOME MEASURES: Healing/reduction of ulcer area, pain, costs for material, nursing time, kilometres driven were registered during a six-week period. RESULTS: Two patients dropped out of the study, one in the gauze-group due to erysipelas, and one in the HCD-group for social reasons. A total of 1234 dressing changes were analysed. Costs for material were similar in the two groups. When the total care including nursing- and travelling time and kilometres driven were analysed, the mean cost for treatment with gauze dressings was 4126 Swedish Kronor (SEK), and with HCD, 1565 SEK. Seven patients in the HCD-group and two in the gauze-group healed during the study. The reduction of the ulcer area was 19% in the gauze-group and 51% in the HCD-group (p < 0.16). CONCLUSION: The total care, analysed in an authentic clinical setting, must be considered when different wound-care methods are discussed. In this study the use of HCD showed lower costs than use of gauze-dressings. As regards healing there was a tendency to improved healing with HCD, but no significant difference. Patients in the HCD-group reported significantly less pain at dressing changes (p < 0.003) than patients in the gauze-group.

Aged↗
PubMed1993

Effects of exposure to an estrous female on forebrain monoaminergic neurotransmission in the non-copulating male rat.

Regional changes in the rate of brain monoamine synthesis were monitored in male rats exposed to, but prevented from physical contact with, an estrous or an ovariectomized female. The in vivo rate of tyrosine and tryptophan hydroxylase activities were estimated by measuring the accumulation of DOPA and 5-HTP following inhibition of cerebral aromatic L-amino acid decarboxylase by means of 3-hydroxybenzylhydrazine (NSD-1015) treatment (100 mg/kg i.p.). 5 min upon NSD-1015 treatment, the males were exposed to an intact estrous female or an ovariectomized female for 20 min before decapitation and brain dissections. Exposure to an estrous female produced an increased rate of tyrosine and tryptophan hydroxylase activity in the medial prefrontal cortex, the dorso-lateral neostriatum and in the ventral neostriatum, in comparison with home-cage controls. By the same comparison, exposure to an ovariectomized female resulted in an increased rate of tyrosine hydroxylase activity in the medial prefrontal cortex, but not in the neostriatal areas, whereas tryptophan hydroxylase activity was unaffected. Finally, exposure to the empty test cage, with no stimulus females present, did not produce any statistically significant changes in the rate of tyrosine or tryptophan hydroxylase activity in any of the brain areas sampled. Taken together with recent findings from this laboratory, the present results demonstrate that the level of sexual motivation brought about by the olfactory, auditory and/or visual stimulation of a receptive female is associated with an increased demand on catecholamine and 5-hydroxytryptamine synthesis in the limbic forebrain of the male rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed1993

High prevalence of asthma in cross country skiers.

OBJECTIVES: To study the prevalence of asthma (asthma symptoms and bronchial hyperresponsiveness) in Swedish cross country skiers compared with non-skiers and monitor changes in symptoms and bronchial hyperresponsiveness during the year. DESIGN: Cross sectional study during the winter ski season and in the summer. SETTING: Six ski clubs for élite skiers (total 47) in two different areas of Sweden. SUBJECTS: 42 élite cross country skiers and 29 non-skiing referents. MAIN OUTCOME MEASURES: Bronchial responsiveness, asthma symptoms, and lung function. RESULTS: Bronchial responsiveness was significantly greater and asthma symptoms more prevalent in the skiers than in the referents. There was no difference in bronchial responsiveness within either group between winter and summer. 15 of the 42 skiers used antiasthmatic drugs regularly and 23 had a combination of asthma symptoms and hyperresponsive airways or physician diagnosed asthma, or both. Altogether 33 skiers had symptoms of asthma or bronchial hyperresponsiveness. One of the referents had symptoms of asthma and bronchial hyperresponsiveness, and none used antiasthmatic drugs regularly. CONCLUSIONS: Asthma, asthma-like symptoms, and bronchial hyperresponsiveness are much more common in cross country skiers than in the general population and non-skiers. Strenuous exercise at low temperatures entailing breathing large volumes of cold air is the most probable explanation of persistent asthma in skiers.

Adolescent↗
PubMed1993

Isolation, partial characterization, and molecular cloning of a human colon adenocarcinoma cell-surface glycoprotein recognized by the C215 mouse monoclonal antibody.

The monoclonal antibody C215 (IgG2a) was obtained by the immunization of BALB/c mice with the human colon adenocarcinoma cell line COLO 205 and used in the targeting of colorectal carcinomas. The partial characterization and purification of the C215 target molecule from solubilized COLO 205 membranes indicated that it is an integral membrane glycoprotein of the non-mucin type. The denatured antigen appeared as a major 40-kDa form in Western blots after SDS-polyacrylamide gel electrophoresis and migrated as a monomeric 36-kDa species after the reductive cleavage of intramolecular disulfide bridges. Using a five-step procedure, the antigen was purified 4,300-fold from COLO 205 tumors raised in nude mice to a homogeneity of 95% when assessed by capillary electrophoresis. Removal of N-linked carbohydrate by peptide:N-glycosidase treatment did not affect the visualization of the purified antigen in immunoblots but resulted in a faster migration in the SDS gels. The amino acid sequence was partially determined. Seventeen contiguous NH2-terminal amino acids were identified and coincided exactly with residues 82-98 of the GA733-2 protein cloned by Szala et al. (Szala, S., Froehlich, M., Scollon, M., Kasai, Y., Steplewske, Z., Koprowski, H., and Linnenback, A. J. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 3542-3546). Therefore, the predicted amino acid sequence of this protein was used to prepare overlapping synthetic peptides that cover the entire extracellular domain in order to identify the C215 epitope. A likely epitope, close to the NH2 terminus and corresponding to the first distinct hydrophilic stretch after the putative signal sequence, was identified in a peptide enzyme-linked immunosorbent assay. Moreover, GA733-2 cDNA was used for the cloning of the C215 protein from COLO 205 cells and the subsequent transfection to K36.16 mouse T cell leukemia cells. The transfected cells were C215 reactive in fluorescence-activated cell sorter analysis, and a 42 kDa band was visualized in Western blots under both non-reducing and reducing conditions. Our findings indicate a close relationship between the C215 antigen and other members of the GA-733 family, some of which are currently being used as targets in clinical trials with monoclonal antibodies. The mammalian expression system described here will enable further studies into the biological role of this protein and the construction of animal models in order to develop optimal therapeutic strategies.

Adenocarcinoma↗
PubMed1993

Controlled short-time terpene exposure induces an increase of the macrophages and the mast cells in bronchoalveolar lavage fluid.

Eight healthy nonsmoking volunteers underwent terpene exposure (450 mg/m3 air) on 4 different occasions within a 2 week period. Total exposure time was 12 hours. Before and after the sequences of exposure, bronchoalveolar lavage was performed. Twenty hours after the exposure there was a significant (p < 0.05) increase of the alveolar cell concentration (median pre-exposure value 76 x 10(6) cells/L, post-exposure value 126 x 10(6) cells/L), predominantly due to an increment of the macrophages (from 72 x 10(6) cells/L to 121 x 10(6) cells/L). The mast cells also increased from 1/10 to 5/10 visual fields. No elevated concentrations of albumin, fibronectin, hyaluronan (hyaluronic acid), and tryptase were observed. We conclude that terpene exposure, in a concentration regarded as moderate, induces an acute alveolar cellular reaction in healthy subjects.

Adult↗
PubMed1993

Neonatal vestibular stimulation and mating in cerebellar mutants.

Two cerebellar mutants, staggerer and reeler, and their congenic nonmutants were used in this experiment. Experimental animals were subjected to intense rotational stimulation on a tilted plane during the first 3 weeks of life, while controls were left nonstimulated. The capacity for mating, as evidenced by vaginal plugs or the occurrence of pregnancy, was assayed during two periods: between 36 and 89 days of age (Experiment A) and between 90 and 120 days of age (Experiment B). During Experiment A the mutants as well as the normals were caged inter se with partners of the opposite sex. During Experiment B the animals were caged with intact, sexually experienced partners. The animals were examined daily for evidence of mating. During Experiment A, only 3 of the 89 couples participating in this study showed evidence of mating. During Experiment B, the number of males of both strains which had mated increased significantly. The staggerer females showed a relatively high level of mating activity, whether stimulated or not. The reeler females, in contrast, rarely mated, although early stimulation significantly increased the level of sexual efficiency. The majority of the normal males and females mated, whether stimulated or not. It was concluded that massive motor-sensory stimulation in infancy, improving gait and body balance in staggerer and reeler mice, may also improve mating efficiency.

Animals↗
PubMed1993

Phospholipase-resistant phosphatidylcholine reduces intra-abdominal adhesions induced by bacterial peritonitis.

The majority of intra-abdominal adhesions develop postoperatively or following peritonitis. We have previously shown that L-phosphatidylcholine reduces postoperative peritoneal adhesions in rats. In the present study, we examined whether adhesion formation after bacterial peritonitis is also reduced by L-phosphatidylcholine or by DL-alpha-phosphatidylcholine, which is degraded only 50% by phospholipase A2. Peritonitis was induced in the rat by caecal ligation and double puncture; cecotomy was performed 12, 15, or 18 h later. Adhesions were assessed blindly by a scoring system 7 days after cecotomy. When cecotomy was scheduled for 18 h after caecal ligation and puncture, the 7-day mortality was 90% (n = 20). When cecotomy was performed at 12 h, no mortality was seen; however, the adhesion score was low (2.3 +/- 0.7). When cecotomy was performed 15 h after caecal ligation and puncture, the mortality was 25% and the adhesion score was 4.3 +/- 0.9. This figure was reduced significantly by intraperitoneal instillation of L-phosphatidylcholine or DL-alpha-phosphatidylcholine for 3 subsequent days. However, the mortality increased by L-phosphatidylcholine (P < 0.01), whereas mortality after DL-alpha-phosphatidylcholine remained at 30%. We conclude that administration of both L-phosphatidylcholine and DL-alpha-phosphatidylcholine decrease adhesion formation after bacterial peritonitis.

Animals↗
PubMed1993

Sexual orientation and sexual motivation of the adult male rat.

Intact sexually experienced male rats were allowed to choose between staying in the vicinity of an estrous female or a sexually active male under different conditions of sexual arousal. In one group, the animals were allowed to perform two intromissions before the start of the partner preference test. In a second group, the subjects were allowed to reach a moderate level of sexual satiation by repeated ejaculations 24 h before testing. A third group was not given any pretreatment. Independently of the conditions of the pretreatment, all groups showed a clear female-oriented behavior. However, animals performing two intromissions before the test spent significantly more time with the female and showed a higher number of visits to her compared to the untreated controls. Males being sexually exhausted after repeated ejaculations showed a significantly lower level of female-oriented behavior than did the controls. It was concluded that the male's readiness to orient towards the female was affected by his motivational state.

Animals↗
PubMed1993

Restoration of staggerer mouse maternal behavior following long-term breeding selection.

Two lines of staggerers from the C57BL/6 strain were tested for disturbances in maternal behavior and locomotion. One line, called Pasteur, included staggerers available at L'Institut Pasteur. The second line, called Selected, included staggerers that had been bred in our laboratory for several generations for their ability to reproduce. While none of the Pasteur animals showed any evidence of maternal behavior, most of the Selected mutant mice became maternal, carrying about 90% of the pups until weaning. No group differences were seen in locomotory behavior. It was concluded that a) as a result of long-term breeding selection, homozygous (sg/sg) animals of the C57BL/6 strain may be able to exhibit maternal behavior from birth on, even under standard laboratory conditions; b) the restoration of the maternal behavior does not equally affect all components of this behavior pattern; and c) the impairment of the maternal behavior showed by the staggerer females is not a necessary consequence of impaired locomotory capacity characteristic of the staggerer.

Animals↗
PubMed1993

Importance of the time interval between FEV1 measurements in a methacholine provocation test.

We examined the hypothesis that a forced expiratory volume in one second (FEV1) manoeuvre (and the preceding deep inhalation) before inhalation of methacholine might influence FEV1 measured after methacholine, if the time between measurements was short. Six to nine healthy subjects inhaled a single dose of methacholine, known to cause about 20% decrease in FEV1, on different days in different test protocols. If an FEV1 manoeuvre was performed immediately before methacholine, the first FEV1 measured 3 min after provocation was higher (77% of basal FEV1) than if a pre-methacholine FEV1 manoeuvre was not performed (64%). This effect of a pre-methacholine FEV1 manoeuvre was also demonstrated at 2, 4 and 6, but not at 10 min after the start of methacholine inhalation. If an FEV1 manoeuvre was not performed before methacholine, the second and subsequent FEV1 measured in constricted airways was higher than the first, and of similar magnitude to the first FEV1 in tests where a pre-challenge FEV1 manoeuvre was performed. In another trial, 10 healthy subjects performed two stepwise methacholine tests, with either 6 or 3 min between dose steps. The percentage decrease in FEV1 per mg of inhaled methacholine decreased from 2.6 (1.9-5.2) to 1.7 (0.8-2.3) (median, interquartile-range) when the time interval was shortened. The results suggest that the deep inhalation associated with the FEV1 manoeuvre decreases the bronchial tone in airways constricted by methacholine for up to 6 min, possibly due to yielding of cross-links in airway smooth muscles.

Adult↗