Search PubMed⌕ Search

Biomedical subjects

B Gustafsson

Publications and source records attributed to B Gustafsson.

At least 73 records · Page 4Linked to original sources
PubMed1995

The experiential meaning of eating, handicap, adaptedness, and confirmation in living with esophageal dysphagia.

This article is mainly based on interview studies of pensioners' (n = 62), patients' (n = 19), and students' (n = 87) experiences of living with longstanding esophageal dysphagia. The aim is to describe the experiential meaning of dysphagic patients' lives by interpreting their experiences, problems, and emotions and by specifying these into scales according to the model of goal-directed action by Pörn [43-49]. The experiential meaning will be articulated in terms of attainment or nonattainment of goals in relation to eating, handicap, adaptedness, and confirmation. In the experiential meaning of eating, the emphasis is on the attainment of nourishing goals or goals attained by means of food with desired hedonistic qualities and linked with feelings of hope or no hope of a shared life. The experiential meaning of handicap is interpreted as the dysphagic individual's experiences of an actual nonattainment of eating goals due to swallowing disabilities and with experiences of nonattainment of other important goals and related emotions; for example, shame for human incompetence. The experiential meaning of adaptedness is understood as the dysphagic individual's experiences of actual capacity for goal attainments interpreted as a sense of control in the daily living with dysphagia and linked with security, or in the negative case, reduced self-esteem and feelings of panic or fear. The experiential meaning of confirmation is interpreted as the dysphagic individual's experiences of actual or potential repertoire for goal attainment, i.e., self-assessment strengthened by evidence obtained in relationships linked with emotions of hope of self-realization. In conclusion, a specific model for understanding the dysphagic patient's concealment of dysphagia in the medical encounter has been developed.

Adaptation, Physiological↗
PubMed1995

Adaptedness and coping in dysphagic students.

Using a definition based on Bowlby and Pörn, an effort is made to interpret adaptedness and coping in 87 dysphagic students (corresponding to a prevalence of dysphagia in 9% of the boys and 12% of the girls) found in a screening study utilizing a questionnaire. Coping patterns and methods of adaptation were explored in a telephone interview with dysphagic students. Those who stated that their dysphagia influenced their daily living were classified as subjectively maladapted (S-maladapted; n = 9). Compared with the S-adapted students, the S-maladapted students reported more defects in ability to eat, more inappropriate beliefs about the causes and management of dysphagia, and greater desires regarding eating than S-adapted students (p < 0.05). The environmental conditions more often impaired the eating ability in S-maladapted students (p < 0.05). Anxiety at mealtime was reported more frequently than in S-adapted students (p < 0.05). Every second S-maladapted student had reduced self-esteem because of dysphagia (p < 0.05). The S-maladapted students had talked about their dysphagia with parents and/or friends and visited a school physician because of dysphagia more often than S-adapted students (p < 0.05). Two of 9 students felt confirmed by the physician and experienced help. There was concordance between the students' own beliefs regarding the causes of dysphagia and corresponding coping strategy.

Adaptation, Physiological↗
PubMed1995

Effects of nandrolone propionate on experimental tumor growth and cancer cachexia.

We studied the tumor host response to excessive doses of an anabolic steroid (nandrolone propionate, 2.5 mg 20 g intraperitoneally every second day for 11 days) with respect to body composition and tumor cell kinetics in MCG 101 sarcoma-bearing mice (C57BL/6J) with progressive cachexia. Although survival and food intake were not affected, a significant weight gain was observed that was essentially attributed to water retention. Net protein content was increased only to a minor extent (15%), of which only the liver accounted for a significant part of the body compartments. Hepatic protein accumulation was obviously caused by decreased protein degradation, since hepatic RNA content was unchanged. After anabolic steroid administration, reduced histochemical staining of succinate dehydrogenase was observed in skeletal muscles rich in oxidative type 1 fibers, but it was not different from that of tumor-bearing control animals, which was also confirmed by measurements of citrate synthase and cytochrome c oxidase activities in skeletal muscle and liver tissue. The anabolic steroid had no significant effect on tumor growth in terms of weight progression, energy state, polyamine synthesis rate, cell division rate, and cell cycle cytocompartments. We conclude that anabolic steroid supplementation is not therapeutically beneficial in counteracting progressive weight loss in experimental cancer.

Anabolic Agents↗
PubMed1995

Long-term potentiation in the hippocampal CA1 region in the presence of N-methyl-D-aspartate receptor antagonists.

The present study deals with the question of whether L-type voltage-gated calcium channels can support the induction of input specific long-term potentiation. Tetanus-induced potentiation of synaptic transmission was examined in the CA1 region of normal and disinhibited guinea-pig hippocampal slices. It was found that afferent tetanization in the presence of 50 microM of the N-methyl-D-aspartate receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid led to a prolonged input specific potentiation. This potentiation was found only in disinhibited slices, its induction required cooperativity, and it was associated with an increase in the early part of the field excitatory postsynaptic potential initial slope. It was not affected by the L-type voltage-gated calcium channel blocker nifedipine, but it was reduced when D(-)-2-amino-5-phosphonopentanoic acid was supplemented with other N-methyl-D-aspartate receptor antagonists. The present study also examined a potentiation that was not restricted to the activated synapses and that was not associated with an increase in the early part of the field excitatory postsynaptic potential initial slope. This potentiation was blocked by the L-type voltage-gated calcium channel antagonist nifedipine. It is concluded that calcium influx through L-type voltage-gated calcium channels participates in the generation of a prolonged potentiation, but not of the input specific N-methyl-D-aspartate receptor-dependent long-term potentiation. The results also suggest that high concentrations of D(-)-2-amino-5-phosphonopentanoic acid can be insufficient to fully prevent N-methyl-D-aspartate receptor activation by strong afferent tetanization in the disinhibited slice.

2-Amino-5-phosphonovalerate↗
PubMed1995

Adult cancer risks among the mothers of children with cancer.

We investigated cancer risk among mothers of 2365 children who were diagnosed with cancer between 1973 and 1989 in Sweden. From the date of birth of the child until 31 December 1989, 38 cases of cancer were diagnosed among the mothers. The expected number of cases, according to national rates, was 30.9. Cancer of the thyroid was the only site showing a significantly increased risk among the mothers (observed = 6, expected = 1.2, P < 0.01), but two cases were medullary cancer associated with an inheritable syndrome, and inherited by their children.

Adult↗
PubMed1995

Increased human hybridoma formation by electrofusion of human B cells with heteromyeloma SPAM-8 cells.

A fusion protocol was designed for the optimal production of hybridomas following electrofusion of human B cells with cells of the heteromyeloma fusion partner SPAM-8. Peripheral blood lymphocytes showed an average fusion efficiency of 0.4 x 10(-4) whereas Epstein-Barr virus-transformed B cells showed fusion efficiencies ranging from 6.2 x 10(-4) to 9.0 x 10(-4). Similar results were obtained with bone marrow-derived lymphocytes. Trypsin treatment of the cells prior to electrofusion further increased the fusion efficiency to 12.3 x 10(-4). In comparison, conventional polyethylene glycol-induced fusion resulted in a fusion efficiency of 0.8 x 10(-4). Thus, electrofusion of human B cells with SPAM-8 heteromyeloma cells introduced a 15-fold increase in hybridoma formation as compared to the conventional fusion method.

Animals↗
PubMed1995

Recombinant human insulin-like growth factor-I decreases serum lipoprotein(a) concentrations in normal adult men.

OBJECTIVE: Lipoprotein(a) is a lipoprotein fraction associated with atherosclerosis. The serum concentration of lipoprotein(a) has been shown to be mainly genetically determined but recently evidence for hormonal regulation has been presented. The aim of the present study was to investigate the effects of insulin-like growth factor-I on serum lipoproteins, especially lipoprotein(a). DESIGN: The effects of one week of IGF-I treatment were studied in an open trial. SUBJECTS: Ten healthy men, who participated in a pharmacokinetic study, were given recombinant human insulin-like growth factor-I (40 micrograms/kg/day) as daily subcutaneous injections. MEASUREMENTS: Serum samples for measurements of lipoproteins were taken after an overnight fast before and after 7 days of treatment. RESULTS: There was decrease in serum lipoprotein(a) concentration (18.5 +/- 5.5%) in nine of the subjects, and a slight increase in one of the subjects with the lowest concentrations. Also serum apolipoprotein (b) (6.3 +/- 2.2%), serum cholesterol (10.6 +/- 1.8%) and serum triglyceride (14.8 +/- 4.8%) concentrations decreased. An unexpected finding was that fasting serum glucose concentrations increased (13 +/- 4%). CONCLUSION: Insulin-like growth factor-I is involved in the regulation of lipoprotein(a) concentrations, which might have novel therapeutic implications.

Adult↗
PubMed1995

On the linkage between AMPA and NMDA receptor-mediated EPSPs in homosynaptic long-term depression in the hippocampal CA1 region of young rats.

Homosynaptic long-term depression (LTD) was studied in hippocampal slices from 12-18-d-old rats using field EPSP recording in the apical dendritic layer of CA1 pyramidal cells. Independent estimates of the alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA) and the N-methyl-D-aspartic acid (NMDA) receptor-mediated components of the field EPSP were obtained in parallel using early and late measurements of a dual-component EPSP in a low-magnesium solution. LTD was induced by low-frequency stimulation (LFS; 2 Hz for 10 min), resulting in equal relative changes of the AMPA and NMDA receptor-mediated components. Under conditions when the AMPA receptor-mediated component was fully blocked, a similarly sized LTD was observed for the pure NMDA receptor-mediated EPSP (measured as initial slope or peak amplitude). Equal changes in AMPA and NMDA receptor-mediated components occurred also upon application of the adenosine agonist N6-cyclohexyladenosine (CHA), known to act by decreasing transmitter release. On the other hand, LTD was found to interact in a multiplicative manner with the presynaptic release changes induced by CHA and by paired-pulse facilitation. The induction of the LTDs of both AMPA and NMDA receptor-mediated EPSPs was blocked by the NMDA receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid and by the phosphatase inhibitor okadaic acid. Partial blockade of LTD by okadaic acid resulted in equal partial blockade of the LTDs of the AMPA and NMDA receptor-mediated components. On the other hand, the L-type calcium channel blocker nifedipine, the metabotropic glutamate receptor antagonist (RS)-alpha-methyl-4-carboxyphenylglycine, the nitric oxide synthase inhibitor N omega-nitro-L-arginine, and the heme oxygenase inhibitor protoporphyrin IX zinc(II) had no effect on LTD of either the AMPA or the NMDA receptor-mediated component. These results of equal changes of AMPA and NMDA receptor-mediated components of the field EPSP in association with LTD, and the consistent parallelism of effects or noneffects on these components by various receptor antagonists and enzyme inhibitors, seem more easily explained by a presynaptic locus for LTD than by a postsynaptic one.

Animals↗
PubMed1994

Long-term depression in the hippocampal CA1 region is associated with equal changes in AMPA and NMDA receptor-mediated synaptic potentials.

In the CA1 hippocampal region low-frequency (1-2 Hz) afferent activation leads to a long-term depression of excitatory synaptic potentials that is induced by calcium influx through postsynaptic N-methyl-D-aspartate receptor channels. In the present experiments using 2- to 3-week-old rats, long-term depressions of field excitatory postsynaptic potentials mediated by amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and by N-methyl-D-aspartate receptor channels were examined in parallel, using a perfusion solution containing low concentrations of an AMPA receptor antagonist and of magnesium (0.1 mM). These experiments revealed that long-term depression was associated with equal relative changes in the two components of the field potential, compatible with a presynaptic location of the expression mechanism for the long-term depression.

Animals↗
PubMed1994

Dissociation between long-term potentiation and associated changes in field EPSP waveform in the hippocampal CA1 region: an in vitro study in guinea pig brain slices.

The present study examines changes in field excitatory postsynaptic potential (EPSP) waveform in association with long-term potentiation (LTP) in the CA1 region of the hippocampal slice preparation. Experiments were performed in the presence of the GABAA-antagonist picrotoxin. With test field EPSP about one-third the size of that evoking spike activity (measured in the cell body layer along the same somatodendritic axis as the dendritic recording) a decreased decay time constant (approximately 8%) was seen in association with LTP. This change in field EPSP waveform was not associated with any apparent spike activity in the cell body recording. Nevertheless, several findings suggest that increased spike activity explains the change in the decay time constant of the field EPSP during LTP. First, when reducing the stimulation strength after the induction of LTP to obtain a field EPSP of the same magnitude as the pretetanus one, the change of the decay time constant was reduced to only 2.8%. Second, when using small test field EPSP (about one-fourth the size of that evoking spike activity) the decay time constant was not significantly affected in association with LTP. Third, when cutting the slice in such a manner that spike activity originating from somatic regions closer to the stimulating electrode was removed, the EPSPs decay time constant was not significantly affected in association with LTP. It is concluded that LTP is not associated with a change in the shape of the field EPSP.

Animals↗
PubMed1994

Time use in child care and housework and the total cost of children.

"The use of time for child care and housework among Swedish families is investigated. We allow the effect of children on child care and housework to vary by age of the child and also by whether the child is cared for outside the home or not. Our estimates allow us to compute the total cost of children in the form of the cost of time, and the cost of goods, services and housing. The result shows that time used for child care decreases sharply with the age of the child but this is not the case for time used for other housework."

Adolescent↗
PubMed1994

A motivational approach to confirmation: an interpretation of dysphagic patients' experiences.

In this paper we articulate confirmation and disconfirmation as components in human motivation. We develop a theory of motivation on the basis of a model of human action and we explore aspects of confirmation and disconfirmation in the context of the meeting of dysphagic patients with their physicians. We distinguish four central elements in confirmation and disconfirmation and use these and the relations between them for the purpose of constructing a typology. Finally, on the basis of the results obtained we interpret a small volume of remarks reflecting the meaning field of some dysphagic patients in relation to their physicians. The underlying motive is to develop tools for understanding health care processes. The "SAUC-Confirmation-Model" and the theoretical framework in which it is embedded should be seen from that point of view.

Adaptation, Psychological↗
PubMed1994

Immunochemical characterization of Micrurus nigrocinctus nigrocinctus venom with monoclonal and polyclonal antibodies.

Eleven murine monoclonal antibodies (MAbs) against Micrurus nigrocinctus nigrocinctus venom were produced and partially characterized. When M. n. nigrocinctus venom proteins were separated by SDS-PAGE under non-reducing conditions four sharp and three diffuse bands were observed. The sharp bands had migration rates comparable to reduced standards of 10, 12, 50 and 72 kDa. The diffuse bands migrate in the range of reduced standards from 14.5 to 32 kDa. When venom proteins were separated under reducing conditions the same sharp bands and an additional prominent 14.5 kDa band were observed. Three antibodies (MAbs 4, 21 and 28) recognized the diffuse bands in western blots of non-reducing SDS-PAGE, whereas MAbs 7G, 22 and 26 reacted with only the 72 kDa protein. MAbs 21 and 28 reacted with the 14.5 kDa band whereas MAb 7G recognized the 72 kDa band in blots of reducing SDS-PAGE. Two M. nigrocinctus antivenoms cross-reacted by ELISA against nine neurotoxic snake venoms, as well as with gamma-toxin from Naja nigricollis and notexin. One antibody (MAb 9A) was used to affinity purify a fraction (called nigroxin) from M. n. nigrocinctus venom. Nigroxin showed phospholipase and myotoxic activities and appeared as a single 15 kDa band in SDS-PAGE under reducing conditions. However, three bands with slight differences in charge were resolved by urea-PAGE, representing isoforms named nigroxin a, b, and c. Nigroxin induced a dose-dependent release of peroxidase trapped in negatively charged liposomes. Nigroxin induced myonecrosis and increased the plasma creatine kinase levels in mice, when injected intramuscularly. The plasma membrane of cultured L6 myoblasts was permeabilized by nigroxin, as evidenced by the release of 3H-uridine nucleotides from prelabelled cells. This effect was completely abolished after preincubation with MAb 9A, although this antibody failed to neutralize the enzymatic activity of nigroxin. Nigroxin was also recognized by MAbs 4, 7H, 21, 27 and 28. Additionally, the epitope recognized by MAb 27 is also present in notexin and beta-bungarotoxin.

Animals↗
PubMed1994

Electrophoretic and immunochemical studies of Micrurus snake venoms.

The electrophoretic mobilities of venom components from 15 Micrurus species were studied by polyacrylamide gel electrophoresis. The venoms showed species-specific protein patterns under native (PAGE) or denaturing (urea-PAGE) conditions. However, electrophoretic patterns obtained by SDS-PAGE under reducing conditions were similar. The proteins of all venoms had mol. wts either in the range of 45 to 75 kDa or lower than 14.5 kDa. PAGE and urea-PAGE of single extraction venom samples from 22 M. nigrocinctus nigrocinctus specimens revealed some proteins completely conserved, whereas others exhibited intraspecies variation. Based on ELISA cross-reactivity studies with 11 monoclonal antibodies against M. n. nigrocinctus venom, venoms from M. n. nigrocinctus, M. nigrocinctus mosquitensis, M. fulvius fulvius, M. dumerilii carnicauda and M. albicinctus were included in the same antigenic group, whereas M. frontalis frontalis and M. frontalis braziliensis venoms constituted a second group. Micrurus alleni and M. spixii spixii showed reactivity patterns similar to groups 1 and 2, respectively. Venoms from M. surinamensis surinamensis, M. corallinus, M. ibiboboca, M. hemiprichii ortoni, M. lemniscatus helleri and M. mipartitus had unique cross-reactivity patterns with monoclonal antibodies against M. n. nigrocinctus venom.

Animals↗
PubMed1994

Onset and stabilization of NMDA receptor-dependent hippocampal long-term potentiation.

This article discusses recent data concerning the temporal development of N-methyl-D-aspartate (NMDA) receptor-dependent potentiation in the hippocampus. It argues against a mechanistic subdivision of NMDA receptor-dependent potentiation into an early short-term potentiation (STP) and a slowly developing long-term potentiation (LTP). Thus, the article proposes that LTP starts a few seconds after the induction event, that it is fully developed within a minute, and that its subsequent stabilization is controlled by the degree of NMDA receptor activation, and associated increase of calcium concentration in the spine, during the induction event. It is suggested that most biochemical interventions that have been reported to interfere with the LTP process, for example application of protein kinase inhibitors, might have acted through an impairment of the induction mechanism rather than through an impairment of specific stabilization or maintenance mechanisms.

Animals↗