Biomedical subjects

L Jansson

Publications and source records attributed to L Jansson.

At least 55 records · Page 3Linked to original sources

PubMed2000

A qualitative study of childbirth as spoken about in midwives' ante- and postnatal consultations.

OBJECTIVE: To describe conversational topics concerning childbirth and illuminate the meanings of childbirth within the discourse of ante- and postnatal midwifery consultations. DESIGN: Video-recordings of midwives' consecutive encounters with women/couples, from early pregnancy until after birth. The encounters were analysed using content analysis and a phenomenological hermeneutic approach. SETTING: Swedish midwifery clinics at primary health care centres. PARTICIPANTS: Five midwives, five women and three men. FINDINGS: Bio-medical aspects of childbirth were given much importance in the consultations relative to the activities and lived experiences of the women and their partners. Two main features of the meanings of childbirth were found in the consultations; one in which childbirth was understood as a spontaneous and risky process needing to be controlled and to which the woman had to adapt; the other was characterised by being woman centred, pointing to her power and abilities in a process during which she is cared for and which leads to a satisfying result. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: A mechanistic and medicalised understanding of childbirth seems to dominate this discourse but the 'natural childbirth perspective' also appears. This study could serve as a basis for reflection on the content and meanings of childbirth in ante- and postnatal midwifery care.

Adult↗

PubMed2000

Progression rate of approximal carious lesions in Swedish teenagers and the correlation between caries experience and radiographic behavior. An analysis of the survival rate of approximal caries lesions.

The objectives were to study the progression rate of approximal caries in 14 to 19-year-old adolescents and to assess the influence of experience of previous caries as a predictor of caries progression during the following years. The study population comprised 100 adolescents, all 19 years old, randomly selected. In all, there were 93 adolescents included in the study, for whom all sets of bitewing radiographs from 14 up to and including the age of 19 were assessed with respect to approximal caries. It could be noted that 32% of the adolescents had had at least one bitewing examination every year from 14 to 19 years of age. At the age of 14, 38% of the males and 24% of the females were radiographically without any sign of caries lesions (caries-free). The median survival time of initial caries in the present study was >5 years, while for manifest caries it was 3.2 years. It was found that 37% of the surfaces with manifest caries in males and 18% of the corresponding surfaces in females were restored within a year. The results show that experience of previous caries does not seem to be a significant indicator and does not influence when the next radiographic examination should be performed. It is thus concluded that individualized bitewing examination is the exception rather than the rule.

Adolescent↗

PubMed2000

Immunoglobulin-secreting cells of maternal origin can be detected in B cell-deficient mice.

It is well known that the transfer of immunoglobulins (Igs) from mother to young via milk contributes to the offspring's immune defense. The present study suggests that not only is IgG transmitted to progeny, but that functional maternal Ig-secreting cells (or B cells) can also be transferred to the neonate. We have used B cell-deficient (micro(-/-)) mice and found that a high proportion of them obtain long-lasting, partial reconstitution of their serum Ig levels if born to micro(+/-) mothers. In some of these serum IgG-positive micro(-/-) mice, Ig-secreting cells were detected in spleen and bone marrow. To ensure that cells of maternal origin were present in the progeny, micro(-/-) offspring born to micro(+/-) dams transgenic for green fluorescent protein (GFP) were used. In spleens and bone marrow from some of these micro(-/-)GFP(-/-) offspring, GFP-positive cells were detected, which demonstrated that cells of maternal origin could infiltrate the progeny. In addition, splenic Ig-secreting cells were detected in micro(-/-) mice that were born to micro(-/-) dams and transferred to a lactating micro(+/+) foster dam at birth. This indicates that maternal Ig-secreting cells can be transferred postnatally via milk.

Adoptive Transfer↗

PubMed2000

Suffering from care as expressed in the narratives of former patients in somatic wards.

To illuminate patients' experiences of suffering from care, ten former patients in somatic wards narrated a desirable care episode (n = 39) and an undesirable care episode (n = 51). The interviews were analysed using a phenomenological hermeneutic method inspired by Ricoeur's philosophy. Four themes were found: having a good rest, suffering through, searching for autonomy and being cared for by attentive and committed staff. The findings were interpreted in light of Eriksson's description of suffering, which describes three kinds of suffering: 'suffering of life', 'suffering of illness' and 'suffering of caring'. Although not mentioned explicitly, it was evident that cases of suffering from care were indicated in the patients' narratives. The themes were related to the patients' states of health, their experience of the care situation and their descriptions of themselves, and could be understood as related to the acts of the 'drama of suffering' described by Eriksson. The study highlights the need for the patient to find a co-actor in the drama of suffering in order to prevent suffering from care, i.e. prevent hindrance to the patient in her/his struggle against the 'suffering of illness' and the 'suffering of life'. The patients must be seen as the directors of their own dramas of suffering.

Humans↗

PubMed2000

Age-induced changes in pancreatic islet blood flow: evidence for an impaired regulation in diabetic GK rats.

The present study aimed to compare longitudinal variations in islet blood perfusion in rats with different degrees of impairment of glucose metabolism. For this purpose, mildly diabetic Goto-Kakizaki (GK) rats, glucose intolerant F(1) hybrids of GK and Wistar (W) rats (H), and control W rats were examined at 5 wk, 12 wk, or 1 yr of age, using the microsphere technique for blood flow measurements. W rats showed progressively increasing islet blood flow (IBF) throughout the experiment. Both GK and H rats demonstrated increasing IBF between 5 and 12 wk. However, H rats showed no further increment in IBF at 1 yr, whereas GK rats displayed a pronounced decrease in IBF between 12 wk and 1 yr of age. The augmented IBF seen in older W rats may constitute an adaptation to the increasing demand for insulin secretion in aging rats. The inability to adapt to the increased demand for insulin secretion by upregulation of islet blood flow could contribute to the progressive deterioration of glucose metabolism seen in the aging GK rat.

Aging↗

PubMed2000

Intraportal glucose infusion and pancreatic islet blood flow in anesthetized rats.

The aim of the study was to evaluate whether a selective increase in portal vein blood glucose concentration can affect pancreatic islet blood flow. Anesthetized rats were infused (0.1 ml/min for 3 min) directly into the portal vein with saline, glucose, or 3-O-methylglucose. The infused dose of glucose (1 mg. kg body wt(-1). min(-1)) was chosen so that the systemic blood glucose concentration was unaffected. Intraportal infusion of D-glucose increased insulin release and islet blood flow; the osmotic control substance 3-O-methylglucose had no such effect. A bilateral vagotomy performed 20 min before the infusions potentiated the islet blood flow response and also induced an increase in whole pancreatic blood flow, whereas the insulin response was abolished. Administration of atropine to vagotomized animals did not change the blood flow responses to intraportal glucose infusions. When the vagotomy was combined with a denervation of the hepatic artery, there was no stimulation of islet blood flow or insulin release after intraportal glucose infusion. We conclude that a selective increase in portal vein blood glucose concentration may participate in the islet blood flow increase in response to hyperglycemia. This effect is probably mediated via periarterial nerves and not through the vagus nerve. Furthermore, this blood flow increase can be dissociated from changes in insulin release.

3-O-Methylglucose↗

PubMed2000

Engraftment and growth of transplanted pancreatic islets.

Transplantation of pancreatic islets may provide a cure for type 1 diabetes. However, this treatment can currently be offered only to very few patients. To improve transplantation success we need to understand better the mechanisms of how the implanted islets survive, grow and/or maintain adequate function. We herein report on our studies to evaluate the factors responsible for the engraftment, i.e. revascularization, reinnervation etc., of transplanted islets and relate these factors to the metabolism and growth of the islets. Graft metabolism can be monitored by microdialysis probes that allow for the measurement of minute amounts of islet metabolites and hormonal products. Growth of the endocrine cells can be stimulated both in vitro before implantation and in vivo post-transplantation. Another problem is rejection of transplanted islets, which may be overcome by the microencapsulation of islets. The knowledge gained by the present studies will enable us to elucidate the optimal treatment of islets to ensure a maximal survival of the transplanted islets, and may be applied also to clinical islet transplantation.

Animals↗

PubMed2000

An exemplar of a positive perspective of being dependent on care.

This article is part of an ongoing study which aims at disclosing the meaning of being dependent on care. From a larger data set derived from 10 patients, interviews with one severely ill patient, her daughter and two of her professional nurses were selected to illuminate a "positive" meaning of being dependent on care. The interviews were tape-recorded and transcribed verbatim and followed by interpretation of transcripts using a phenomenological-hermeneutic approach inspired by Paul Ricoeur's philosophy. The interpretation discloses the meaning of being dependent on care as balancing between being free and negotiating when receiving care. Whether or not dependency on care is negotiated about seems to be about how the power that lies in the existing differences in ability is used. When ability, that is, power, is used to compensate inability, the patient appears free to be dependent on care. Dependency on care is accepted for what it is, when it is. When dependency on care is negotiated about, the differences in ability, that is, power, risk setting limits for what dependency on care is to be. There is a risk that dependency on care will be limited within the frame of what is regarded as polite, appealing and pleasing.

Activities of Daily Living↗

PubMed1999

Angiogenesis and angioarchitecture of transplanted fetal porcine islet-like cell clusters.

Normoglycemic, athymic nude mice were implanted with 3 microl (approximately 250) fetal, porcine islet-like cell clusters under the renal capsule. The angioarchitecture of the transplanted islets was studied by microvascular corrosion casts 3 or 52 weeks after implantation. Arterioles were few, and observed mainly in the older age group. This is likely to be due to the fact that the arterioles were derived from intrarenal blood vessels, i.e., they were not visible on the graft surface. Within the grafts nests of capillaries, probably supplying a single islet-like cell clusters, could be seen in both groups. Numerous capillary sprouts were seen within the graft after 3 weeks, and to a slighter extent also after 1 year. Moreover, especially in grafts examined 3 weeks, but also 52 weeks, after transplantation, holes were observed in dilated capillary segments, suggesting that intussusceptive microvascular growth occurred in parallel with angiogenesis. A well-developed microvasculature could be observed 52 weeks after transplantation, whereas the number of capillaries in the implant was less pronounced 3 weeks postimplantation. The efferent venules were located peripherally in the islets and drained immediately into larger veins, derived from capsular veins clearly seen on the surface of the graft. It is concluded that xenotransplanted islet-like cell clusters develop an autonomous microcirculation by stimulating angiogenesis from surrounding blood vessels. Our findings suggest that single islet-like cell clusters remain morphologically intact after transplantation, and probably function as single endocrine units rather than forming a single homogenous endocrine tissue. Furthermore, it seems as if a continuous reorganization of the vasculature, with an associated angiogenesis, occurs throughout the observation period.

Animals↗

PubMed1999

Identification of genes controlling collagen-induced arthritis in mice: striking homology with susceptibility loci previously identified in the rat.

The susceptibility to collagen-induced arthritis in the highly susceptible DBA/1 mouse has earlier been shown to be partly controlled by the MHC class II gene Aq. To identify susceptibility loci outside of MHC, we have made crosses between DBA/1 and the less susceptible B10.Q strain, both expressing the MHC class II gene Aq. Analysis of 224 F2 intercross mice with 170 microsatellite markers in a genome-wide scan suggested 4 quantitative trait loci controlling arthritis susceptibility located on chromosomes 6, 7, 8, and 10. The locus on chromosome 6 (Cia6), which was associated with arthritis onset, yielded a logarithm of odds score of 4.7 in the F2 intercross experiment and was reproduced in serial backcross experiments. Surprisingly, the DBA/1 allele had a recessive effect leading to a delay in arthritis onset. The suggestive loci on chromosomes 7 and 10 were associated with arthritis severity rather than onset, and another suggestive locus on chromosome 8 was most closely associated with arthritis incidence. The loci on chromosomes 7, 8, and 10 all appeared to contain disease-promoting alleles derived from the DBA/1 strain. Interestingly, most of the identified loci were situated in chromosomal regions that are homologous to regions in the rat genome containing susceptibility genes for arthritis; the mouse Cia6 locus is homologous with the rat Cia3, Pia5, Pia2, and Aia3; the locus on chromosome 7 (Cia7) is homologous with the rat Cia2; and the locus on chromosome 10 (Cia8) is homologous with the rat Cia4.

Animals↗

PubMed1999

A humanized model for multiple sclerosis using HLA-DR2 and a human T-cell receptor.

Multiple sclerosis (MS) is a complex chronic neurologic disease with a suspected autoimmune pathogenesis. Although there is evidence that the development of MS is determined by both environmental influences and genes, these factors are largely undefined, except for major histocompatibility (MHC) genes. Linkage analyses and association studies have shown that susceptibility to MS is associated with genes in the human histocompatibility leukocyte antigens (HLA) class II region, but the contribution of these genes to MS disease development less compared with their contribution to disorders such as insulin-dependent diabetes mellitus. Due to the strong linkage disequilibrium in the MHC class II region, it has not been possible to determine which gene(s) is responsible for the genetic predisposition. In transgenic mice, we have expressed three human components involved in T-cell recognition of an MS-relevant autoantigen presented by the HLA-DR2 molecule: DRA*0101/DRB1*1501 (HLA-DR2), an MHC class II candidate MS susceptibility genes found in individuals of European descent; a T-cell receptor (TCR) from an MS-patient-derived T-cell clone specific for the HLA-DR2 bound immunodominant myelin basic protein (MBP) 4102 peptide; and the human CD4 coreceptor. The amino acid sequence of the MBP 84-102 peptide is the same in both human and mouse MBP. Following administration of the MBP peptide, together with adjuvant and pertussis toxin, transgenic mice developed focal CNS inflammation and demyelination that led to clinical manifestations and disease courses resembling those seen in MS. Spontaneous disease was observed in 4% of mice. When DR2 and TCR double-transgenic mice were backcrossed twice to Rag2 (for recombination-activating gene 2)-deficient mice, the incidence of spontaneous disease increased, demonstrating that T cells specific for the HLA-DR2 bound MBP peptide are sufficient and necessary for development of disease. Our study provides evidence that HLA-DR2 can mediate both induced and spontaneous disease resembling MS by presenting an MBP self-peptide to T cells.

Animals↗

PubMed1999

Detection of Helicobacter pylori antibodies in a pediatric population: comparison of three commercially available serological tests and one in-house enzyme immunoassay.

A serum immunoglobulin G enzyme immunoassay (EIA) for Helicobacter pylori antibodies already in use in adults was evaluated with 99 pediatric serum samples to determine its usefulness for the study of H. pylori disease in children. The reference method used was either the (13)C-urea breath test or a biopsy culture of gastric mucosa. In children, an EIA cutoff of 0.35 absorbancy unit yielded sensitivity, specificity, and positive and negative predictive values of 93, 97, 93, and 97%, respectively. The cutoff recommended when this EIA was published for use in adults was 0.70 absorbancy unit (H. Gnarpe, P. Unge, C. Blomqvist, and S. Mäkitalo, APMIS 96:128-132, 1988). Another subset of 169 serum samples taken from children was analyzed by four serological tests in order to compare the performance of the in-house EIA with the Pyloriset, HM-CAP, and Helico-G kits. For the 169 samples, 10 (5.9%) false-positives and no false-negatives occurred with the Helico-G, 3 (1.8%) false-positives and no false-negatives occurred with the Pyloriset, and 3 (1.8%) false-positives and 1 (0.6%) false-negative occurred with the HM-CAP. For the 169 samples, 1 (0.6%) false-positive and no false-negatives occurred with the in-house EIA. Serological detection of H. pylori antibodies with our EIA seems to be valuable in diagnosing H. pylori infection in children, but only if a lowered, specific pediatric cutoff is established. The commercial kits, particularly the Helico-G, seem to overdiagnose pediatric H. pylori infection. A positive serological test for H. pylori infection, particularly for children, needs to be confirmed by a reference method because of the possibility of spontaneous eradication of infection, with a lingering serological response.

Adolescent↗

PubMed1999

Stimulation of intestinal glucoreceptors in rats increases pancreatic islet blood flow through vagal mechanisms.

The aim of the study was to evaluate whether intestinal glucoreceptors participate in the regulation of pancreatic islet blood flow. For this purpose, anesthetized rats were infused (0.1 ml/min for 3 min) with saline, glucose, or 3-O-methylglucose directly into the duodenum. The glucose (1 mg/kg body wt) infusion rate was chosen to prevent any effects on systemic or intraportal blood glucose concentrations. Intraduodenal infusion of D-glucose increased both serum insulin concentration and islet blood flow, whereas the osmotic control substance 3-O-methylglucose had no such effects. A bilateral abdominal vagotomy performed before the infusions totally abolished both the insulin and blood flow response to glucose infusion. The absence of an increased islet blood flow in response to glucose infusion in the denervated, transplanted pancreas was a further indication of the crucial importance of the regulation of islet blood flow by the vagus nerves. It is concluded that intestinal glucoreceptors participate in the mediation of glucose-induced islet blood flow increase.

3-O-Methylglucose↗

PubMed1999

Crisis phenomena after stroke reflected in an existential perspective.

The study gains a deeper understanding of crisis phenomena emerging after stroke and focuses on these phenomena viewed in an existential perspective. Ten stroke victims narrated their experiences of their new life situation in open-ended interviews, conducted during the first few months after discharge. The participants were analyzed using a phenomenological-hermeneutic approach. This analysis disclosed an extremely distressing situation related to the individuals' struggle to manage in various dimensions of life. The phenomena were intertwined in a complex way and the critical interpretation involved a transcendence to the existential dimension of life. The situation was metaphorically depicted as "a struggle in the darkness" in a "boundary situation," where the issues ultimately touched on life and death, fate and future, meaning and meaninglessness. The study indicates the significance of existential issues pervading the seemingly concrete struggle to manage life after stroke.

Aged↗

PubMed1999

Radiographic examinations as an aid to orthodontic diagnosis and treatment planning.

Seventy consecutive adolescents were examined to evaluate radiographic examinations as an aid to orthodontic diagnosis and treatment planning in combination with clinical examination. The clinical examination included dental impressions and extra- and intraoral photographs. The radiographic examination comprised a panoramic radiograph, a lateral cephalogram and six intraoral anterior periapical radiographs. Initially, only records from the clinical examination were used for diagnosis and treatment planning. If required, the dentist could choose any of the radiographs to accomplish the task. The number of radiographs ordered, the sequence of ordering and any change in diagnosis and treatment plan caused by the radiographs were registered. In 29% of the cases the initial diagnosis, based on the clinical examination, study models and photographs, coincided with the final diagnosis. In 93% of all cases the initial treatment plan coincided with the final one. Although the panoramic examination was the most common choice, it had only a minor effect on diagnostic and treatment decisions, while the cephalometric examination had a major impact on the diagnosis. In most cases the clinical examination, supplemented with study models and photographs, can provide adequate information for orthodontic treatment planning. The result stresses the importance of using individually based selection criteria for radiographic examination in order to prevent radiographs being obtained routinely.

Adolescent↗

PubMed1998

Evidence of a negative feedback system regulating the total beta-cell volume in nondiabetic rats that received pancreas transplants.

BACKGROUND: The aim of the present study was to investigate the long-term regulation of pancreatic beta-cell volume after pancreas transplantation into adult rats. METHODS: A syngeneic pancreaticoduodenal transplantation was made in normoglycemic Wistar-Furth rats. By this means, the recipients doubled their pancreatic islet volume. Nine months after transplantation, the total beta-cell volume was measured in serial pancreatic sections immunostained for insulin from both the native and transplanted pancreata, and in the native pancreas of age-matched Wistar-Furth rats that did not receive transplants. RESULTS: No changes in the volume of individual beta-cells were seen. A 50% decrease in total beta-cell volume was observed in both the native and transplanted pancreas when compared with that of age-matched controls. However, the combined beta-cell volumes of the native and transplanted pancreas in the rats that received transplants were similar to those of the native pancreas in control animals. No signs of increased apoptosis in any of the glands could be seen during the first postoperative week or after 9 months. CONCLUSIONS: These findings provide evidence of a negative feedback system, which regulates the total beta-cell volume to the levels seen in age-matched rats that did not receive transplants. The underlying mechanisms for the decreased beta-cell volume are unknown, but may involve a diminished replicatory rate of the beta-cells.

Animals↗

PubMed1998

Genetic linkage analysis of collagen-induced arthritis in the mouse.

The genetic susceptibility to collagen-induced arthritis (CIA) in mice, the most commonly used model for rheumatoid arthritis, has been analyzed. The highly susceptible B10.RIII strain was crossed with the resistant RIIIS/J strain and the F2 intercross mice were subjected to genomic screening using microsatellite markers. These strains share the MHC region on chromosome 17, known to be of importance in CIA (this locus is named Mcia1). The same cross has earlier been used to map the major genes outside the MHC controlling chronic relapsing experimental allergic encephalomyelitis (EAE). It was found that the major locus controlling CIA (Mcia2; lod 4.12) was located on chromosome 3 in the same region as one of the major loci controlling EAE (Eae3). The linkage was reproduced in a mouse strain in which the locus was isolated on the B10.RIII background at the N4I2 generation. A second putative locus was identified on chromosome 13 (lod 3.13). The present finding identifies new loci outside the MHC controlling CIA and provides evidence that mouse CIA is controlled by polymorphic genes.

Animals↗

PubMed1998

Estrogen-mediated immunosuppression in autoimmune diseases.

Gender affects the susceptibility to many autoimmune diseases. Women have an increased risk of developing diseases such as rheumatoid arthritis and multiple sclerosis compared with men. The female preponderance is believed to depend in part on the influence of sex hormones on the immune system. The mechanism of estrogen-induced immune suppression both in human autoimmune diseases and their experimental animal model counterparts is discussed. In addition, the mechanisms of estrogen and anti-estrogens are discussed in relation to their possible use as future therapeutic anti-inflammatory agents.

Animals↗