Biomedical subjects

L Jansson

Publications and source records attributed to L Jansson.

At least 19 recordsLinked to original sources

PubMed2001

Microcirculation of human pancreatic islets transplanted under the renal capsule of nude mice.

BACKGROUND: The aim was to measure the capillary blood pressure in transplanted human islets. METHODS: Human islets were isolated at the Central Unit of the beta-cell Transplant in Brussels, Belgium. After transport to our laboratory, the islets were implanted under the renal capsule of normoglycemic nude mice. Two weeks later the capillary and venous blood pressures in the islet graft and adjacent renal parenchyma were measured with a micropuncture technique. RESULTS: Capillary blood pressure was approximately 5-8 mmHg in both graft and renal capillaries: twice as high as in native islets. Venous blood pressures were similar (4-5 mmHg) in the veins draining the graft and in the renal interlobular veins. All veins leading from the graft emptied into the renal parenchyma, that is, into interlobular veins. CONCLUSIONS: The capillary hypertension seen in transplanted human islets is probably necessary to secure adequate drainage through the renal veins. Whether this contributes to the poor results of long-term islet graft survival is unknown.

Adolescent↗

PubMed2001

Reinnervation of syngeneic pancreatico-duodenal grafts in rats.

BACKGROUND: Knowledge on the reinnervation of transplanted organs is scarce, and the aim of the study was therefore to evaluate to what degree syngeneic pancreas grafts were reinnervated in rats. METHODS: Syngeneic pancreatico-duodenal transplantations were performed in normoglycemic Wistar-Furth rats. Native and transplanted pancreas and duodenum were removed 4 or 40 weeks after implantation, and processed for indirect immunofluorescence using antibodies directed against vasoactive intestinal peptide, substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), tyrosine hydroxylase (TH), or the general neuronal marker protein gene product 9.5. RESULTS: Four weeks after transplantation a moderate to rich number of protein gene product 9.5-positive nerve fibers were found homogeneously distributed through the pancreas, probably representing the intrapancreatic nervous system, because the grafted pancreas lacked both a sympathetic (TH/NPY) and sensory (SP/CGRP) innervation 4 weeks after implantation. In a few of the animals there was a marked increase in SP-immunoreactive nerves (lacking CGRP), most conspicuous in the duodenal portion, both 4 and 40 weeks after transplantation probably secondary to a chronic pancreatitis. The fibers seemed to emanate from intrapancreatic ganglia and possibly also from enteric neurons in adjacent parts of the duodenum. A few scattered vasoactive intestinal peptide-containing nerve fibers probably also emanating from local ganglia could be seen throughout the grafted pancreas both 4 and 40 weeks after transplantation. At 40 weeks after transplantation sympathetic (TH- and NPY-positive) nerve fibers were regularly seen, whereas CGRP-positive nerve fibers were still virtually lacking in the pancreas. To trace the origin of the ingrowing nerve fibers, the tracer True Blue was injected into the grafted pancreas of some rats 38 weeks after transplantation, i.e., 2 weeks before killing. True Blue-labeled nerve cell bodies were numerous in the celiac ganglion (presumably sympathetic nerves) and few in dorsal root ganglia (sensory nerves). CONCLUSIONS: The data suggest that the transplanted rat pancreas becomes reinnervated by mainly sympathetic nerve fibers.

Animals↗

PubMed2001

Enhancement of collagen-induced arthritis in female mice by estrogen receptor blockage.

OBJECTIVE: To determine whether estrogen-mediated suppression of collagen-induced arthritis (CIA) in mice acts via the nuclear estrogen receptors (ERs). METHODS: CIA was induced in noncastrated normal (B10.Q x DBA/1)F1 (QD) female mice. The mice were treated with the ER antagonist ICI 182,780, which binds to both ERalpha and ERbeta, either on days 2, 6, 10, and 14 or on days 14, 18, 22, and 26 after type II collagen (CII) immunization. The effects of treatment and development of arthritis were correlated with the estrus cycle by inspection of vaginal smears (VS). By a combination of treatments with both estriol (E3) and ICI 182,780 during the time of expected onset of CIA in castrated QD female mice, the protective effect of E3 in CIA was analyzed. RESULTS: Treatment with ICI 182,780 of QD female mice immunized with CII triggered an earlier onset of arthritis during the period when the estrus cycle was blocked. The arthritis-modulating effect of ICI 182,780 was even obtained at doses that were insufficient to block estrus cycling, as observed in the VS response. E3 is an estrogen with low estrogenic potency but with a relatively potent antiarthritis effect. Doses of ICI 182,780 that were suboptimal for blocking estrus cycling blocked the E3-mediated suppression of CIA in castrated female mice. CONCLUSION: These findings show that estrogen-induced suppression of CIA is mediated via the nuclear ERs and is operating at physiologic, possibly even subphysiologic, levels of estrogens.

Animals↗

PubMed2001

Secretin and pancreatic islet blood flow in anesthetized rats: increased insulin secretion with no augmentation of blood perfusion.

Secretin is a stimulator of both endocrine and exocrine secretions of the pancreas, and we aimed to evaluate its effects on splanchnic blood flow in rats with a microsphere technique. Anesthetized rats were infused with secretin (0.5 or 2.0 micrograms/kg body weight/hr) for 10 minutes. Some animals were normoglycemic, whereas other received a glucose injection 3 minutes before blood flow measurements. Secretin did not affect serum insulin concentrations in normoglycemic animals but consistently led to higher insulin concentrations in the hyperglycemic rats. Total pancreatic blood flow was increased by the highest secretin dose in normoglycemic animals, whereas no effects were seen in the hyperglycemic rats. Administration of glucose caused a pronounced increase in islet and fractional islet blood flow in saline-infused animals. Secretin affected neither islet nor fractional blood flow in normoglycemic or hyperglycemic rats. Glucose administration increased duodenal blood flow in animals infused with saline and both duodenal and colonic blood flow in rats given the lowest dose of secretin. No effects on either colonic or duodenal blood perfusion were seen in animals infused with the highest dose of secretin. Secretin mainly affects blood flow to the whole pancreas and not that of the islets. Furthermore, glucose-induced insulin release can be achieved without a simultaneous increase in islet blood flow; that is these two events may be dissociated from one another.

Analysis of Variance↗

PubMed2001

Visual binding abilities in the initial and advanced stages of schizophrenia.

OBJECTIVE: The study tests the hypothesis that intramodal visual binding is disturbed in schizophrenia and should be detectable in all illness stages as a stable trait marker. METHOD: Three groups of patients (rehospitalized chronic schizophrenic, first admitted schizophrenic and schizotypal patients believed to be suffering from a pre-schizophrenic prodrome) and a group of normal control subjects were tested on three tasks targeting visual 'binding' abilities (Muller-Lyer's illusion and two figure detection tasks) in addition to control parameters such as reaction time, visual selective attention, Raven's test and two conventional cortical tasks of spatial working memory (SWM) and a global local test. RESULTS: Chronic patients had a decreased performance on the binding tests. Unexpectedly, the prodromal group exhibited an enhanced Gestalt extraction on these tests compared both to schizophrenic patients and to healthy subjects. Furthermore, chronic schizophrenia was associated with a poor performance on cortical tests of SWM, global local and on Raven. This association appears to be mediated by or linked to the chronicity of the illness. CONCLUSION: The study confirms a variety of neurocognitive deficits in schizophrenia which, however, in this sample seem to be linked to chronicity of illness. However, certain aspects of visual processing concerned with Gestalt extraction deserve attention as potential vulnerability- or prodrome- indicators. The initial hypothesis of the study is rejected.

Adult↗

PubMed2001

Relationship between oral health and mortality in cardiovascular diseases.

BACKGROUND, AIMS: The purpose of the study was to investigate the relationship between periodontal health and fatal cardiovascular diseases (CVD). METHODS: The investigation was conducted on a sample of 1393 individuals in the County of Stockholm. The subjects were examined in an epidemiological study in 1970 with respect to dental health. At a follow-up in 1997, the mortality rate of the sample during the years 1970-1996 was registered as well as cause of death according to the death certificate. Stepwise logistic regression analysis was performed in order to evaluate the influence of the investigated variables on the incidence of death from CVD. RESULTS: The interactional effect between plaque and oral health score (a sum of scores for number of missing teeth, apical lesions, caries lesions and marginal bone loss), adjusted for age, gender, smoking and CVD at baseline, was significantly correlated to fatal coronary events. For individuals younger than 45 years of age, the age-adjusted incidence odds ratio of death due to CVD was 2.7 (p=0.04) if subjects with mean marginal bone loss of >10% were compared with subjects with mean marginal bone loss < or =10 %. If the stratum of individuals <45 years of age is confined to smokers, the odds ratio was found to be 3.4 (p=0.03). CONCLUSION: Dental health was found to be a risk indicator of death due to CVD, especially in combination with another risk factor, smoking habits.

Adult↗

PubMed2001

Being overwhelmed by the feeling of having a home and family. One aspect of the meaning of being dependent on care: a study of one patient and two of his nurses.

RATIONALE: This article is part of an ongoing study which aims at disclosing the meaning of being dependent on care. From a larger body of data, interviews with one patient and two of his nurses were selected to study. AIM: The aim was to deepen understanding of the meaning of being dependent on care when this appears desirable for the patient. METHODS: A phenomenological-hermeneutic approach was used to interpret the material. Interviews were recorded and transcribed verbatim. FINDINGS/DISCUSSION: The interpretation discloses the meaning of being dependent on care as an overwhelming, unfamiliar feeling of having a home and family. The patient is beguiled into believing he is the ruler in an established relationship and his dependency on care gives him an opportunity to be surrounded by loving, altruistic, helpful people. Being dependent on care is overwhelming and irresistible, i.e. coveted, but simultaneously it is like walking on thin ice, i.e. treacherous. The irresistible desire concerns being unconditionally cared about. The danger is that this 'family membership' will not last. It is brought to the patient because of his dependency on care and it is based on his terms. There is reflection about the patient being unprepared for dealing with his own world of loneliness.

Activities of Daily Living↗

PubMed2001

Interaction relating to privacy, identity, autonomy and security. An observational study focusing on a woman with dementia and "behavioural disturbances", and on her care providers.

AIM: The study aims to illuminate how one woman with severe dementia and so-called behavioural disturbances acts in relation to her care providers and how the care providers act in relation to her. METHODS: Fourteen participant observations, including one woman with dementia and six care providers, were performed. A reflective dialogue focusing on the interaction between the woman and her care providers followed each observation. The tape-recorded observational notes and reflective dialogues were fixed as a text, which was subjected to a thematic content analysis. FINDINGS: The main findings are that the interaction between a woman with severe dementia and "behavioural disturbances" and her care providers relates to privacy, identity, autonomy and security. The phenomena are intertwined and also in conflict with each other. Interaction is a complex dialectic process in which those who are engaged meet problems that can be solved and are involved in dilemmas that cannot be solved, only related to.

Activities of Daily Living↗

PubMed2001

Cardiac natriuretic peptides and pancreatic islet blood flow in anesthetized rats.

The aim of the study was to evaluate effects of cardiac natriuretic peptides on splanchnic circulation, especially to the pancreatic islets. Pentobarbital-anesthetized rats were infused intravenously (0.01 ml/min for 20 min) with saline, atrial natriuretic peptide (ANP; 0.25 or 0.5 microg/kg BW/min), brain natriuretic peptide (BNP; 0.5 microg/kg BW/min) or C-type natriuretic peptide (CNP; 0.5 or 2.0 microg/kg BW/min). Splanchnic blood perfusion was then measured with a microsphere technique. Mean arterial blood pressure was decreased by ANP and BNP, but not by CNP. The animals given the highest dose of ANP became markedly hypoglycemic, whilst no such effects were seen in any of the other groups of animals. Total pancreatic blood flow was decreased by the highest dose of CNP, whereas no change was seen after administration of the other peptides. Islet blood flow was increased by the highest dose of ANP. Neither BNP nor CNP affected islet blood flow. None of the natriuretic peptides influenced duodenal, colonic or arterial hepatic blood flow. It is concluded that cardiac natriuretic peptides exert only minor effects on splanchnic blood perfusion in anesthetized rats. However, islet blood perfusion may be influenced by ANP.

Animals↗

PubMed2001

Capillary blood pressure in the endocrine and exocrine parenchyma of rat pancreas transplants.

BACKGROUND: Transplantation of isolated organs or cells leads to a functional denervation of the organ, which may cause a hyperperfusion of blood. The current study evaluated to what extent blood perfusion and capillary blood pressures were affected in the transplanted rat pancreas. METHODS: Inbred, male Wistar-Furth rats underwent transplantation with a syngeneic pancreaticoduodenal graft. Four weeks later, blood flow to the native and transplanted pancreases was measured with a microsphere technique. Capillary pressures were measured by direct micropuncture technique. RESULTS: An increased islet blood flow was consistently observed in the transplanted pancreas as compared with the native organ, while whole pancreatic and duodenal blood flow was similar in the native and transplanted organs. The capillary pressure was twice as high in the exocrine pancreas (6-7 mm Hg) of both the native and transplanted glands when compared with that of the islets (approximately 3 mm Hg). There were no differences in the capillary pressures in either the islets or exocrine gland when native and transplanted pancreases were compared. CONCLUSIONS: We conclude that the transplanted whole pancreas retains a low islet capillary blood pressure after transplantation despite having a higher islet blood perfusion.

Animals↗

PubMed2001

Caregivers' descriptions of patients with advanced breast cancer in connection with supervision sessions in a surgical ward.

The purpose of this study was to describe the content of caregivers' (health care professionals') presentation of care situations as told at supervision sessions. For 1 year, 21 caregivers in a surgical ward of a county hospital in the middle of Sweden participated in a clinical supervision session 2 hours every third week. The participants in the supervision sessions were divided so as to form three mixed groups composed of registered nurses, practical nurses, physiotherapists, and physicians. The purpose of the supervision sessions was to give caregivers the opportunity to reflect on different care situations in a way that contributed to the development of patient care. The 38 supervision sessions were tape-recorded and transcribed verbatim. The transcripts were analyzed using a qualitative content analysis. The caregivers described difficult care situations focusing on the feelings of patients, relatives, and caregivers, with an emphasis on the caregivers' being dominant. Difficult care situations were described as giving caregivers feelings of discomfort, powerlessness, and reduced self-esteem. These feelings were described as arising in connection with caring for women with advanced breast cancer and other seriously ill patients in an organization lacking clear goals and rules. This study found that supervision sessions offering an opportunity to reflect on the difficult care situations are important for caregivers. These sessions seem therefore to be of vital importance for the future development of cancer care on the surgical ward.

Adult↗

PubMed2001

The meaning of skilled care providers' relationships with stroke and aphasia patients.

Little is known about the reciprocal influence of communication difficulties on the care relationship. To illuminate care providers' lived experiences of relationships with stroke and aphasia patients, narrative interviews were conducted with providers particularly successful at communicating with patients. A phenomenological hermeneutic analysis of the narratives revealed three themes: Calling forth responsibility through fragility, restoring the patient's dignity, and being in a state of understanding. The analysis disclosed caring with regard to the patient's desire, which has its starting point in intersubjective relationship and interplay, in which nonverbal communication is essential--that is, open participation while meeting the patient as a presence. Thus, care providers prepare for deep fellowship, or communion, by being available. They described an equality with patients, interpreted as fraternity and reciprocity, that is a necessary element in presence as communion. The works of Marcel, Hegel, Stern, and Ricoeur provided the theoretical framework for the interpretation.

Adult↗

PubMed2001

The pancreatic islets in spontaneously hypertensive rats: islet blood flow and insulin production.

The aim of the study was to investigate if hypertension affects pancreatic islet blood flow and endocrine function. For this purpose, spontaneously hypertensive rats (SHR) were compared with normotensive control Wistar-Kyoto rats (WKY). Both islet size and islet cell replication in 4-month-old SHR was increased compared with WKY. The (pro)insulin biosynthesis was reduced in islets isolated from SHR, whereas the insulin content was unchanged. A hyperinsulinemic response to glucose in vivo was observed in 4- and 12-month-old SHR. Pancreatic blood flow, measured using a microsphere technique, was lower in SHR than in WKY in rats aged 5 weeks, 4 months or 1 year. Islet blood flow was lower in 4-month-old and 1-year-old SHR. In 4-month-old animals, islet blood flow was unaffected by administration of enalaprilate and prazosin in both strains, but was markedly decreased by the administration of N(G)-methyl-L-arginine. It was concluded that the islets of SHR have a decreased insulin production in vitro and a decreased islet blood perfusion. The reasons for this are likely to be multifactorial. Because SHR maintained an essentially normal glucose tolerance, an adaptation of the beta-cells to the metabolic and hemodynamic changes imposed by hypertension occurred.

Adrenergic alpha-Antagonists↗

PubMed2000

Winter birth and biological family history in adopted schizophrenics.

To investigate relationships between birth season and biological family history in schizophrenia, this study used a sample of schizophrenics that had the advantages of (a) particularly thorough diagnostic assessments of schizophrenics' relatives, including information from direct interviews as well as chart reviews, and (b) schizophrenic probands who were adopted at early age, mitigating the usual confounding of genetic and postnatal environmental influences of the family. Adopted schizophrenics with no biological family history of schizophrenia-spectrum disorders were significantly more likely to be born in winter months than were either (a) their own biological relatives, including their sibs and half-sibs, (b) schizophrenics with a positive family history for schizophrenia-spectrum disorders, or (c) people in the general population. Family-history-positive schizophrenics and their schizophrenic relatives were, in turn, significantly less likely than their own non-schizophrenic biological relatives to be born in the winter; schizophrenics in these families tended to be born in the milder-weather seasons, particularly the spring and fall. Results suggest that environmental factors associated with winter birth may be etiologically important in schizophrenia, particularly for cases in which familial liability factors are weak. By contrast, a familial, probably genetic, liability factor may be especially important in schizophrenics born in mild weather.

Adoption↗

PubMed2000

Local blood flow regulation in transplanted rat pancreatic islets: influence of adenosine, angiotensin II, and nitric oxide inhibition.

BACKGROUND: Transplanted islets lack endothelial cells immediately after implantation and therefore depend on an adequate revascularization for their survival and function. However, the functional properties of the newly formed islet graft microvessels are largely unknown. This study aimed to investigate the blood flow regulation of transplanted pancreatic islets. METHODS: Pancreatic islets were syngeneically transplanted beneath the renal capsule of control and streptozotocin-diabetic rats. Blood flow measurements were performed 4 weeks later using laser-Doppler flowmetry. Adenosine (0.6 mg x kg(-1) x min(-1), angiotensin II (AT II; 0.17 microg x kg(-1) x min(-1)) and the nitric oxide synthase inhibitor NG-nitro-L-arginine (25 mg/ kg) were given to each animal. RESULTS: An increased basal blood flow and basal vascular conductance in the islet grafts, but not in the renal cortex, were seen in diabetic rats compared with control rats. Adenosine increased, and AT II decreased, the vascular conductance of the islet grafts in both nondiabetic and diabetic animals. A more pronounced circulatory response to AT II was observed in kidneys of diabetic animals, whereas there was no difference in the islet graft blood flow response between nondiabetic and diabetic animals. NG-Nitro-L-arginine decreased islet graft blood flow and vascular conductance in both nondiabetic and diabetic recipients, but the effect was more pronounced in the non-diabetic animals. CONCLUSIONS: Islet graft blood flow was influenced by adenosine, AT II, and nitric oxide inhibition in all animals. However, diabetic animals were less dependent on nitric oxide to maintain a basal blood flow in the islet graft.

Adenosine↗

PubMed2000

T cells that are naturally tolerant to cartilage-derived type II collagen are involved in the development of collagen-induced arthritis.

The immunodominant T-cell epitope that is involved in collagen-induced arthritis (CIA) is the glycosylated type II collagen (CII) peptide 256-270. In CII transgenic mice, which express the immunodominant CII 256-270 epitope in cartilage, the CII-specific T cells are characterized by a partially tolerant state with low proliferative activity in vitro, but with maintained effector functions, such as IFN-gamma secretion and ability to provide B cell help. These mice were still susceptible to CIA. The response was mainly directed to the glycosylated form of the CII 256-270 peptide, rather than to the nonglycosylated peptide. Tolerance induction was rapid; transferred T cells encountered CII within a few days. CII immunization several weeks after thymectomy of the mice did not change their susceptibility to arthritis or the induction of partial T-cell tolerance, excluding a role for recent thymic emigrants. Thus, partially tolerant CII autoreactive T cells are maintained and are crucial for the development of CIA.

Animals↗

PubMed2000

Women's experience of suffering repeated severe attacks of acute intermittent porphyria.

The aim of this study was to elucidate the experiences of the women with severe, recurrent attacks of porphyria and how they coped with them successfully. A total of five women were interviewed and were encouraged to describe their experiences. Thematic content analysis was used to interpret the significance of their narratives. The result demonstrated that the women's experience was of living in deepest darkness with inexpressible pain, both physical and mental. Coming into contact with health care had its good and bad points. It was often difficult to cope with life during severe periods of the disease. The process of maturation towards a more positive existence seemed to follow a pattern of accepting the disease, continuing the fight until it was finally possible to discover a pattern and meaning in life that suited the individual concerned.

Abdominal Pain↗

PubMed2000

Communicating with people with stroke and aphasia: understanding through sensation without words.

To illuminate the phenomena of 'communicating with people with stroke and aphasia without words', 10 care providers particularly successful at communicating with stroke and aphasia patients who were working at a stroke rehabilitation ward narrated their experiences of communicating with such patients. A phenomenological hermeneutic approach, inspired by Ricoeur's philosophy, was used in the analysis. Two main themes were found: facilitating openness and being in wordless communication. The care providers sensed the feelings of the patients and experienced similar feelings themselves, thus, the communication is guided by the shared feelings between the care provider and the patient, i.e. communion. For this 'communication through sensation' to take place, the following factors were found to be necessary: creative closeness in combination with protective distance; striving for satisfaction and against exhaustion and desperation; meeting the patient halfway to gain understanding; exhibiting attention and accessibility to the patient; and trust and confidence for both care providers and patients. The findings were interpreted and discussed in the light of works by Levinas, Lögstrup and Stern.

Adult↗