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Biomedical subjects

L Jansson

Publications and source records attributed to L Jansson.

At least 235 records · Page 13Linked to original sources
PubMed1986

Selenium content of breast milk sampled in 1978 and 1983 in Sweden.

Selenium in human milk sampled at different intervals after parturition was analyzed on two occasions five years apart. The selenium content of colostrum and transitional milk was higher than that of mature milk. Mature milk sampled in 1983 contained more selenium than mature milk sampled in 1978 (11.9 (0.8) vs. 9.4 (0.5) micrograms/l, mean (SD), p less than 0.01). The selenium and protein content in milk were positively correlated, which may be explained by the occurrence of seleno-amino acids in proteins. The selenium content was not correlated to that of tocopherol or of highly unsaturated fatty acids in mature milk. The values for the selenium content in human milk found here are lower than those previously reported from other countries.

Fatty Acids, Unsaturated↗
PubMed1986

Flow distribution between the endocrine and exocrine parts of the isolated rat pancreas during perfusion in vitro with different glucose concentrations.

Previous studies in our laboratory have indicated that pancreatic islet blood flow is stimulated by glucose. In an attempt to evaluate to what extent intrapancreatic control mechanisms are involved in the glucose modulation of islet blood flow the distribution of flow between the endocrine and exocrine parts of the rat pancreas during perfusion in vitro with different glucose concentrations have now been studied. For this purpose pancreatic glands from 29 rats were perfused at a flow rate of 1.5 ml min-1 for 95 min with low (2.8 mM) or high (16.7 mM) glucose-containing media. Maintenance of vascular reactivity of this preparation in spite of a marked exocrine oedema was confirmed by administration to the perfusion medium of adrenaline, which immediately raised the perfusion pressure. Insulin concentrations in the effluent media were measured to correlate rates of insulin release to changes in islet flow and to assess the functional viability of the preparation. In each experiment non-radioactive microspheres with a diameter of 10 micron were injected into the perfusion medium at one of four time-points: 15, 30, 35 or 80 min after the beginning of the perfusion. Two of these injections (15 and 80 min) took place during perfusion with the low-glucose media and the remaining two during perfusion with high-glucose medium. The microspheres were counted separately in the endocrine and exocrine parts of the pancreas. The results showed that all preparations had a biphasic insulin response to glucose.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Glucose-induced changes in pancreatic islet blood flow mediated by central nervous system.

Earlier experiments with the microsphere technique suggested that a heightened serum glucose concentration consistently leads to an increase in islet blood flow (IBF). Several lines of evidence suggest that this glucose-sensitive control mechanism is located at an extrapancreatic site. The purpose of this study was to define the possible role of the central nervous system in such a mechanism. D-glucose, L-glucose, 3-O-methylglucose, or saline were therefore infused into the carotid artery, each at a dose of 1 mg X kg body wt-1 X min-1 for 3 min, and the pancreatic and islet blood flows were measured. None of these substances affected the systemic serum glucose level. The intracarotid infusion of D-glucose, however, caused a rapid increase in both the serum insulin concentration and IBF. The blood flow to the whole pancreas nevertheless remained unchanged, indicating a redistribution of flow within the gland. Carotid infusion of the other test substances or a similar amount of D-glucose given in a femoral vein did not affect these parameters. Both the increase in serum insulin concentration and the increase in IBF caused by D-glucose could be abolished by vagotomy or administration of atropine. When the systemic blood glucose concentration was increased by intraperitoneal glucose administration (2 g/kg body wt), vagotomy blocked the increase in islet blood flow but not the concomitant insulin release. These observations suggest that the glucose-induced increase in IBF is mediated by vagal cholinergic influences.

3-O-Methylglucose↗
PubMed1986

Follow-up of agoraphobic patients treated with exposure in vivo or applied relaxation.

The present study describes the results of a 7-month and a 15-month follow-up of 32 agoraphobic patients treated with exposure in vivo or applied relaxation. During the follow-up period, all patients were given self-exposure instructions. Assessments were made in three response systems--subjective-cognitive, behavioural, and physiological--at the follow-up points. The study showed overall maintenance of treatment results in all three response systems for exposure-treated patients. For applied relaxation/self-exposure, there was a relapse on delta heart-rate at 7 months for physiologically reactive patients, but the improvement was regained at the 15 month follow-up. Furthermore, a large proportion of the total improvement occurred during the follow-up period: 36% and 22% for exposure and applied relaxation/self-exposure respectively. The proportion of patients reaching a clinically significant improvement was 50% at the end of treatment and 66% at the 15 month follow-up.

Adult↗
PubMed1985

Vascular permeability of pancreatic islets after administration of streptozotocin.

In the present study we have investigated whether the pancreatic B-cell toxic agent streptozotocin (SZ) induces increased vascular permeability as an indicator of lesions in the pancreatic islets. SZ was given either in multiple low doses, providing an animal model for Type I diabetes mellitus with signs of autoimmunity, or by a single diabetogenic dose to C57BL/KsJ mice. The vascular reactions were detected by administration of Monastral blue B and the pancreatic islets were visualized by a freeze-thawing technique which made it possible to count the number of stained and unstained islets. This proved to be a rapid and sensitive technique for detection of early lesions within the islets after administration of SZ. It was found that the islets showed an increased vascular staining before the animals had become diabetic by either mode of SZ treatment and also before signs of pancreatic insulitis were found after the multiple low-dose injections of SZ. It is suggested that both types of SZ administration induce a B-cytotoxic reaction, essential for the development of hyperglycaemia. This leads to an activation of cells dealing with the disposal of cell debris, a process which probably also involves the release of substances mediating increased vascular permeability.

Animals↗
PubMed1985

Bombesin, neurotensin and pro-gamma-melanotropin immunoreactants in human milk.

The concentration of bombesin-like, neurotensin-like and pro-gamma-melanotropin-like immunoreactants in human skim milk was measured by radioimmunoassay and found to be 235 pg/ml (mean, n = 13, range 60-430 pg/ml), 63 pg/ml (mean, n = 13, range 20-105 pg/ml) and 2.4 ng/ml (mean, n = 6, range 1.2-5 ng/ml), respectively. The concentrations were 5-10 times higher than in plasma. High performance liquid chromatography showed that the neurotensin and pro-gamma-melanotropin immunoreactants co-eluted with the authentic peptides. Bombesin gave three peaks, one co-eluting with authentic bombesin and one with porcine gastrin releasing peptide 14-27, whereas another one had a shorter elution time, suggesting a less hydrophobic fragment, possibly even smaller than gastrin releasing peptide 14-27.

Bombesin↗
PubMed1985

Content analysis of speech of schizophrenic and control adoptees and their relatives: preliminary results.

Speech samples were collected on 20 Danish schizophrenic adoptees, along with 26 control adoptees and their respective biological and adoptive relatives. Typewritten transcripts of these speech samples were scored using the Gottschalk-Gleser Social Alienation-Personal Disorganization (SA-PD), or "Schizophrenic', content analysis scale. Both mean scale scores and the proportion of subjects with extremely high (i.e. deviant) scores were significantly higher in schizophrenic adoptees than in either (a) subjects with no psychiatric disorder or (b) the sample with psychiatric disorders other than schizophrenia. The proportion of deviant scores was also notably high among subjects who, though not schizophrenic, had schizotypal features on the SADS-L interview. Scores were particularly high in schizophrenic adoptees who had a biological parent or sibling with schizophrenia or schizotypal features. By contrast, scores of 29 adoptive relatives of the schizophrenic probands were quite low. The present study appears to corroborate the results of previous studies done in the U.S.A. and Great Britain which suggest that high scores on the SA-PD scale tend to characterize those schizophrenics for whom genetic liability appears to be strongest.

Adoption↗
PubMed1985

Measurement of functional residual capacity by sulfur hexafluoride washout.

Measurement of functional residual capacity (FRC) by the open-circuit multiple breath tracer gas washout technique is an established method. A system based upon washout of sulfur hexafluoride (SF6) during mechanical ventilation is described. The central unit in the system is a sensitive and rapid-response infrared SF6 analyzer. SF6 is washed in until the alveolar concentration of SF6 is 0.5%, a concentration so low that the supply of other gases is hardly influenced. During washout, the flow of SF6 from the lungs is calculated by a computer every 10 ms from signals representing expiratory flow and SF6 concentration. The total volume of SF6, washed out, is calculated by integration of SF6 flow. Since the alveolar concentration at the end of washin is known, the lung volume may be obtained. The measurement procedure is highly automated and the result is presented by the computer immediately after washout. Accurate and reproducible results in model lung tests were obtained during air and N2O/O2 ventilation. Comparison with body plethysmography (FRCBOX) in eight sitting healthy subjects gave the following: FRCSF6 = 7 ml + 0.98 X FRCBOX, r = 0.99. Comparison with nitrogen washout (FRCN2) in five postoperative patients gave the following: FRCSF6 = 59 ml + 0.97 X FRCN2, r = 0.97. FRCSF6 during N2O/O2 ventilation was the same as during air/O2 ventilation in a group of paralyzed patients. The measurement system has not been tested in patients with obstructive lung disease.

Adolescent↗
PubMed1985

Relationship of mean platelet volume to platelet count in morphologic evaluation of thrombopoiesis.

A graph of the relationship between mean platelet volume (MPV) and platelet count (TPK) was constructed out of 158 haematologically normal individuals, 19 patients with thrombocytopenia and 63 patients with thrombocytosis. Patients with thrombocytopenia and thrombocytosis whose bone marrows were found to show adequate or increased, morphologically normal, thrombopoiesis were included in the graph. The graph was found to exhibit the previously known inverse relationship between TPK and MPV extended into thrombocytopenic values and is thought to represent an intact marrow function capable of meeting the increased demands of thrombopoiesis. On the other hand, 15 patients whose bone marrows were showing evidence of hypoplastic thrombopoiesis fell outside the region representing intact marrow function. The position of an individual's values of MPV vs TPK in a coordinate system with these variables on the axes correlates well with the morphologic evaluation of thrombopoietic function and seems to be clinically useful.

Blood Platelets↗
PubMed1985

Mitogenic activity and epidermal growth factor content in human milk.

The concentration of epidermal growth factor (EGF) was determined by radioimmunoassay in colostral and mature human milk. The content of EGF in colostral milk was 25-38 ng/ml compared to 5.2-11.5 ng/ml in samples of mature milk. The radioimmunoassayable EGF content in mature milk was not influenced by pasteurization and EGF was detected in a preparation of human milk protein at a concentration similar to that found in mature milk. The growth promoting activity in human milk measured by 3H-thymidine incorporation in human fibroblasts was higher in colostral milk (stimulated incorporation 8.7 fold) than in mature milk (stimulated incorporation about 7-fold).

Cell Division↗
PubMed1985

Dissociation between pancreatic islet blood flow and insulin release in the rat.

The blood flow to the pancreatic islets was estimated with the aid of microspheres in fed or starved (72 h) rats. The total pancreatic blood flow (PBF) in fed animals was 0.55 +/- 0.04 ml X min-1 X g pancreas and in the starved animals 0.30 +/- 0.04 ml X min-1 X g pancreas (P less than 0.001), and the corresponding islet blood flow (IBF) 82.0 +/- 12.4 and 50.5 +/- 9.7 microliter min-1 X g pancreas respectively (P greater than 0.05). Intraperitoneal injection of 2 ml of a 30% glucose solution caused a marked increase in IBF in both fed (P less than 0.05) and starved (P less than 0.01) animals to approximately the same level. The circulating insulin concentration remained unaffected by glucose in the starved rats but increased (P less than 0.001) in the fed rats, indicating that insulin release does not necessarily rise in parallel with an elevated IBF. Intraperitoneal injection of 2 ml of a 30% solution of mannoheptulose, an inhibitor of islet glucose metabolism, decreased the serum insulin concentrations although the serum glucose concentrations rose significantly in both fed (P less than 0.001) and starved (P less than 0.001) animals. This treatment, however, caused both IBF and PBF to increase significantly in both groups. The data support the view that islet blood flow is not necessarily related to the metabolic status of the islet cells or to the insulin release.

Animal Feed↗
PubMed1985

Pancreatic islet circulation in relation to the diabetogenic action of streptozotocin in the rat.

A possible relationship between pancreatic islet blood flow (IBF) and the diabetogenic action of streptozotocin (STZ) has been investigated in rats injected ip with saline, glucose, propranolol, phentolamine, yohimbine, or adrenaline. A low dose (25 mg/kg BW) of STZ was given iv 10 min later, and serum glucose concentrations were determined after 3 and 7 days. Measurements of IBF were performed in separate experiments with a microsphere technique 10 min after injection of the drugs. Administration of phentolamine, glucose, or yohimbine was followed by overt diabetes, whereas animals injected with saline, adrenaline, or propranolol failed to become diabetics. Blood flow measurements showed an increase in IBF 10 min after the injection of glucose or propranolol, while there were no significant effects of the other drugs. It is concluded that changes in IBF are of minor importance for the action of agents modulating the diabetogenic effect of STZ. However, the potentiated hyperglycemic effects by glucose, phentolamine, or yohimbine in combination with STZ seemed to coincide with increased insulin secretion, as reflected by elevated serum insulin concentrations at the time of STZ administration.

Animals↗