Biomedical subjects
Publications and source records attributed to L Gustafsson.
Superior mesenteric artery syndrome (SMAS) is a rare clinical condition. Eleven cases of SMAS treated surgically are reported after follow-up periods of 6 months to 6 years. The value of hypotonic duodenography in the diagnosis of the syndrome is emphasized.
Pulse-chase experiments in conjunction with subcellular fractionation and quantitative immunoprecipitation have been used to study the intracellular transport of four secretory proteins, albumin, transferrin, prealbumin and retinol-binding protein, in isolated rat hepatocytes. The proteins were found to be transported from the endoplasmic reticulum (ER) to the Golgi complex (GC) at greatly different rates (t1/2 = 14-137 min), indicating that transport of secretory proteins between these organelles is effected by a selective, possibly receptor-mediated process and not through bulk phase transfers. The transport from the Golgi complex to the medium was rapid for all proteins (t1/2 approximately 15 min) and possibly occurred at the same rate. Consistent with these kinetic data, the amount of a rapidly transported protein (albumin) in the GC fraction was found to be high (relative to its amount in the ER fraction) whereas the amount of a slowly transported protein (transferrin) in the GC fraction was found to be low, as determined by radioimmunoassays.
Four cases are presented in which the first clinical evidence of acute pancreatitis was the development of a late complication-pleural effusion, abscess formation or jaundice. The designation "silent pancreatitis" is proposed for acute or relapsing acute pancreatitis without initial abdominal symptoms.
Pancreatic trauma is associated with high mortality and high incidence of complications. A pancreatic injury is easily overlooked at laparotomy, unless complete exploration of the gland is performed. There are often associated visceral and vascular injuries. Three cases of severe pancreatic trauma treated during the past three years are discussed as regards surgical management and the treatment of subsequent complications.
Explore the source record for details and available documents.
Accidents constitute perhaps the greatest threat to children's health today in all the Nordic countries. Considerable knowledge exists regarding the epidemiology of accidents among children, and generally speaking this information forms a good basis for preventive measures. What is needed in addition is a larger number of epidemiological studies on a smaller scale, concentrating on local conditions, since preventive activities on a local and regional level require a knowledge of the local scene with respect to accidents and injuries. In addition, the plans for the prevention of accidents need to be revised and improved. The child health services still play a leading role, but in order to keep risks such as those connected with traffic and drowning under control, parents, organizations and authorities need to be activated. To train parents as child environment ombudsmen might be one solution.
The aim of the present study was to investigate the dental health of 100 Finnish 4-6-year-old children in Luleå, in the north of Sweden, and to compare data with those from a matched control group of Swedish children of the same age, sex and social background. The study also included attitudes to dental health among the parents. The clinical examination included registration of decayed, extracted and filled teeth and surfaces (deft and defs), gingival bleeding points (GBI) and presence of open bite or crossbite. Posterior bitewings were taken. Data concerning among other things oral habits, dietary habits and fluoride prophylaxis were taken. A questionnaire about the parents' attitudes to their own and their children's dental health as well as their opinion about the dental care received by their children was filled in. The results showed that the average defs in the Finnish group was 12.2 compared to 6.4 in the Swedish group. The percentage of children with a defs greater than 12 was 43% in the Finnish group and 19% in the Swedish. The mean GBI% was 11.2% in the Finnish and 8.2% in the Swedish group. The results showed a statistically significant difference in tooth brushing frequencies between the groups, and a tendency to better dietary habits in the Swedish group. There were no differences in the use of fluoride tablets or fluoridated toothpaste. Forty-seven percent of the Finnish parents were denture wearers compared to 10% of the Swedish. The attitudes to dental health among the Finnish parents differed from those in the Swedish group. This difference in attitudes together with language problems were the factors found that could explain the difference in dental health between the immigrant group and the Swedish group.
The influence of local adenosine infusion into the celiac artery on the gastric contractile responses to centrifugal vagal nerve stimulation was studied in anesthetized rabbits, and was compared with the effects of systemic administration of equivalent amounts of adenosine. Close arterial infusion of adenosine caused a marked reduction of gastric contractions induced by nerve stimulation, whereas corresponding responses to close arterial infusions of acetylcholine were enhanced during adenosine. The comparison with systemic adenosine administration revealed that the influence on gastric neurotransmission was not related to the hypotensive effect of the compound. No effects of adenosine were seen on bronchial activity as measured by insufflation pressure. Variable effects were obtained on cardiac responses to vagal stimulation. Gastric smooth muscle contractions elicited in vitro by transmural nerve stimulation were affected by adenosine in a biphasic manner, initial inhibition followed by potentiation of the apparently cholinergic responses. It is suggested that adenosine may modulate cholinergic neurotransmission in vivo by a dual effect, prejunctional inhibition and postjunctional enhancement.
The ability of theophylline and other phosphodiesterase inhibitors to alter contractile responses to cholinergic nerve stimulation was investigated in isolated longitudinal muscle of the guinea pig ileum. Theophylline in low concentrations (10-100 microM), having no or little effect on measured phosphodiesterase activity, antagonized inhibitory effects of exogenous adenosine. In higher concentrations (0.1-10 mM), shown to be effective in inhibiting phosphodiesterase, theophylline as well as a "pure" cAMP phosphodiesterase inhibitor, ZK 62, 711, inhibited contractile responses. Dipyridamole and dilazep, inhibitors of adenosine inactivation, and also selective inhibitors of cAMP and cGMP phosphodiesterase, respectively, were found to enhance effects of exogenous adenosine and to cause a marked leftward shift to adenosine threshold dose. When dipyridamole and dilazep by themselves had inhibitory effects these could be antagonized by theophylline, suggesting an action through increased levels of endogenous adenosine. As a further indication of endogenous adenosine modulating neurotransmission low concentrations of theophylline enhanced responses to transmural stimulation. Endogenous purine concentrations in tissues and bath media were measured by HPLC. Because of tissue and microbial adenosine inactivation direct estimates of extracellular adenosine concentration could not be obtained. However, adenosine levels increased during transmural stimulation, and during inhibition of adenosine inactivation were sufficient, even in the bath medium, to interfere with the cholinergic neurotransmission.
The effects of increased plasma viscosity and induced red blood cell (RBC) aggregation on apparent viscosity of blood in vivo in the skeletal muscle of the dog were studied. Apparent viscosity in vivo was determined in the isolated and vasodilated calf muscles of one hindlimb by comparing pressure-flow relationships for RBC suspensions with pressure-flow relationships for a Newtonian solution of known viscosity. RBC suspensions of increased plasma viscosity with and without RBC aggregation were obtained by substituting plasma with isoviscous solutions of high- and low-molecular-weight dextran in saline. Hematocrits of the suspensions were adjusted to either 45 or 60%. The viscosities of the suspensions in vitro were determined in a Wells-Brookfield viscometer. Apparent viscosity of blood in vivo was found to be mainly dependent on the viscosity of plasma. RBC aggregation had no significant influence on the viscosity in vivo.
We studied the effect of high and low molecular weight dextran on blood flow and in vivo apparent viscosity in the vasodilated vascular bed of working and non-working skeletal muscle. In 12 mongrel dogs, the calf muscle of one hindlimb was isolated. Vasodilation was induced either by sciatic stimulation setting the muscle at rhythmic work or by intraarterial infusion of papaverine. Blood flow was measured electromagnetically at different perfusion pressures. In vivo apparent viscosity was calculated by comparing pressure-flow relationship for blood and a reference solution. Viscosity in vitro was determined in a cone-plate viscometer. A hyperviscous state was induced by intravenous infusion of high molecular weight dextran (HMWD). Hemodilution subsequently was produced by administration of low molecular weight dextran (LMWD). After HMWD, blood flow decreased to 30% of control values in the non-working group and to 45% of control values in the working group. After subsequent infusion of LMWD, blood flow returned to 60% of control values in the non-working group and to 70% of control values in the working group. In vivo apparent viscosity increased to values 250% above control in the non-working group and to 120% above control in the working group following HMWD. After subsequent infusion of LMWD in vivo, apparent viscosity decreased, but remained at values 65% above control in the non-working group and 45% above control in the working group. Thus, the flow impairment induced by HMWD was less pronounced in the working muscle, indicating a flow-preserving effect of rhythmic muscle contractions in this state of disturbed blood rheology. In contrast, the flow-improving effect of LMWD by hemodilution was more pronounced in the non-working muscle.
The aim of the study was to examine dental health in three groups of national servicemen in Umeå, Västerbotten, to compare the dental health of the groups and to evaluate need for treatment. The material consisted of 282 recruits, 79 from Stockholm County (STHLM group) 96 from the urban parts of the County of Västerbotten (V-urban group) and 107 from the rural parts (V-rural group) of that county. The examination included registration of caries and restorations, gingival status, presence of calculus, pathological pockets and alveolar bone loss. Questions about oral hygiene measures, knowledge about and attitudes to dental health were also included. The results showed that the mean values for DFT and DFS were 13.7 and 24.0 respectively. The mean DFS-value was significantly lower in the V-urban group than in the STHLM group (P less than 0.01) and the V-urban group (P less than 0.001). The mean GBI% was 38.3 in the STHLM group, 32.9 in the V-urban group and 40.4 in the V-rural group. The mean value for surfaces in need of operative treatment was 2.9, with the highest value for the STHLM group (3.5). The mean number of surfaces with initial approximal caries lesions was 2.7. A more prophylactic approach by the military dental services would be desirable, and in future planning the need for dental hygienists should be considered.
Isokinetic and static maximum plantar flexion torques were measured in 135 adults with sedentary professions. Close associations between isokinetic and static peak torques were found. Between the ages 20--49 years strength did not differ. Thereafter strength declined as a function of age. Maximum strength was 35% lower in females than in males. The right plantar flexion strength was slightly lower than the left. Maximum plantar flexion strength was about 15% lower with flexed than with extended knees. A negative exponential model characterized the decline of strength as a function of increased isokinetic velocity of angular motion. Seventy per cent or more of the variations in maximum static and isokinetic strength could be explained by anthropometric variables and by age, and by the extent of physical activity in subjects younger than 50 years. Formulas for estimation of expected static and isokinetic strengths are given.
The effect of acutely induced polycythemia on blood flow and viscosity in the vasodilated vascular bed of working and non-working skeletal muscle was studied. In 12 mongrel dogs anesthetized with thiopental sodium the calf muscle of one hind limb was isolated. Vasodilation was induced either by sciatic stimulation setting the muscle at maximal work or by i.a. infusion of papaverine. Blood flow was measured at different perfusion pressure before and after infusion of 300 ml packed homologous red cells. Blood viscosity in vitro was determined in a coneplate viscometer. Apparent viscosity in vivo was analyzed by comparing pressure-flow relationships for blood and a reference solution. Polycythemia decreased blood flow by 35% in the non-working muscle but less than 10% in the working muscle at comparable perfusion pressures. Blood viscosity in vitro increased by 35% at low shear rates. Apparent viscosity in vivo increased by 35% in the non-working muscle but less than 10% in the working muscle. The flow impairment induced by polycythemia was far more pronounced in the non-working skeletal muscle indicating a flow facilitation by the rhythmic muscle contractions. Erythrocyte flow in fact increased in the working muscle after induced polycythemia while decreased in the non-working muscle.
Explore the source record for details and available documents.
The effects of prostaglandin E2, arachidonic acid, prostaglandin synthetase inhibitors and atropine on cholinergic neuromuscular transmission were examined in isolated guinea pig ileum longitudinal muscle and bovine iris sphincter muscle. Prostaglandin E2 and arachidonic acid markedly enhanced contraction responses induced by nerve stimulation. In addition, prostaglandin E2, enhanced contraction responses to acetylcholine and direct muscle stimulation, approximately to the same extent as those to nerve stimulation. Prostaglandin synthetase inhibitors (indomethacin, meclofenamic acid and eicosatetraynoic acid) very effectively reduced contraction responses to nerve stimulation or acetylcholine, and they annulled the stimulant effect of arachidonic acid. Basal and nerve-induced efflux of acetylcholine from the eserinized tissues, as measured by mass fragmentography, was unaltered by prostaglandin E2, but diminished slowly during indomethacin. Subsequent prostaglandin administration caused a slight increase of nerve-induced release of acetylcholine. Atropine markedly increased overflow of acetylcholine form stimulated preparations of both types. This indicates that muscarinic receptors, causing diminished acetylcholine release in eserinized tissue, may be present also at postganglionic terminals. During atropine, an effect of prostaglandin E2 on acetylcholine release could still not be seen. Thus, using physicochemical determination of acetylcholine, we could not verify earlier reports, employing bioassay, claiming enhanced release of transmitter during prostaglandin E2 treatment. However, it seems likely that prostaglandin E2 takes part in the regulation of contractility and tone of the smooth muscle cells.
Explore the source record for details and available documents.
To determine the number of adipocytes and cells developing into adipocytes (preadipocytes) in the epididymal fat pad of normal Sprague-Dawley rats, two methods were developed. Liberation of all cells from the tissue was obtained by a combination of lytic enzymes and mechanical treatment with only a limited loss of cell integrity; with large tissue masses, an initial perfusion was necessary. These cells were cultured in medium 199 supplemented with serum, glucose, insulin, a triglyceride emulsion, and methyl cellulose to form a culture medium with high viscosity in which it has been shown that the cells do no multiply. In this medium some of the cells developed into adipocytes and could be recognized and counted. The results show that there are about twice as many preadipocytes as mature adipocytes in the smallest rats examined (about 50 g). With increasing weight and age the mature adipocytes increased while the number of preadipocytes seemed to be constant up to a weight of about 150 g, after which they continuously diminished and could not be found in rats weighing more than 300 g. Here the number of mature fat cells had reached a constant level. These results are consistent with the formation of new preadipocytes up to a rat weight of about 150 g. In normal rats these cells successively fill up with triglyceride and disappear at a body weight of about 300 g when they have been transformed into mature adipocytes. The results are also consistent with the concept that no new adipocytes are formed spontaneously in the adult Sprague-Dawley rat. It was shown, however, that in media without methyl cellulose, isobutylmethylxanthine probably could induce the formation of new adipocytes in the cells isolated from all rats, including the heaviest (oldest). This finding shows that the potential of cells to develop into adipocytes also seems to exist in the adult rat under certain circumstances.