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Biomedical subjects

S Arvidsson

Publications and source records attributed to S Arvidsson.

At least 37 records · Page 2Linked to original sources
PubMed1990

Clinical evaluation of an ensemble-averaging impedance cardiograph for monitoring stroke volume during spontaneous breathing.

Simultaneous determination of stroke volume (SV) with an ensemble-averaging impedance cardiograph (AIGG) and the thermodilution technique (TD) was compared in 10 patients scheduled for major vascular surgery. A small, successive increase in SV was achieved by a step-wise infusion of dextran-70 and elevation of the patient's legs. The patients were allowed to breathe normally during the measurement procedures. There was no difference between the ability of AICG and TD to monitor changes in SV and the correlation coefficient for the measurement of changes in SV by the two methods was 0.88. There was no difference between the reproducibility of AICG- (4.6 ml) and TD- (9.2 ml) determined SV or between the coefficient of variation for AICG (4.8%) and TD (9.9%). The mean difference between AICG- and TD-determined SV at the different measurement points (range 1.3-4.2 ml) was well within acceptable limits. In conclusion, the ensemble-averaging impedance cardiograph described in this study was found to be reliable for monitoring changes in SV during uninterrupted, spontaneous breathing.

Aged↗
PubMed1990

The influence of a histamine2-receptor antagonist on the healing of an experimentally induced gastric mucosal lesion.

The effect of an H2-receptor antagonist (ranitidine) on the healing of gastric mucosal lesions was studied. Mucosal lesions were induced by a standardized thermo-mechanical technique. The healing process was assessed by macro- and light microscopical examination. It was further evaluated by measurements of the tissue contents of hydroxyproline, a chemical compound reflecting collagen, and of DNA and RNA, reflecting cell frequency and protein synthesis respectively, in the gastric wall from both injured and wound-free areas. The healing process was more rapid in ranitidine-treated animals than in controls. After four weeks, however, the lesion in nine out of ten animals had healed in the ranitidine-treated group and seven of nine rats in the control group. At that time the amounts of hydroxyproline, DNA and RNA did not differ between the two groups. These findings may be taken as an indication that the tissue components of the healed lesions were similar in ranitidine-treated rats and in the saline controls, i.e. the different speeds of the healing process did not seem to influence the components of the scar tissue.

Animals↗
PubMed1990

Effect of basolateral acidification on the frog oxynticopeptic cell.

The effects of intracellular acidosis induced by acidification of the basolateral (nutrient) perfusate on the structure and function of the oxynticopeptic cell were studied in in vitro frog gastric mucosa. Changing the pH of the unbuffered nutrient perfusate (UNB) from 7.2 to 3.5 acidified the oxynticopeptic cell with no change in potential difference (PD) or resistance (R). Intracellular pH (pHi), PD, and R were 7.05 +/- 0.01, 16 +/- 1 mV, 165 +/- 7 omega.cm2 before and 6.44 +/- 0.01, 16 +/- 2 mV, 170 +/- 9 omega.cm2 after nutrient acidification. Acid secretion (H+) increased from 0.86 +/- 0.07 to 1.88 +/- 0.18 mu eq.cm-2.h-1. Addition of forskolin to tissues perfused with nutrient pH (pHn) 3.5 decreased PD to 2 +/- 2 mV and further increased H+ to 3.07 +/- 0.19 mu eq.cm-2.h-1. By light and electron microscopy oxynticopeptic cells perfused with UNB, pHn 3.5, appeared normal. Oxynticopeptic cells in tissues pretreated with omeprazole and then exposed to UNB, pHn 3.5, had extensive morphological damage. On increasing the pH of the nutrient perfusate from 3.5 to 7.2 there was prompt recovery of pHi in untreated and forskolin-stimulated mucosae (pHi 6.87 +/- 0.06 and 6.85 +/- 0.04) but no recovery of pHi in tissues pretreated with omeprazole or cimetidine (pHi 6.26 +/- 0.04 and 6.44 +/- 0.06, n = 6, 30 min after reexposure to UNB, pHn 7.2). We conclude that in a secreting mucosa intracellular acidification of the oxynticopeptic cell to pHi 6.4 is associated with normal morphology, PD, R, and increased H+, and that intracellular acidosis is not de facto deleterious.

Animals↗
PubMed1990

Feline E. coli bacteremia--effects of misoprostol/scavengers or methylprednisolone on hemodynamic reactions and gastrointestinal mucosal injury.

Live E. coli were infused i.v. in cats to induce gastrointestinal mucosal injury and the gastric mucosa was exposed to bile and a luminal pH of 1. A gastric lesion index was calculated and intestinal injury was graded. The effects of i.v. methylprednisolone before and after induction of bacteremia were compared with those of intragastric misoprostol combined with i.v. superoxide dismutase (SOD) and catalase and with a control group. Methylprednisolone, but not misoprostol/SOD/catalase, significantly reduced the gastric lesion index (p less than 0.05). The duodenum/small intestine was significantly injured in 4/6, 2/6 and 4/6 cats in the misoprostol/SOD/catalase, methylprednisolone and control groups, respectively (NS). End gastric luminal pH was 3.9, 2.7 and 4.5 in the respective groups (p less than 0.05), with systemic arterial pH 7.15, 7.15 and 7.32 (NS). Mean arterial pressure and cardiac output were improved with methylprednisolone. Misoprostol/SOD/catalase reduced late hypotension. Pulmonary arterial pressure rose to c. 200% of basal in all groups. Methylprednisolone, but not misoprostol/SOD/catalase, thus protected the gastric mucosa from sepsis-induced gastric injury concomitant with reduced disappearance of protons from the gastric lumen, but did not significantly affect small-bowel damage. Hemodynamic responses were significantly improved in methylprednisolone-pretreated cats.

Acid-Base Equilibrium↗
PubMed1989

Influence of prostanoids on gastrointestinal mucosal injury in experimental septic shock.

Capillary stasis and mucosal injury in the stomach and small intestine were studied in septic shocked pigs. Septicemia was induced by live E. coli i.v. in 28 animals. Additionally, five animals were infused with Ringer's solution and served as sham controls. The 28 E. coli-infused animals were pretreated with either a cyclooxygenase inhibitor--indomethacin, n = 6, a thromboxane (TxA2)-synthetase inhibitor--UK 38,485 alone, n = 6, or combined with a serotonin-antagonist--ketanserin, n = 9. Seven E. coli-infused animals were left untreated and served as septic controls. The sham controls were hemodynamically stable and had normal histological findings. All bacteria-infused animals exhibited signs of septic shock with pronounced hemodynamic reactions. Attenuation of the bacteria-induced increase in pulmonary arterial blood pressure was found in all pretreated animals but most pronounced in the indomethacin-pretreated group which also showed protection against gastric mucosal injury and capillary stasis. TxA2-inhibited animals had aggravated capillary stasis and mucosal injuries. It is concluded that gastric mucosal damage could be modified by drugs influencing the prostanoid system. The "cytoprotective" effect of prostaglandins seem to be of minor importance for the prevention of the gastro-intestinal mucosal injury seen in some series.

Animals↗
PubMed1989

Protein C deficiency and splanchnic venous thrombosis. Case report.

A patient with splanchnic venous thrombosis due to heterozygous deficiency of protein C is reported. A review of the literature revealed that out of nine previously reported patients an isolated protein C deficiency was present in only one. Anticoagulant regimen carries a risk of hypercoagulability and certain precautions with such regimens are therefore necessary when treating patients in this condition.

Aged↗
PubMed1988

Differences in caries status and caries recording within and between two counties in Sweden.

One-hundred and seventy-six randomly selected 16-year-old children from six clinics in two neighbouring counties were examined by the dentists who see the patients every year, as well as by two calibrated examiners (two of the authors). Compared to the dentists, working in the dental clinics, the authors consistently noted a higher total caries score (DMFS + incipient lesions). The differences were statistically significant in four of the six clinics and most pronounced on incipient lesions. Furthermore, there was a significant difference in caries prevalence between the two counties. Possible explanations for the difference are resources available and efforts put into preventive dentistry.

Adolescent↗
PubMed1987

Secretory state and acute gastric mucosal injury in sepsis.

Cats were subjected to a standardized 3-h septicemia by intravenous infusion of live Escherichia coli in an LD50 dose. The effect of pentagastrin stimulation on the development of gastric mucosal injury was studied. There was no hemodynamic difference between the series during septicemia. Thus, pentagastrin did not induce increased gastric blood flow during the period of E. coli infusion. Intraluminal gastric pH was lower in the series given pentagastrin during the last 2 h of septicemia. Nevertheless, the extent of gastric mucosal injury was similar in the two groups, whereas the depth of injury was, if anything, less pronounced in the pentagastrin-stimulated group.

Acute Disease↗
PubMed1986

The influence of ketanserin on hemostasis in vitro.

Ketanserin is a new selective 5-HT2 receptor blocker. It has been used to indirectly study the influence of serotonin on hemostatic function in vitro. Coagulation and fibrinolysis in vitro were not affected. In high doses adrenalin induced platelet aggregation was inhibited but no influence was seen on collagen or ADP induced aggregation. It can be concluded that it is not very likely that serotonin plays an important role in initial hemostasis. However, the findings ought to be confirmed in vivo.

Adenosine Diphosphate↗
PubMed1986

A comparison of static cytofluorometry and flow cytometry for the estimation of ploidy and DNA replication in human breast cancer.

332 primary invasive breast carcinomas were analysed by static cytofluorometry and flow cytometry. The ploidy distributions were similar, and 54% of the tumors were judged DNA aneuploid by both methods. The coefficient of variation of the G0-G1 peaks ranged from 2.0 to 8% with both techniques, but the mean was somewhat lower with flow cytometry--4.1%, compared to 4.9% for the static measurements. The proportion of S-phase cells was possible to estimate from 80% of the flow histograms and 70% of the static histograms. S-phase was not estimated from the static histograms if less than 150 tumor cells were measured. With 160 tumors S-phase was measured by both methods. The range was 0 to 27% with the static measurements and 0.7 to 25% with flow cytometry. Corresponding mean values were 7.6% and 8.2%, which are similar to thymidine labeling index results with breast cancers reported in some studies. A close correlation was obtained (r = 0.927) comparing S-phase fractions estimated from aneuploid tumors with flow cytometry and static cytofluorometry if more than 200 cells were measured with the latter. The proportion of S-phase cells was significantly lower for the diploid tumors. We conclude that both techniques can be useful for the estimation of DNA ploidy and replication in human breast cancer.

Aneuploidy↗
PubMed1986

Adenosine in the inhibition of diazepam sedation by aminophylline.

Aminophylline in a low dose has been shown to reverse diazepam sedation. The present investigation was performed as a double-blind study to compare the effects of aminophylline and enprofylline on deep diazepam sedation after surgery. Enprofylline is a xanthine derivative with anti-asthmatic effect but, in contrast to aminophylline, enprofylline has very weak adenosine antagonistic properties. A comparison should make it possible to evaluate if adenosine is involved in the observed effects. Twenty male patients undergoing transurethral surgery in spinal anaesthesia were given diazepam during surgery to maintain a state of deep sedation. Postoperatively aminophylline or enprofylline was given from coded ampoules in equipotent anti-asthmatic doses (4.5 or 1.5 mg/kg). The degree of sedation was assessed prior to and after the injections. A difference between the groups was obvious. Patients given aminophylline showed rapid reversal of sedation, persisting throughout the 2-h observation period. Following enprofylline, a markedly slower reversal of sedation was observed. It is likely that aminophylline antagonises diazepam sedation by blocking adenosine receptors. Some clinical implications are outlined.

Adenosine↗
PubMed1986

Proliferative index, cytosol estrogen receptor and axillary node status as prognostic predictors in human mammary carcinoma.

The predictive value of tumor cell estrogen receptor (ER) content, DNA ploidy, proliferative index (PI) and lymph node involvement was examined in 210 women operated on for primary breast cancer in 1979. At a minimum follow-up of 60 months the highest relapse free survival was observed in patients whose tumours had ER greater than 0.30 fmole/micrograms DNA (ER rich) and PI less than 5% (PI low). Subclassification of tumors in euploid and aneuploid groups gave no prognostic information. When examined by axillary node status (no nodal involvement - involved nodes) both ER and PI contributed prognostic information. Multivariate analysis using Cox proportional hazards model showed that nodal involvement was the strongest predictor of recurrence (p = 0.0007). However, ER and PI contributed significant independent prognostic information (p = 0.048 and p = 0.038), respectively.

Adult↗
PubMed1985

Gastric mucosal damage in sepsis--effects of pretreatment with a synthetic prostaglandin E1 analogue.

An experimental model was used which includes intragastric instillation of 80 mM HCl and 0.6 ml bile/kg followed by intravenous infusion of live E coli in cats for up to three hours. This procedure regularly induces gastric mucosal ulcerations. Mucosal blood flow was measured by microspheres before, early, and late in sepsis. Total gastric blood flow was recorded electromagnetically. Mucosal regeneration capacity as reflected by the RNA/DNA ratio was measured. Misoprostol (a PGE1 analogue) was infused iv (5 micrograms/kg X h) or given locally in the stomach (10 micrograms/kg) before bacteriemia. Misoprostol did not influence the haemodynamic response to bacteria. The gastric mucosal damage was assessed either as an index representative for the entire corpus-fundus region or as the number of areas with intact surface epithelium within the series. Misoprostol iv protected the mucosa from ulceration compared with untreated septic controls while misoprostol intragastrically significantly reduced the number of damaged areas only. Topical misoprostol increased total gastric and mucosal blood flows early in sepsis compared to iv or no pretreatment while no difference was seen during late sepsis. The protective effect of misoprostol was thus not dependent on increased gastric mucosal blood flow. Nor was it mediated through effects on mucosal nucleic acid concentrations or ratio.

Animals↗
PubMed1985

Dental health, dental care, and dietary habits in children in different parts of Sweden.

An epidemiological study of dental health, dental health care, and sociodemographic data in 817 4-, 8-, and 13-year-old children was carried out in 1980/81 in two areas in the county of Västerbotten, northern Sweden, and in one area in the northern part of the county of Alvsborg, in southwestern Sweden. Dietary habits and nutrient intake were studied in 738 of the children. The aim of the study was to examine the dental health in the different areas and to study the importance of variations in related background factors. The results showed great differences in dental health in all age groups between the two counties. There were also differences between the two areas in the north, but these were not as evident. A discriminant function analysis showed that age when organized dental care started and tooth-brushing frequency had greater explanatory power on dental caries than food habit factors.

Adolescent↗
PubMed1985

Infant feeding and dental caries--a longitudinal study of Swedish children.

The aim of the study was to compare dietary habits in children at the age of 12 months with the caries status at the age of 3. In 312 children, residing in 3 different parts of Sweden, a dietary study was carried out at 12 mo. of age, and in 275 (88%) a caries examination was performed at the age of 3. At 12 months of age, higher education of the mother was positively correlated with consumption of bread, vegetables, fruit and meat and negatively with frequency of sucrose-rich foods. At the age of 3, caries was diagnosed in 16% of the children. The prevalence of cavities was related to the level of education of the mother in all 3 areas, cavities being most numerous in children whose mother had received a shorter education. A discriminant analysis showed that the equation discriminating the two a priori defined groups, one with and one without caries at the age of 3, contained a number of sucrose-rich foods. The 3-year-old children with caries had generally consumed cakes, butter, bread and sweet soups more frequently at the age of 12 months than the children in the non-caries group. The analysis thus indicated that - on the group level at least - a dietary pattern, which may be casually linked with future dental caries development, was already established at the age of 12 months. Dietary counselling, when the child is 12-18 mo. of age and based upon information about the dietary habits of the child could thus be of value to prevent caries in the preschool child.

Age Factors↗
PubMed1985

Role of free oxygen radicals in the development of gastrointestinal mucosal damage in Escherichia coli sepsis.

Live Escherichia coli were infused into anesthetized cats given 0.6 ml bile/kg and 80 mM HCl into the stomach. Systemic and pulmonary arterial blood pressures, cardiac output, and gastric blood flow were monitored. Gastrointestinal total wall and mucosal blood flow were measured by microspheres. The microscopic mucosal damage was graded 0-4 (stomach) or 0-5 (intestine). One group of cats (N = 8) received 5 mg yeast CuZn superoxide dismutase (SOD) as a bolus before bacteria followed by infusion 50 mg/3 hr. Four of these cats were also given catalase in the same dose. Controls (N = 8) had no treatment. After 3 hr gastric ulceration (grades 2-4) was found in controls but only in 50% of treated cats (P less than 0.1). About 50% and 25% of the cats in both groups developed significant small intestinal and colonic mucosal damage, respectively. SOD or SOD/catalase had no effect on late systemic hypotension, decrease in cardiac output, or transient increase in pulmonary pressure. Total gastric blood flow did not change, while at late sepsis gastric mucosal flow was decreased in the treated group. Small intestinal mucosal flow decreased in both series. It is concluded that free oxygen radicals may be of partial importance in the development of sepsis-induced gastric, but not intestinal, mucosal damage.

Animals↗