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Biomedical subjects

M Eriksson

Publications and source records attributed to M Eriksson.

At least 307 records · Page 17Linked to original sources

Gentamicin-resistant Klebsiella spp. and Escherichia coli in a neonatal intensive care unit.

A case of septicemia in a 7-day-old infant with a gentamicin-resistant strain of Klebsiella oxytoca prompted an epidemiological survey in a neonatal unit. Within a 3-month period 7 patients presented with symptomatic infection with gentamicin-resistant gram-negative bacilli. Another 3 patients were asymptomatic and only harboured the organisms in the stool. The aminoglycoside modifying enzyme ANT(2")-a was identified with a probe technique in different gram-negative species indicating the spread of a plasmid. After the replacement of gentamicin with amikacin and the adherence to proper barrier precautions the gentamicin-resistant strains disappeared from the ward.

Ampicillin Resistance↗

Bordetella pertussis adenylate cyclase activity in nasopharyngeal aspirates for rapid diagnosis of whooping cough in relation to culture and serology.

Adenylate cyclase activity, measured in 201 nasopharyngeal aspirates from patients presenting with own or parental suspicion of whooping cough, was compared to diagnosis made by culture and by serology in the culture negative cases. The median amount of cyclic AMP in samples from culture negative patients (n = 145) was 0.60 pmoles which differed significantly (p less than 0.001) from the median value 3.28 in samples from culture positive patients (n = 56). The median value 0.70 pmoles of cyclic AMP in samples from culture negative patients who were positive by serology (n = 54) did not differ significantly from the value of 0.57 pmoles in samples from serology negative patients (n = 91). With a limit for positive cyclic AMP set at 2 pmoles, 45 samples were positive. The sensitivity of the assay was 66% (37/56) in culture positive patients while the specificity was 93% (85/91) in the serology negative patients. The positive predictive value for the c-AMP test was 82% (37/45) in relation to culture and 87% (39/45) in relation to culture and/or serology. The results confirmed that measurement of adenylate cyclase activity in nasopharyngeal aspirates by an 1-h incubation method can serve as an early and rapid diagnostic method of pertussis infection. The low sensitivity of the c-AMP assay in samples from serology positive but culture negative patients indicates however, that this assay will have to be supplemented by serology for a high diagnostic sensitivity in all cases of pertussis.

Adenylyl Cyclases↗

Effects of pravastatin and cholestyramine on products of the mevalonate pathway in familial hypercholesterolemia.

Patients with heterozygous familial hypercholesterolemia (n = 12) were treated either with pravastatin, a specific inhibitor of HMG-CoA reductase, or cholestyramine, followed by a period of combined treatment with both drugs. Initially, these patients had increased serum levels of low density lipoprotein (LDL) cholesterol (8.77 +/- 0.48 mmol/l; SEM), lathosterol (5.32 +/- 0.60 mg/l), and ubiquinone (0.76 +/- 0.09 mg/l), while the serum dolichol concentration was in the normal range. Cholestyramine treatment (n = 6) decreased the levels of LDL cholesterol (-32%) and increased lathosterol (+125%), but did not change dolichol or ubiquinone levels in a significant manner. Pravastatin treatment (n = 6) decreased LDL cholesterol (-27%), lathosterol (-46%), and ubiquinone (-29%). In this case, the amount of dolichol in serum also showed a small but statistically insignificant decrease (-16%) after 12 weeks of treatment. Combined treatment with cholestyramine and pravastatin (n = 6) resulted in changes that were similar to, but less pronounced than, those observed during pravastatin treatment alone. In no case was the ratio between ubiquinone and LDL cholesterol reduced. Possible effects on hepatic cholesterol, ubiquinone, and dolichol concentrations were studied in untreated (n = 2), cholestyramine-treated (n = 2), and pravastatin-treated (n = 4) gallstone patients and no consistent changes could be observed. The results indicate that treatment with pravastatin in familial hypercholesterolemia decreases serum ubiquinone levels in proportion to the reduction in LDL cholesterol.

Adult↗

DNA-bound proteins contribute much more than soluble intracellular compounds to the intrinsic protection against radiation-induced DNA strand breaks in human cells.

To assess the role of soluble intracellular compounds and DNA-bound proteins in the intrinsic protection against radiation-induced DNA strand breaks, the alkaline unwinding technique was applied to cellular, nuclear, and nucleoid monolayers. It was found that, when the soluble intracellular compounds were removed from human fibroblasts by permeabilization (nuclear monolayers) and irradiated in a phosphate buffer containing 150 mM monovalent cations (Na+ and K+) and 0.8 mM MgCl2, the frequency of radiation-induced DNA strand breaks increased twofold. Removal of both soluble intracellular compounds and DNA-bound proteins from the cells by a pretreatment with 2 M NaCl (nucleoid monolayers) resulted in a 100-fold increase in the frequency of strand-break induction by gamma radiation. Expressed as percentage of total intrinsic protection against radiation-induced DNA strand breaks, DNA-bound protein contributed 99% compared to 1% by soluble intracellular compounds. Using a different experimental approach it was found that the radioprotective capacity of soluble intracellular compounds was equivalent to about 5 mM dimethyl sulfoxide (DMSO) and DNA-bound proteins to about 70 mM DMSO. It is concluded that DNA-bound proteins play a much greater role than soluble intracellular compounds in the intrinsic protection against radiation-induced DNA strand breaks in cultured human cells.

Cells, Cultured↗

Khat-chewing during pregnancy-effect upon the off-spring and some characteristics of the chewers.

In a study of 1,141 consecutive deliveries at delivery centres in the Yemen Arab Republic, the effects of khat (catha edulis) upon the offspring have been studied. The leaves of the shrub khat contain euphorizing compounds and are chewed often, even daily, by many inhabitants. Non-users of khat (n = 427) had significantly fewer low birth-weight babies (less than 2,500 gram) compared to occasional users (n = 223) and regular users (n = 391). The khat-chewing mother was older, of greater parity and had more surviving children than the non-chewers. Significantly more khat-chewers had concomitant diseases. There was no difference in rates of stillbirth or congenital malformations.

Birth Weight↗

Apolipoprotein(a) and ischaemic heart disease in familial hypercholesterolaemia.

Serum concentrations of apolipoprotein(a) were measured in patients with heterozygous familial hypercholesterolaemia. The levels in 47 patients were a median of 2.5 times higher than those in controls matched for age and sex (240 [range 25-1245] vs 97 [7-1040] mg/l). Among patients with familial hypercholesterolaemia apo(a) levels were higher in those with (n = 48) than in those without (n = 72) ischaemic heart disease (283 [18-1245] vs 144 [7-741] mg/l); both in univariate and multivariate analysis serum apo(a) was the most significant variable distinguishing between the groups. Despite reducing LDL cholesterol by 30%, treatment with cholestyramine or pravastatin did not reduce apo(a) levels in these patients. These findings support the concept that apo(a) concentration is a genetic trait predisposing to ischaemic heart disease and imply that it may be useful in the identification of familial hypercholesterolaemia patients at high risk of coronary disease.

Adult↗

Exposure to dioxins as a risk factor for soft tissue sarcoma: a population-based case-control study.

In a case-control study including 237 cases with soft tissue sarcoma and 237 controls, previous jobs and exposures to different agents, including pesticides, were assessed. Exposure to phenoxyacetic acids or chlorophenols gave a statistically significant increased rate ratio (RR) of 1.80 [95% confidence interval (CI) = 1.02-3.18] for soft tissue sarcoma. Exposure to phenoxyacetic acids of all types gave a nonsignificantly increased RR of 1.34 (95% CI = 0.70-2.56). During the 1950s, exposure to 2,4,5-trichlorophenoxyacetic acid gave a threefold significantly increased risk. High-grade exposure to chlorophenols, which are also contaminated by dioxins, gave an RR of 5.25 (95% CI = 1.69-16.34). The increased risk was thus attributed to dioxin-contaminated phenoxyacetic acids or chlorophenols that gave an RR of 2.43 (95% CI = 1.30-4.54).

Adult↗

Characterization of immunostimulating complexes (ISCOMS) of HIV-1.

HIV-1, strain HTLV-III, propagated in H9 cells and purified by sucrose gradient centrifugation, was used as native antigen source for the preparation of immunostimulating complexes, HIV-iscoms. The major antigen detected in the iscom was the cell-derived HLA-DR, which readily could be removed from the virus lysate by immunosorbent. In the iscoms the HIV structural proteins MA p17, p55 and TM gp41 were identified; SU gp120 was present in only minute amounts in the virus lysate. The iscom particles appeared well preserved after freeze drying with a round shape, approximately 35 nm in diameter, comprising morphological subunits, assembled with icosahedral symmetry. Immunization experiments in mice reflected the antigen content of the iscoms. High antibody response was induced to HLA-DR in non-depleted iscoms. Major humoral responses were observed to the viral structural proteins MA p17, CA p24, p55, and also to TM gp41. A low or negligible antibody response to SU gp120 was induced by the HIV-iscoms. The negligible response was, however, overcome by the addition of recombinant gp160 to the virus lysate prior to formation of iscoms, resulting in a preparation evoking a clear serum antibody to gp160.

Animals↗

Biliary lipids in familial combined hyperlipidaemia: effects of acipimox therapy.

Biliary lipid composition and plasma lipoprotein levels were determined in nine gallstone-free male patients with familial combined hyperlipidaemia (FCHL). In the basal situation, stimulated fasting duodenal bile from the patients contained a higher relative concentration of cholesterol than bile obtained from age- and sex-matched normal controls (n = 22), 6.5 +/- 0.3 (SEM) vs. 4.7 +/- 0.2 mol % (P less than 0.01). This resulted in a higher cholesterol saturation of bile from FCHL patients, 85 +/- 6 vs. 70 +/- 2% (P less than 0.05). After 6 weeks of treatment with acipimox, 750 mg day-1, total plasma triglycerides were lowered from 7.5 +/- 1.5 to 4.6 +/- 0.7 mmol l-1 (P less than 0.05) and plasma cholesterol decreased from 8.0 +/- 0.1 to 7.1 +/- 0.3 mmol l-1 (P less than 0.05) in the FCHL patients. These changes were mainly due to a decrease in very low density lipoprotein concentrations while low density lipoprotein levels remained unaltered. The relative proportion of cholesterol in stimulated fasting duodenal bile was reduced from 6.5 +/- 0.3 to 4.3 +/- 0.5 mol % (P less than 0.01), resulting in 'normalization' of biliary cholesterol saturation, from 85 +/- 6 to 58 +/- 6% (P less than 0.005). No correlations between the changes in biliary lipid composition and those in plasma lipoprotein levels were observed. The results indicate that treatment with acipimox in patients with FCHL, a disorder commonly associated with supersaturated bile, does not increase biliary cholesterol, and presumably not the risk for gallstone formation.

Adult↗

Treatment of familial hypercholesterolaemia: a controlled trial of the effects of pravastatin or cholestyramine therapy on lipoprotein and apolipoprotein levels.

The efficacy and safety of a new, selective inhibitor of cholesterol synthesis, pravastatin, and the bile acid-binding resin, cholestyramine, were compared in a randomized, double-blind study of 120 patients with familial hypercholesterolaemia. After a run-in period of 8-10 weeks with assessment of dietary habits, the patients were treated with pravastatin + placebo, placebo + cholestyramine, or placebo alone. Active pravastatin therapy was initiated with 10 mg b.i.d. for 6 weeks, and was increased to 20 mg b.i.d. for the following 6 weeks. Cholestyramine was given at 24 g d-1, or the highest tolerable dose. After 6 weeks of therapy, serum total and LDL cholesterol levels were reduced by 17% and 21%, respectively, on pravastatin treatment, whereas the corresponding reductions with cholestyramine treatment were 24% and 30%, respectively. With an increased dose of pravastatin, serum and LDL cholesterol concentrations were reduced by 23% and 28%, respectively, after 12 weeks; the effect of cholestyramine was unchanged. HDL cholesterol levels increased in response to pravastatin, by 7% and 9% after 6 and 12 weeks, respectively. Concomitant changes in the concentrations of apolipoproteins B and AI were observed. Three patients discontinued the study because of side-effects: two subjects were treated with pravastatin and one was given placebo. The prevalence of side-effects (including laboratory abnormalities) was 35% for pravastatin, 30% for placebo, and 53% (significantly higher) for cholestyramine. We conclude that pravastatin, in a 40 mg daily dose, is as effective as cholestyramine in lowering LDL cholesterol in familial hypercholesterolaemia. Since the frequency of side-effects is higher with cholestyramine, pravastatin offers a promising alternative for the therapy of this genetic disease.

Adult↗

Socio-economic variables and pregnancy outcome. 2. Infant and child survival.

The effects of various social indicators on infant and child mortality were studied in Sweden with the use of a medical birth register to which census information was linked. Two years were studied: 1976 births linked to the 1975 census, and 1981 births linked to the 1980 census. Survival was followed to the age of 5 by linkage of the birth register with the death certificate register. The only statistically significant effect of a single socio-economic variable was that of housing conditions on perinatal death rate and postperinatal death rate up to the age of one. The family situation (e.g., cohabitation or not) had some effect, although it was not statistically significant. On the basis of cohabitation status and other social indicators, including housing conditions, we selected two groups: one privileged and the other underprivileged. Using crude mortality rates, we found no definite difference. There was evidence that the mortality rate had decreased more between 1976 and 1981 in the privileged than in the underprivileged group, but the difference may have been coincidental. After standardization for maternal age and parity, however, a difference appeared with a ratio of 1.14 between the underprivileged and the privileged groups, which was valid for deaths up to the age of one. After that age, no difference was seen. Following standardization for birthweight, the opposite was found: a higher weight-specific mortality rate in the privileged group than in the underprivileged group. The interpretation of these findings is discussed.

Birth Weight↗

Plasma levels of vasoactive intestinal polypeptide and oxytocin in response to suckling, electrical stimulation of the mammary nerve and oxytocin infusion in rats.

The aim of the present study was to measure plasma levels of vasoactive intestinal polypeptide (VIP) and oxytocin following suckling, electrical stimulation of the mammary nerve and oxytocin infusion in lactating rats. Trunk blood was collected by decapitation after 5 and 20 min of suckling in conscious lactating rats. Repeated blood samples were drawn from the carotid artery in anesthetized rats, in connection with suckling, oxytocin infusion (0.22 nmol/l/kg/h) and electrical stimulation of the mammary nerve (5 V, 5 Hz, 2 ms). VIP and oxytocin levels were measured by radioimmunoassay. In conscious rats, VIP levels rose significantly from 18 +/- 5 to 102 +/- 30 pM after 5 min of suckling and to 123 +/- 25 pM after 20 min of suckling when milk ejection occurred. Oxytocin levels rose significantly from 90 +/- 24 to 269 +/- 45 pM during milk ejection. Suckling, oxytocin infusion and mammary nerve stimulation in anesthetized rats raised VIP levels significantly from 13 +/- 2, 18 +/- 5 and 10 +/- 2 to 43 +/- 8, 45 +/- 16 and 53 +/- 22 pM, respectively, whereas oxytocin levels rose from 111 +/- 34 to 294 +/- 66 pM after 20 min of suckling and to a peak value of 500 +/- 70 pM after oxytocin infusion. This study shows that VIP is elevated in plasma in lactating rats when the pups are suckling. The results showing that VIP levels rise following mammary nerve stimulation and oxytocin infusions indicate that both neurogenic and hormonal mechanisms can contribute to the regulation of VIP levels in plasma.

Anesthesia↗

Suckling-induced release of cholecystokinin into plasma in the lactating rat: effects of abdominal vagotomy and lesions of central pathways concerned with milk ejection.

Plasma levels of cholecystokinin were increased in response to suckling in lactating rats. Efferent electrical stimulation of the vagal nerve increased the concentration of cholecystokinin in plasma. Abdominal vagotomy was found to block the suckling-induced release of cholecystokinin. Furthermore, lesions to the lateral midbrain, which disrupt the oxytocin-mediated milk-ejection reflex, were shown to inhibit the increase in plasma cholecystokinin. These results show that the suckling-induced release of cholecystokinin into plasma in lactating rats is dependent upon the vagal nerves and the central neural structures concerned with milk let-down.

Animals↗

Nerve-mediated effect of ethanol on sodium and fluid transport in the jejunum of the rat.

The hypothesis tested in this study is whether a potential harmful substance such as ethanol causes secretion in the small intestine and, if so, whether the secretion is mediated via intestinal nerve reflexes or a direct effect on the epithelium. The jejunum of anaesthetized Sprague-Dawley rats was perfused in vivo with a modified Krebs-Henseleit solution. Three per cent ethanol had no significant effect, whereas 8% ethanol in the perfusate elicited a net secretion of fluid and sodium in the intestine. This secretion was reversed by ganglionic blockade with hexamethonium (10 mg/kg intravenously). The ethanol absorption from the perfusate, on the other hand, was not affected by the ganglionic blockade. We concluded that ethanol dose-dependently caused a nerve-mediated secretion of sodium and fluid in the rat small intestine. Ethanol was probably absorbed by diffusion.

Animals↗

Hypocholesterolaemia and increased elimination of low-density lipoproteins in metastatic cancer of the prostate.

To study the influence of tumour mass on lipid metabolism, the lipoprotein pattern in untreated patients with newly diagnosed cancer of the prostate was examined. Total cholesterol levels were reduced in patients with evidence of metastasis (n = 30) compared with those without metastasis (n = 73). Since the major fraction of serum cholesterol is contained in low-density lipoproteins (LDL), turnover of LDL was studied in detail in 8 patients compared with 12 age-matched healthy men. LDL were cleared faster in the 3 patients with metastatic disease than in the patients without metastasis and in controls, indicating faster catabolism of LDL. Thus in prostatic cancer an increased tumour burden is associated with increased elimination of LDL, which contributes to reduced serum cholesterol levels.

Aged↗