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Biomedical subjects

S Salminen

Publications and source records attributed to S Salminen.

At least 55 records · Page 3Linked to original sources

Lactobacillus crispatus and its nonaggregating mutant in human colonization trials.

A wild-type Lactobacillus crispatus, showing a cell aggregation phenotype and its spontaneous nonaggregating mutant were compared for their in vitro adhesion properties to human ileal mucus and to a cultured human colonic cell line (Caco2) and for their in vivo colonization and adhesion potential with colonoscopy patients as volunteers in feeding trials. The wild-type strain adhered better to mucus or to Caco2 cells than did the mutant. Altogether, three human trials with the wild type and two with the mutant strain were performed. In two of the trials, the wild type could be recovered from either fecal samples or biopsies taken from the colon, while the mutant strain could not be demonstrated in either of the trials where it was used. The L. crispatus colonies recovered from the trials were often mixed, and several enterococci and lactobacillus strains coaggregating with L. crispatus wild type could be isolated. The results indicate that the surface-mediated properties, such as aggregation, of lactobacilli can have a role in adhesion and colonization.

Bacterial Adhesion↗

Aflatoxin B1 binding by dairy strains of lactic acid bacteria and bifidobacteria.

Various food commodities including dairy products may be contaminated with aflatoxins, which, even in small quantities, have detrimental effects on human and animal health. Several microorganisms have been reported to bind or degrade aflatoxins in foods and feeds. This study assessed the binding of aflatoxin B1 (AFB1) from contaminated solution by 20 strains of lactic acid bacteria and bifidobacteria. The selected strains are used in the food industry and comprised 12 Lactobacillus, five Bifidobacterium, and three Lactococcus strains. Bacteria and AFB1 were incubated (24 h, +37 degrees C) and the amount of unbound AFB1 was quantitated by HPLC. Between 5.6 and 59.7% AFB1 was bound from solution by these strains. Two Lactobacillus amylovorus strains and one Lactobacillus rhamnosus strain removed more than 50% AFB1 and were selected for further study. Bacterial binding of AFB1 by these strains was rapid, and more than 50% AFB1 was bound throughout a 72-h incubation period. Binding was reversible, and AFB1 was released by repeated aqueous washes. These findings further support the ability of specific strains of lactic acid bacteria to bind selected dietary contaminants.

Aflatoxin B1↗

Do combined elimination diet and prolonged breastfeeding of an atopic infant jeopardise maternal bone health?

BACKGROUND: Prolonged breastfeeding, and intervention in the maternal diet during breastfeeding, have been suggested as a means to treat atopic symptoms of infants. The impact of these actions on the mother's skeletal health has remained unclear. OBJECTIVE: The purpose of this study was to determine factors that are associated with bone mineral density (BMD) and serum lipid fatty acid profile in mothers of atopic infants. METHODS: BMD at the lumbar spine, right femoral neck and dominant distal radius of 24 mothers of atopic infants (study group) and 25 mothers of healthy infants (control group) were measured with dual energy X-ray absorptiometry postpartum after the resumption of menses. In addition, the fatty acid profile of their serum cholesteryl esters was determined. RESULTS: A systematic trend for 4-6% lower BMD was observed in the study group, but this difference was mainly attributable to a difference in body weight between the groups. In addition, the omega (omega)-3 fatty acid metabolite EPA showed a positive association with femoral neck BMD. Mothers of atopic infants had a significantly lower proportion of omega-6 fatty acid parent LA and a higher proportion of omega-6 fatty acid metabolite GLA than the control mothers. These differences were associated not only with dietary factors but also with the duration of postpartum amenorrhea and total lactation. CONCLUSIONS: Neither the breastfeeding nor the mother's short-term elimination diet per se seemed to be associated with low BMD in the mothers of atopic infants. Thus, if an elimination diet benefits the infant, it can be recommended for a limited period. However, it may be advisable to give special dietary counselling, especially to low body weight mothers, in order to ensure adequate nutrient intake and to minimize the possible risk of potential bone loss.

Adult↗

Distributions of Li+, Na+ K+, Rb+, and Cs+ tracer ions in erythrocytes at 38 degrees C in relation to entry rates of these ions into cells at 0 degree C.

Forces that are able to transport Na+ and K+ into two compartments were investigated. A modified Nernst-Planck equation for coupled flows of electric current, water, and ions was integrated. The result shows that if alkali ions in the ion channel of the cell membrane are separated by their electric-current-induced inward flows against an electro-osmotic outward flow of water, the logarithms of the stationary cell/medium distributions of these ions should be proportional to the inverse of their diffusion mobilities. The relationship was tested in human erythrocytes. From inward and outward movements of tracer alkali ions, calculations were made to obtain their stationary distributions at infinite time. The cell/medium distributions determined in this way at 38 degrees C are Li+ = 0.59, 22Na+ = 0.044, 42K+ = 10.0, 86Rb+ = 11.9, and 137Cs+ = 3.07. The entry rates of ions into the cell at 0 degrees C are understood to represent their diffusion mobilities in the pump channel. The entry rates are Li+ = 1.44, 2Na+ = 1, 42K+ = 2.22, 86Rb+ = 2.39, and 137Cs+ = 1.72 relative to that of 22Na+. There is an expected negative correlation between the logarithms of the stationary cell/ medium distributions at 38 degrees C and the inverse of the entry rates into the cell at 0 degrees C for the five ions. It is suggested that the proposed physical forces cause the separation of alkali ions in the channel of Na,K-ATPase.

Biological Transport, Active↗

Response of articular cartilage and subchondral bone to internal fixation devices made of poly-L-lactide: a histomorphometric and microradiographic study on rabbits.

To study the tissue response of articular cartilage and subchondral bone to biodegradable fixation devices, pins and rods made of poly-L-lactide with a fibers-in-matrix texture were implanted through the articular surface of the intercondylar portion of the distal rabbit femur. The initial raw material viscosity average molecular weight of the polymer was 660,000. One pin or screw was implanted per animal. The pins were cylindrical and measured 4.5 mm in transverse diameter. The screws had a core diameter of 3.2 mm and an outer diameter of 4.5 mm. At insertion, the implants were cut flush with the articular surface. After follow-up times of 36 and 48 weeks, the specimens were examined histomorphometrically and microradiographically. The intact contralateral femur served as a control for comparison. No signs of erosion or degradation of the polymer could be seen in the specimens. A brim of reparative tissue was formed at the entrance of the implant channel. The width of the reparative tissue from the tissue-implant boundary towards the center of the entrance hole varied greatly between the specimens, from 30 to 950 microm. In most specimens this bridging tissue consisted of undifferentiated mesenchymal tissue. Only two out of 24 specimens showed a near-normal metachromatic toluidine-blue staining of the matrix. Degenerative chondrocyte clustering occurred in the pre-existing cartilage within a 400 microm wide zone from the tissue-implant interface into the recipient tissues. Some new-bone formation was seen to envelop the implant in all specimens, but the fractional osteoid formation surface of the trabeculae showed a value significantly higher than that of the intact control side only in the screw-implanted 36-week specimens. Because of the long degradation time of poly-L-lactide, the restoration process of the articular cartilage was slow, and with regard to the quality and quantity of the reparative tissue, very variable. Large implants made of poly-L-lactide may not be suitable for insertion through intra-articular surfaces.

Animals↗

Does breast cancer change patients' dietary habits?

PURPOSE: The results of epidemiological studies on diet and cancer are often difficult to interpret on an individual level and may influence patients' beliefs, attitudes and behaviour. This study investigated the behaviour of breast cancer patients and their attitudes to dietary changes and the need of dietary advice during their disease. PATIENTS AND METHODS: The study population consisted of breast cancer patients visiting the Department of Oncology in Turku University Hospital for treatment or follow-up in August and September 1999. A questionnaire was given to a total of 123 subjects. RESULTS: The majority, 65%, were attending the clinic for treatment, 35% for follow-up. Ninety-seven patients (86%) consumed a normal Finnish diet, six (5.3%) were vegetarians and 10 (8.1%) vegetarians consuming fish and chicken occasionally. Eleven patients (8.9%) considered diet a factor contributing to their breast cancer and 38 (31.9%) had changed their dietary habits after the diagnosis of breast cancer. The numbers were higher in younger patients with higher educational background. The main reason for change in diet was the desire to be cured of cancer (52.9% of those patients who had changed their dietary habits), in 11.8% to alleviate the symptoms of nausea and 11.8% were advised by health care professionals. The main changes reported included a reduction in the consumption of animal fat, sugar and red meat and increased consumption of fruit, berries and vegetables. Forty-nine patients (39.8%) used vitamin and mineral supplements and 27 (21.9%) consumed dietary supplements including natural products and probiotics. The source of information on how to change the diet was for 33.3% the mass media, 19.4% were advised by doctors and nurses and 11.1% by dietitians. One-third of the patients expressed a need for more information on dietary factors. CONCLUSION: Breast cancer patients' need of control over their own life prompts an interest in alternative dietary habits after diagnosis, the focus being on a healthier diet. Expert dietary information is considered important. Many patients mentioned a lack of precise dietary recommendations for their individual disease situation and depended on information from outside their treatment centre.

Adult↗

Probiotics in the management of atopic eczema.

BACKGROUND: Over the last two decades the incidence of allergic diseases has increased in industrialized countries, and consequently new approaches have to be explored. OBJECTIVE: The potential of probiotics to control allergic inflammation at an early age was assessed in a randomized double-blind placebo-controlled study. METHODS: A total of 27 infants, mean age 4.6 months, who manifested atopic eczema during exclusive breast-feeding and who have had no exposure to any infant or substitute formula were weaned to probiotic-supplemented, Bifidobacterium lactis Bb-12 or Lactobacillus strain GG (ATCC 53103), extensively hydrolysed whey formulas or to the same formula without probiotics. The extent and severity of atopic eczema, the growth and nutrition of infants, and concentrations of circulating cytokines/chemokines and soluble cell surface adhesion molecules in serum and methyl-histamine and eosinophilic protein X in urine were determined. RESULTS: The SCORAD score reflecting the extent and severity of atopic eczema was 16 (7-25) during breast-feeding, median (interquartile range). After 2 months, a significant improvement in skin condition occurred in patients given probiotic-supplemented formulas, as compared to the unsupplemented group; chi(2) = 12.27, P = 0.002. SCORAD decreased in the Bifidobacterium lactis Bb-12 group to 0 (0-3.8), and in the Lactobacillus GG group to 1 (0.1-8.7), vs unsupplemented 13.4 (4.5-18.2), median (interquartile range), in parallel with a reduction in the concentration of soluble CD4 in serum and eosinophilic protein X in urine. CONCLUSION: The results provide the first clinical demonstration of specific probiotic strains modifying the changes related to allergic inflammation. The data further indicate that probiotics may counteract inflammatory responses beyond the intestinal milieu. The combined effects of these probiotic strains will guide infants through the weaning period, when sensitization to newly encountered antigens is initiated. The probiotic approach may thus offer a new direction in the search for future foods for allergy treatment and prevention strategies.

Bifidobacterium↗

Wheat or rye supplemented diets do not affect faecal mucus concentration or the adhesion of probiotic micro-organisms to faecal mucus.

In a crossover study, volunteers consumed a diet supplemented with either wheat or rye bread. Levels of faecal mucus were determined and the adhesion of five selected probiotics to immobilized intestinal mucus, was assessed. No significant difference in the concentration of faecal mucus or adhesion of the probiotics to the mucus was observed during the two dietary periods. However, male subjects were observed to excrete significantly more mucus during the rye bread supplemented diet. From these observations it was concluded that these two diets, with a low or high fibre content, did not change the potential binding sites for the tested probiotics or affect the level of mucus excreted in the faeces, however, on a high fibre diet men excrete more faecal mucus.

Bacterial Adhesion↗

Adhesion of inactivated probiotic strains to intestinal mucus.

It has been suggested that probiotics should be viable in order to elicit beneficial health effects. Inactivation of probiotics has been suggested to interfere with the binding to the mucosa and thereby with the immune modulating activity of probiotics. The effect of different inactivation methods on the mucus adhesion of nine probiotic strains was studied. Inactivation by heat or gamma-irradiation generally decreased the adhesive abilities. However, heat treatment increased the adhesion of Propionibacterium freudenreichii and gamma-irradiation enhanced the adhesion of Lactobacillus casei Shirota. Inactivation by u.v. was not observed to modulate the adhesion of the tested strains and it was concluded to be the most appropriate method for studying non-viable probiotics and preparing control products.

Bacterial Adhesion↗

Occupational accidents of Finnish- and Swedish-speaking workers in Finland: a mental model view.

This article is based on 2 studies. The aim of the first study was to examine the differences in occupational accident frequency between the 2 main language groups in Finland. Based on 3 independent statistical data sets, it was shown that Swedish-speaking workers had about 40% fewer occupational accidents than Finnish-speaking workers. The aim of the second study was to confirm the difference at company level. A field study in the province of Vaasa with 14 small and medium-sized manufacturing companies revealed that the accident frequency of Swedish-speaking workers was 21% lower than that of Finnish-speaking workers.

Accidents, Occupational↗

Quantitative approach in the study of adhesion of lactic acid bacteria to intestinal cells and their competition with enterobacteria.

To describe the phenomena of bacterial adhesion to intestinal cells and the competition for adhesion between bacteria, mathematical equations based on a simple dissociation process involving a finite number of bacterial receptors on intestinal cell surface were developed. The equations allow the estimation of the maximum number of Lactobacillus sp. and Escherichia coli cells that can adhere to Caco-2 cells and intestinal mucus; they also characterize the affinity of the bacteria to Caco-2 cells and intestinal and fecal mucus and the theoretical adhesion ratio of two bacteria present in a mixed suspension. The competition for adhesion between Lactobacillus rhamnosus GG and E. coli TG1 appeared to follow the proposed kinetics, whereas the competition between Lactobacillus casei Shirota and E. coli TG1 may involve multiple adhesion sites or a soluble factor in the culture medium of the former. The displacement of the adhered Lactobacillus by E. coli TG1 seemed to be a rapid process, whereas the displacement of E. coli TG1 by the Lactobacillus took more than an hour.

Bacterial Adhesion↗

Ability of Lactobacillus and Propionibacterium strains to remove aflatoxin B, from the chicken duodenum.

The ability of Lactobacillus rhamnosus strains GG and LC-705 to remove AFB1 from the intestinal luminal liquid medium has been tested in vivo using a chicken intestinal loop technique. In this study, the GG strain of L. rhamnosus decreased AFB1 concentration by 54% in the soluble fraction of the luminal fluid within 1 min. This strain was more efficient in binding AFB1 compared with L. rhamnosus strain LC-705 (P < 0.05) that removed 44% of AFBl under similar conditions. Accumulation of AFB1 into the intestinal tissue was also determined. There was a 74% reduction in the uptake of AFB1 by the intestinal tissue, in the presence of L. rhamnosus strain GG compared with 63% and 37% in the case of Propionibacterium freudenreichii ssp. shermanii JS and L. rhamnosus strain LC-705, respectively. The complexes formed in vitro between either L. rhamnosus strain GG or L. rhamnosus strain LC-705 and AFB1 were stable under the luminal conditions for a period of 1 h.

Aflatoxin B1↗

Ability of dairy strains of lactic acid bacteria to bind aflatoxin M1 in a food model.

Aflatoxin M1 (AFM1) is a highly toxic compound found in milk. Its occurrence poses a threat to the health of consumers, especially young children, and leads to economic losses due to contaminated milk. The problem is global but more severe in developing countries. Consequently, there is a great demand for novel strategies to prevent the contamination and adverse effects of AFM1. To develop a safe and practical decontamination method, a preliminary study was carried out with specific lactic acid bacteria strains that were tested for their ability to remove AFM1 from liquid media. All strains, whether viable or heat-killed, could reduce the AFM1 content of a liquid medium. Two most effective strains were also tested using contaminated skim and full cream milk. The results indicate that specific lactic acid bacteria used in dairy products can offer novel means of decontaminating aflatoxin M1 from milk.

Aflatoxin M1↗

Milk hypersensitivity in young adults.

OBJECTIVE: To estimate the prevalence of milk hypersensitivity in Finnish adults. DESIGN: Cross-sectional study. SUBJECTS: Two hundred men and 206 women aged 27 y randomly recruited from the population register in southwestern Finland. INTERVENTIONS: The subjects were interviewed about their dairy product consumption, abdominal discomfort after dairy product intake and lactose intolerance. From serum samples, serum reactivity to milk protein and milk-specific IgG1, IgG2, IgG3 and IgA were measured. RESULTS: About 20% of the subjects reported abdominal discomfort after dairy product intake, whereas only 6.4% had been diagnosed to have lactose intolerance. The amount of milk consumed correlated well with the serum assay results in subjects reporting abdominal discomfort but not in subjects who were free from these symptoms. Among subjects with no record of dairy product restriction or lactose intolerance, those experiencing abdominal discomfort after dairy product intake had significantly higher serum reactivity to milk protein than those without such discomfort. The concentrations of serum milk-specific antibodies did not differ between these two groups. The prevalence of milk hypersensitivity in this population was estimated to be 3-6%. CONCLUSIONS: Milk hypersensitivity may be as common in adults as in infants. The measurement of serum reactivity to milk protein may prove useful in screening milk hypersensitivity in subjects who have not restricted their dairy product consumption.

Abdominal Pain↗

Mode of delivery directs the phagocyte functions of infants for the first 6 months of life.

Factors that direct the immune responsiveness of the newborn beyond the immediate post-natal period are not known. We investigated the influence of mode of delivery and type of feeding on the phagocyte activity during the first 6 months of life. Sixty-four healthy infants (34 delivered vaginally and 30 by elective Caesarean section) were studied at birth and at the ages of 2 and 6 months. Phagocyte functions were studied by measuring the chemiluminescence (CL) activity of whole blood and isolated leucocytes and by investigating the expression of phagocyte receptors (FcgammaRI (CD64), FcgammaRII (CD32), FcgammaRIII (CD16), CR1 (CD35), CR3 (CD11b) and FcalphaR (CD89)) on neutrophils, monocytes and eosinophils by using receptor-specific MoAbs and immunofluorescence flow cytometry. Infants born by elective Caesarean section had significantly higher CL activity than those delivered vaginally during the entire 6-month follow up. In addition, infants who received formula feeds had significantly higher CL activity at 6 months of age and higher expression of FcgammaRI-, Fcalpha- and CR3-receptors on neutrophils than infants exclusively breast-fed. We suggest that stress reaction associated with labour influences the phagocytic activity measured in the cord blood but later during infancy the intraluminal antigens, gut microflora and diet, become important determinants in immune programming of human individuals.

Animals↗