Soluble transferrin receptor : Role in detection of iron deficiency

Background and aims: Iron deficiency (ID) is probably the single most common nutrient deficiency in the world. It affects especially elderly persons, menstruating women, adolescent girls and infants. The concentration of the soluble transferrin receptor (sTfR) in the plasma is a relatively new laboratory test to detect ID. The aims of this study were to produce reference intervals (RIs) for sTfR and other hematological laboratory tests, to examine the influence of subclinical ID on the RIs and to establish the appropriate cut-off values for sTfR with regard to subclinical ID in elderly people, adolescent girls and preterm and full-term infants. A further objective was to establish the physiological changes of the hematological laboratory values during the first year of life among preterm and full-term infants. Results and conclusions: In elderly people and adolescent girls, the upper reference limit of sTfR declined when the RIs were based on the values of an iron-replete reference group compared to a conventional reference group. This indicates that the reference individuals, selected conventionally, may have had subclinical ID which influenced the RIs of sTfR and other markers of iron status. In infants, the RIs were the same when based on the iron-replete reference group as the whole reference group. This suggests that ID was not a marked problem for infants of this study. The iron-replete RIs for sTfR were 1.0–2.4 mg/L and 0.9–2.4 mg/L for elderly people and adolescent girls, respectively. In preterm infants, the RIs of sTfR increased from 1.1–2.2 mg/L to 1.2–2.4 mg/L with advancing age from 20 weeks to 60 weeks. The upper reference limits of the RIs of sTfR may thus be used as decision limits for ID. The values for the preterm and full-term infants provide also valuable information about the kinetics of the hematological laboratory values during the first year of life and may help physicians to interpret the results of these markers for clinical decision-making.Liukoinen transferriinireseptori – Rooli raudanpuutteen toteamisessa Tausta ja tavoitteet: Raudanpuutteen arvioidaan olevan yleisin yksittäisen ravintoaineen puutos maailmassa. Erityisesti iäkkäät henkilöt, hedelmällisessä iässä olevat naiset, murrosikäiset tytöt ja imeväisikäiset ovat raudanpuutteen riskiryhmiä. Plasman liukoinen transferriinireseptori (sTfR) on verrattain uusi laboratoriotutkimus raudanpuutteen toteamiseksi. Tämän tutkimuksen tavoitteena oli tuottaa viitearvot sTfR:lle ja muille rautataloutta kuvaaville laboratoriotutkimuksille, tutkia mahdollisen piilevän raudanpuutteen vaikutuksia viitearvoihin ja selvittää sTfR:lle päätösrajat raudanpuutteen toteamiseksi vanhuksilla, murrosikäisillä tytöillä sekä keskosina ja täysiaikaisina syntyneillä. Lisäksi pyrkimyksenä oli esittää raudanpuutteen ja verenkuvan laboratoriotutkimuksien normaaleja muutoksia ensimmäisen elinvuoden aikana ja selvittää, miten näiden tutkimuksien arvot eroavat keskosten ja täysiaikaisena syntyneiden välillä. Tulokset ja loppupäätelmät: Kun viitevälit laskettiin iäkkäille henkilöille ja murrosikäisille tytöille ryhmästä, josta oli poistettu todennäköisestä raudanpuutteesta kärsivät, sTfR:n viitevälin yläraja laski verrattuna normaalista viiteryhmästä määritettyihin viiteväleihin. Tämän perusteella normaalin viitearvoryhmän yksittäisillä henkilöillä oleva piilevä raudanpuute voi vääristää sTfR:n ja myös muiden raudanpuutetta kuvaavien laboratoriotutkimusten viitevälejä. Imeväisikäisillä viitevälit pysyivät samalla tasolla verrattuna koko viitearvoryhmään, kun viitevälit laskettiin ryhmästä, josta oli poistettu ilmeiset raudanpuutteesta kärsivät. Kun raudanpuutteesta kärsivät oli poistettu viitearvoryhmistä, sTfR:n viitearvoiksi saatiin vanhuksille 1,0-2,4 mg/l ja tytöille 0,9-2,4 mg/l. Keskosilla sTfR:n viiteväli nousi 20 viikon ikäisten viitevälistä 1,1-2,2 mg/l tasoon 1,2-2,4 mg/l 60 viikon ikäisillä. Näiden sTfR:n viitevälien ylärajoja esitetään päätösrajoiksi raudanpuutteen toteamiseksi. Esitetyt imeväisikäisten verenkuvan ja rautataloutta kuvaavien laboratoriotulosten muutokset ensimmäisen elinvuoden aikana voivat antaa kliinikoille hyödyllistä tietoa näiden tulosten tulkintaan

Heterologous Expression of the Leuconostoc Bacteriocin Leucocin C in Probiotic Yeast Saccharomyces boulardii

The yeastSaccharomyces boulardiiis well known for its probiotic effects such as treating or preventing gastrointestinal diseases. Due to its ability to survive in stomach and intestine,S. boulardiicould be applied as a vehicle for producing and delivering bioactive substances of interest to human gut. In this study, we cloned the genelecCencoding the antilisterial peptide leucocin C from lactic acid bacteriumLeuconostoc carnosuminS. boulardii. The constructedS. boulardiistrain secreted a peptide, which had molecular weight corresponding to leucocin C in SDS-PAGE. The peptide band inhibitedListeria monocytogenesin gel overlay assay. Likewise, concentratedS. boulardiiculture supernatant inhibited the growth ofL. monocytogenes. The growth profile and acid tolerance of the leucocin C secretingS. boulardiiwere similar as those of the strain carrying the empty vector. We further demonstrated that the cells of the leucocin C producingS. boulardiiefficiently killedL. monocytogenes, also without antibiotic selection pressure. These results showed that antilisterial activity could be added to the arsenal of probiotic activities ofS. boulardii, demonstrating its potential as a carrier for therapeutics delivery.Peer reviewe

Short-term bone biochemical response to a single bout of high-impact exercise

Bone response to a single bout of exercise can be observed with biochemical markers of bone formation and resorption. The purpose of this study was to examine the response of bone biochemical markers to a single bout of exhaustive high-impact exercise. 15 physically active young subjects volunteered to participate. The subjects performed continuous bilateral jumping with the ankle plantarflexors at 65 % of maximal ground reaction force (GRF) until exhaustion. Loading was characterized by analyzing the GRF recorded for the duration of the exercise. Venous blood samples were taken at baseline, immediately after, 2h and on day 1 and day 2 after the exercise. Procollagen type I amino terminal propeptide (P1NP, marker of bone formation) and carboxyterminal crosslinked telopeptide (CTx, marker of bone resorption) were analyzed from the blood samples. CTx increased significantly (32 %, p = 0.015) two days after the exercise and there was a tendensy towards increase seen in P1NP (p = 0.053) one day after the exercise. A significant positive correlation (r = 0.49 to 0.69, p &le; 0.038) was observed between change in P1NP from baseline to day 1 and exercise variables (maximal slope of acceleration, body weight (BW) adjusted maximal GRF, BW adjusted GRF exercise intensity and osteogenic index). Based on the two biochemical bone turnover markers, it can be concluded that bone turnover is increased in response to a very<br /

Complete Genome Sequence of Nisin-Producing Lactococcus lactis subsp. lactis N8

We report here the genome sequence of Lactococcus lactis subsp. lactis N8, a nisin producer isolated in the 1960s from a dairy product in Finland. The genome consists of a 2.42-Mb chromosome and two plasmids of 80.3 and 71.3 kb.Peer reviewe

Phenotypic comparison and DNA sequencing analysis of a wild-type and a pediocin-resistant mutant of Listeria ivanovii

Listeria ivanovii is one of the two pathogenic species within the genus Listeria, the other being L. monocytogenes. In this study, we generated a stable pediocin resistant mutant Liv-r1 of a L. ivanovii strain, compared phenotypic differences between the wild-type and the mutant, localised the pediocin-induced mutations in the chromosome, and analysed the mechanisms behind the bacteriocin resistance. In addition to pediocin resistance, Liv-r1 was also less sensitive to nisin. The growth of Liv-r1 was significantly reduced with glucose and mannose, but less with cellobiose. The cells of Liv-r1 adsorbed less pediocin than the wild-type cells. Consequently, with less pediocin on the cell surface, the mutant was also less leaky, as shown as the release of intracellular lactate dehydrogenase to the supernatant. The surface of the mutant cells was more hydrophobic than that of the wild-type. Whole genome sequencing revealed numerous changes in the Liv-r1 chromosome. The mutations were found e.g., in genes encoding sigma-54-dependent transcription regulator and internalin B, as well as in genes involved in metabolism of carbohydrates such as glucose and cellobiose. Genetic differences observed in the mutant may be responsible for resistance to pediocin but no direct evidence is provided.Peer reviewe

Generation of lactose and protease positive probiotic Lacticaseibacillus rhamnosus GG by conjugation with Lactococcus lactis NCDO 712

Lacticaseibacillus rhamnosus GG (LGG) is the most studied probiotic bacterium in the world. It is used as a probiotic supplement in many foods, including various dairy products. However, LGG grows poorly in milk, as it neither metabolizes the main milk carbohydrate lactose nor degrades the major milk protein casein effectively. In this study, we made L rhamnosus GG lactose and protease positive by conjugation with the dairy Lactococcus lactis strain NCDO 712 carrying the lactose-protease plasmid pLP712. A lactose-hydrolyzing transconjugant colony was obtained on agar containing lactose as the sole source of carbohydrates. By microscopic analysis and PCR with LGG- and pLP712-specific primers, the transconjugant was confirmed to have originated from LGG and to carry the plasmid pLP712. The transconjugant was named L. rhamnosus LAB49. The isolation of plasmids revealed that not only pLP712 but also other plasmids had been transferred from L lactis into LGG during conjugation. With plasmid-specific PCR primers, four additional lactococcal plasmids were detected in LAB49. Proteolytic activity assay and SDS-PAGE analysis verified that L rhamnosus LAB49 effectively degraded beta-casein. In contrast to its parental strain, LGG, the ability of LAB49 to metabolize lactose and degrade casein enabled strong and fast growth in milk. As strains with new properties made by conjugation are not regarded as genetically modified organisms (GM05), L. rhamnosus LAB49 could be beneficial in dairy fermentations as a probiotic starter culture. IMPORTANCE Probiotic strain Lacticaseibacillus rhamnosus GG (LGG) is widely sold on the market as a probiotic or added as a supplement in dairy foods because of its benefits in human health. However, due to the deficiency of lactose and casein utilization, LGG does not grow well in milk. On the other hand, lactose intolerance and cow's milk protein allergy are the two major problems related to milk consumption. One option to help with these two conditions is the use of probiotic or lactose- and casein-hydrolyzing bacteria in dairy products. The purpose of this study was to equip LGG with lactose/casein-hydrolyzing ability by bacterial conjugation. As a result, we generated a non-GMO LGG derivative with improved properties and better growth in milk.Peer reviewe

Desulfovibrio Bacteria Are Associated With Parkinson's Disease

Parkinson's disease (PD) is the most prevalent movement disorder known and predominantly affects the elderly. It is a progressive neurodegenerative disease wherein alpha-synuclein, a neuronal protein, aggregates to form toxic structures in nerve cells. The cause of Parkinson's disease (PD) remains unknown. Intestinal dysfunction and changes in the gut microbiota, common symptoms of PD, are evidently linked to the pathogenesis of PD. Although a multitude of studies have investigated microbial etiologies of PD, the microbial role in disease progression remains unclear. Here, we show that Gram-negative sulfate-reducing bacteria of the genus Desulfovibrio may play a potential role in the development of PD. Conventional and quantitative real-time PCR analysis of feces from twenty PD patients and twenty healthy controls revealed that all PD patients harbored Desulfovibrio bacteria in their gut microbiota and these bacteria were present at higher levels in PD patients than in healthy controls. Additionally, the concentration of Desulfovibrio species correlated with the severity of PD. Desulfovibrio bacteria produce hydrogen sulfide and lipopolysaccharide, and several strains synthesize magnetite, all of which likely induce the oligomerization and aggregation of alpha-synuclein protein. The substances originating from Desulfovibrio bacteria likely take part in pathogenesis of PD. These findings may open new avenues for the treatment of PD and the identification of people at risk for developing PD.Peer reviewe