Lacticaseibacillus rhamnosus GG DSM 33156 effects on pathogen defence in the upper respiratory tract: a randomised, double-blind, placebo-controlled paediatric trial.

Acute upper respiratory tract infections (URTIs) are caused by numerous viruses and bacteria. URTIs can be a cause of morbidity and are among the most common reasons for visiting healthcare practitioners and prescribing antibiotics to children in addition to causing absenteeism from school and work. Oral intake of Lacticaseibacillus rhamnosus GG DSM 33156 has shown beneficial health effects in several clinical trials, primarily relating to immune function and gastrointestinal health in children and adults. It has also been suggested that oral intake of L. rhamnosus GG DSM 33156 can reduce the incidence rate and alleviate symptoms of URTIs in children. We here report the results of a randomised, double-blind, placebo-controlled trial of 619 children aged 2-6 years conducted at a single centre in Scotland. The children, who were in day care or primary school, were followed over a 16-week intervention period with 309 randomised in the active group and 310 in the placebo group. The parents or guardians reported a daily healthcare status and any presumed episodes of URTI, which were subsequently confirmed by a general practitioner. The investigational product was well tolerated in the trial. Although a general trend towards a beneficial effect was observed, this trial did not demonstrate that L. rhamnosus GG DSM 33156 significantly reduced the incidence of URTIs, diagnosed by a general practitioner according to prespecified criteria (primary endpoint). Moreover, none of the secondary efficacy endpoints were met. Applying a Ward's hierarchical clustering, two separate clusters, focussing on four quality of life-related endpoints, were identified. Cluster 1 was associated with more severe URTI characteristics than cluster 2. Cluster 2 was significantly enriched with children who consumed the product, indicating that the symptoms children experience during an URTI are alleviated by the intake of L. rhamnosus GG DSM 33156. The study is registered at ClinicalTrials.gov ID: NCT03636191.

The glucose-dependent transport of L-malate in Zygosaccharomyces bailii.

Zygosaccharomyces bailii possesses a constitutive malic enzyme, but only small amounts of malate are decomposed when the cells ferment fructose. Cells growing anaerobically on glucose (glucose cells) decompose malate, whereas fructose cells do not. Only glucose cells show an increase in the intracellular concentration of malate when suspended in a malate-containing solution. The transport system for malate is induced by glucose, but it is repressed by fructose. The synthesis of this transport system is inhibited by cycloheximide. Of the two enantiomers L-malate is transported preferentially. The transport of malate by induced cells is not only inhibited by addition of fructose but also inactivated. This inactivation is independent of the presence of cycloheximide. The transport of malate is inhibited by uranyl ions; various other inhibitors of transport and phosphorylation were of little influence. It is assumed that the inducible protein carrier for malate operates by facilitated diffusion. Fructose cells of Z. bailii and cells of Saccharomyces cerevisiae do not contain a transport system for malate.

Axonal transport and transcellular transfer of nucleosides and polyamines in intact and regenerating optic nerves of goldfish: speculation on the axonal regulation of periaxonal cell metabolism.

The axonal transport, metabolism, and transcellular transfer of uridine, adenosine, putrescine, and spermidine have been examined in intact and regenerating optic nerves of goldfish. Following intraocular injection of labeled nucleosides, axonal transport was determined by comparing left-right differences in tectal radioactivity, and transcellular transfer was indicated by light autoradiographic analysis. The results demonstrated axonal transport, transcellular transfer, and periaxonal cell utilization of both nucleosides in intact axons and severalfold increases of all of these processes in regenerating axons. Experiments in which the metabolism of the nucleosides was studied resulted in data which suggested that uridine and adenosine, when delivered to the tectum by axonal transport, are protected from degradation and thus are relatively more available for periaxonal cell utilization than nucleosides reaching these cells via the blood. In intact axons, the majority of the nonmetabolized radioactivity was present as UMP, UDP, and UTP following [3H]uridine injections, whereas the majority of the radioactivity following [3H]adenosine injections was present as adenosine, with the phosphorylated derivatives constituting a smaller proportion. During nerve regeneration, the relative proportion of nucleosides to nucleotides was reversed, with uridine being the principal labeled compound in the first case, and AMP, ADP, and ATP being the major labeled compounds in the latter case. The nucleosides also were found to be different from each other in that adenosine, but not uridine, can be taken up by optic axons and transported retrogradely from the tectum to retinal ganglion cell bodies in the eye. Following intraocular injection of [3H]spermidine, radioactivity was transported to the optic tectum and transferred to tectal cells in the vicinity of the regenerating axons. Following [3H]putrescine injections, silver grains were found over periaxonal glia, but preliminary findings suggest that they are not present over tectal neurons nor over radial glial cells in the periependymal layers. Analysis of tectal radioactivity showed in each case that it was composed primarily of the injected compounds. These studies indicate that, following axonal transport, the polyamines do not remain within regenerating axons but are transferred to cells surrounding the axon. On the basis of these and previous findings, we speculate that the axonal transport and transcellular transfer of uridine, adenosine, polyamines, and perhaps other small molecules are means of communication between axons and periaxonal cells; that the axon can affect RNA and protein synthesis in periaxonal cells by regulating the availability of these small molecules; and that, during nerve regeneration, the increased metabolic needs of periaxonal cells are met by an increased axonal supply of precursors (adenosine and uridine) and other molecules (polyamines) critical for protein synthesis.