Influence of a combination of two potential probiotic strains, Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® on bowel habits of healthy adults

Aims: This study aims to investigate the effect of different kinds of food products enriched with a combination of two potential probiotic strains, Lactobacillus rhamnosus IMC 501^® and Lactobacillus paracasei IMC 502^®, on bowel habits of healthy adults. Methods and Results: Fifty healthy volunteers took part in a double‐blind placebo probiotic feeding study (25 fed probiotics, 25 fed placebo) for 12 weeks. Each volunteer ingested daily one or more food products enriched with a combination of the two potential probiotic strains (probiotic group) or the same food products without the probiotics (control group). Faecal samples were collected before, at the end and 2 weeks later the intervention period, and some of the main groups of faecal bacteria were enumerated by plate count and real‐time PCR. Questionnaires on bowel habits were submitted to volunteers. After the intervention, a significant increase in faecal lactobacilli and bifidobacteria were observed in the probiotic group, and stool frequency and stool volume were higher in the probiotic group than in the placebo group. Conclusions: Daily consumption of food products enriched with the two potential probiotic strains, Lact. rhamnosus IMC 501^® and Lact. paracasei IMC 502^®, contributes to improve intestinal microbiota with beneficial properties and enhances bowel habits of healthy adults. Significance and Impact of the Study: The study revealed that Lact. rhamnosus IMC 501^® and Lact. paracasei IMC 502^® exert a positive effect, in terms of improved bowel habits, on healthy adults.     

The effects of grazing depend on productivity,and what else?

In this issue of the Journal of Vegetation Science, Lezama et al. confirm the hypothesis that the effects of grazing increase with productivity, based on data from steppes and prairies in Argentina and Uruguay. Their study can serve as a starting point for further studies addressing questions on the mechanisms behind vegetation dynamics in grassland, emphasizing the need for experimental studies over larger climatic gradients.     

Cloning,expression and some properties of α-carbonic anhydrase from Helicobacter pylori

The α-carbonic anhydrase gene from Helicobacter pylori strain 26695 has been cloned and sequenced. The full-length protein appears to be toxic to Escherichia coli, so we prepared a modified form of the gene lacking a part that presumably encodes a cleavable signal peptide. This truncated gene could be expressed in E. coli yielding an active enzyme comprising 229 amino acid residues. The amino acid sequence shows 36% identity with that of the enzyme from Neisseria gonorrhoeae and 28% with that of human carbonic anhydrase II. The H. pylori enzyme was purified by sulfonamide affinity chromatography and its circular dichroism spectrum and denaturation profile in guanidine hydrochloride have been measured. Kinetic parameters for CO₂ hydration catalyzed by the H. pylori enzyme at pH 8.9 and 25°C are k_cat=2.4×10⁵ s⁻¹, K_M=17 mM and k_cat/K_M=1.4×10⁷ M⁻¹ s⁻¹. The pH dependence of k_cat/K_M fits with a simple titration curve with pK_a=7.5. Thiocyanate yields an uncompetitive inhibition pattern at pH 9 indicating that the maximal rate of CO₂ hydration is limited by proton transfer between a zinc-bound water molecule and the reaction medium in analogy to other forms of the enzyme. The 4-nitrophenyl acetate hydrolase activity of the H. pylori enzyme is quite low with an apparent catalytic second-order rate constant, k_enz, of 24 M⁻¹ s⁻¹ at pH 8.8 and 25°C. However, with 2-nitrophenyl acetate as substrate a k_enz value of 665 M⁻¹ s⁻¹ was obtained under similar conditions.     

Bibliometric analysis of Helicobacter pylori resistance—from 2002 to 2022

Background

Drug resistance in Helicobacter pylori severely affects the efficacy of eradication therapy, and a number of studies have been conducted on this issue. The aim of this study was to assess the progress in this field using a bibliometric approach.

Materials and Methods

Publications related to H. pylori resistance from 2002 to 2022 were retrieved from the Web of Science database. Relevant information including titles, authors, countries, and keywords was extracted, and the data were processed using Excel, VOSviewer, and CiteSpace software for co-authorship, co-citation, and co-occurrence analysis.

Results

From 2002 to 2022 (as of 09/24/2022), the field of H. pylori–resistance research produced a total of 2677 publications with a total of 75217 citations, with an overall upward trend in the annual number of articles published, reaching a peak of 204 in 2019. Articles were mainly published in Q1 or Q2 journals, with Helicobacter (TP = 261) publishing the most literature, Baylor College of Medicine (TP = 68) and Deng-chyang wu (TP = 38) being the most prolific institutions and authors, respectively. China and the United States were the locations of most of the articles, accounting for 35.08% of the global publication volume. Keyword co-occurrence analysis divided H. pylori-resistance research into four clusters: “Therapeutic Strategies,” “Diseases,” “Mechanism Research and Epidemiology,” and “Drug Research.” “Drug research” and burst detection indicate that the current research hotspot involves the selection and analysis of treatment strategies.

Conclusions

H. pylori–resistance research has become a popular research field, and although there are significant contributions from Europe, the United States, and East Asia, there are significant imbalances between regions that cannot be ignored. In addition, the exploration of treatment strategies remains a key issue for research at the current stage.     

The first 5 years of Helicobacter pylori research—With an emphasis on the United Kingdom

In the 1970s, 1% of the UK population consulted with dyspepsia; fiberoptic gastroscopy allowed biopsy specimens under direct vision enabling systematic histopathology. Steer et al described clusters of flagellated bacteria closely apposed to the gastric epithelium associated with chronic active gastritis. The first UK series of Helicobacter pylori following Marshall's 1983 visit to Worcester confirmed the association of H. pylori with gastritis. UK researchers completed much early helicobacter research as there were many UK campylobacteriologists. Steer and Newell proved the Campylobacter-like organisms grown on culture were the same as those seen in the gastric mucosa using antiserum raised by inoculating rabbits with H. pylori from cultures. Wyatt, Rathbone, and others showed a strong correlation between the number of organisms, type and severity of acute gastritis, immunological response, and bacterial adhesion similar to enteropathogenic E coli. Seroprevalence studies indicated H. pylori increased with age. Histopathologists also showed peptic duodenitis was in effect “gastritis in the duodenum” caused by H. pylori, unifying its role in the pathogenesis of both gastritis and duodenal ulceration. These bacteria were initially called Campylobacter pyloridis and then C. pylori. However, electron microscopy suggested that the bacteria were not campylobacters, and this was supported by differences in fatty acid and polyacrylamide electrophoresis profiles. In-vitro tests indicated that H. pylori was susceptible to penicillins, erythromycin, and quinolones, but not trimethoprim or cefsulodin allowing development of selective media for culture. Monotherapy with erythromycin ethylsuccinate was ineffective, and patients treated with bismuth subsalicylate initially responded with clearance of H. pylori and the associated gastritis, but then many relapsed. Thus, pharmacokinetic and treatment studies were important to direct suitable dual and triple treatments. Work optimized serology, and the rapid biopsy urease and urea breath tests. The link between H.pylori and gastric cancer was established in large seroprevalence studies, and H. pylori test and treat for dyspepsia became routine.     

Anti-inflammatory and anti-catabolic effects of TENDOACTIVE® on human tenocytes in vitro

Tendons have a limited capacity for self-repair due to the low density and mitotic activity of tenocytes. Pro-inflammatory cytokines such as interleukin-1β (IL-1β) have been identified as the main initiators of tendinopathies, stimulating inflammation, apoptosis and extracellular matrix (ECM) degradation. The aim of this study was to evaluate the potential of Tendoactive?, a newly developed proprietary nutraceutical formulation that includes mucopolysaccharides, collagen and vitamin C, in an in vitro model of tendon inflammation. The effects of Tendoactive? were studied in primary cultures of human tenocytes treated with IL-1β for up to 72 h. Expression of collagen type I, integrin β1, cyclo-oxygenase-2 (COX-2), caspase-3 and matrix metalloproteinase-1 (MMP-1) was monitored by western blotting. The effects of Tendoactive? on the expression, phosphorylation and nuclear translocation of protein components of the NF-κB system were studied by western blotting and immunofluorescence respectively. Treatment of tenocytes with Tendoactive? suppressed IL-1β-induced NF-κB activation and p65 nuclear translocation. These events correlated with down-regulation of NF-κB targets including COX-2, MMP-1 and activated caspase-3. Tendoactive? also reversed the IL-1β-induced down-regulation of collagen type I and β1-integrin receptor expression. These results indicate that Tendoactive? has nutraceutical potential as an anti-inflammatory agent for treating tendinopathy through suppression of NF-κB mediated IL-1β catabolic signalling pathways in tenocytes.     

Comparable Effects of Low-intensity Electromagnetic Irradiation at the Frequency of 51.8 and 53 GHz and Antibiotic Ceftazidime on Lactobacillus acidophilus Growth and Survival

The effects of low-intensity electromagnetic irradiation (EMI) with the frequencies of 51.8 and 53 GHz on Lactobacillus acidophilus growth and survival were revealed. These effects were compared with antibacterial effects of antibiotic ceftazidime. Decrease in bacterial growth rate by EMI was comparable with the inhibitory effect of ceftazidime (minimal inhibitory concentration—16 μM) and no enhanced action was observed with combined effects of EMI and the antibiotic. However, EMI-enhanced antibiotic inhibitory effect on bacterial survival. The kinetics of the bacterial suspension oxidation–reduction potential up to 24 h of the growth was changed by EMI and ceftazidime. The changes were more strongly expressed by combined effects of EMI and antibiotic especially up to 12 h. Moreover, EMI did not change overall energy (glucose)-dependent H⁺ efflux across the membrane but it increased N,N′-dicyclohexylcarbodiimide (DCCD)-inhibited H⁺ efflux. In contrast, this EMI in combination with ceftazidime decreased DCCD-sensitive H⁺ efflux. Low-intensity EMI had inhibitory effect on L. acidophilus bacterial growth and survival. The effect on bacterial survival was more significant in the combination with ceftazidime. The H⁺-translocating F ₀ F ₁-ATPase, for which DCCD is specific inhibitor, might be a target for EMI and ceftazidime. The revealed bactericide effects on L. acidophilus can be applied in biotechnology, food producing and safety technology.     

The relative efficiency of ‘swing through’ gait on axillary,elbow and Canadian crutches compared to normal walking

The subjective impression of many patients using ‘swing through’ gait, in which the body is swung over the crutches with both feet clear of the ground, is that elbow crutches are less stable and more difficult to use than conventional underarm crutches (known as axillary crutches). A study was undertaken on ten normal subjects to see if objective measurements of speed and relative energy expenditure by means of heart rate monitoring via radio telemetry could confirm these impressions when both types of crutch were compared to normal walking. The results unexpectedly showed that heart rates were higher for axillary crutches, even though all subjects considered them easier to use than elbow crutches. The increase in heart rate using axillary crutches requires further study, but it was considered that it might in part be due to pressure on the thoracic cage. Because of this, Canadian crutches, which are a compromise between the two former types and do not bear on the thorax, were similarly monitored. Results from this third trial showed a marked decrease in heart rate with a marginal increase in speed over both axillary and elbow crutches. Because of this a recommendation is made for Canadian crutches to be used more frequently.     

Arginine in α-defensins: differential effects on bactericidal activity correspond to geometry of membrane curvature generation and peptide-lipid phase behavior

The conserved tridisulfide array of the α-defensin family imposes a common triple-stranded β-sheet topology on peptides that may have highly diverse primary structures, resulting in differential outcomes after targeted mutagenesis. In mouse cryptdin-4 (Crp4) and rhesus myeloid α-defensin-4 (RMAD4), complete substitutions of Arg with Lys affect bactericidal peptide activity very differently. Lys-for-Arg mutagenesis attenuates Crp4, but RMAD4 activity remains mostly unchanged. Here, we show that the differential biological effect of Lys-for-Arg replacements can be understood by the distinct phase behavior of the experimental peptide-lipid system. In Crp4, small-angle x-ray scattering analyses showed that Arg-to-Lys replacements shifted the induced nanoporous phases to a different range of lipid compositions compared with the Arg-rich native peptide, consistent with the attenuation of bactericidal activity by Lys-for-Arg mutations. In contrast, such phases generated by RMAD4 were largely unchanged. The concordance between small-angle x-ray scattering measurements and biological activity provides evidence that specific types of α-defensin-induced membrane curvature-generating tendencies correspond directly to bactericidal activity via membrane destabilization.     

The Benefits of Ambiol® in Promoting Germination, Growth, and Drought Tolerance can be Passed on to Next-Generation Tomato Seedlings

Seed preconditioning with Ambiol^® has been shown to improve germination, growth, and drought tolerance in seedlings of many species. Attempts to understand the mode of action of Ambiol have found that seed preconditioning triggers several new proteins, which suggests that Ambiol-induced benefits may persist beyond seedlings and, perhaps, into the next generation. Seeds were preconditioned with 0 and 10 mg l^?1 Ambiol to determine effects on germination, seedling growth, and yield of parent tomato plants. Seeds were collected from plants in each treatment and then sown to determine effects on germination and seedling growth in the next generation. Key parameters such as percent germination, leaf area, shoot mass, root mass, and photosynthesis were significantly improved in parents and in progeny. In addition, there was a 141% increase in tomato yield in preconditioned parents. It was concluded that Ambiol-induced benefits continue throughout plant development and into the next generation, potentially having significant horticultural and economic ramifications.     

Tigers and Telazol®: The Unintended Evolution of Caution to Contraindication

Abstract: Scientific writing depends on citing accurate sources. There can be real-world consequences for failing to do so. As an example, several authors have stated that tiletamine-zolazepam (Telazol®) is contraindicated for tiger (Panthera tigris) immobilization. This admonition has virtually evolved into dogma in the field of wildlife chemical immobilization and was recently used to challenge field research. However, a literature review revealed that no author cited the primary reference that raised concern about the use of Telazol in tigers. We conducted an internet-based inquiry of zoo veterinarians combined with personal communications and other field reports to gather data on the use of Telazol in tigers. These data indicated that the mortality rate (1.3%) of tigers given Telazol was similar to other immobilization regimens in other species, which suggested that, although adverse reactions may still occur, tiletamine-zolazepam should not be contraindicated in tigers. This investigation emphasized the need to conduct thorough literature reviews before making unsubstantiated claims.     

The quest for a vaccine against Helicobacter pylori: how to move from mouse to man?

Several lines of evidence from experimental animal models of infection have clearly demonstrated the feasibility of a prophylactic and therapeutic vaccine against Helicobacter pylori. However, comparatively few clinical studies have been carried out to evaluate whether the positive results obtained in animals can be reproduced in humans. The preliminary results obtained with single component, mucosally delivered vaccines have shown very limited results thus far. Very good immunogenicity and safety profiles are now being obtained with parenterally delivered, aluminium hydroxide-adjuvanted multicomponent candidate vaccines. For sure, better vaccine formulations, better antigen preparation(s), better adjuvants, and better delivery systems have to be designed and tested for safety and immunogenicity. These studies are also needed for deciphering those aspects of the effector immune responses that correlate with protection against H. pylori infection and disease.     

Early vaccination with Improvac®: effects on performance and behaviour of male pigs

The aim of this study was to investigate the effect of giving a two-dose regimen of gonadotropin-releasing hormone vaccine, Improvac® (Pfizer Ltd), earlier than currently recommended, on performance and behaviour of growing/finishing pigs. Cross-bred male pigs (n = 192) were randomly allocated, within a litter, into four groups at birth: one group of pigs surgically castrated without anaesthesia before one week of age, a second group of early vaccinated pigs given Improvac at 10 and 14 weeks of age, a third group of standard vaccinated pigs given Improvac at 16 and 20 weeks of age, so that the second vaccination was given 4 to 6 weeks before slaughter as recommended by the manufacturer, and a fourth group of entire male pigs. The experiment started when the pigs were 12 weeks old and lasted until 25 weeks of age, when the pigs were slaughtered. The pigs were fed restrictedly. Daily weight gain and feed conversion during the entire raising period did not differ significantly between groups. Estimated lean meat content of early vaccinated and surgically castrated pigs was lower when compared with entire male pigs, whereas standard vaccinated pigs did not differ from entire males. Dressing percentage was higher in early vaccinated and surgically castrated pigs than in standard vaccinated and entire male pigs, partly because of lower size and weight of reproductive organs. For both groups of vaccinated pigs, both problematic and non-problematic behaviours decreased after their second injection, from the levels of entire males to those of surgically castrated pigs. After the second injection, pigs of both vaccination groups performed no mountings, in contrast with entire male pigs of the same age. Skin lesions at slaughter were fewer and less severe for vaccinated pigs compared with entire male pigs. No difference in income per carcass was observed for surgically castrated or vaccinated pigs. However, for entire male pigs the income was lower, as the payment system in Sweden also takes into consideration the additional cost for boar taint analyses and reduced payment for tainted carcasses. Under our experimental conditions, early vaccination with Improvac can be used as an alternative to the recommended schedule to minimise problematic behaviour with unaffected profitability.     

The effects ofγ-irradiation on the hydration characteristics of DNA and polynucleotides

Summary The effects of-irradiation and changes in the macromolecular structure on the water proton resonance spectra observed in frozen and liquid solutions have been compared for the DNA and polynucleotide solutions, using H₂O or mixed H₂O/D₂O solvents. The results indicate that in order to obtain information concerning the role of hydration water in mediating the overall radiation damage, the NMR studies must be performed in the frozen state.Member of the Euratom biology division     

In vitro and in silico approaches to quantify the effects of the Mitraclip® system on mitral valve function

Mitraclip^® implantation is widely used as a valid alternative to conventional open-chest surgery in high-risk patients with severe mitral valve (MV) regurgitation. Although effective in reducing mitral regurgitation (MR) in the majority of cases, the clip implantation produces a double-orifice area that can result in altered MV biomechanics, particularly in term of hemodynamics and mechanical stress distribution on the leaflets.In this scenario, we combined the consistency of in vitro experimental platforms with the versatility of numerical simulations to investigate clip impact on MV functioning. The fluid dynamic determinants of the procedure were experimentally investigated under different working conditions (from 40 bpm to 100 bpm of simulated heart rate) on six swine hearts; subsequently, fluid dynamic data served as realistic boundary conditions in a computational framework able to quantitatively assess the post-procedural MV biomechanics. The finite element model of a human mitral valve featuring an isolated posterior leaflet prolapse was reconstructed from cardiac magnetic resonance. A complete as well as a marginal, sub-optimal grasping of the leaflets were finally simulated.The clipping procedure resulted in a properly coapting valve from the geometrical perspective in all the simulated configurations. Symmetrical complete grasping resulted in symmetrical distribution of the mechanical stress, while uncomplete asymmetrical grasping resulted in higher stress distribution, particularly on the prolapsing leaflet.This work pinpointed that the mechanical stress distribution following the clipping procedure is dependent on the cardiac hemodynamics and has a correlation with the proper execution of the grasping procedure, requiring accurate evaluation prior to clip delivery.