Body mass change and ultraendurance performance: a decrease in body mass is associated with an increased running speed in male 100-km ultramarathoners

We investigated, in 50 recreational male ultrarunners, the changes in body mass, selected hematological and urine parameters, and fluid intake during a 100-km ultramarathon. The athletes lost (mean and SD) 2.6 (1.8) % in body mass (p < 0.0001). Running speed was significantly and negatively related to the change in body mass (p < 0.05). Serum sodium concentration ([Na?]) and the concentration of aldosterone increased with increasing loss in body mass (p < 0.05). Urine-specific gravity increased (p < 0.0001). The change in body mass was significantly and negatively related to postrace serum [Na?] (p < 0.05). Fluid intake was significantly and positively related to both running speed (r = 0.33, p = 0.0182) and the change in body mass (r = 0.44, p = 0.0014) and significantly and negatively to both postrace serum [Na?] (r = -0.42, p = 0.0022) and the change in serum [Na?] (r = -0.38, p = 0.0072). This field study showed that recreational, male, 100-km ultramarathoners dehydrated as evidenced by the decrease in >2 % body mass and the increase in urine-specific gravity. Race performance, however, was not impaired because of the loss in body mass. In contrast, faster athletes lost more body mass compared with slower athletes while also drinking more. The concept that a loss of >2% in body mass leads to dehydration and consequently impairs endurance performance must be questioned for ultraendurance athletes competing in the field. For practical applications, a loss in body mass during a 100-km ultramarathon was associated with a faster running speed.     

Production of canine mesenchymal stem cells from adipose tissue and their application in dogs with chronic osteoarthritis of the humeroradial joints

Autologous AD-MSC [adipose-derived MSC (mesenchymal stem cell)] therapy involves harvesting fat from the patient by isolating the stem and regenerative cells and administering the cells back to the patient. This study evaluated the production of canine AD-MSCs and their possible application in cellular therapy for dogs. To assess whether cellular therapy can replace drug therapy, the clinical effect of a single intra-articular injection of AD-MSCs was evaluated on 4 dogs with lameness associated with OA (osteoarthritis) of the humeroradial joints. MSCs were readily isolated from adult dog adipose tissue, and their ability to form colony and differentiate into various phenotypes was confirmed. AD-MSCs expressed OCT4, NANOG and SOX2 at the mRNA level, pluripotency markers usually ascribed to embryonic stem cells. The results suggest the stemness of the cells isolated from canine fat, and good quality control made them available for both experimental and clinical use. Follow-up studies to evaluate the effects of AD-MSC therapy showed that OA of the elbow joints improved with time, indicating significant potential for clinical use in the treatment of lameness, particularly when administered before the injury becomes severe.     

An in vitro evaluation of the effect of probiotics and prebiotics on the metabolic profile of human microbiota

In the current study, batch culture fermentations on fecal samples of 3 healthy individuals were performed to assess the effect of the addition of prebiotics (FOS), probiotics (Bifidobacterium longum Bar33 and Lactobacillus helveticus Bar13) and synbiotics (B. longum Bar33 + L. helveticus Bar13 + FOS) on the fecal metabolic profiles. A total of 84 different metabolites belonging to the families of sulfur compounds, nitrogen compounds, aldehydes, ketones, esters, alcohols, phenols, organic acids, and hydrocarbons were detected by GC-MS/SPME analysis. The highest number of metabolites varied in concentration in the models with added FOS and synbiotics, where several metabolic signatures were found in common. The increase of butyrate represented the greatest variation registered after the addition of FOS alone. Following the B. longum Bar33 addition, 2-methyl butyrate underwent the most evident variation. In the batch fermentation with added L. helveticus Bar13, the decrease of pyridine and butandiene was observed together with the increase of 2-methyl-5-ethyl-pyrazine, 2-butanone and butyrate. The modification of the fecal metabolic profiles induced by the simultaneous addition of B. longum Bar33 and L. helveticus Bar13 was very similar to that observed after the supplementation with L. helveticus Bar13, regarding mainly the decrease of pyridine and the increase of butyrate.     

DNA Damage and Repair Biomarkers in Cervical Cancer Patients Treated with Neoadjuvant Chemotherapy: An Exploratory Analysis

Cervical cancer cells commonly harbour a defective G₁/S checkpoint owing to the interaction of viral oncoproteins with p53 and retinoblastoma protein. The activation of the G₂/M checkpoint may thus become essential for protecting cancer cells from genotoxic insults, such as chemotherapy. In 52 cervical cancer patients treated with neoadjuvant chemotherapy, we investigated whether the levels of phosphorylated Wee1 (pWee1), a key G₂/M checkpoint kinase, and γ-H2AX, a marker of DNA double-strand breaks, discriminated between patients with a pathological complete response (pCR) and those with residual disease. We also tested the association between pWee1 and phosphorylated Chk1 (pChk1), a kinase acting upstream Wee1 in the G₂/M checkpoint pathway. pWee1, γ-H2AX and pChk1 were retrospectively assessed in diagnostic biopsies by immunohistochemistry. The degrees of pWee1 and pChk1 expression were defined using three different classification methods, i.e., staining intensity, Allred score, and a multiplicative score. γ-H2AX was analyzed both as continuous and categorical variable. Irrespective of the classification used, elevated levels of pWee1 and γ-H2AX were significantly associated with a lower rate of pCR. In univariate and multivariate analyses, pWee1 and γ-H2AX were both associated with reduced pCR. Internal validation conducted through a re-sampling without replacement procedure confirmed the robustness of the multivariate model. Finally, we found a significant association between pWee1 and pChk1. The message conveyed by the present analysis is that biomarkers of DNA damage and repair may predict the efficacy of neoadjuvant chemotherapy in cervical cancer. Further studies are warranted to prospectively validate these encouraging findings.     

Biocatalytic, Enantioselective Preparations of (R)- and (S)-Ethyl 4-Chloro-3-Hydroxybutanoate, a Useful Chiral Synthon

The synthesis of optically active ethyl 4-chloro-3-X-butanoate derivatives la-d (X = OH, a; OCOCH₃, b; OCOC₃H₇, c; OCH₂C₆H₅, d) was realized using various biocatalytic approaches such as microbiological reduction of ethyl 4-chloro-3-oxobutanoate 2 with lactic acid bacteria, hydrolysis of lb-d by the hydrolytic enzymes PLE and BChE and the transesterification of la catalyzed by a lipase from Pseudomonas fluorescens (PFL).     

Analysis of the Salmonella fim gene cluster: Identification of a new gene (fimI) encoding a fimbrin-like protein and located downstream from the fimA gene

Abstract The fimA gene coding for the major component (fimbrin) of type 1 fimbriae was mapped within the Salmonella typhi fim gene cluster, and its nucleotide sequence determined. The deduced amino acid sequence of S. typhi fimbrin is highly homologous to that of S. typhimurium type 1 fimbrin and showed similarity to that of other enterobacterial type 1 fimbrins. Downstream of fimA , an open reading frame was found, named fimI , able to encode a fimbrin-like protein. The fimI product could represent the counterpart, in type 1 fimbriae, of the PapH protein involved in cell anchoring and length modulation of Escherichia coli Pap pili. This genetic organization was found to be common to other Salmonella serovars, including S. typhimurium and S. choleraesuis .     

Polymorphism detection among wild Saccharomyces cerevisiae strains of different wine origin

In this study, wild Saccharomyces cerevisiae strains, isolated from spontaneously fermenting grapes of different varieties and origins, were submitted to genetic analysis using different molecular techniques, such as amplification of genes coding for cell wall proteins and containing minisatellite-like sequences, karyotyping, mtDNA-RFLP, and analysis of the δ region. The lowest discriminative power was obtained by minisatellites analysis, in particular the amplification of AGA1 genes. Karyotyping and mtDNA-RFLP analysis yielded the same differentiation among the strains, whereas the PCR amplification of δ sequences resulted the best method as it was fast and it showed a very high discriminative power. In any case, it has to be underlined that some strains, showing the same delta profiles, exhibited a different mtDNA restriction profile and electrophoretic karyotype, suggesting that more than one molecular marker is required for reliable strain discrimination. Although the techniques used revealed a different resolution power, they all revealed a genetic relationship among strains isolated from spontaneous fermentation of grapes of different origins. In fact, none of the typing methods was able to discriminate some strains isolated from different areas.     

Mechanisms of block of muscle type CLC chloride channels (Review)

CLC proteins are a nine-member gene family of Cl - channels that have diverse roles in the plasma membrane and in intracellular organelles. The recent structure determination of bacterial CLC homologues by Dutzler et al. was a break-through for the structure-function analysis of CLC channels. This review describes the mechanisms of inhibition of muscle type CLC channels by two classes of small organic substances: 9-anthracene carboxylic acid (9AC) and p-chlorophenoxy propionic acid (CPP). Both substances block muscle type CLC channels (CLC-0 and CLC-1) from the intracellular side. For CPP, one could show that it inhibits the individual protopores of the double-barrelled channel. A major difference between the two types of blockers is the extremely slow binding- and unbinding-kinetics of 9AC (time scale of min), compared to that of CPP block (time scale of s), while the general mechanism of block seems to be quite similar. In the case of the chiral CPP only the S(-) enantiomer is effective. Both substances exhibit a strongly voltage-dependent block with strong inhibition at negative voltages and relief of block at depolarizing potentials at which the channels tend to open maximally. A quantitative kinetic model was developed for the CPP block of CLC-0 in which the closed state has a much larger affinity for CPP than the open state and opening of drug-bound channels is greatly slowed compared to drug-free channels. First experiments with mutated CLC-0 channels and with derivatives of CPP strongly support the pore localization of the CPP binding site. This work provides the basis for the use of these small organic substances as tools to investigate the pharmacological properties of mammalian CLC channels guided by the crystallographic structure of bacterial CLC homologues. They might also turn out to be useful to obtain information about the intricate coupling of gating and permeation that characterizes CLC channels.