LAC Group Research Articles

Laccase-loaded CaCO3 sustained-release microspheres modified SBES anode for enhance performance in the remediation of soil contaminated with phenanthrene and pyrene

This study aimed to enhance the efficiency of SBES in remediating polycyclic aromatic hydrocarbon (PAH)-contaminated soils by modifying the anode with laccase. The experiment involved four SBES anodes: a carbon nanotube-modified anode (CNT), a free laccase-modified anode (Lac), a gelatin-encapsulated laccase-modified anode (Lac-Gel), and a CaCO3 sustained-release microsphere-loaded laccase-modified (CaCO3-SMs@Laccase) anode (Lac-SMs). The CaCO3-SMs@Laccase notably extended the active period of laccase, with laccase activity in the Lac-SMs measured at 1.646 U/g after 16 days, which was significantly higher than the 0.813 U/g observed in the Lac-Gel group and the 0.206 U/g in the Lac group. The superior electricity generation and degradation efficiency observed in the Lac-SMs group were due to the sustained enzymatic activity provided by the CaCO3-SMs@Laccase. The prevention of anode acidification through CaCO3 decomposition, and promote the forward progress of electrochemical reactions. The phenanthrene (Phe) and pyrene (Pyr) removal efficiency in the soil of the Lac-SMs reached 90.78% and 84.72%, surpassing those of the Lac-Gel (80.36% and 79.14%), Lac (79.38% and 69.31%), and CNT (63.22% and 56.98%). The degradation pathway from Pyr to Phe was possible started with hydroxylation. In addition, the laccase also transformed the predominant microbial communities and metabolism pathways.

Bacterial Community Influences the Effects of Lactobacillus acidophilus on Lipid Metabolism, Immune Response, and Antioxidant Capacity in Dogs.

Lactobacillus acidophilus (L. acidophilus), the most prevalent probiotic, has demonstrated the ability to improve the relative abundance of intestinal microorganisms and boost immunity. However, the underlying mechanisms of these effects remain unclear. This study evaluated body weight, nutrient apparent digestibility, serum indices, and bacterial communities in Chinese rural dogs from a L. acidophilus supplementation group (Lactobacillus acidophilus, n = 6) and a control group (CON, n = 6). The results indicated that L. acidophilus had no significant impact on the body weight and apparent nutrient digestibility of Chinese rural dogs. In comparison with the CON group, L. acidophilus significantly reduced the levels of cholesterol (CHO) and increased the levels of IgA, IFN-α, and T-AOC. Bacterial diversity indices were significantly reduced in the LAC group compared to the CON groups, and MetaStat analysis demonstrated notable distinctions in 14 bacterial genera between the groups. These bacterial genera exhibited correlations with physiological indices such as CHO, IgA, IFN-α, and T-AOC. In conclusion, L. acidophilus can modulate lipid metabolism, immunity, and antioxidant capacity by regulating the relative abundance of specific bacterial communities, which helps dogs to adapt to today's lifestyle.

Effects of post-exercise intake of exogenous lactate on energy substrate utilization at rest.

This study investigated the effects of exogenous lactate intake on energy metabolism during 1 h of rest after acute exercise. Eight-week-old ICR mice were randomly divided into four groups: SED (no treatment), EXE (exercise only), LAC (post-exercise oral lactate administration), and SAL (post-exercise saline administration) (n=8 per group). The exercise intensity was at VO2max 80% at 25 m/min and 15° slope for 50 min. After acute exercise, the LAC and SAL groups ingested lactate and saline orally, respectively, and were allowed to rest in a chamber. Energy metabolism was measured for 1 h during the resting period. LAC and SAL group mice ingested lactate and saline, respectively, after exercise and the blood lactate concentration was measured 1 h later through tail blood sampling. Blood lactate concentration was not significantly different between the two groups. Energy metabolism measurements under stable conditions revealed that the respiratory exchange ratio in the LAC group was significantly lower than that in the SAL group. Additionally, carbohydrate oxidation in the LAC group was significantly lower than that in the SAL group at 10-25 min. No significant difference was observed in the fat oxidation level between the two groups. We found that post-exercise lactate intake modified the respiratory exchange ratio after 1 h of rest. In addition, acute lactate ingestion inhibits carbohydrate oxidation during the post-exercise recovery period.

Yuanzhi Powder inhibits tau pathology in SAMP8 mice: Mechanism research of a traditional Chinese formula against Alzheimer's disease.

Yuanzhi Powder (YZP), a classical Chinese medicine formula, is good at tonifying heart-Qi and improving cognitive ability. YZP has been reported to show therapeutic effect on alleviating the symptoms of Alzheimer's disease (AD). This study was conducted to observe the effects of YZP on improving the cognitive abilities of SAMP8 mice, and explore the involved mechanisms on inhibiting the excessive accumulation of phosphorylated tau. Thirty SAMP8 mice were randomly divided into five groups: AD group, AD+DO group, AD+YZP group, AD+LAC group and AD+LAC+YZP group. Age-matched SAMR1 mice were served as CTL group. AD+LAC group and AD+LAC+YZP group received 1μg Lactacystin solution via intra-cerebroventricular injection. All mice (except the CTL group and AD+LAC group) were intragastrically administrated for 8 consecutive weeks. Then, the Morris Water Maze (MWM) test was conducted for evaluation of learning and memory abilities. The pathological changes of hippocampal CA1 were observed by Hematoxylin & eosin (H&E) staining. The expression of 26S proteasome in the hippocampus was measured by Western Blot (WB) and immunohistochemistry (IHC). The expressions of total tau (Tau5) and hyperphosphorylated tau (pS199, pT231 and pS396) were detected by WB. The aggregation of hyperphosphorylated tau and the binding ability of tau protein to microtubules were evaluated respectively by immunostaining and Thioflavin-S staining and double-label immunofluorescence. SAMP8 mice showed serious cognitive impairment in behavioral tests. However, treatment of YZP significantly ameliorated the cognitive deficits of SAMP8 mice. The H&E staining suggested that YZP could protect against neuronal loss in SAMP8 mice. The IHC and WB results showed that YZP increases 26S proteasome expression in SAMP8 mice and 26S proteasome expression was effectively inhibited by Lactacystin. Meanwhile, The WB results demonstrated that YZP can inhibit the expression of hyperphosphorylated tau (pT231, pS396 and pS199). Furthermore, the immunostaining and Thioflavin-S staining and double-label immunofluorescence results indicated that YZP attenuates the excessive aggregation of hyperphosphorylated tau and enhances the binding ability of tau to stabilize microtubules in SAMP8 mice. YZP could enhance cognitive performance and learning of AD, ameliorate tau pathology and significantly improve the binding ability of tau to microtubules, based potentially on inhibiting the excessive aggregation of hyperphosphorylated tau via the 26Sproteasome pathway but not necessarily the only one.

Lactobacillus rhamnosus GG ATCC53103 and Lactobacillus plantarum JL01 improved nitrogen metabolism in weaned piglets by regulating the intestinal flora structure and portal vein metabolites.

At present, most studies have shown that probiotics have a positive regulatory effect on the nutritional metabolism of the body, but the mechanism is still unclear. Here, 48 piglets were divided into four groups. The control group was not fed probiotics, the Lac group was fed L. Rhamnosus GG ATCC53103, the Rha group was fed L. Plantarum JL01, and the mix group was fed two types of probiotics. Nitrogen metabolism and mRNA levels of mTOR and S6K in skeletal muscle were observed in each group. Then, metagenome and non-targeted metabonomics were used to observe the changes of intestinal microorganisms and plasma metabolites in portal channels after probiotics feeding. Finally, we combined the results of omics analysis to reveal the mechanism of probiotics on nitrogen metabolism in weaned piglets. The results showed that L. Rhmnosus GG ATCC53103 and L. Plantarum JL01 increased nitrogen apparent digestibility, nitrogen deposition rate, and nitrogen utilization rate of weaned piglets (P < 0.05); the relative expression of mTOR and SK6 mRNA in skeletal muscle increased significantly (P < 0.05). When L. rhamnosus GG ATCC53103 and L. plantarum JL01 were combined, we found that Clostridium and Prevotella significantly increased in the jejunum (P < 0.05). The relative abundance of Lactobacillus, Ruminococcus, Streptococcus, and Prevotella in the ileum increased significantly (P < 0.05). Compared with the control group, L-Tryptophan, 3-Phosphonyloxypyruvate, cis-Aconitate, and Carbamoyl phosphate were significantly increased in the mixed group portal vein. The result of the combinatorial analysis showed that the significantly increased microorganisms could encode the enzyme genes for the synthesis of L-Tryptophan, 3-Phosphonooxypyruvate, cis-Aconitate, and Carbamoyl phosphate. In summary, our results demonstrated that L. Rhamnosus GG ATCC53103 and L. Plantarum JL01 could stimulate the expression of skeletal muscle protein synthesis genes of weaned piglets by modulating the structure of the gut microbiota and its metabolites, thereby improving nitrogen metabolism in weaned piglets.

Lower adiponectin is associated with higher anthropometry and insulin resistance but not with low cardiorespiratory fitness in adolescents.

The aim of this study was to analyze the relationship between adiposity, cardiometabolic risk and cardiorespiratory fitness (CRF) according to different groups of adiponectin concentration. 255 adolescents of both sexes, aged 11-17years old, participated. Anthropometric and biochemical parameters such as body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass, fat-free mass, total cholesterol (TC), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), triglycerides (TG), glucose, insulin, adiponectin, blood pressure, peak oxygen consumption (VO2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), waist-to-height ratio (WHtR), homeostasis model to assessment insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were calculated. Adiponectin was categorized: low adiponectin concentration (LAC ≤ 5.18µg/mL-1), intermediate (IAC = 5.18 and 7.63µg/mL-1) and high (HAC ≥ 7.63µg/ml-1). LAC showed higher BMI, BMI-z and TMI than the other groups (p < 0.05) and higher AC, WC and WHtR that the HAC (p < 0.05). IAC showed lower values of TC, LDL-c and TG, and the LAC presented the highest values of insulin, HOMA-IR and QUICKI (p < 0.05) to the IAC and HAC. HAC presented the lower VO2peak than the other groups (p < 0.01). BMI, TMI, glucose, insulin, HOMA-IR showed inverse, and QUICKI a direct and weak correlation with adiponectin (p < 0.05). No significant association was found between adiponectin and VO2peak (p > 0.05). The LAC group had higher means in the anthropometric variables and the worst results related to insulin resistance and sensitivity. Thus, adiponectin may play an important role in obesity and reduced concentration may be a factor in the development of obesity-associated morbidities.

Inhibitory Effects of Lactulose on Enteric Bacterial Dynamics and Gut Permeability in Bile-Duct Ligated Rats

Background and Aim: The prebiotic potential of lactulose is well known, but its effect to inhibit enteric bacterial dynamics and gut permeability has not yet been investigated in experimental studies. The present study aims to assess the effects of lactulose on the enteric bacterial dynamics gut permeability in a model of bile duct ligation in Wistar rats. Methods: Wistar rats were assigned into 3 groups, the Sham-operated control, bile duct ligated (BDL) and BDL+ Lac group on the 28th day of bile duct ligation. Animals of BDL + Lac groups were treated with lactulose (1.0 g/kg), administrated by gavage, once a day for 7 days. Bacterial translocation into the organs and bacterial overgrowth as the indicators of the enteric bacterial dynamics and the levels of DAO and D-lactate as the biochemical makers of the gut permeability were measured in each group. Results: The bacterial colony forming units (CFU) in spleen and liver of BDL+Lac group was significantly decreased compared with BDL model group (P&lt;0.01) and significant decrease of bacterial CFU was seen in the intestinal lavage in BDL+Lac group compared to BDL group (P&lt;0.01). On the other hand, Lactulose revealed significant inhibitory effect as evidence by decreasing plasma DAO activity and D-lactate levels (P&lt;0.01) in this model. Conclusion: These results indicate that lactulose can inhibit the enteric bacterial overgrowth, bacterial translocation (BT) and increasing gut permeability by opening the mucosa tight junction in ductal obstruction and obviate even systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) induced by obstructive jaundice.

Isolation and identification of ligninolytic bacterium (Bacillus cereus) from buffalo (Bubalus bubalis) rumen and its effects on the fermentation quality, nutrient composition, and bacterial community of rape silage.

This study aimed to isolate and identify a ligninolytic bacterium from the rumen of buffalo (Bubalus bubalis) and investigate its effects as a silage additive for whole-plant rape. Three lignin-degradation strains were isolated from the buffalo rumen, with AH7-7 being chosen for further experiments. Strain AH7-7, with acid tolerance and a 51.4% survival rate at pH 4, was identified as Bacillus cereus. It exhibited a lignin-degradation rate of 20.5% after being inoculated in a lignin-degrading medium for 8 days. We divided the rape into four groups according to the various additive compositions to examine the fermentation quality, nutritional value, and bacterial community after ensiling: Bc group (inoculated with B. cereus AH7-7 3.0 × 106 CFU g FW-1), Blac group (inoculated with B. cereus AH7-7 1.0 × 106 CFU g FW-1, L. plantarum 1.0 × 106 CFU g FW-1, and L. buchneri 1.0 × 106 CFU g FW-1), Lac group (inoculated with L. plantarum 1.5 × 106 CFU g FW-1 and L. buchneri 1.5 × 106 CFU g FW-1), and Ctrl group (no additives). After 60 days of fermentation, the application of B. cereus AH7-7 was potent in modulating the fermentation quality of silage, especially when combined with L. plantarum and L. buchneri, as indicated by lower dry matter loss and higher contents of crude protein, water-soluble carbohydrate, and lactic acid. Furthermore, treatments with the B. cereus AH7-7 additive decreased the contents of acid detergent lignin, cellulose, and hemicellulose. The B. cereus AH7-7 additive treatments reduced the bacterial diversity and optimized the bacterial community compositions of silage, with an increase in the relative abundance of beneficial Lactobacillus and a decrease in the relative abundance of undesirable Pantoea and Erwinia. Functional prediction revealed that inoculation with B. cereus AH7-7 could increase the cofactors and vitamins metabolism, amino acid metabolism, translation, replication and repair, and nucleotide metabolism, while decreasing the carbohydrate metabolism, membrane transport, and energy metabolism. In brief, B. cereus AH7-7 improved the microbial community, fermentation activity, and ultimately the quality of silage. The ensiling with B. cereus AH7-7, L. plantarum, and L. buchneri combination is an effective and practical strategy to improve the fermentation and nutrition preservation of rape silage.

Efficacy of fermented grain using Bacillus coagulans in reducing visceral fat among people with obesity: a randomized controlled trial.

Obesity is a socioeconomic problem, and visceral obesity, in particular, is related to cardiovascular diseases or metabolic syndrome. Fermented grains and various microorganisms are known to help with anti-obesity effects and weight management. Studies on the relationship between Bacillus coagulans and anti-obesity effects are not well known, and studies on the application of fermented grains and microorganisms to the human body are also insufficient. This study aimed to evaluate the efficacy of Curezyme-LAC, an ingredient mixed with six-grain types fermented by B. coagulans, in reducing fat mass in adults with obesity. In this randomized double-blinded placebo-controlled study, 100 participants [aged 40-65 years; body mass index (BMI) ≥ 25 to ≤ 33 kg/m2) were randomly allocated to two groups: 4 g/day Curezyme-LAC administered as a granulated powder or placebo (steamed grain powder mixture). After 12 weeks, visceral adipose tissue decreased significantly in the Curezyme-LAC group compared with that in the placebo group (mean ± standard error, SE of -9.3 cm2 ± 5.1) vs. (6.8 cm2 ± 3.4; p = 0.008). Compared to the placebo group, the Curezyme-LAC group also showed significant reductions in total fat mass (-0.43 ± 0.24 kg vs. 0.31 ± 0.19 kg, p = 0.011), body weight (-0.4 ± 0.3 kg vs. 0.3 ± 0.2 kg, p = 0.021), BMI (-0.14 ± 0.12 vs. 0.10 ± 0.07, p = 0.028), and waist circumference (-0.6 ± 0.2 cm vs. -0.1 ± 0.2 cm, p = 0.018) without a change in dietary intake and physical activity. Curezyme-LAC supplementation for 12 weeks may benefit individuals with obesity by reducing visceral fat mass.

Effect of different surgical routes on pregnancy outcome of history-indicated cervical cerclage

ObjectiveTo study the guiding significance of medical history on laparoscopic and vaginal cervical cerclage in the treatment of cervical incompetence and its influence on pregnancy outcome.MethodsA total of 53 cases by laparoscopic abdominal cervical cerclage (LAC group) before pregnancy and 73 cases by transvaginal cervix cerclage (TVC group) at 12–14 weeks of pregnancy were collected. Multivariate logistic regression analysis was performed on the influencing factors of delivery gestational weeks. Furthermore, the gestational weeks after cervical cerclage were compared between the two groups with high- and low-risk grades.ResultsThe number of previous uterine cavity operations in LAC group was more than that TVC group, and the costs of operation were more than TVC group. At the same time, the hospitalization days and operation time were longer than those in TVC group, and the delivery rate of cesarean section was higher than TVC group, but the total hospitalization times were less than TVC group (P < 0.05). The rate of delivery before 34 weeks of pregnancy and the incidence of premature rupture of membranes or premature labor in LAC group were lower than those in TVC group (P < 0.05). In TVC group, the increased number of prior PTB or STL and the history of cervical cerclage failure would increase the risk of premature delivery before 34 weeks of pregnancy. There was no increased risk of preterm delivery before 34 weeks of pregnancy in LAC group (P > 0.05). According to the risk level, in the high-risk group, the delivery rate of LAC group at gestational weeks < 37 weeks, < 34 weeks and < 28 weeks was lower than that of TVC group.ConclusionLaparoscopic cervical cerclage might be more effective in preventing premature delivery before 34 weeks of gestation, and its influence on delivery gestational weeks was not affected by related medical history. For high-risk patients with the history of prior PTB or STL and failed cerclage, laparoscopic cervical cerclage might be more effective than vaginal cervical cerclage in preventing extremely preterm before 28 weeks, premature delivery before 34 weeks and premature delivery before 37 weeks. Therefore, our limited experience suggested that LAC can be a recommended option for patients with high-risk history.

Prognostic Value of Left Atrial Calcification After Catheter Ablation for Atrial Fibrillation

BackgroundLeft atrial calcification (LAC) has occasionally been observed in patients who underwent catheter ablation for atrial fibrillation (AF) by chest computed tomography (CT). However, the evidence regarding the clinical impact of LAC in patients with AF is lacking. ObjectivesThis study aims to investigate the prevalence of LAC in AF patients and evaluate its clinical significance after AF ablation. MethodsThis observational registry included AF patients who received computed tomography and serial transthoracic echocardiography between January 2010 and November 2017. The primary composite outcome included cardiovascular death, hospitalization for worsening heart failure, and ischemic stroke. ResultsAmong 534 patients (age 72 ± 13 years, 62.5% men) who met the inclusion criteria, 31 (5.8%) had LAC. In multivariable analysis, AF ablation was associated with an 11.8-fold (OR: 11.8; 95% CI: 2.03-227.65) increased risk of the development of LAC in AF patients. Among 218 patients with AF ablation, LAC was detected in 30 (13.8%) patients. Prior stroke (HR: 2.73; 95% CI: 1.08-6.93) and multiple ablation procedures (HR: 4.21; 95% CI: 1.63-10.87) were independently associated with the development of LAC in AF-ablation patients. During a median follow-up of 5.8 years, the primary composite outcome occurred in 11 patients in the LAC group (39.8 per 1,000 person-years) and 10 patients in the non-LAC group (8.9 per 1,000 person-years). The adjusted HR for the primary composite outcome in the LAC group, as compared with the non-LAC group, was 2.81 (95% CI: 1.16-6.84; P = 0.02). ConclusionsThe presence of LAC was a significant and independent prognostic factor for identifying major adverse cardiovascular events after AF ablation.

Lactate Mediates the Bone Anabolic Effect of High-Intensity Interval Training by Inducing Osteoblast Differentiation.

High-intensity interval training (HIIT) reportedly improves bone metabolism and increases bone mineral density (BMD). The purpose of the present study was to investigate whether lactate mediates the beneficial effects of exercise on BMD, bone microarchitecture, and biomechanical properties in an established osteoporotic animal model. In addition, we hypothesized that lactate-induced bone augmentation is achieved through enhanced osteoblast differentiation and mineralization. A total of 50 female C57BL/6 mice were randomly allocated into 5 groups: the nonovariectomized group, the ovariectomized group (OVX), the HIIT group (OVX + HIIT), the HIIT with lactate transporter inhibition group (OVX + HIIT + INH), and the lactate subcutaneous injection group (OVX + LAC). After 7 weeks of intervention, bone mass, bone strength, and bone formation/resorption processes were evaluated via microcomputed tomography (micro-CT), biomechanical testing, histological analysis, and serum biochemical assays; in vitro studies were performed to explore the bone anabolic effect of lactate at the cellular level. Micro-CT revealed significantly increased BMD in both the OVX + HIIT group (mean difference, 41.03 mg hydroxyapatite [HA]/cm 3 [95% CI, 2.51 to 79.54 mg HA/cm 3 ]; p = 0.029) and the OVX + LAC group (mean difference, 40.40 mg HA/cm 3 [95% CI, 4.08 to 76.71 mg HA/cm 3 ]; p = 0.031) compared with the OVX group. Biomechanical testing demonstrated significantly improved mechanical properties in those 2 groups. However, the beneficial effects of exercise on bone microstructure and biomechanics were largely abolished by blocking the lactate transporter. Notably, histological and biochemical results indicated that increased bone formation was responsible for the bone augmentation effects of HIIT and lactate. Cell culture studies showed a marked increase in the expression of osteoblastic markers with lactate treatment, which could be eliminated by blocking the lactate transporter. Lactate may have mediated the bone anabolic effect of HIIT in osteoporotic mice, which may have resulted from enhanced osteoblast differentiation and mineralization. Lactate may mediate the bone anabolic effect of HIIT and serve as a potential inexpensive therapeutic strategy for bone augmentation.

Impact of access to care and race/ethnicity on IVF care discontinuation

Research questionIs race/ethnicity or access to care, as defined by insurance coverage, distance to the clinic and zip code (postal code), associated with care discontinuation following IVF? DesignA retrospective cohort study of 878 diverse women who underwent 1571 IVF cycles from 2014 to 2018 at a Southeastern academic medical centre was performed. Women were divided into low (LAC) and high (HAC) access to care groups. HAC was defined as possessing IVF insurance coverage, living ≤25 miles from the clinic, and living in a zip code with a median income ≥$75,000. Access groups and racial/ethnic groups were compared for differences in relative risk of care discontinuation following an unsuccessful IVF cycle. ResultsWomen with HAC had a poorer IVF prognosis than the LAC group, which possibly impacted the association with care discontinuation. Distance to the clinic, but not insurance coverage or zip code, was associated with increased risk of care discontinuation. Among women ≤34 years, HAC showed some evidence of an association with an increased risk of care discontinuation (adjusted relative risk 2.5, 95% confidence interval 0.8–8.1). Despite having higher rates of insurance coverage (51.2% versus 36.5%), non-Hispanic Black women were more likely to discontinue care (58.3% versus 40.2%) and less likely to achieve a live birth (53.0% versus 68.0%) than non-Hispanic White women. ConclusionsIdentification as non-Hispanic Black, and distance to the clinic, but not insurance coverage or zip code, were associated with increased risk of care discontinuation following an unsuccessful IVF cycle. In women ≤34 years old, HAC may be associated with a higher rate of care discontinuation.

Combination Effect of Diurnal Exposure to Sucrose and Nocturnal Exposure to Lactose on Enamel Demineralization

We have hypothesized that the association between human milk and caries in breastfeeding children could be explained by the combination of a diurnal cariogenic diet with the nocturnal lactose fermentation, conditions simulated in this experimental study. Cariogenic biofilm was formed on bovine enamel slabs, which were exposed 8x/day for 3 min to a 10% sucrose solution, simulating a highly cariogenic diurnal diet, or 50 mM NaCl solution (control). Simulating the nocturnal retention of milk in mouth, biofilms were transferred to culture medium containing 0.7% lactose for 2 h, or only to culture medium (control). Four groups were designed (n = 12): Ctrl, no exposure to diurnal sucrose or nocturnal lactose; Lac, only nocturnal exposure to lactose (2 h); Suc, only diurnal exposure to sucrose (8x/day); and Suc→Lac, diurnal exposure to sucrose (8x/day) followed by nocturnal exposure to lactose (2 h). The medium was changed 3x/day, at the beginning of the day and after diurnal and nocturnal exposures. Calcium in the medium was determined as a chemical indicator of partial demineralizations occurred during the diurnal and the nocturnal treatments; the medium pH was also determined. After 96 h of growth, biofilms were harvested to evaluate CFU, biomass, and extracellular polysaccharides, soluble and insoluble. The percentage of enamel surface hardness loss (%SHL) was evaluated as cumulative demineralization. Data were analyzed by one-way ANOVA and Tukey’s test (α = 5%). Highest %SHL (p < 0.05) was found for the Suc→Lac (40.6%) group when compared to Suc (32.1%), Lac (6.6%), and Ctrl (2.4%) groups. Calcium released during the diurnal and nocturnal treatments was, respectively, Suc→Lac = Suc > Lac = Ctrl and Suc→Lac > Lac > Suc = Ctrl (p < 0.05). Regarding the Ctrl group, calcium released from nocturnal lactose fermentation by the Suc→Lac group was 4-fold greater than that provoked by the Lac group. The findings were supported by the pH of the media. The data suggest that the biofilm formed under diurnal exposure to sucrose enhances the cariogenicity of nocturnal exposure to lactose.

Lipidomics Identified Lyso-Phosphatidylcholine and Phosphatidylethanolamine as Potential Biomarkers for Diagnosis of Laryngeal Cancer.

BackgroundLaryngeal cancer (LaC) remains one of the most common tumors of the respiratory tract with higher incidence in men than in women. The larynx is a small but vital organ on the neck. The dysfunction of the larynx can cause serious health problems such as hoarseness, respiratory distress, and dysphonia. Many lipids (e.g. phospholipid, cholesterol, fatty acid) have been recognized as a crucial role in tumorigenesis. However, the lipid biomarkers are lacking and the lipid molecular pathogenesis of LaC is still unclear.MethodsThis study aims to identify new LaC-related lipid biomarkers used for the diagnosis or early diagnosis of LaC and to uncover their molecular characteristics. Thus, we conducted serum and tissue nontargeted lipidomics study from LaC patients (n = 29) and normal controls (NC) (n = 36) via ultra-high performance liquid chromatography (UHPLC) coupled with high resolution mass spectrometry (HRMS). Multivariate and univariate statistics analyses were used to discriminate LaC patients from NC.ResultsAs expected, a lipid panel including LPC (16:0) and PE (18:0p_20:4) was defined to distinguish the LaC patients from healthy individuals with very high diagnosis performance (area under the curve (AUC) value = 1.000, sensitivity value = 1.000, and specificity value = 1.000). In addition, the levels of Cer, CerG1, SM, PC, PC-O, PE, PI, PS, and ChE in the LaC group significantly increased as compared with the NC group. However, the levels of LPC, LPC-O, LPE, LPE-p, and DG in the LaC group significantly deceased when the one was compared with the NC group. Among significantly changed lipid species, lysophospholipids containing a palmitoyl chain or an arachidonic acid acyl chain remarkably decreased and phospholipids including a palmitoyl chain or an arachidonic acid acyl chain increased in the LaC patients.ConclusionOur results not only indicate that lipidomics is powerful tool to explore abnormal lipid metabolism for the laC, but suggest that lysophospholipids and phospholipids may serve as potential biomarkers for diagnosis of LaC.

Effect of endoscopic surgical skill qualification system for laparoscopic multivisceral resection: Japanese multicenter analysis.

The efficacy of laparoscopic multivisceral resection (Lap-MVR) has been reported by several experienced high-volume centers. The Endoscopic Surgical Skill Qualification System (ESSQS) was established in Japan to improve the skill of laparoscopic surgeons and further develop surgical teams. We examined the safety and feasibility of Lap-MVR in general hospitals, and evaluated the effects of the Japanese ESSQS for this approach. We retrospectively reviewed 131 patients who underwent MVR between April 2016 and December 2019. Patients were divided into the laparoscopic surgery group (LAC group, n = 98) and the open surgery group (OPEN group, n = 33). The clinicopathological and surgical features were compared between the groups. Compared with the OPEN group, BMI was significantly higher (21.9 vs 19.3kg/m2, p = 0.012) and blood loss was lower (55 vs 380ml, p < 0.001) in the LAC group. Operation time, postoperative complications, and postoperative hospital stay were similar between the groups. ESSQS-qualified surgeons tended to select the laparoscopic approach for MVR (p < 0.001). In the LAC group, ESSQS-qualified surgeons had superior results to those without ESSQS qualifications in terms of blood loss (63 vs 137ml, p = 0.042) and higher R0 resection rate (0% vs 2.0%, p = 0.040), despite having more cases of locally advanced tumor. In addition, there were no conversions to open surgery among ESSQS-qualified surgeons, and three conversions among surgeons without ESSQS qualifications (0% vs 15.0%, p = 0.007). Multivariate analysis revealed blood loss (odds ratio 1.821; 95% CI 1.324-7.654; p = 0.010) as an independent predictor of postoperative complications. Laparoscopic approach was not a predictive factor. The present multicenter study confirmed the feasibility and safety of Lap-MVR even in general hospitals, and revealed superior results for ESSQS-qualified surgeons.

Lactate is involved in the occurrence of neurological damages after experimental cardiac arrest in rabbits

Lactate can be used by neurons as a metabolic substrate after an ischemic injury. Though, its consequences on neuronal mortality are still unknown after cardiac arrest. We investigated the neurological consequences of blood lactate after cardiac arrest by administration of exogenous lactate or pyruvate, its main metabolite. Then, we tested the effect of oxamate, which inhibits the reduction of lactate to pyruvate. Anesthetized rabbits were submitted to 10 min of ventricular fibrillation and resuscitated. In a first set of experiments, they randomly received saline (Control group, n = 7), lactate (Lac group, 10 mg/kg/min, n = 6) or pyruvate (Pyr group, 10 mg/kg/min, n = 7). In a second set of experiments, they randomly received saline (Control group, n = 7) or oxamate (Oxa group, 37.5 mg/kg/min, n = 6). Animals were followed during 48 h for neurological and survival evaluation. Neuronal death and astrogliosis were quantified by immunostaining (fluorojade C and GFAP, respectively). Lactate and pyruvate administration significantly exacerbated blood lactate levels 30 min after cardiac arrest as compared to Control group (15.8 ± 0.8 and 15.0 ± 0.8 vs. 13.1 ± 0.9 mmol/L in Lac, Pyr and Control groups, respectively). This led to a greater neuronal death and neurological dysfunction vs. Control (66 ± 12 and 100 ± 6 vs. 48 ± 8% of neuronal dysfunction after 48 h, in Lac, Pyr and Control groups respectively). Astrogliosis significantly increased after pyruvate infusion vs. other groups (68 ± 5 vs. 49 ± 4 and 54 ± 3 reactive astrocytes per field, in Pyr, Lac and Control groups respectively). In the second set of experiment, oxamate infusion was potently neuroprotective (13 ± 5 vs. 60 ± 10% of neuronal dysfunction after 48 h, in Oxa and Control groups, respectively). Lactate and pyruvate administration enhances blood lactate levels and worsen the neurological death while inhibition of lactate dehydrogenase is neuroprotective.

Carbon Source Affects Synthesis, Structures, and Activities of Mycelial Polysaccharides from Medicinal Fungus Inonotus obliquus.

The effects of various carbon sources on mycelial growth and polysaccharide synthesis of the medicinal fungus Inonotus obliquus in liquid fermentation were investigated. After 12-d fermentation, mycelial biomass, polysaccharide yield, and polysaccharide content were significantly higher in Glc+Lac group (glucose and lactose used as combined carbon source) than in other groups. Crude polysaccharides (CIOPs) and the derivative neutral polysaccharides (NIOPs) were obtained from mycelia fermented using Glc, fructose (Fru), Lac, or Glc+Lac as carbon source. Molecular weights of four NIOPs (termed as NIOPG, NIOPF, NIOPL, and NIOPGL) were respectively 780.90, 1105.00, 25.32, and 10.28 kDa. Monosaccharide composition analyses revealed that NIOPs were composed of Glc, Man, and Gal at different molar ratios. The NIOPs were classified as α-type heteropolysaccharides with 1→2, 1→3, 1→4, 1→6 linkages in differing proportions. In in vitro cell proliferation assays, viability of RAW264.7 macrophages was more strongly enhanced by NIOPL or NIOPGL than by NIOPG or NIOPF, and proliferation of HeLa or S180 tumor cells was more strongly inhibited by NIOPG or NIOPGL than by NIOPF or NIOPL, indicating that immune-enhancing and anti-tumor activities of NIOPs were substantially affected by carbon source. qRT-PCR analysis revealed that expression levels of phosphoglucose isomerase (PGI) and UDP-Glc 4-epimerase (UGE), two key genes involved in polysaccharide synthesis, varied depending on carbon source. Our findings, taken together, clearly demonstrate that carbon source plays an essential role in determining structure and activities of I. obliquus polysaccharides by regulating expression of key genes in polysaccharide biosynthetic pathway.

A learning curve in using organ retractor for single-incision laparoscopic right colectomy

Single-incision laparoscopic surgery (SILS) has the potential to improve perioperative outcomes, including less postoperative pain, shorter operation time, less blood loss, and shorter hospital stay. However, SILS is technically difficult and needs a longer learning curve. Between April 2016 and September 2019, a total of 198 patients with clinical stage I/II right colon cancer underwent curative resection. In the case of the SILS approach, an organ retractor was usually used to overcome SILS-specific restrictions. The patients were divided into two groups by surgical approach: the SILS with organ retractor group (SILS-O, n = 33) and the conventional laparoscopic surgery group (LAC, n = 165). Clinical T status was significantly higher in the LAC group (p = 0.016). Operation time was shorter and blood loss was lower in the SILS-O group compared to the LAC group (117 vs. 197 min, p = 0.027; 10 vs. 25 mL, p = 0.024, respectively). In the SILS-O group, surgical outcomes including operation time, blood loss, number of retrieved lymph nodes, and postoperative complications were not significantly different between those performed by experts and by non-experts. Longer operation time (p = 0.041) was significantly associated with complications on univariate and multivariate analyses (odds ratio 2.514, 95%CI 1.047–6.035, p = 0.039). SILS-O was safe and feasible for right colon cancer. There is a potential to shorten the learning curve of SILS using an organ retractor.

The Administration of the Synbiotic Lactobacillus bulgaricus 6c3 Strain, Inulin and Fructooligosaccharide Decreases the Concentrations of Indoxyl Sulfate and Kidney Damage in a Rat Model.

Indoxyl sulfate (IS) is involved in the progression of chronic kidney disease (CKD) and in its cardiovascular complications. One of the approaches proposed to decrease IS is the administration of synbiotics. This work aimed to search for a probiotic strain capable to decrease serum IS levels and mix it with two prebiotics (inulin and fructooligosaccharide (FOS)) to produce a putative synbiotic and test it in a rat CKD model. Two groups of Sprague-Dawley rats were nephrectomized. One group (Lac) received the mixture for 16 weeks in drinking water and the other no (Nef). A control group (C) included sham-nephrectomized rats. Serum creatinine and IS concentrations were measured using high-performance liquid chromatography with diode array detector (HPLC-DAD). Optical microscopy and two-photon excitation microscopy was used to study kidney and heart samples. The Lac group, which received the synbiotic, reduced IS by 0.8% while the Nef group increased it by 38.8%. Histological analysis of kidneys showed that the Lac group increased fibrotic areas by 12% and the Nef group did it by 25%. The synbiotic did not reduce cardiac fibrosis. Therefore, the putative synbiotic showed that function reducing IS and the progression of CKD in a rat model, but no heart protection was observed.