OBJECTIVETo preliminarily investigate the relationship between the Lactate dehydrogenase (LDH) activity of Streptococcus mutans (S. mutans) and dental caries initiation.

METHODS100 S. mutans strains derived from caries-active and caries-free individuals were cultured in BHI medium supplemented with glucose. Cells were extracted and ruptured, and the extracted liquid protein was quantified with Coomassie brilliant blue G250 staining methods. LDH activity was assayed using the pyruvate-dependent oxidation of NADH-with and without FDP.

RESULTSLDH activity of the two groups strains had no difference (P > 0.05), but the distribution of differ class enzyme activity strains in the two groups was different (P < 0.05).

CONCLUSIONLDH activity of S. mutans is correlated to the initiation of dental caries to some extent. The measurement methods in this study can be applied in preliminary quantitation of LDH activity and the screening of S. mutans strains.

Case-Control Studies ; Dental Caries ; microbiology ; Humans ; Lactate Dehydrogenases ; Oxidation-Reduction ; Streptococcus mutans ; metabolism

Animals ; Creatine Kinase ; blood ; Energy Metabolism ; Lactate Dehydrogenases ; blood ; Male ; Pressure ; adverse effects ; Rabbits ; Serum ; enzymology

OBJECTIVE: To analyze the expression and correlation of microRNA-195 (miR-195), miR-125 and calreticulin in diffuse large B-cell lymphoma (DLBCL). METHODS: From April 2020 to April 2021, 80 DLBCL patients with complete data archived by the Pathology Department of Handan First Hospital and The Second Hospital of Hebei Medical University were selected as the study group, and 70 patients with reactive lymph node hyperplasia were selected as the control group. The expressions of miR-195 and miR-125 were detected by real-time fluorescence quantitative PCR, and the expression of calreticulin was detected by Western blot. Pearson correlation was used to analyze the correlation between miR-195, miR-125, calreticulin and DLBCL, and ROC curve was used to analyze the predictive value of miR-195, miR-125 and calreticulin for DLBCL. RESULTS: Compared with the control group, the expression of miR-195 decreased but miR-125 and calreticulin increased in the study group (P<0.001). The expression levels of miR-195, miR-125 and calreticulin were not related to sex, age, primary site and B symptoms of patients with DLBCL, but related to immunophenotype, Ann Arbor stage, lactate dehydrogenase, IPI score, nodule involvement and Ki-67 index. The expression of miR-195 decreased and the expression of miR-125 and calreticulin increased in DLBCL paitents with non-germinal center source, Ann Arbor stage III-IV, lactate dehydrogenase > 245 U/L, IPI score 3-5, nodule involvement≥2 and Ki-67 index≥75% (P<0.05). Pearson correlation analysis showed that miR-195 and miR-125 were negatively correlated (r=-0.536, P=0.001), miR-195 and calreticulin were negatively correlated (r=-0.545, P=0.001), while miR-125 and calreticulin were positively correlated (r=0.523, P=0.001). ROC curve showed that compared with the single diagnosis of miR-195, miR-125 and calreticulin, the combination of the three items had higher predictive value for DLBCL (P<0.001). CONCLUSION The expression of miR-195 decreases and the expression of miR-125 and calreticulin increase in patients with DLBCL. Along with the increase of disease stage and IPI score, the decrease of miR-195 and the increase of miR-125 and calreticulin aggravate gradually. The three items may participate in the occurrence and progress of DLBCL.
Humans ; MicroRNAs/genetics* ; Ki-67 Antigen/metabolism* ; Calreticulin/metabolism* ; Prognosis ; Lymphoma, Large B-Cell, Diffuse/genetics* ; Lactate Dehydrogenases/metabolism*

Animals ; Cadmium Compounds ; toxicity ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Cricetinae ; Cricetulus ; Fibroblasts ; drug effects ; metabolism ; Lactate Dehydrogenases ; metabolism ; Lung ; cytology ; Malondialdehyde ; metabolism ; Quantum Dots

AIMTo observe protective effects and involved mechanism of ginsenoside Rb3 on hypoxic/ischemic brain injury, using cultured hippocampal neurons, rat hippocampal slices and intact animals.

METHODS(1) Mice were tightly closed in glasses of 150 ml, and then survival time of them was observed. (2) During simulated ischemia and after reoxygenation, changes of orthodromic population spikes (OPS) in the area CA1 of hippocampal slice were investigated. (3) By using histochemistry, the expressions of NOS in CA1 area of rat hippocampus after hypoxic exposure were observed. (4) Using LDH detection, tests of total NOS, iNOS and cNOS activity, the protective effects of ginsenoside Rb3 were investigated on cultured hippocampal neurons treated with hypoxia.

RESULTS(1) Given ginsenoside Rb3 (10 mmol/L), mice survived significantly longer than that of control group. (2) The occurrence of HIP (hypoxic injury potentials) decreased after administration of ginsenosides Rb3 (60 micromol/L) in many slices, while the recovery rate and amplitude of OPS after reoxygenation were significantly higher than those of the control group. (3) In CA1 area of rat hippocampus, NOS-positive neurons increased at the end of 24 h hypoxia and further 24 h reoxygenation, while the number of NOS-positive neurons decreased after treatment with ginsenoside Rb3. (4) The LDH leakage rate of cultured rat hippocampal neurons increased at the end of hypoxia, while it decreased after treatment with Rb3. Moreover the total NOS, especially iNOS activity of these neurons also decreased.

CONCLUSIONGinsenoside Rb3 has a significant protective effect on hypoxic-ischemic injury of neurons, and this involves the stabilization of the cell membrane, the inhibition of the expression and activity of NOS, especially iNOS activity.

Animals ; Cell Survival ; drug effects ; Female ; Ginsenosides ; pharmacology ; Hypoxia-Ischemia, Brain ; metabolism ; Lactate Dehydrogenases ; metabolism ; Male ; Membrane Potentials ; Mice ; Mice, Inbred ICR ; Nitric Oxide Synthase Type II ; metabolism

Adolescent ; Adult ; Aged ; Aspartate Aminotransferases ; metabolism ; Case-Control Studies ; Electrocardiography ; Endosulfan ; poisoning ; Female ; Humans ; Lactate Dehydrogenases ; metabolism ; Male ; Middle Aged ; Young Adult

Animals ; Cells, Cultured ; Gluconates ; pharmacology ; Lactate Dehydrogenases ; metabolism ; Myocardial Reperfusion Injury ; prevention & control ; Myocytes, Cardiac ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

AIMTo investigate changes of VEC and CEC under acute hypoxia.

METHODSObserve CEC in blood under acute hypoxia morphologically and count the number of CEC by optical microscope, measure LDH activity of young CEC and VEC by histochemical staining image analysis.

RESULTSLDH activities of VEC in hypoxic groups are lower than that in the group before hypoxia and decrease progressively with hypoxia time. LDH activities of young CEC in groups after hypoxia and before hypoxia are the same and are apparently lower than that of VEC. Before hypoxia most of CEC are aging, the number of CEC from hypoxic groups is greater than that before hypoxia and increases progressively with hypoxia time and most of CEC from hypoxic groups are young.

CONCLUSIONThe morphology and number of CEC may reflect the extent to which the vascular is injured. LDH activity of VEC may reflect the transformation from VEC into CEC. LDH activity of young CEC may reflect the extent to which the VEC is injured when falling from vascular wall.

Animals ; Blood Cell Count ; Blood Circulation ; Endothelial Cells ; cytology ; Endothelium, Vascular ; cytology ; Hypoxia ; Lactate Dehydrogenases ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Rats, Wistar

OBJECTIVETo study the cytotoxicity induced by chrysotile asbestos (CA), rock wool (RW) and wollastonite (WS).

METHODSV79 cells were divided into 4 groups. i.e. CA group, WS group, RW group and control group (200 microl PBS). The exposure concentration of dusts was 100 mg/L, The cell viability was detected by MTT and lactate dehydrogenase (LDH) activity assays. The technique of scanning electron microscopy was used to examine the change of V79 cells.

RESULTSSiO2 was main constituent for 3 kinds of dusts. In MTT assay, the cell viability of RW and WS groups was 64.8% and 65.7%, respectively, which were significantly higher than that (54.5%) of CA group (P < 0.01). In LDH assay, the LDH activity of RW and WS groups [(15.7 +/- 50.9), (12.3 +/- 3.7) U/L, respectively] was significantly lower than that [(20.2 +/- 0.9) U/L] of CA group (P < 0.05). In scanning electron microscopy examination, it was found that the two ends of V79 cells in CA group contained a great deal of fibers remaining bodies, but the V79 cell appearance in RW and WS groups was normal.

CONCLUSIONThe cytotoxicity induced by RW and WS is significantly lower than that induced by CA for V79 cell.

Animals ; Asbestos, Serpentine ; toxicity ; Calcium Compounds ; toxicity ; Cell Line ; drug effects ; Cricetinae ; Cytotoxins ; toxicity ; Lactate Dehydrogenases ; metabolism ; Mineral Fibers ; toxicity ; Silicates ; toxicity

OBJECTIVE: To investigate the effect of lidocaine on LPS induced apoptosis of cultured adult rat alveolar Type II (AT-II) cells. METHODS: Cultured cells were exposed to LPS and lidocaine for 24 hours. Apoptosis and necrosis rates of cells were detected by flow cytometry and electron microscope. The activity of lactic dehydrogenase (LDH) was analyzed by using LDH kits. RESULTS: LPS induced the AT-II cell injuries by increasing not only the necrosis and apoptosis rates but also the LDH release of cultured AT-II in vitro. Lidocaine decreased the necrosis and apoptosis rates of AT-II cells. CONCLUSION Lidocaine can directly inhibit the apoptosis and necrosis induced by LPS in cultured AT-II cells.
Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Epithelial Cells ; pathology ; Flow Cytometry ; Lactate Dehydrogenases ; metabolism ; Lidocaine ; pharmacology ; Lipopolysaccharides ; Necrosis ; Protective Agents ; pharmacology ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley