Measurement Of Lactate Dehydrogenase Activity Research Articles

Cardiac endothelial ischemia/reperfusion injury-derived protein damage-associated molecular patterns disrupt the integrity of the endothelial barrier

Human cardiac microvascular endothelial cells (HCMECs) are sensitive to ischemia and vulnerable to damage during reperfusion. The release of damage-associated molecular patterns (DAMPs) during reperfusion induces additional tissue damage. The current study aimed to identify early protein DAMPs in human cardiac microvascular endothelial cells subjected to ischemia-reperfusion injury (IRI) using a proteomic approach and their effect on endothelial cell injury. HCMECs were subjected to 60 min of simulated ischemia and 6 h of reperfusion, which can cause lethal damage. DAMPs in the culture media were subjected to liquid chromatography-tandem mass spectrometry proteomic analysis. The cells were treated with endothelial IRI-derived DAMP medium for 24 h. Endothelial injury was assessed by measuring lactate dehydrogenase activity, morphological features, and the expression of endothelial cadherin, nitric oxide synthase (eNOS), and caveolin-1. The top two upregulated proteins, DNAJ homolog subfamily B member 11 and pyrroline-5-carboxylate reductase 2, are promising and sensitive predictors of cardiac microvascular endothelial damage. HCMECs expose to endothelial IRI-derived DAMP, the lactate dehydrogenase activity was significantly increased compared with the control group (10.15 ± 1.03 vs 17.67 ± 1.19, respectively). Following treatment with endothelial IRI-derived DAMPs, actin-filament dysregulation, and downregulation of vascular endothelial cadherin, caveolin-1, and eNOS expressions were observed, along with cell death. In conclusion, the early protein DAMPs released during cardiac microvascular endothelial IRI could serve as novel candidate biomarkers for acute myocardial IRI. Distinct features of impaired plasma membrane integrity can help identify therapeutic targets to mitigate the detrimental consequences mediated of endothelial IRI-derived DAMPs.

Atividade da lactato desidrogenase e proteína total como marcadores diagnósticos de efusões cavitárias e identificação de efusões neoplásicas em cães e gatos

ABSTRACT: The analysis and classification of cavitary effusions play a crucial role in determining a patient’s diagnosis and prognosis. This prospective study assed ed the activity of Lactate Dehydrogenase (LDH) and the concentration of Total Protein (TP) in serum, pleural, and peritoneal effusions in dogs and cats. Effusions were categorized into three groups: GI (low protein transudate), GII (high protein transudate), and GIII (exudate) following conventional classification. These groups, irrespective of species, were further divided into NPG (neoplastic) and NNG (non-neoplastic) groups. In dogs, significant differences were observed among groups GI, GII, and GIII in terms of effusion LDH activity/serum LDH (LDHR), effusion LDH activity, serum TP/effusion TP (TPR), and effusion TP. Increased LDH activity in effusion was associated with the presence of neoplasia. The groups organized based on the etiopathogenesis of the effusion exhibited varying values of serum TP, TPR, LDHR, effusion TP, and LDH activity in the effusion. Conversely, statistical analysis of the data from cats showed no differences between the groups for the parameters evaluated in this study. Compared to conventional classification, Light’s criteria demonstrated greater sensitivity in distinguishing between transudates and exudates and higher specificity in identifying transudates. We propose the use of established biochemical analyses to discern the mechanism of cavitary effusion formation and advocate for LDH activity measurement in effusions as a complementary diagnostic tool for cavitary neoplasms, especially in cases where cytological analysis of the effusion yields inconclusive results.

Evaluating phytochemical constituents and in-vitro antiplasmodial and antioxidant activities of Fadogiella stigmatoloba, Hygrophylla auriculata, Hylodesmum repandum, and Porphyrostemma chevalieri extracts

IntroductionFadogiella stigmatoloba, Hygrophylla auriculata, Hylodesmum repandum and Porphyrostemma chevalieri are used against malaria in traditional medicine in the Democratic Republic of the Congo (DRC). To evaluate their potential in the treatment of this disease, the in vitro antiplasmodial property of these four plants was evaluated. All experiments were conducted on methanolic extracts performed on selected organ parts of these plants. MethodsThe methanolic extracts, obtained by maceration, were firstly screened in vitro against the chloroquine sensitive (3D7) and resistant (W2) Plasmodium falciparum strains by the measurement of lactate dehydrogenase activity, and on human keratinocytes (HaCat) cells by the MTT assay to determine their selectivity indices (SI). Secondly, the antioxidant activity of the same extracts was evaluated using DPPH and FRAP assays. Finally, the presence of specific phytochemical constituents was evaluated using standard methods and tentatively identified by GC-MS. ResultsAn optimum antiplasmodial activity (IC50 = 3.4 ± 0.7 μg/mL, for 3D7, SI = 58.2; IC50 = 7 ± 1.0 μg/mL, for W2, SI = 28.3) was obtained with the leave extract of P. chevalieri. The leaves (for F. stigmatoloba and H. repandum), and the aerial part (for H. repandum) extracts showed promising and moderate antiplasmodial activities against respectively the 3D7 strain (IC50: <15 μg/mL), and W2 strain (IC50:15–50 μg/mL). All extracts presented a weak cytotoxic effect (IC50: >100 μg/mL) on HaCat cells. For the antioxidant test, the most interesting activity was obtained with the leaf extract of P. chevalieri. The GC–MS analysis of these four plants species extracts revealed the presence of various compounds, such as Ethyl 2-nonenoate, 2-(2-Hydroxy-2-phenylethyl)-3,5,6-trimethyl pyrazine, Palmitic Acid, Ethyl palmitate, Ethyl linolenate, and N-Acetyltyramine. ConclusionBased on the obtained results, P. chevalieri could be selected for further investigations or ⁄and for the management of malaria after standardization.

Population balance modelling captures host cell protein dynamics in CHO cell cultures.

Monoclonal antibodies (mAbs) have been extensively studied for their wide therapeutic and research applications. Increases in mAb titre has been achieved mainly by cell culture media/feed improvement and cell line engineering to increase cell density and specific mAb productivity. However, this improvement has shifted the bottleneck to downstream purification steps. The higher accumulation of the main cell-derived impurities, host cell proteins (HCPs), in the supernatant can negatively affect product integrity and immunogenicity in addition to increasing the cost of capture and polishing steps. Mathematical modelling of bioprocess dynamics is a valuable tool to improve industrial production at fast rate and low cost. Herein, a single stage volume-based population balance model (PBM) has been built to capture Chinese hamster ovary (CHO) cell behaviour in fed-batch bioreactors. Using cell volume as the internal variable, the model captures the dynamics of mAb and HCP accumulation extracellularly under physiological and mild hypothermic culture conditions. Model-based analysis and orthogonal measurements of lactate dehydrogenase activity and double-stranded DNA concentration in the supernatant show that a significant proportion of HCPs found in the extracellular matrix is secreted by viable cells. The PBM then served as a platform for generating operating strategies that optimise antibody titre and increase cost-efficiency while minimising impurity levels.

Proteomics Indicates Lactate Dehydrogenase Is Prognostic in Acetaminophen-Induced Acute Liver Failure Patients and Reveals Altered Signaling Pathways.

Better biomarkers to predict death early in acute liver failure (ALF) are needed. To that end, we obtained early (study day 1) and later (day 3) serum samples from transplant-free survivors (n = 28) and nonsurvivors (n = 30) of acetaminophen-induced ALF from the NIH-sponsored Acute Liver Failure Study Group and from control volunteers (n = 10). To identify proteins that increase early in serum during ALF, we selected individuals from this cohort for whom alanine aminotransferase was lower on day 1 than day 3, indicating a time point before peak injury (n = 10/group). We then performed untargeted proteomics on their day 1 samples. Out of 1682 quantifiable proteins, 361 were ≥ 4-fold elevated or decreased in ALF patients versus controls and 16 of those were further elevated or decreased ≥ 4-fold in nonsurvivors versus survivors, indicating potential to predict death. Interestingly, 1 of the biomarkers was lactate dehydrogenase (LDH), which is already measured in most clinical laboratories. To validate our proteomics results and to confirm the prognostic potential of LDH, we measured LDH activity in all day 1 and 3 samples from all 58 ALF patients. LDH was elevated in the nonsurvivors versus survivors on both days. In addition, it had prognostic value similar to the model for end-stage liver disease and outperformed the King's College Criteria, while a combination of model for end-stage liver disease and LDH together outperformed either alone. Finally, bioinformatics analysis of our proteomics data revealed alteration of numerous signaling pathways that may be important in liver regeneration. Overall, we conclude LDH can predict death in APAP-induced ALF.

Composite Bioinks With Mesoporous Bioactive Glasses-A Critical Evaluation of Results Obtained by In Vitro Experiments.

Besides osteoconductivity and a high degradation rate, mesoporous bioactive glasses (MBGs) are specific for their highly ordered channel structure and high specific surface area, making them suitable as drug and/or growth factor delivery systems. On the other hand, the mesoporous channel structure and MBG composition can have an effect on common cell evaluation assays, leading to inconclusive results. This effect is especially important when MBG is mixed in composite bioinks, together with cells. Additionally, the hydrogel component of the ink can influence the degradation of MBG, leading to different ion releases, which can additionally affect the analyses. Hence, our aim here was to show how the MBG structure and composition influence common cell viability and differentiation assays when calcium (Ca)- or magnesium (Mg)-containing glass is part of an alginate-based composite bioink. We suggested pre-labeling of cells with DiI prior to bioprinting and staining with calcein-AM to allow identification of metabolically active cells expressing signals in both green and red channels, allowing the use of fluorescence imaging for cell viability evaluations in the presence of high amounts (7 wt %) of MBGs. The release and uptake of ions during degradation of CaMBG and MgMBG were significantly changed by alginate in the composite bioinks, as confirmed by higher release and uptake from bulk glasses. Additionally, we detected a burst release of Mg2+ from composites only after 24 h of incubation. Furthermore, we demonstrated that released ions and the mesoporous channel structure affect the measurement of lactate dehydrogenase (LDH) and alkaline phosphatase activity (ALP) in bioprinted composite scaffolds. Measured LDH activity was significantly decreased in the presence of CaMBG. On the other hand, the presence of MgMBG induced increased signal measured for the ALP. Taken together, our findings show how composite bioinks containing MBGs can interfere with common analyses, obtaining misleading results.

Cardioprotecive Properties of Known Agents in Rat Ischemia-Reperfusion Model Under Clinically Relevant Conditions: Only the NAD Precursor Nicotinamide Riboside Reduces Infarct Size in Presence of Fentanyl, Midazolam and Cangrelor, but Not Propofol.

Background: Cardioprotective strategies against ischemia-reperfusion injury (IRI) that remain effective in the clinical arena need to be developed. Therefore, maintained efficacy of cardioprotective strategies in the presence of drugs routinely used clinically (e.g., opiates, benzodiazepines, P2Y12 antagonist, propofol) need to be identified in preclinical models.Methods: Here, we examined the efficacy of promising cardioprotective compounds [fingolimod (Fingo), empagliflozin (Empa), melatonin (Mela) and nicotinamide riboside (NR)] administered i.v. as bolus before start ischemia. Infarct size as percentage of the area of risk (IS%) was determined following 25 min of left ascending coronary (LAD) ischemia and 2 h of reperfusion in a fentanyl-midazolam anesthetized IRI rat model. Plasma lactate dehydrogenase (LDH) activity at 30 min reperfusion was determined as secondary outcome parameter. Following pilot dose-response experiments of each compound (3 dosages, n = 4–6 animals per dosage), potential cardioprotective drugs at the optimal observed dosage were subsequently tested alone or in combination (n = 6–8 animals per group). The effective treatment was subsequently tested in the presence of a P2Y12 antagonist (cangrelor; n = 6/7) or propofol aesthesia (n = 6 both groups).Results: Pilot studies suggested potential cardioprotective effects for 50 mg/kg NR (p = 0.005) and 500 μg/kg melatonin (p = 0.12), but not for Empa or Fingo. Protection was subsequently tested in a new series of experiments for solvents, NR, Mela and NR+Mela. Results demonstrated that only singular NR was able to reduce IS% (30 ± 14 vs. 60 ± 16%, P = 0.009 vs. control). Mela (63 ± 18%) and NR+Mela (47 ± 15%) were unable to significantly decrease IS%. NR still reduced IS in the presence of cangrelor (51 ± 18 vs. 71 ± 4%, P = 0.016 vs. control), but lost protection in the presence of propofol anesthesia (62 ± 16 vs. 60 ± 14%, P = 0.839 vs. control). LDH activity measurements supported all IS% results.Conclusion: This observational study suggests that NR is a promising cardioprotective agent to target cardiac ischemia-reperfusion injury in clinical conditions employing opioid agonists, benzodiazepines and platelet P2Y12 inhibitors, but not propofol.

Antibacterial Optimization of Highly Deformed Titanium Alloys for Spinal Implants.

The goal of the work was to develop materials dedicated to spine surgery that minimized the potential for infection originating from the transfer of bacteria during long surgeries. The bacteria form biofilms, causing implant loosening, pain and finally, a risk of paralysis for patients. Our strategy focused both on improvement of antibacterial properties against bacteria adhesion and on wear and corrosion resistance of tools for spine surgery. Further, a ~35% decrease in implant and tool dimensions was expected by introducing ultrahigh-strength titanium alloys for less-invasive surgeries. The tested materials, in the form of thin, multi-layered coatings, showed nanocrystalline microstructures. Performed direct-cytotoxicity studies (including lactate dehydrogenase activity measurement) showed that there was a low probability of adverse effects on surrounding SAOS-2 (Homo sapiens bone osteosarcoma) cells. The microbiological studies (e.g., ISO 22196 contact tests) showed that implanting Ag nanoparticles into Ti/TixN coatings inhibited the growth of E. coli and S. aureus cells and reduced their adhesion to the material surface. These findings suggest that Ag-nanoparticles present in implant coatings may potentially minimize infection risk and lower inherent stress.

L-タイプワコーLD・IF試薬の基本性能の評価と基準範囲に関る検討―乳酸脱水素酵素活性測定のIFCC法とJSCC法の比較―

L-タイプワコーLD・IF試薬の基本性能の評価と基準範囲に関る検討―乳酸脱水素酵素活性測定のIFCC法とJSCC法の比較―

Evaluation of Lung Cell Toxicity of Surfactants for Inhalation Route

Few data are available for excipients administered by inhalation route. This study evaluated the in vitro potential toxicity of three surfactants (Polysorbate 20, Polysorbate 80 and Poloxamer 188) by using an original air-liquid interface (ALI) method of exposure compared to liquid/liquid (L/L) model. Two cell toxicity tests were conducted on BEAS-2B cells, a human immortalized bronchial epithelial cell lines; measurement of Lactate Dehydrogenase activity and XTT cell proliferation assay. We found that Polysorbate 20 appeared to be more toxic than Polysorbate 80, Poloxamer 188. An increased toxicity of Polysorbate 20 in L/L system as shown in comparison to ALI exposure. A toxicity was also observed for polysorbate 80 but at higher concentrations and without difference between L/L and ALI exposure. No toxicity was observed for Poloxamer 188 at high concentrations. Poloxamer 188 seems to be the better candidate, out of the three tested, for galenic formulations designed to the inhalation route such as biotherapies. To evaluate the cytotoxicity of excipients for inhalation route the ALI exposure have to be used instead of L/L.

New lupeol esters as active substances in the treatment of skin damage.

The purpose of the research was to obtain new derivatives of natural triterpene lupeol and to evaluate their potential as active substances in the treatment of skin damage. Four new lupeol esters (propionate, succinate, isonicotinate and acetylsalicylate) and lupeol acetate were obtained using an eco-friendly synthesis method. In the esterification process, the commonly used hazardous reagents in this type of synthesis were replaced by safe ones. This unconventional, eco-friendly, method is particularly important because the compounds obtained are potentially active substances in skin care formulations. Even trace amounts of hazardous reagents can have a toxic effect on damaged or irritated tissues. The molecular structure of the esters were confirmed by 1H NMR, 13C NMR and IR spectroscopy methods. Their crystal structures were determined using XRD method. To complete the analysis of their characteristics, physicochemical properties (melting point, lipophilicity, water solubility) and biological activity of the lupeol derivatives were studied. Results of an irritant potential test, carried out on Reconstructed Human Epidermis (RHE), confirmed that the synthesized lupeol derivatives are not cytotoxic and they stimulate a process of human cell proliferation. The safety of use for tested compounds was determined in a cell viability test (cytotoxicity detection kit based on the measurement of lactate dehydrogenase activity) for keratinocytes and fibroblasts. The results obtained showed that the modification of lupeol structure improve its bioavailability and activity. All of the esters penetrate the stratum corneum and the upper layers of the dermis better than the maternal lupeol. Lupeol isonicotinate, acetate and propionate were the most effective compounds in a stimulation of the human skin cell proliferation process. This combination resulted in an increase in the concentration of cells of more than 30% in comparison to control samples. The results indicate that the chemical modification of lupeol allows to obtain promising active substances for treatment of skin damage, including thermal, chemical and radiation burns.

Changes in the inline lactate dehydrogenase according to the cow’s production and reproduction status

The aim of the present study was to investigate inline lactate dehydrogenase (LDH) changes in clinically healthy dairy cows according to the number and stage of lactations, milk yield, and the reproduction status The LDH activity (μmol/min per litre) was measured using the dry-stick technology. A total of 378 cows were selected and classified according to their reproductive status into the following groups: fresh (1–44 days after calving); open (45–65 days after calving); inseminated (1–35 days after insemination); pregnant (35–60 days after insemination). According to their milk productivity, the cows were classified into the following groups: &lt;15 kg/d, 15–25 kg/d, &gt;25–35 kg/d, and &gt;35 kg/d. They were milked with a DeLaval milking robot in combination with a Herd Navigator analyser. The results showed that the inline LDH concentration had a tendency to increase along with the increase in the number of lactation periods (P &lt; 0.05). The highest level of LDH was observed in fresh cows 5–10 days in milk (DIM), and the highest LDH concentration was found in the milk of fresh cows. A positive statistically reliable relationship was found between the milk yield and LDH concentration (P &lt; 0.05); LDH and milk somatic cell counts (SCC) were positively related in all groups of cows, although LDH concentration and SCC were the highest correlated variables in inseminated cows (P &lt; 0.05). The present study shows that measuring LDH activity in milk is both easy and cost effective with high sensitivity and specificity, having a great potential as a diagnostic tool for detection of subclinical mastitis.

Antiproliferative Effect of Trifolium Pratens L. Extract in Human Breast Cancer Cells

Breast cancer is currently the most common cancer in women worldwide. Tamoxifen is used for the treatment of both early and advanced estrogen receptor positive breast cancer. Trifolium pratense L. has been suggested for cancer treatment in traditional medicine. The effect of T. pratense extract on breast cell lines (MCF-7 and MDA-MB-231) was investigated here. The cells were treated with T. pratense extract and cell viability was evaluated using trypan blue staining, MTT assay and lactate dehydrogenase activity measurement. Apoptosis, autophagy cell death was detected using fluorescent dye staining. Griess assay was performed to nitric oxide (No) measurement. Change in expression level of some apoptotic and autophagic- related genes was detected using real-time PCR. The combination effect of exteract and tamoxifen was evaluated by calculating the combination index and dose reduction index (DRI) values. T. pratense extract reduced the cell viability in dose and time- dependent manner. Apoptosis and autophagy was increased after treatment with T. pratense extract. Nitric oxide production significantly reduced in cells and combination of tamoxifen and T. pratense extract had a synergistic cytotoxic effect on breast cancer cell lines. T. pratense as a dietary supplement can be beneficial for some patients with breast cancer who receive conventional chemotherapy.

Evaluation of Hydro-Alcoholic Extract of Trifolium Pratens L. for Its Anti-Cancer Potential on U87MG Cell Line.

Objective Glioblastoma multiforme is the most malignant form of brain tumors. Trifolium pratense L. has been suggested for cancer treatment in traditional medicine. Here we have investigated the effects of T. pratense extract on glioblastoma multiforme cell line (U87MG). Materials and Methods In this experimental study the effect of T. pratense extract on cell viability was investigated using trypan blue staining, MTT assay, and lactate dehydrogenase activity measurement. Apoptosis and autophagy cell death were detected by fluorescent staining. Nitric oxide (No) production was measured using Griess reaction. Expression levels of some apoptotic and autophagic-related genes were detected using real-time polymerase chain reaction (PCR). The combination effects of T. pratense extract and temozolomide (TMZ) were evaluated by calculating the combination index and dose reduction index values. Results After treatment with T. pratense extract, the cell viability was significantly reduced in a time- and dose- dependent manner (P<0.05). Apoptosis and autophagy of U87MG cells were significantly increased (P<0.05). Also, T. pratense extract significantly decreased NO production (P<0.05) by U87MG cells. Combination of TMZ and T. pratense extract had a synergistic cytotoxic effect. ConclusionT. pratense showed anti-cancer properties via induction of apoptosis and autophagy cell death.

Anticancer activity of some polyamine derivatives on human prostate and breast cancer cell lines.

The aim of this study was to expand our knowledge about anticancer activity of some polyamine derivatives with quinoline or chromane as terminal moieties. Tested compounds were evaluated in vitro towards metastatic human prostate adenocarcinoma (PC3), human carcinoma (DU145) and mammary gland adenocarcinoma (MCF7) cell lines. Cell viability was estimated on the basis of mitochondrial metabolic activity using water-soluble tetrazolium WST1 to establish effective concentrations of the tested compounds under experimental conditions. Cytotoxic potential of polyamine derivatives was determined by the measurement of lactate dehydrogenase activity released from damaged cells, changes in mitochondrial membrane potential, the cell cycle distribution analysis and apoptosis assay. It was revealed that the tested polyamine derivatives differed markedly in their antiproliferative activity. Bischromane derivative 5a exhibited a rather cytostatic than cytotoxic effect on the tested cells, whereas quinoline derivative 3a caused changes in cell membrane integrity, inhibited cell cycle progression, as well as induced apoptosis of prostate and breast cancer cells which suggest its potential application in cancer therapy.

Co-infection with EHEC and C. albicans in vitro enhances invasion and tissue damage of enterocytes induced by C. albicans

Objective To investigate, in vitro, the co-infection of Caco-2 cells (epithelial cells of intestinal mucosa) with Candida albicans and Enterohemorrhagic escherichia coli (EHEC). Methods The ability of both species to invade the Caco-2 cells was evaluated by inverted microscopy. Damage to Caco-2 cells was evaluated by measuring lactate dehydrogenase (LDH) activity. C. albicans virulence gene expression (ALS3, PLB1 and SAP4) was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Results Compared to simple infections with C.albicans alone, a co-infection invaded Caco-2 cells more rapidly, and C. albicans tended to proliferate more easily presenting in cluster shape of distribution. In addition, the LDH activity in the co-infection group (group 3) was the highest compared to groups 1, 2, 4 and 5, (F values of 14.48, 5.48, 11.74 and 3.45 respectively; all P <0.05); There was no significant difference in LDH activity found between the secondary fungous infection group (group 5) and the EHEC infection group (group 2) (F=2.03, P=0.54) or between the secondary bacterial infection group (group 4) and the Candida albicans infection group (group 1) (F=2.74, P=0.11). The LDH activities in groups 2 and 5 were significantly higher than that in groups 1 and 4 (all P <0.05). In addition, an up-regulation of toxicity-related genes (PLB1 and SAP4) were detected. The expression of PLB1 was higher in group 3 than that in group 1(P=0.014 3)and SAP4 was higher in groups 3 and 5 than that in group 1(P=0.027 2, P=0.001 8, respectively). Conclusions Using Caco-2 cells for an infection model, this study demonstrated that co-infecting in vitro enterocytes with C.albicans and EHEC enhanced the invasiveness and tissue damaging effects of C.albicans. Key words: Enterohemorrhage escherichia coli; Candida albicans; Co-infection; Invasion; Tissue damage; Inverted microscope; LDH; qRT-PCR

Novel multi-functional europium-doped gadolinium oxide nanoparticle aerosols facilitate the study of deposition in the developing rat lung.

Ambient ultrafine particulate matter (UPM), less than 100 nm in size, has been linked to the development and exacerbation of pulmonary diseases. Age differences in susceptibility to UPM may be due to a difference in delivered dose as well as age-dependent differences in lung biology and clearance. In this study, we developed and characterized aerosol exposures to novel metal oxide nanoparticles containing lanthanides to study particle deposition in the developing postnatal rat lung. Neonatal, juvenile and adult rats (1, 3 and 12 weeks old) were nose only exposed to 380 μg m(-3) of ∼30 nm europium doped gadolinium oxide nanoparticles (Gd2O3:Eu(3+)) for 1 h. The deposited dose in the nose, extrapulmonary airways and lungs was determined using inductively-coupled plasma mass spectroscopy. The dose of deposited particles was significantly greater in the juvenile rats at 2.22 ng per g body weight compared to 1.47 ng per g and 0.097 ng per g for the adult and neonate rats, respectively. Toxicity was investigated in bronchoalveolar lavage fluid (BALF) by quantifying recovered cell types, and measuring lactate dehydrogenase activity and total protein. The toxicity data suggests that the lanthanide particles were not acutely toxic or inflammatory with no increase in neutrophils or lactate dehydrogenase activity at any age. Juvenile and adult rats had the same mass of deposited NPs per gram of lung tissue, while neonatal rats had significantly less NPs deposited per gram of lung tissue. The current study demonstrates the utility of novel lanthanide-based nanoparticles to study inhaled particle deposition in vivo and has important implications for nanoparticles delivery to the developing lung either as therapies or as a portion of particulate matter air pollution.

Assessment of Lactate Dehydrogenase Enzyme Activity in Milk as a Marker for Detection of Subclinical Mastitis

Sub clinical mastitis is responsible for heavy economic losses throughout the world in dairy sector. The objective of present study was to investigate lactate dehydrogenase (LDH) enzyme activity in milk for detection of subclinical mastitis in buffaloes Milk samples from 60 buffaloes, including 40 subclinical infected and 20 healthy were subjected to the estimation of LDH using a LDH activity assay kit. LDH concentration in milk of buffaloes having subclinical mastitis was reported to be high (1.88±0.91 μmole/ml/min) as compared to healthy animals (0.26±0.10 μmole/ml/min). The receiver operating characteristics analysis at cut off value of 0.44 μmole/ml/min for LDH activity exhibited sensitivity and specificity of 95% each and area under curve was 0.959. Results of the correlation matrix revealed significantly strong positive interdependence of somatic cell count with enzyme LDH (r = 0.722**; P <0.01). Measuring LDH activity in milk was found both easy and cost effective with high sensitivity and specificity indicating that LDH activity has great potential as a diagnostic tool for detection of sub clinical mastitis in buffaloes.

Determination of optimal storage temperature and duration for analysis of total and isoenzyme lactate dehydrogenase activities in canine serum and cerebrospinal fluid.

Lactate dehydrogenase (LDH) exists as 5 isoenzymes in both serum and cerebrospinal fluid (CSF). Human studies have demonstrated that changes in LDH activity can be correlated with a particular disease. Conflicting reports regarding the stability of LDH made it necessary to determine storage conditions before further study of the diagnostic power of this enzyme's activity can be pursued in dogs. The purpose of this study was to optimize measurement of LDH activity and analysis of its isoenzyme profile in canine serum and CSF through proper storage. Serum and CSF were collected from 5 healthy dogs. Samples were stored at 22°C, 4°C, or -20°C for up to 2months. Total LDH activity was measured spectrophotometrically. Isoenzyme profiles were determined using the QuickGel LDH Isoenzyme technique and densitometric scanning. Retention of >70% LDH activity in stored samples was considered clinically acceptable. Serum and CSF stored at -20°C retained >85% of the total LDH activity for 4weeks, although CSF total LDH activity degraded by >10% within 24hours of storage. All serum LDH isoenzymes retained >85% activity for up to 4weeks at -20°C. CSF LDH isoenzyme activity degraded rapidly, therefore CSF LDH should be evaluated within 72hours to assure >75% of LDH isoenzyme activity. Proper storage at -20°C can optimize detection of total LDH activity and the LDH isoenzyme profile in canine serum and CSF. This information is important for evaluating the potential usefulness of LDH in veterinary medicine.

Combination of imatinib and clotrimazole enhances cell growth inhibition in T47D breast cancer cells

Imatinib mesylate (IM), a tyrosine kinase inhibitor, is used as targeted cancer therapy. However, mono-targeting by IM does not always achieve full tumor eradication and thus it is recommended to combine IM with other anticancer agents. Clotrimazole (CLT) is an antifungal azole derivative with promising anticancer effects due to inhibiting the activity of glycolytic enzymes. The present study aimed to evaluate the effect of combining CLT with IM on breast cancer cell line in an attempt to establish effective new combination. T47D human breast cancer cell line was treated with different concentrations of IM and/or CLT for 48h. IM–CLT interaction was determined by isobologram equation and combination index. Cell viability was confirmed by measuring LDH activity. As indicators of glycolysis inhibition, the expression of hexokinase-2 (HK-2) and 6-phosphofructo-1-kinase (PFK-1) plus the activity of intracellular lactate dehydrogenase (LDH) and pyruvate kinase (PK) were determined. In addition, glucose consumption and adenosine triphosphate (ATP) production were measured. Moreover, nitric oxide (NO), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-α (HIF-α) were also determined as they are modulators for glycolysis. This study demonstrated that IM or CLT synergistically inhibited cell growth in T47D as shown by combination and dose reduction indices. The combination of 15μM IM and 20μM CLT significantly decreased glucose consumption, activity of both PK and intracellular LDH, while increased leaked LDH, VEGF and NO in the medium compared to each drug alone. Furthermore the combination decreased gene expression of HK-2, PFK-1 and ATP content compared to the control. In conclusion, the synergistic effect of CLT on IM cytotoxicity in T47D cell line maybe mediated through inhibition of glycolysis and increasing both NO and VEGF. Further studies are required to confirm the efficiency and safety of this combination.