ASSOCIATION OF SERUM LACTATE LEVELS WITH CREATINE KINASE – MB AND LACTATE DEHYDROGENASE IN PATIENTS WITH MYOCARDIAL INFARCTION

Objectives: Myocardial infarction is the most common form of coronary heart disease, the commonest cause of worldwide mortality. The present biochemical markers take atleast 6 hours for elevation following an episode of myocardial infarction. There is a need for sensitive marker for early diagnosis and prognosis. Lactate, the end product of anaerobic glycolysis is found to be elevated in many critical illnesses. Thus the study was undertaken to assess the levels of serum lactate in patients with myocardial infarction and to correlate it with the frequently used enzymatic markers for the diagnosis of myocardial infarction, i.e creatine kinase – MB and lactate dehydrogenase Methods: Fifty age and sex matched controls and fty cases of myocardial infarction were included in the study. Serum creatine kinase – MB, lactate dehydrogenase and lactate were estimated in these subjects. Results:The serum lactate levels were signicantly higher among cases when compared to controls. The serum lactate levels positively correlated with serum creatine kinase – MB among cases but not with lactate dehydrogenase. Conclusions: We conclude that serum lactate is altered in patients with myocardial infarction and may be considered as a prognostic risk factor in these patients. Further studies are needed to nd the cut-off value of serum lactate for assistance in the hemodynamic management of these patients.

Effect on Mouse Liver Morphology of CeO2, TiO2 and Carbon Black Nanoparticles Translocated from Lungs or Deposited Intravenously

Exposure to nanoparticles by various routes results in size-dependent translocation of nanoparticles to the systemic circulation and subsequent accumulation in the liver. The purpose of this study was to determine possible adverse effects in the liver of long-lasting nanoparticle presence in the organ. Mice exposed to a single dose (162 µg/animal equivalent to 9 mg/kg body weight) of TiO2, CeO2 or carbon black nanoparticles by intratracheal instillation or intravenous injection, resulting in relatively low or high liver burdens, were followed for 1, 28 or 180 days. Clinical appearance, feed intake, body and liver weights, hematological indices, and transaminases and alkaline phosphatase activities were unaffected by exposure. Exposure-related foreign material persisted in the liver up to 180 days after intratracheal and intravenous exposure, mainly in sinusoids, near Kupffer cells, or around blood vessels. Increased incidences of histological findings after intratracheal or intravenous exposure included: initially, prominent nuclei of Kupffer cells, the apparent increase in binucleate hepatocytes (TiO2 and carbon black) and inflammatory infiltrations (CeO2); later, cytoplasmic vacuolation, pyknosis and necrosis, especially for CeO2. Thus, neither low nor high nanoparticle burden in the liver affected enzymatic markers of liver injury, but indications of exposure-related necrotic changes, particularly for CeO2 nanoparticles, were noted.

Changes in Aphid–Plant Interactions under Increased Temperature

Thermal stress in living organisms causes an imbalance between the processes of creating and neutralizing reactive oxygen species (ROS). The work aims to explain changes in the aphid–host plant interaction due to an increase in temperature. Tests were carried out at three constant temperatures (20, 25, or 28 °C). Firstly, changes in development of Macrosiphum rosae were determined. Secondly, the activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO), and peroxidase (POD)) in aphid M. rosae tissues and host plant were analyzed at all temperatures. An increase in temperature to 28 °C had a negative effect on the biology of M. rosae by shortening the period of reproduction and longevity, thus reducing the demographic parameters and fecundity. Two stages of the aphid’s defensive response to short-term (24–96 h) and long-term (2 weeks) thermal stress were observed. Aphid defense responses varied considerably with temperature and were highest at 28 °C. In turn, for the plants, which were exposed to both abiotic stress caused by elevated temperature and biotic stress caused by aphid feeding, their enzymatic defense was more effective at 20 °C, when enzyme activities at their highest were observed.

Biomarker identification of isolated compartments of the cell wall, cytoplasm and vacuole from the internodal cell of characean Nitellopsis obtusa

Cells of characean algae are attractive for plant cell physiologists because of their large size and their close relation to higher plant cells. The objective of our study was to evaluate the purity of the compartments (cell wall, cytoplasm with plastids, mitochondria, nuclei and endomembrane system, and vacuole) separated mechanically from the internodal cells of Nitellopsis obtusa using enzymatic markers. These included α-mannosidase and malate dehydrogenase, vacuolar and cytoplasmic enzymes, respectively. The biomarkers applied revealed the degree of compartment contamination with the material from unwanted cell parts. The cell wall was contaminated slightly by vacuole and cytoplasm residuals, respectively by 12.3 and 1.96% of corresponding biomarker activities. Relatively high activity of vacuolar marker in the cell wall could be associated with the cell vacuoles in the multicellular structure of the nodes. The biomarkers confirmed highly purified vacuolar (99.5%) and cytoplasmic (86.7%) compartments. Purity estimation of the cell fractions enabled reevaluating nCuO related Cu concentrations in the compartments of charophyte cell. The internalisation of CuO nanoparticles in N. obtusa cell occurred already after 0.5h. In general, the approach seems to be useful for assessing the accumulation and distribution of various xenobiotics and/or metabolites within plant cell. All this justifies N.obtusa internodal cells as a model organism for modern studies in cell biology and nanotoxicology.

Enzymatic Defense Response of Apple Aphid Aphis pomi to Increased Temperature

Climate change, and in particular the increase in temperature we are currently observing, can affect herbivorous insects. Aphids, as poikilothermic organisms, are directly exposed to temperature increases that influence their metabolism. Heat stress causes disturbances between the generations and the neutralization of reactive oxygen species (ROS). The aim of this work is focused on explaining how the aphid, using the example of Aphis pomi, responds to abiotic stress caused by temperature increase. The experiment was carried out under controlled conditions at three temperatures: 20, 25, and 28 °C. In the first stage, changes in the activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO), and peroxidase (POD)) were determined in aphid tissues, at each temperature. In the second stage, microcalorimetry monitored changes in heat emitted by aphids, at each temperature. Our results showed that A. pomi defense responses varied depending on temperature and were highest at 28 °C. The flexible activity of enzymes and increase in the metabolic rate played the role of adaptive mechanisms and ran more effectively at higher temperatures. The A. pomi thus protected itself against ROS excessive induction and the aphids were able to respond quickly to environmental stress.

Hepatic and Renal Toxicity Induced by TiO2 Nanoparticles in Rats: A Morphological and Metabonomic Study

Titanium dioxide (TiO2) nanoparticles (NPs) are produced abundantly and are frequently used as a white pigment in the manufacture of paints, foods, paper, and toothpaste. Despite the wide ranges of uses, there is a lack of information on the impact of NPs on animal and human health. In the present study, rats were exposed to different doses of TiO2 nanoparticles and sacrificed, respectively, 4 days, 1 month, and 2 months after treatment. Dosage of TiO2 in tissues was performed by ICP-AES and revealed an important accumulation of TiO2 in the liver. The nanoparticles induced morphological and physiological alterations in liver and kidney. In the liver, these alterations mainly affect the hepatocytes located around the centrilobular veins. These cells were the site of an oxidative stress evidenced by immunocytochemical detection of 4-hydroxynonenal (4-HNE). Kupffer cells are also the site of an important oxidative stress following the massive internalization of TiO2 nanoparticles. Enzymatic markers of liver and kidney functions (such as AST and uric acid) are also disrupted only in animals exposed to highest doses. The metabonomic approach allowed us to detect modifications in urine samples already detectable after 4 days in animals treated at the lowest dose. This metabonomic pattern testifies an oxidative stress as well as renal and hepatic alterations.

Knockdown of a disintegrin A metalloprotease 12 (ADAM12) during adipogenesis reduces cell numbers, delays differentiation, and increases lipid accumulation in 3T3-L1 cells

Mouse models have shown that a disintegrin A metalloprotease 12 (ADAM12) is implicated during adipogenesis; the molecular pathways are not well understood. Stealth RNA interference was used to knock down ADAM12 in 3T3-L1 cells. Using gene profiling and metabolic enzymatic markers, we have identified signaling pathways ADAM12 impacts upon during proliferation, differentiation, and maturation of adipocytes. ADAM12 reduced cell numbers in proliferating preadipocytes, delayed differentiation of preadipocytes to adipocytes, and increased lipid accumulation in mature adipocytes. The pathway most affected by ADAM12 knockdown was regulation of insulin-like growth factor (IGF) activity by insulin-like growth factor binding proteins (IGFBPs); ADAM12 is known to cleave IGFBP3 and IGFBP5. The IGF/mTOR signaling pathway was down-regulated, supporting a role for ADAM12 in the IGFBP/IGF/mTOR-growth pathway. PPARγ signaling was also down-regulated by ADAM12 knockdown. Gene ontology (GO) analysis revealed that the extracellular matrix was the cellular compartment most impacted. Filtering for matrisome genes, connective tissue growth factor ( Ctgf) was up-regulated. CTGF and IGBP3 can interact with PPARγ to hinder its regulation. Increased expression of these molecules could have influenced PPARγ signaling reducing differentiation and an imbalance of lipids. We believe ADAM12 regulates cell proliferation of preadipocytes through IGFBP/IGF/mTOR signaling and delays differentiation through altered PPAR signaling to cause an imbalance of lipids within mature adipocytes.

Hepatic stem cells and their enzymatic markers- A review

Stem cells are those cells which show capacity for self-renewal and ability to give rise to multiple differentiated cellular populations. Enzymatic activity, as a marker for cell proliferation and cell viability, is used by metabolic activity assays. Liver stem cells/progenitor cells can be a useful source of liver treatment. They can repopulate and restore injured liver. Fetal liver stem/ progenitor cells have been found to be more capable in this, but are subjected to ethical issues. Adult liver stem cells and stem cells from animals can be used. Alkaline phosphatase and lactate dehydrogenase are enzymatic markers of in vitro hepatocyte culture. During in vitro cell culture, in the culture medium, secreted alkaline phosphatase activity increases during exponential growth of cells, whereas low extracellular lactate dehydrogenase activity indicates increased number of viable cells. Alkaline phosphatase and lactate dehydrogenase activities can be used to assess hepatocytes proliferation in vitro.