Degenerative Changes In Cells Research Articles

Transcriptome Changes Reveal the Toxic Mechanism of Cadmium and Lead Combined Exposure on Silk Production and Web-Weaving Behavior of Spider A. ventricosus.

The combined exposure of multiple metals imposes a substantial burden on the ecophysiological functions in organisms; however, the precise mechanism(s) remains largely unknown. Here, adult female A. ventricosus were exposed to single and combined exposure to cadmium (Cd) and lead (Pb) through the food chain. The aim was to explore the combined toxicity of these metals on silk production and web-weaving behavior at physiological, cellular morphological, and transcriptomic levels. The Cd and Pb combined exposure significantly inhibited the ability of silk production and web-weaving, including reduced silk fiber weight and diameter of single strands, lowered weaving position, induced nocturnal weaving, and increased instances of no-web, and showed a dose-response relationship on the Cd and Pb bioaccumulation. Concurrently, severe oxidative stress and degenerative changes in cells were observed. In addition, the combined pollution of Cd and Pb demonstrated synergistic effects, influenced by variations in concentration, on the enrichment of metals, inhibition of silk weight, oxidative damage, and cellular degeneration. At the transcriptome level, the upregulated ampullate spidroin genes and downregulated amino acid anabolic genes, upregulated Far genes and downregulated cytoskeleton-related TUBA genes, and overexpressed AChE and Glu genes may tend to present promising potential as biomarkers for silk protein synthesis, cellular degeneration, and neurotransmitter induction. This study offers an enormous capability for a comprehensive understanding of the eco-toxicological effects and mechanisms of multiheavy metals pollution.

The Exposure and Hazards of Zinc Oxide Nanoparticles: In Vitro and In Vivo Studies

Background: Extensive application of zinc oxide nanoparticles has increased the likelihood of its release into the environment and subsequent human exposure and toxicity. The toxicity is thought to be a combined effect of intracellular particles and the release of dissolved zinc ions. Objectives: This review outlines the possible mechanisms of zinc oxide toxicity in biological organs through in vitro and in vivo experiments. Methods: We reviewed articles published between 2001 and 2021. In this way, we did a manual search of Google Scholar and scientific databases, including PubMed, Web of Science, Scopus, and Embase, with keywords such as “zinc oxide nanoparticles”, “toxicity mechanism”, and “in vivo and in vitro studies”. The other qualified papers contained the history of identifying zinc oxide nanoparticles, the toxicity of metallic nanoparticles, and physical, chemical, and biological side effects with topical and systematic approaches. Results: The main mechanism suggested for zinc-based nanoparticles-induced cell damage is via the induction of increased levels of reactive oxygen species, which are oxidative stress markers. This mechanism has also been found to be a key mechanism for the cytotoxicity of other metal nanomaterials. Zinc-based nanoparticles were found to induce oxidative DNA damage, inflammation, progressive degenerative cell changes, cell cycle arrest, cytogenetic alterations, and ROS-triggered mitochondria-mediated apoptosis in human organs. Conclusion: This review sheds light on the full understanding of in vitro and in vivo toxicity assessment of zinc oxide nanoparticles, highlighting the health concerns from the perspective of ZnO nanoparticles release to the ecosystem after their increasing application.

Study of the toxic effect of trichothecene mycotoxin produced by <i>Fusarium sporotrichioides</i> in an experiment on pigs

Aim . To assess the consequences of long‐term consumption by pigs of feed experimentally contaminated with T‐2 toxin in an amount close to the most commonly found in feed. Material and Methods . The experiments were carried out on pigs, which were fed food contaminated with T‐2 toxin in the amount of 200 mkg/kg for 45 days. During the experiment, the clinical condition of animals, feed and water consumption, the dynamics of live weight, analysis of blood parameters, the state of internal organs and tissues and statistical processing of the data obtained by conventional methods were undertaken. Results . Long‐term consumption of feed contaminated with mycotoxin T‐2 by pigs did not cause a pronounced clinical picture of toxicosis. However, the treated animals had diarrhea and lag in growth and development. According to the results of the blood test, it was concluded that the toxin suppressed the hematopoiesis process, inhibited protein synthesis, reduced resistance and microphagocytic function of the body, metabolic disorders and the functioning of most organs and systems. Pathological conditions and degenerative changes of cells and tissues of internal organs were recorded and mediated by the initiation of oxidative stress, inflammatory processes and cytotoxic effect. Conclusions . The consumption of feed contaminated with T‐2 toxin in a dose of 200 mkg /kg by pigs was accompanied by disturbances of metabolic processes, functions of organs and systems, manifested by a decrease in growth intensity, changes in the blood picture, activity of enzyme systems, induction of oxidative stress, immunosuppressive and inflammatory reactions and pathomorphological disorders. Thus, the oral intake of T‐2 toxin, even in small concentrations, was found to have a complex negative effect on the body.

АНДРОКЛИННЫЕ КАЛЛУСЫ ПШЕНИЦЫ: ДАННЫЕ СКАНИРУЮЩЕЙ ЭЛЕКТРОННОЙ МИКРОСКОПИИ

The processes of formation different types of calli, as well as the morphogenesis pathways in morphogenic calli, were studied by scanning electron microscopy (SEM) during anther culture in vitro in hybrid line Fotos of spring soft wheat. The microspore haploid origin of calli has been proven. The morphological status of the obtained calli was determined. It was shown that morphogenic callus consists of small densely packed meristematic cells covered with extracellular substance. This type of calli was obtained using a variant of the Potato II induction culture medium, added by 1.0 mg/l synthetic auxin 2,4-D. Nonmorphogenic callus consists of large, elongated, loosely located cells with a smooth surface. This type of calli was obtained using a variant of the Potato II culture medium, added by 2.0 mg/l 2,4-D. It was found that the introduction of various IAA concentrations into the Blaydes nutrient medium for regeneration in morphogenic calli implements the following pathways of morphogenesis in vitro: embryoidogenesis (without IAA addition), gemmorhizogenesis (0.5 mg/l), and rhizogenesis (1.5 mg/l). Revealed degenerative changes in cells of nonmorphogenic calli. The fundamental possibility of regulating of the morphogenesis pathways of in vitro of morphogenic calli in the direction necessary for research in biotechnological research has been confirmed.

Etiology, frequency and clinical signs of aseptic jumping joint inflammation in horses

Articular pathologies in horses participating in sports and kupkari are recorded mainly at the end of the autumn season, in winter and spring, in the republic's farms out of 466 horse heads, 44 heads (9.4%) had various aseptic inflammations, for example, 8 animals have acute synovitis, 21 horses have chronic synovitis and 15 animals have periarticular fibrositis, traumatic injuries are considered the main cause of joint disease in horses participating in the Kupkari. Under the influence of the above etiological factors, degenerative changes in cells and tissues are observed, as a result of which the necessary processes in the body are disrupted and, as a result, the protective properties of the body are reduced. The animal felt pain during passive movement, and low to moderate chromate levels were observed during movement. When you press your finger on one of the tubercles of the joint, the movement of fluid towards the second tubercle is clearly felt. In animals with periarticular fibrosis, the fibrous capsule increases, the ligaments thicken, and their elasticity decreases. At the onset of the disease, pain was observed on palpation of the joint capsule and ligaments, at rest no pain was observed, but severe lameness was observed during movement, work.

Санація перещеплюваних ліній клітин від мікоплазменної інфекції

From the early 50's of last century and to nowadays the cell culture lines are a cornerstone in virological, cytological, biochemical and other biological studies. Cell cultures are essential in studying of cellular regulation mechanisms, virus interaction processes during their replication in sensitive cells, and in production of biologically active materials, including vaccines, enzymes, hormones, and monoclonal antibodies. However, today there is very common and often catastrophic problem that connected with cell line contamination by other microorganisms. Contamination with mycoplasma is of particular concern to scientists around the world. Due to difficulties in its detection, it stays unnoticed in cell cultures, having detrimental effect on cell function and morphological status. Cell cultures contamination with mycoplasmas can lead to degenerative changes in cells and their complete loss and represents a potential source of artifacts in cytological, virological and biochemical studies. Mycoplasma-contaminated cell lines are a major problem in research center laboratories and biotechnology facilities. Mycoplasmas are ultramicroscopic free-living prokaryotes whose sizes range from 200 to 400 nm. They lack a cell wall, which makes it impossible to detect them even with an ordinary microscope. In addition, mycoplasmas do not cause turbidity in cell culture media, which often accompanies bacterial or fungal cell culture contamination. The most important thing is that mycoplasma infection usually does not lead to cell death. Therefore, they can multiply and go unnoticed in a cell culture flask for a long period, becoming a major obstacle to reliable and standard in vitro experiments. Nowadays, the rehabilitation of the cell line from mycoplasmas is a very complex and urgent problem. According to many researchers, their attempts to decontaminate cell culture from mycoplasmas have been ineffective. Due to conclusions from their work, all cell lines infected with mycoplasmas are subject to immediate destruction. At the same time, the purchase of new cell lines requires considerable material costs. Therefore, there is a need to find real approaches in the rehabilitation of cell culture lines in research and production laboratories. The article represents the results of experimental studies focus on the decontamination of 12 cultures cell lines of animal origin from mycoplasmas. The research was conducted during 2019-2020 at the department of biotechnology and viral vaccine control (culture line sector) of State scientific control institute of biotechnology and strains of microorganisms. The cell culture lines with PCR-detected mycoplasma infection were used in the experiments, namely: FLK - sheep embryonic kidney cell line; PO - sheep kidney cell line; RK-13- rabbit kidney cell line; RK-15 - pig kidney cell line; MDBK- bovine kidney embryo cells; Vero- African green monkey kidney cells; Marc-145 - African green monkey kidney-derived MA-104 cells; BGM - African green monkey kidney cells; BHK-21 / clone 13 - Syrian hamster kidney cells; KST (KST) - cells of coronary vessels of cattle; SPEV (original name - SNEV) - pig kidney cells; A-72 - culture of subcutaneous tumor cells in dogs. On the early stages of the study, the optimal allowable concentration of the drug ciprofloxacin, which was used in our laboratory to rehabilitate cell cultures from mycoplasmas, was determined. It has been experimentally established that ciprofloxacin at concentration of 20 μg/cm3 completely inhibits the reproduction and life cycle of mycoplasmas and does not cause a significant effect on the cells themselves. Ciprofloxacin in concentration of 20 μg/cm3 was added into the growth and maintenance medium for five consecutive passages to the flasks with mycoplasma-contaminated cell cultures. After forming a cell monolayer in the flasks, it was always thoroughly washed five times with Hanks' solution, and only then the medium was replaced with a supportive one. Thus, the full cycle of cell culture remediation, from the moment of seeding the cells in the flasks until the next reseeding of cells took 3-4 days. 5 cycles were performed with each cell culture affected by mycoplasmas. At the completion of rehabilitation process, the samples of cell culture supernatant from each cell culture line were collected and examined by PCR for the presence of mycoplasmas. As a result, after remediation process of cell cultures mycoplasma infection was detected in only one sample. The efficiency is 88.9% and it proves that the drug ciprofloxacin can be successfully used for decontamination of cell cultures in scientific and industrial virological laboratories.

Cytotoxic effect of unclassified group K rotaviruses on T98G and U87MG glioblastoma cells in vitro.

e15597 Background: Oncolytic virotherapy is developing intensively in modern oncology. Viruses demonstrate the ability to the direct oncolysis and to the stimulation of antitumor immune activity; this experiment was aimed at solving the question of the prevalence of one of them. Glial tumors are the most common brain tumors; oncolytic viruses show certain prospects in their treatment due to the ability to penetrate the blood-brain barrier. The aim of the study was to determine the possible oncolytic effect of new unclassified group K rotaviruses (RVK) on T98G and U87MG glioblastoma cells in vitro. Methods: T98G and U87MG cell cultures were received from Russian banks of cell lines of human and animal tissues. Standard culturing was performed with attenuated apatogenic RVK strains No. 100 and No. 228 at a concentration of 108, 107, 106 and 105 particles/mL. The cytotoxic effect was determined with MTT and Annexin V assays, cell morphology was evaluated by the light-optical method. Results: Both RVK strains demonstrated a dose-dependent cytotoxic activity; the maximal effect was observed in strain No.100 at a dose of 108 particles/mL on U87MG cells (predominantly apoptosis). Studies of cell morphology showed a pronounced effect of RVK on the cell culture: significant degenerative changes in cells, a tendency to a decrease in cluster size, a change in their shape and granularity. Cluster formation in culturing in the serum-free medium is considered in the literature as a property of cancer stem cells responsible in vivo for tumor recurrence and its chemo- and radio-resistance. T98G cells demonstrated morphological changes: nuclear segmentation, diffused cytoplasm, indistinct cell borders with signs of syncytium formation. Conclusions: The established oncolytic effect of RVK strain No. 100 in vitro on glioma cells, presumably with tumor stem cells, indicates a significant potential for the use of these rotaviruses in treatment of glial tumors.

Features of macro- and microstructure of the liver, pancreas, stomach, small and large intestinesin the study of chronic toxicity of tablets "Trianol".

Background. Due to the increased requirement for evaluation of safety, drugsafety and toxicological testing of new drugs take one of the most important places in pre-clinical studies. Objective: to identify features of the macro – and microstructure of the liver, pancreas, stomach, small intestine and colon in the study of chronic toxicity of tablets Trianol. Methods. This study researched the characteristics of macro- and microstructure of the liver, pancreas, stomach, small intestine and colon in the study of chronic toxicity of tablets Trianol. Experiments performed on rats of Vistar line of both sexes weighing 180-230g, obtained from the nursery of the Institute of Pharmacology and toxicology of NAMS of Ukraine, contained in a vivarium and receiving standard diet. When working with experimental animals was guided by the requirements of the European Convention for the protection of vertebrate animals used for experimental and other scientific purposes (Strasbourg, 18.03.86). Studied the toxicity of three doses of “Trianol”: minimum (therapeutic) dose for tablets amounted to 50.0 mg/kg, intermediate – 250,0 mg/kg, maximum (subtoxic) – 500,0 mg/kg. Results . It is established that chronic introduction of trianol in a therapeutic dose induces hypertrophy of the gastric mucosa and the appearance of liver hepatocytes with signs of degeneration in cytoplasm. Identified changes are reversible. Conclusion . Intermediate and subtoxic doses cause the appearance of toxic changes in the form of swelling of the mucous membrane of the stomach, degenerative changes in cells and destruction of liver cells that must be considered when prescribing the drug. Immunotoxicaction on Peyer’s patch is not revealed.

EFFECT OF LONG-TERM VAGOTONIA ON STRUCTURAL CHANGES IN THE WALL OF ABDOMINAL AORTA DURING IMMOBILIZATION STRESS IN EXPERIMENTAL STUDY

This work covers current questions on studying structural changes in the wall of the abdominal aorta during the modelled long-term immobilization stress against vagotonia. The purpose of this study was to reveal the effect of prolonged vagotonia on the structure of the wall of the abdominal aorta in rats in the experiment. The studies were performed on three comparable groups of hundred-day Wistar rats, which were exposed to immobilization stress and vagotonia for a period of 10 days. Immobilization was chosen as a method to induce stress model. The rats were placed into a special plastic box, in this way limiting their movements for four hours at room temperature. Vagotonia was modelled by the administration of pyridostigmine bromide, reversible anticholinesterase. Histological preparations of the abdominal aorta were studied by x40, x100, x400 magnification using the Primo Star 5 microscope (Carl Zeiss, FRG) followed by photography of microscopic images. Computer morphometry was performed with x100 and x400 magnification and then the image were displayed on the computer monitor using the DVR and AxioVision image analysis software (Rel.4.8.2) in μm. We assessed the thickness of the subendothelial layer, and namely an internal elastic membrane and media. The ratio of the extent of the abdominal aorta lumen to the vascular wall was calculated in the Adobe Photoshop program by the A. A. Glagoliev method through overlaying of point grids on sections, the results were converted into percentages. The studies were carried out in five fields of five different sections in each rat. The results of the variation analysis of the morphological data obtained have revealed some features of restructuring the vascular wall of the abdominal aorta due to prolonged immobilization stress accompanied by vagotonia. It has been found out that prolonged exposure of hundred-day Wistar rats to immobilization stress leads to a decrease in thickness and certain morphological changes in all layers of the abdominal aorta wall and a decrease in the percentage of the component of the vessel wall. When accompanied by prolonged immobilization and vagotonia, preservation of the endothelial layer of the abdominal aorta was observed against the background of a decrease in intimal thickness and degenerative cell changes, as well as media thickening and focal changes in adventitia.

FORENSIC EFFICIENCY OF THE CYTOLOGICAL METHOD OF CEREBROSPINAL LIQUID RESEARCH IN POST-MORTEM INTERVAL ESTIMATION

Post-mortem interval estimation is one of the outstanding issues of forensic practice. Objective: to estimate interval and accuracy of the post-mortem interval by generalizing the time dependence of the morphology and the number of cerebrospinal fluid cells. Materials and methods. The object of study was stained samples of the cerebrospinal fluid film and its centrifuge from 30 corpses of both sexes (the main study group) with a PMI from 1 to 26 hours and 19 healthy volunteers (a comparison group). Samples of the cerebrospinal fluid (before and after centrifuging) were stained with Samson reagent and investigated in a Goryaev cell counting camera to estimate the cytosis. Subsequently, they were stained by Rosina's method and examined using light microscope to detect morphological changes in cell samples. Results. An analysis of the cytological data on morphological changes in the cells of the cerebrospinal fluid at different time intervals after the death did not reveal stable relationships between changes in cell structure and post-mortem interval. Although there is a general tendency to increase the number of cells in the first 12-14 hours (χ2=8,078; df=6; Р=0,132), further this calculation becomes impossible due to significant degenerative cell changes. Conclusion. The classic method of cytological study of biological fluids of the human body is not effective in post-mortem interval estimation.

Effect of Sanitary-Environmental Conditions of Diabetic Hypertension Incidence in Displaced Persons.

BACKGROUND:The abnormal conditions of life and genetic factors often play a major role in the incidence of “diabetes - diabetes”, heart disease and vascular disease, jaundice and posttraumatic stress.AIM:Trauma and posttraumatic stress are most common in the displaced persons, and the focus of this paper is to focus on this issue regarding cases in former Yugoslavia, and now in our country. These diseases are caused by increased beta-cell sensitivity to viruses, the development of autoimmune antibodies attacking their pancreas cells, degenerative changes in cells that result in the change of structure and of insulin production.MATERIALS AND METHODS:In this paper, we have taken into account the traumatic events and long-term psychosocial consequences for internally displaced persons, several years after displacement, and found a high level of PTSD symptoms.RESULTS:This stress is present in almost 1/3 of internally displaced persons, and every sixth person has suffered from PTSD in the past. Respondents suffer from symptoms of intrusion, but there was a large number of symptoms, such as avoidance and increased arousal. We also found that gender, age and education are related to the symptoms.CONCLUSION:Females, and older respondents and internally displaced persons with lower levels of education show a higher level of PTSD symptoms.

Ultrastructural Analysis of the Prostate Gland under the Effect of Factors of Chemical Industry.

We analyzed ultrastruciture of the cell populations in the prostate gland in chronic nonbacterial prostatitis in a chemical industry worker. It was shown that ultrastructural reorganization of the epithelium consisted in reduction of the secretory compartment of the cytoplasm and dystrophic-degenerative changes in cell organelles. Endothelial cells of the capillaries showed signs of significant degeneration and low intensity of micropinocytosis. Most of the smooth muscle cells underwent dystrophic-degenerative modifications of ultrastructural elements. The dominance of degenerative cell changes in the epithelial and stromal cell populations along with intensification of collagen formation in the absence of inflammatory elements allows us to interpret this pathological condition of the prostate gland as prostate pathology of occupational or mixed genesis.

Studies of Frequency–Dependent Changes under Modulated Ultrasound Exposure on Cells in Suspension

Characteristics of the modulated ultrasound effect (range of modulation frequencies 10Hz–1000Hz intensity 0.2 W/cm 2 ) on white blood cells (WBCs) from different animals were studied. The quantitative ratio of WBCs was the most strongly altered by ultrasonic modulation frequency 1000 Hz. This frequency led to degenerative changes of cells. The presence of non-typeable or destroyed cells in smears was indicated. The results obtained demonstrated the possibility of directed impact on different WBC forms.

Infectivity assays of human rhinovirus-A and -B serotypes.

Infectivity is a fundamental property of viral pathogens such as human rhinoviruses (HRVs). This chapter describes two methods for measuring the infectivity of HRV-A and -B serotypes: end point dilution (TCID50) assay and plaque assay. End point dilution assay is a quantal, not quantitative, assay that determines the dilution of the sample at which 50 % of the aliquots have infectious virus. It can be used for all the HRV-A and -B serotypes and related clinical isolates that grow in cell culture and induce cytopathic effect (CPE), degenerative changes in cells that are visible under a microscope. Plaque assay is a quantitative assay that determines the number of infectious units of a virus in a sample. After an infectious unit of virus infects one cell, the infected cell produces progeny viruses that then infect and kill a circle of adjacent cells. This circle of dead cells detaches from the dish and thus leaves a clear hole in a cell monolayer. Plaque assay works only for HeLa-adapted HRV-A and -B serotypes that can make visible plaques on the cell monolayer. Currently the end point dilution assay and plaque assay have not been developed for the newly discovered HRV-C.

Overview of aging research using nonhuman primate models

Overview of aging research using nonhuman primate models

Age-related changes in human and non-human primate white matter: from myelination disturbances to cognitive decline.

The cognitive decline associated with normal aging was long believed to be due primarily to decreased synaptic density and neuron loss. Recent studies in both humans and non-human primates have challenged this idea, pointing instead to disturbances in white matter (WM) including myelin damage. Here, we review both cross-sectional and longitudinal studies in humans and non-human primates that collectively support the hypothesis that WM disturbances increase with age starting at middle age in humans, that these disturbances contribute to age-related cognitive decline, and that age-related WM changes may occur as a result of free radical damage, degenerative changes in cells in the oligodendrocyte lineage, and changes in microenvironments within WM.

Antifibrotic effects of tocotrienols on human Tenon’s fibroblasts

To compare the antifibrotic effect of vitamin E isoforms alpha-, gamma-, and delta-tocotrienol on human Tenon's fibroblasts (hTf) to the antimetabolite mitomycin C. Antifibrotic effects of alpha- (40, 60, 80, 100, and 120 microM), gamma- (10, 20, 30, and 40 microM) and delta-tocotrienol (10, 20, 30, and 40 microM) on hTf cultures were evaluated by performing proliferation, migration and collagen synthesis assays. Whereas for vitamin E the exposure time was set to 7 days to mimic subconjunctival application, cultures were exposed only 5 min to mitomycin C 100 microg/ml to mimic intraoperative administration. Cell morphology (phase contrast microscopy) as an assessment for cytotoxicity and cell density by measuring DNA content in a fluorometric assay to determine proliferation inhibition was performed on day 0, 4, and 7. Migration ability and collagen synthesis of fibroblasts were measured. All tested tocotrienol isoforms were able to significantly inhibit hTf proliferation in a dose-dependent manner (maximal inhibitory effect without relevant morphological changes at day 4 for alpha-tocotrienol 80 microM with 36.7% and at day 7 for alpha-tocotrienol 80 microM with 42.6% compared to control). Degenerative cell changes were observed in cultures with concentrations above 80 microM for alpha- and above 30 microM for gamma- and delta-tocotrienol. The highest collagen synthesis inhibition has been found with 80 microM alpha-tocotrienol (62.4%) and no significant inhibition for mitomycin C (2.5%). Migration ability was significantly reduced in cultures exposed to 80 microM alpha- and 30 microM gamma-tocotrienol (inhibition of 82.2% and 79.5%, respectively, compared to control) and also after mitomycin C treatment (60.0%). Complete growth inhibition without significant degenerative cell changes could only be achieved with mitomycin C. In vitro, all tested tocotrienol isoforms were able to inhibit proliferation, migration and collagen synthesis of human Tenon's fibroblasts and therefore may have the potential as an anti-scarring agent in filtrating glaucoma surgery.

Accumulation and Effects of Nodularin from a Single and Repeated Oral Doses of Cyanobacterium Nodularia spumigena on Flounder (Platichthys flesus L.)

Nodularin (NODLN) is a cyclic pentapeptide hepatotoxin produced by the cyanobacterium Nodularia spumigena, which occurs regularly in the Baltic Sea during the summer season. In this study flounder (Platichthys flesus L.) was orally exposed to NODLN either as a single dose or as three repeated doses 3 days apart. Liver and bile samples of the fish were taken 4 days after the last dose. Liver glutathione-S-transferase (GST) activity was also measured and the histopathology of the liver was investigated. The liver of the exposed fish was analyzed by liquid chromatography-mass spectrometry for NODLN concentration. The content of NODLN-like compounds in the bile was analyzed by enzyme-linked immunosorbent assay. NODLN exposure caused slightly incoherent liver architecture and degenerative cell changes in both groups. The mean liver GST activity was significantly higher in the repeatedly dosed flounders than in the singly dosed flounders or in the control. In conclusion, the significantly lower NODLN concentration and the increased GST activity in the liver of the repeatedly dosed flounders compared to the singly dosed flounders suggest that NODLN is rapidly detoxificated. The absence of NODLN glutathione conjugates and the low concentrations of NODLN-like compounds in the bile indicate that detoxification products disintegrate or they are rapidly excreted.

NOX enzymes as novel targets for drug development

The members of the NOX/DUOX family of NADPH oxidases mediate such physiologic functions as host defense, cell signaling, and thyroid hormone biosynthesis through the generation of reactive oxygen species (ROS), including superoxide anion and hydrogen peroxide. Moreover, ROS are involved in a broad range of fundamental biochemical and cellular processes, and data accumulated in recent years indicate that the NOX enzymes comprise one of the most important biological sources of ROS. Given the high biochemical reactivity of ROS, it is not surprising that they have been implicated in a wide variety of pathologies and diseases. Prominent among the settings that feature ROS-mediated tissue injury are disorders associated with inflammation, aging, and progressive degenerative changes in cells and organ systems, and it appears that essentially no organ system is exempt. Among the disorders currently believed to be mediated at least in part by NOX-derived ROS are hypertension, aortic aneurysm, myocardial infarction (and other ischemia-reperfusion disorders), pulmonary fibrosis and hypertension, amyotropic lateral sclerosis, Alzheimer's disease, Parkinson's disease, ischemic stroke, diabetic nephropathy, and renal cell carcinoma. Several small-molecule and peptide inhibitors of the NOX enzymes have been useful in experimental studies, but issues of specificity, potency, and toxicity militate against any of the existing published compounds as candidates for drug development. Given the broad array of disease targets documented in recent work, the time is here for vigorous efforts to develop clinically useful inhibitors of the NOX enzymes. As most (though not all) NOX-related diseases appear to be mediated by a single member of the NOX family, agents with isoform specificity will be preferred, although broadly active NOX inhibitors may prove to be useful in some settings.

Atrial natriuretic peptide preconditioning protects against hepatic preservation injury by attenuating necrotic and apoptotic cell death

Background/Aims: Preconditioning of livers with the atrial natriuretic peptide (ANP) markedly reduces hepatic ischemia-reperfusion injury. Aim of this study was to characterize the influence of ANP preconditioning on necrotic and apoptotic cell death and on proliferation. Methods: Rat livers were perfused with Krebs-Henseleit buffer with or without ANP or its second messenger analogue 8-Bromo cyclic guanosine monophosphate (8-Br cGMP) for 20 min, stored in cold University of Wisconsin solution (24 h), and reperfused for up to 120 min. Apoptosis and necrosis were determined using biochemical and morphological criteria, proliferation was assessed by Ki67 histochemistry. Results: Apoptosis peaked after 24 h of cold ischemia. Preconditioning with both ANP and 8-Br-cGMP significantly reduced caspase-3-like activity and the number of triphosphate nick-end labelling-positive cells. Reduction of apoptosis was significant for hepatocytes, but not for endothelial cells. After ischemia, degenerative cell changes were clearly reduced in ANP pretreated livers. After reperfusion, ANP preconditioning led to a significant reduction of necrotic hepatocytes and endothelial cells in periportal zones. Cell proliferation was not affected by preconditioning. Conclusions: ANP reduces necrotic and apoptotic cell death without affecting the proliferation status. The protection takes place mainly in the periportal area and seems to be most prominent against necrosis of hepatocytes and endothelial cells during reperfusion.