Pathobiochemical Changes Research Articles

Comparative Evaluation of the Effect of Hepatoprotectors on Oxidative Homeostasis in the Blood of Patients with Alcoholic Hepatitis: A Randomized Experimental Study

Background. An analysis of published results on the chemical structure, pharmacodynamics and pharmacokinetics of hepatoprotective agents, as well as their practical application, shows that a holistic view on the pharmacology of hepatoprotective agents is yet to be developed. Thus, the relationship between antioxidant activity and the effectiveness of reducing hepatocyte cytolysis remains unclear. Another difficult question concerns indications for the application of hepatoprotectors, selection of a particular drug and treatment duration.Objectives. To investigate the effects of hepatoprotective agents with different mechanisms of action on the indicators of oxidative metabolism in the blood of patients with alcoholic hepatitis.Methods. Four groups of patients were involved in the study. The 1st group consisted of relatively healthy male patients (n = 15). The remaining groups (10 individuals in each) were represented by patients with moderate alcoholic hepatitis. Patients of the 2nd group received remaxol; patients of the 3rd group received ademetionine; patients of the 4th group received ursodeoxycholic acid. Prior to and following treatment, the indicators of cytolysis and oxidative stress in blood were determined. Statistical data processing was carried out using the StatPlus v 7 (AnalystSoft Inc.) software package.Results. According to the observed changes in the cytolytic syndrome marker enzymes, all three hepatoprotectors under study expressed comparable efficacy. After treatment according to any of the applied schemes, the ALT and AST activity in the blood plasma decreased by 56–68% and 75–81%, respectively, compared to their initial values. In comparison with the control group, the total antioxidant activity of the blood plasma decreased by 20–27%; the content of TBA-reactive products in the erythrocyte suspension increased by 61–87%. The remaxol, ademethionine or ursodeoxycholic acid therapy led to a partial normalization of the abovementioned parameters without significant differences between the experimental groups. The concentration of reduced glutathione in the erythrocyte suspension and the content of thiol groups in the blood plasma of patients were reduced in comparison with the control group by 16% and 26%, respectively. After therapy, these indicators also increased by 12–15%, although no predominant effect of either of the studied hepatoprotectors was revealed.Conclusion. The conducted comparative study indicated the absence of a specific antioxidant effect among the pharmacological mechanisms of action of remaxol, ademethionine and ursodeoxycholic acid. In this regard, further research should be carried out to investigate the effect of hepatoprotective drugs on pathobiochemical changes and to analyse a relationship between the antioxidant effect and the efficacy of reducing the level of hepatocyte cytolysis.

Proteomic Identification of Markers of Membrane Repair, Regeneration and Fibrosis in the Aged and Dystrophic Diaphragm.

Deficiency in the membrane cytoskeletal protein dystrophin is the underlying cause of the progressive muscle wasting disease named Duchenne muscular dystrophy. In order to detect novel disease marker candidates and confirm the complexity of the pathobiochemical signature of dystrophinopathy, mass spectrometric screening approaches represent ideal tools for comprehensive biomarker discovery studies. In this report, we describe the comparative proteomic analysis of young versus aged diaphragm muscles from wild type versus the dystrophic mdx-4cv mouse model of X-linked muscular dystrophy. The survey confirmed the drastic reduction of the dystrophin-glycoprotein complex in the mdx-4cv diaphragm muscle and concomitant age-dependent changes in key markers of muscular dystrophy, including proteins involved in cytoskeletal organization, metabolite transportation, the cellular stress response and excitation-contraction coupling. Importantly, proteomic markers of the regulation of membrane repair, tissue regeneration and reactive myofibrosis were detected by mass spectrometry and changes in key proteins were confirmed by immunoblotting. Potential disease marker candidates include various isoforms of annexin, the matricellular protein periostin and a large number of collagens. Alterations in these proteoforms can be useful to evaluate adaptive, compensatory and pathobiochemical changes in the intracellular cytoskeleton, myofiber membrane integrity and the extracellular matrix in dystrophin-deficient skeletal muscle tissues.

DYNAMICS OF MMP8 AND OSTEOPONTIN CONTENT IN ORAL LIQUID OF PATIENTS WITH ORAL DISEASES IN THE PRESENCE OF ONCOPATHOLOGY

According to WHO, breast cancer is one of the most common forms of cancer in women. In 2020, 2.3 million women were diagnosed with breast cancer and 685,000 deaths from the disease were reported worldwide. This research aims to study the dynamics of the concentration of MMP8, osteopontin, and Ca2+ ions, as well as the pH level in patients with breast cancer during chemotherapy and specific dental treatment. Materials and methods. The study involved 60 patients, both men and women. All respondents were divided into groups by their oncological diseases: group 1 consisted of 20 patients with stage II and III breast cancer after chemotherapy, without prior dental treatment, group 2 comprised 20 patients with breast cancer after chemotherapy, with previous dental treatment, the control group included 20 people without cancer and dental pathology. Results and discussion. Dental diseases in patients of both groups were manifested by significant changes in bone metabolism, which was accompanied with sharp rise of MMP8 concentration in oral fluid during reducing osteopontin concentration. It is worth noting that the above pathobiochemical changes occurred against the background of a fall in the Ca2+ ion content and a pH shift towards the acidic side. The increase in Ca2+ is associated with a decrease in MMP8 level and the elevation in pH and osteoponine. In turn, the pH has medium power feedback with MMP8 and a direct relationship of medium force with osteoponin. MMP8 and osteopontin are associated with strong feedback, that is, an increase in the level of one of them can be displayed about reducing osteopontin. Conclusion. This study has established a statistically significant increase in MMP 8 against the background of the reducing concentration of osteoponitis. Pathobiochemical changes in bone tissue were found against the background of significant loss of Ca2+ ions and pH. Dental treatment for this category of patients has led to the improvement in the concentration of these markers. The data obtained justifies the necessity of their use as diagnostic markers and laboratory screening of the effectiveness of dental treatment in patients of this category.

The evolution of ideas about the treatment of Alzheimer’s disease: from the past to the present day

Cognitive disorders are one of the most important manifestations of various cerebral pathologies. Among all the nosological forms that occur with the formation of dementia, Alzheimer’s disease is the most common. At various stages of historical development, scientists conducted numerous studies aimed at establishing effective means of its therapy. In ancient times, the emphasis was on the use of such means as baths, diets, wine, massage, mental training. In addition, various rites and rituals were practiced. A large role was given to the use of decoctions, tinctures based on medicinal plants, often with the addition of minerals and animal products. In the XIX century, physical care, being in a family environment, attempts to involve in everyday activities, restrictive measures became widespread. In the process of the development of sciences at the beginning of the XX century, pharmacological preparations began to be used. Initially, these were sedatives and diuretics based on bromine and iodine. Then vasodilating and other “vascular” means came into practice. As data on the pathogenesis of the disease accumulated, drugs that affect cholinergic transmission and other mediator systems were developed. There have also been attempts to use drugs with neurotrophic, antioxidant, and anti-inflammatory properties. The most modern direction of therapy, taking into account the main pathobiochemical changes formed in the brain in Alzheimer’s disease, is an antiamyloid strategy aimed at modifying the course of the disease.

ЕНДОТЕЛІАЛЬНА ДИСФУНКЦІЯ В УМОВАХ ЕКСПЕРИМЕНТАЛЬНОГО СУБАРАХНОЇДАЛЬНОГО КРОВОВИЛИВУ. МОЖЛИВІ ШЛЯХИ ФАРМАКОКОРЕКЦІЇ

Purpose of the article: to study the effect of acelysine and nimodipine on certain endothelial dysfunction indicators and to evaluate their therapeutic efficacy after subarachnoid hemorrhage in rats. Materials and Methods: an experimental study was carried out using 50 Wistar rats of both sexes. Spontaneous subarachnoid hemorrhage was modeled in animals. Three groups of animals were identified: a control group, a group of animals received a standard therapeutic dose of acelysine, and a group received a standard therapeutic dose of nimotop. Each group included 15 animals. There were also 5 intact animals. The animals were withdrawn from the experiment on days 4 and 7 after the motor and exploratory activity determination. Motor and exploratory activity determination was carried out following SAH with the “Open Field” technique. Determination of biochemical markers of endothelial dysfunction was performed in a rat brain homogenate. Results and discussion. It was found that modeling of subarachnoid hemorrhage (SAH) led to the oxidative stress development development and the product of oxidative modification of proteins (nitrotyrosine (Ntz) on the 4th and especially on the 7th day of the experiment) increase in the brain tissues. Starting from the 4th day, we registered a compensatory increase in the activity of NO-synthase (NOS) - by 56%, followed by a decrease in its activity on the 7th day, by more than 33% against the intact group of animals. It was registered a compensatory increase in VEGF-A in rats with SAH modeling on the 4th day of the experiment and its further decrease on the 7th day. The established pathobiochemical changes in the brain tissue were accompanied by the cognitive deficit development in experimental animals, especially on the 7th day of the SAH. SAH led to a significant decrease in the total activity of animals by 2.63 times, a decrease in the distance traveled by animals by 1.89 times, the number of freezes increased by 1.86 times and the immobility of animals increased when moving from the periphery to the center and immobility in the center of the arena (anxiety, fear, disorientation), as well as a decrease in the distance traveled and the speed of movement in illuminated center of the arena 2 and 2.6 times, respectively. Experimental therapy with acelysine 15 mg/kg led to the normalization of biochemical indicators of endothelial dysfunction: concentration of nitrotyrosine, starting from the 4th day of the experiment, increased eNOS activity and VEGF-A concentration (by 75% and 64% on 7th day). The administration of namidopine led to less pronounced effects, statistically significant changes occurred only in relation to the VEGF-A concentration. Administration of namidopine resulted in only a slight increase in VEGF-A concentration. Acelysine and nimotope significantly increased the total activity of rats on the 7th day after SAH by 76.3% and 48.8%, respectively. In animals treated with acelysine, anxiety and fear decreased. The animals were less aggressive and more empathic - long-term grooming increased 3 times. The administration of nimotop in rats survived SAH had a less pronounced positive effect on behavior. Nimotop did not effect on indicators of general activity and did not increase the total distance traveled. Animals received nimtop were inactive by the 7th day of treatment. Conclusions: Experimental therapy with acelysine led to the normalization of biochemical parameters of endothelial dysfunction, namely nitrotyrosine concentration, starting from the 4th day of the experiment and increased eNOS activity and VEGF-A concentration. It should be noted that, in contrast to the rats of the control group, under prescription of acelysine, there was an increase in the concentration of eNOS and VEGF-A both on the 4th and 7th days of the experiment. The administration of namidopine led to less pronounced effects, statistically significant changes occurred only in relation to the VEGF-A concentration. The administration of acelysin to animals after SAH had a beneficial effect on the emotional status and behavior of animals, and also led to the normalization of their general activity and orientation-exploratory activity. The mechanism of edotheliotropic effect of acelysine, in our opinion, is associated with its antioxidant effects, modulating impact on endothelial NOS, as well as its property, indirectly, to influence on increase VEGF content. Nimotope therapy had no effect on the emotional status and behavior of the animals. The use of calcium channel blockers revealed such side effects as depression, drowsiness, diplopia, and disorientation

State of the antioxidant protection system of rat liver in ischemia and reperfusion

Purpose: determination of the state of the antioxidant protection system of the cytosolic fraction and suspension of rat liver mitochondria after experimental ischemia and reperfusion. Materials and methods: the study was conducted using white mature rats, divided into 3 groups: the control group (n = 15); The 2nd group of animals (n = 15), from which the liver was taken after 15 minutes of liver ischemia; the 3rd group of rats (n = 15), from which the liver was taken after a 15-minute reperfusion period, followed by a 15-minute ischemic period. Mitochondrial suspension and cytosolic fraction were isolated from liver tissue. Results: the obtained research results showed the presence of certain pathobiochemical changes in the suspension of mitochondria and the cytosolic fraction after ischemia or reperfusion. In the mitochondrial suspension during the reperfusion period it was found an adaptive increase in the activity of glutathione peroxidase by 39% and glutathione reductase by 61%. In the cytosolic fraction, it was the most remarkable increase of the total antioxidant capacity by 38% already during ischemia and a progressive decrease in the level of reduced glutathione form by 26% in ischemic and 55% in reperfusion period. The change in the state of the antioxidant system occurred against the background of an increase in the number of products of oxidative modifications of biomolecules by 40% during ischemia and 2.2 times after reperfusion. Conclusion: The results indicate the need to develop not only a mitochondria-oriented correction of oxidative disorders, but also active support for the components of the cytosol, which provide the main accumulation of free radical damage products and their subsequent removal from the cell, which is essential for survival.

Biochemical and ultrastructural changes in the ovaries of red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) following acute imidacloprid poisoning

Abstract This study aims to inspect the effects of Imidacloprid (IMI) acute toxicity in the ovaries of the red palm weevil (Rhynchophorus ferrugineus). The LC50 of IMI was determined to be 15.7 ppm. We assessed the biochemical changes resulting from treatment with four IMI concentrations (10, 15, 20 and 30 ppm). IMI reduced acetylcholine esterase activity in a dose-dependent manner. Glutathione (GSH) content decreased with increasing concentration of IMI; however, GSH was not affected and accompanied by an increase in catalase activity with the highest concentration of IMI. Lipid peroxidation increased steadily as IMI concentration increased. Based on the ultrastructural analyses of the follicle cells and the ooplasm of developing oocytes, acute IMI toxicity produced damaged yolk bodies, pale nuclei, and shrinking microvilli. Fractionation of rough endoplasmic reticulum, deformed mitochondria, and autophagic bodies were also observed. In conclusion, these ovarian pathobiochemical changes could be used as biomarkers of acute IMI exposure.

Infectious agents as a risk factor for Alzheimer’s disease

Cognitive disorders are one of the relevant problems of modern clinical medicine. This is due to both their high frequency of occurrence and significant negative impact, which has a violation of higher cortical functions on the quality of life of patients due to the deterioration of their social communication, as well as reducing the effectiveness of professional and household functions. The main cause of cognitive disorders is Alzheimer’s disease. At the same time, according to statistical studies, a significant increase in the incidence of the number of persons in the human population as a whole suffering from this pathology is predicted. At the heart of Alzheimer’s disease is a complex of pathobiochemical changes leading to synaptic dysfunction, accompanied by the development of atrophic changes in certain areas of the brain, against which a specific clinical picture is formed. The earliest and most important manifestation of Alzheimer’s disease is memory impairment for current events, which are subsequently joined by a number of other symptoms. The literature describes certain risk factors that contribute to the development of the disease, among which a certain place is occupied by infectious pathology. However, this aspect remains largely outside the traditional study of the pathogenesis of Alzheimer’s disease. In the review the analysis of the results of modern studies confirm the possible involvement of infections in the development of dementia of Alzheimer’s type.

Proteomic identification of elevated saliva kallikrein levels in the mdx-4cv mouse model of Duchenne muscular dystrophy

Dystrophinopathies are multi-system disorders that affect the skeletal musculature, the cardio-respiratory system and the central nervous system. The systematic screening of suitable biofluids for released or altered proteins promises new insights into the highly complex pathophysiology of X-linked muscular dystrophy. However, standard detection approaches using antibody-based assays often fail to reproducibly detect low-abundance protein isoforms in dilute biological fluids. In contrast, mass spectrometric screening approaches enable the proteome-wide identification of minor protein changes in biofluids. This report describes the findings from the comparative proteomic analysis of whole saliva samples from wild type versus the established mdx-4cv mouse model of highly progressive muscular dystrophy, focusing on the kallikrein protein family. Kallikrein-1 (Klk1) and 13 Klk1-related peptidases were identified in saliva and serum from normal mice. Comparative proteomics revealed elevated saliva levels of the Klk1-related peptidases Klk1-b1, Klk1-b5 and Klk-b22, as well as an increased Klk-1 concentration, which agrees with higher Klk-1 levels in serum from mdx-4cv mice. This indicates altered cellular signaling, extracellular matrix remodeling and an altered immune response in the mdx-4cv mouse, and establishes liquid biopsy procedures as suitable bioanalytical tools for the systematic survey of complex pathobiochemical changes in animal models of muscular dystrophy.

Gender-Specific Degeneration of Dementia-Related Subcortical Structures Throughout the Lifespan.

Age-related changes in brain structure are a question of interest to a broad field of research. Structural decline has been consistently, but not unambiguously, linked to functional consequences, including cognitive impairment and dementia. One of the areas considered of crucial importance throughout this process is the medial temporal lobe, and primarily the hippocampal region. Gender also has a considerable effect on volume deterioration of subcortical grey matter (GM) structures, such as the hippocampus. The influence of age×gender interaction on disproportionate GM volume changes might be mediated by hormonal effects on the brain. Hippocampal volume loss appears to become accelerated in the postmenopausal period. This decline might have significant influences on neuroplasticity in the CA1 region of the hippocampus highly vulnerable to pathological influences. Additionally, menopause has been associated with critical pathobiochemical changes involved in neurodegeneration. The micro- and macrostructural alterations and consequent functional deterioration of critical hippocampal regions might result in clinical cognitive impairment-especially if there already is a decline in the cognitive reserve capacity. Several lines of potential vulnerability factors appear to interact in the menopausal period eventually leading to cognitive decline, mild cognitive impairment, or Alzheimer's disease. This focused review aims to delineate the influence of unmodifiable risk factors of neurodegenerative processes, i.e., age and gender, on critical subcortical GM structures in the light of brain derived estrogen effects. The menopausal period appears to be of key importance for the risk of cognitive decline representing a time of special vulnerability for molecular, structural, and functional influences and offering only a narrow window for potential protective effects.

ПОКАЗНИКИ ЕНДОТОКСЕМІЇ ПАЦІЄНТІВ ІЗ ІШЕМІЧНИМ ІНСУЛЬТОМ ТА ЦУКРОВИМ ДІАБЕТОМ ДРУГОГО ТИПУ

Diabetes is one of the generally accepted factors of acute cerebral blood flow disorders. Numerous studies have shown involvement of many factors in the pathogenesis of diabetic cerebral disorders, the most important of which are the metabolic changes, including endotoxication. The aim of this study was to measure the endotoxication parameters and total protein and albumin contents in the blood of patients with ischemic stroke and patients with stroke complicated by type 2 diabetes. Also the average sex, age of the patients, body mass index (BMI) and blood glucose and lipoproteins levels, different disease complication presents and NIH Stroke Scale with Barthel index were determined. The investigation had shown that patients with ischemic stroke, including complicated by insulin independent diabetes, were characterized by hypoproteinemia with the absence of marked changes of albumin content. The middle mass molecule (MSM) and oligopeptide contents revealed the presence of endogenous intoxication. These parameters, exceeding the control by 1.5 times, were high independently of hyperglycemia presence. The results also allowed to establish differences in BMI, hyperlipoproteinemia and increasing of NIHSS in patients with ischemic stroke and diabetes mellitus type 2 comparing with stroke alone. Thus, the development of ischemic stroke separately and under conditions of type II diabetes was characterized by increasing rates of endotoxication (middle mass molecule and oligopeptides contents) in the blood of patients, that with hypoproteinemia and hyperlipidemia may cause the secondary pathobiochemical changes in the head brain cells and mediate the negative effects of acute disorders of cerebral blood circulation.

Pharmacologicalmodification of thegabaergicsystem as a potentialvariant of cerebral protection in acute cerebral ischemia

The aim is to study the possible impact of some derivatives of gamma-aminobutyric acid (GABA), piracetam, picamilon and Krebs cycle intermediates - succinate (as sodium salt) on the pathobiochemical changes in the central nervous system, that occur under experimental playing of acute ischemic tissue damage of the cerebrum.Research methods: The study was conducted in 96 rats Wistar, who were on a standardized vivarium diet. Cerebral ischemia was caused by bond of the unilateral common carotid artery. All drugs were administered intraperitoneally once daily for 4 days after modeling of an acute cerebral ischemia after which animals were withdrawn from experiment. In the brain tissues concentrations of pyruvic, izocitric, dairy and apple acids were determined. The activity of antioxidant enzymes: catalase and superoxide dysmutaza. In addition, the brain tissues the contents of lipid peroxidation products were evaluated – diene conjugates and malonic dialdehyde. Level of brain energy production was judged by the content of the adenylic nucleotide and also phosphocreatine . The degree of destruction of the brain cells was assessed by activity of the enzyme lactate dehydrogenase in the blood and brain fraction of the creatine phosphokinase.Research results: As a result of studies, on the 4th day of ischemia a significant carbohydrate metabolism is detected, which is reflected in the sharp strengthening of anaerobic glycolysis and reduced activity of the Krebs cycle reactions, as evidenced by a significant increase in quantity of lactate and decrease in quantity of malate, isocitrate and pyruvate.A sharp strengthening of anaerobic glycolysis results in the accumulation of oxidized products and intermediates especially the latter product – lactic acid. Metabolic acidosis develops against the background of energy failure, which leads to activation of lipid peroxidation reactions. Courses appointment of the cyclic derivatives of GABA piracetam, especially Picamilon, resulted in significantly greater improvement in metabolic parameters compared with sodium succinate may to some extent explained by the higher bioavailability of these agents cells. The impact of these drugs on the nodal points of disturbed metabolism was almost equal and different in antioxidant activity. As to normalization of lipid peroxidation reactions Picamilon was most active.Conclusions: Thus, as a result of the research the following conclusions may be done.1. Bilateral bond of the common carotid artery, accompanied by severe biochemical changes in the brain tissues, that is largely similar to clinical manifestations of acute ischemic stroke.2. Course appointment of GABA derivatives in the acute period of ischemic lesions of the tissues in varyious degrees improves metabolic status of the ischemic brain and detect different degrees of manifestation of cerebral protective action.3. The activity of various GABA derivatives in respect to the different links of pathogenesis of ischemic stroke is not the same, that leads to insufficient sustainable improvement of impaired metabolism when used alone, in the long run may be justification for finding effective combinations of cerebral protective means with different mechanism of action.4. Among the studied drugs, the most active and balanced action was presented by Picamilon drug

Chaperoning heat shock proteins: Proteomic analysis and relevance for normal and dystrophin‐deficient muscle

Molecular chaperones play a key role in normal muscle function and during physiological adaptations to extensive exercise and numerous forms of cellular stress. The various classes of HSPs and related chaperones are also involved in the molecular pathogenesis of a large number of neuromuscular diseases. Several MS-based proteomic studies have recently shown that the expression levels of molecular chaperones are severely altered in dystrophin-deficient muscles. Dystrophin isoform Dp427 (where Dp427 is dystrophin protein of 427 kDa) is a large membrane cytoskeletal protein and its deficiency is the primary underlying cause of Duchenne muscular dystrophy. Current efforts have focused on the establishment of a comprehensive biomarker signature of dystrophinopathy in order to improve diagnostic methods, establish reliable prognostic factors and identify novel therapeutic targets. Following an introduction into the biology of HSPs and their general role in skeletal muscle, this review outlines the proteomic profiling of molecular chaperones in dystrophinopathy. The focus is especially on the molecular fate of HSPs cardiovascular HSP (HSPB7), αBC (HSPB5), HSP70 (HSPA) and HSP90 (HSPC) in dystrophin-deficient muscles and their involvement in progressive muscular dystrophy. Furthermore, the potential usage of distinct chaperones as disease markers of secondary pathobiochemical changes for the evaluation of novel treatment options is discussed.

Molecular and biochemical aspects of the neuroprotective effect of the selective estrogen receptor modulator tamoxifen in a model of acute cerebral ischemia

We studied the neurochemical aspects of the neuroprotective action of a selective modulator of the estrogen receptors, tamoxifen citrate, in a model of acute cerebral ischemia (ACI). It was shown that modeling of cerebral ischemia is followed by pathobiochemical changes in the brain tissue: a rapid shift of thioldisulfide homeostasis, intensification of free radical oxidation, and impaired synthesis of the cytoprotective protein Hsp70. A course of the 1 mg/kg tamoxifen citrate led to the normalization of the thiol-disulfide system due to an increase of the glutathione level in the brain tissue which, in turn, restricted the development of oxidative and nitrosative stress. In addition, Western blot analysis showed that treatment with tamoxifen citrate increased the Hsp70 level in the brain tissue, which resulted from genomic and non-genomic actions. The neuroprotective profile of tamoxifen citrate that we found here opens the future perspective of the studies in this field for introduction of this agent as a neuroprotective drug into clinical practice.

Pathobiochemical Changes in Diabetic Skeletal Muscle as Revealed by Mass-Spectrometry-Based Proteomics

Insulin resistance in skeletal muscle tissues and diabetes-related muscle weakness are serious pathophysiological problems of increasing medical importance. In order to determine global changes in the protein complement of contractile tissues due to diabetes mellitus, mass-spectrometry-based proteomics has been applied to the investigation of diabetic muscle. This review summarizes the findings from recent proteomic surveys of muscle preparations from patients and established animal models of type 2 diabetes. The potential impact of novel biomarkers of diabetes, such as metabolic enzymes and molecular chaperones, is critically examined. Disease-specific signature molecules may be useful for increasing our understanding of the molecular and cellular mechanisms of insulin resistance and possibly identify new therapeutic options that counteract diabetic abnormalities in peripheral organ systems. Importantly, the biomedical establishment of biomarkers promises to accelerate the development of improved diagnostic procedures for characterizing individual stages of diabetic disease progression, including the early detection of prediabetic complications.

The zinc/thiolate redox biochemistry of metallothionein and the control of zinc ion fluctuations in cell signaling

Free zinc ions are potent effectors of proteins. Their tightly controlled fluctuations (“zinc signals”) in the picomolar range of concentrations modulate cellular signaling pathways. Sulfur (cysteine) donors generate redox-active coordination environments in proteins for the redox-inert zinc ion and make it possible for redox signals to induce zinc signals. Amplitudes of zinc signals are determined by the cellular zinc buffering capacity, which itself is redox-sensitive. In part by interfering with zinc and redox buffering, reactive species, drugs, toxins, and metal ions can elicit zinc signals that initiate physiological and pathobiochemical changes or lead to cellular injury when free zinc ions are sustained at higher concentrations. These interactions establish redox-inert zinc as an important factor in redox signaling. At the center of zinc/redox signaling are the zinc/thiolate clusters of metallothionein. They can transduce zinc and redox signals and thereby attenuate or amplify these signals.

Effect of coenzyme Q<sub>10</sub> supplementation in the rat model of adjuvant arthritis

Adjuvant arthritis (AA) is a model of chronic inflammation induced by Mycobacterium butyricum and characterized by similar pathophysiological and pathobiochemical changes as rheumatoid arthritis (RA) in humans. In this study the antirheumatic activity of coenzyme Q(10) supplementation was tested not only as to its capability to suppress the inflammation edema of the hind paw and to improve the body weight of the arthritic animals, but also to improve so important biochemical parameters as markers of inflammation and oxidative stress, and of mitochondrial bioenergetics. Despite the unfavorable effects on the rheumatic processes observed by monitoring biometric parameters (hind paw volume, relative body weight, relative weight of spleen), a significant protective effect was observed on the level of mitochondrial energetic and antioxidant disbalance. This finding speaks in favor of CoQ(10) supplementation in rheumatic patients, presumably as combinatory therapy with classical antirheumatics, e.g. NSAIDs.

Cerebral acid—base homeostasis after severe traumatic brain injury

Brain tissue acidosis is known to mediate neuronal death. Therefore the authors measured the main parameters of cerebral acid-base homeostasis, as well as their interrelations, shortly after severe traumatic brain injury (TBI) in humans. Brain tissue pH, PCO2, PO2, and/or lactate were measured in 151 patients with severe head injuries, by using a Neurotrend sensor and/or a microdialysis probe. Monitoring was started as soon as possible after the injury and continued for up to 4 days. During the 1st day following the trauma, the brain tissue pH was significantly lower, compared with later time points, in patients who died or remained in a persistent vegetative state. Six hours after the injury, brain tissue PCO2 was significantly higher in patients with a poor outcome compared with patients with a good outcome. Furthermore, significant elevations in cerebral concentrations of lactate were found during the 1st day after the injury, compared with later time points. These increases in lactate were typically more pronounced in patients with a poor outcome. Similar biochemical changes were observed during later hypoxic events. Severe human TBI profoundly disturbs cerebral acid-base homeostasis. The observed pH changes persist for the first 24 hours after the trauma. Brain tissue acidosis is associated with increased tissue PCO2 and lactate concentration; these pathobiochemical changes are more severe in patients who remain in a persistent vegetative state or die. Furthermore, increased brain tissue PCO2 (> 60 mm Hg) appears to be a useful clinical indicator of critical cerebral ischemia, especially when accompanied by increased lactate concentrations.

Age-associated biochemical changes, Alzheimer’s disease and neuroprotection

Age is the central risk factor in the pathogenesis of the majority of Alzheimer’s disease cases. The analysis of the molecular interplay between the basic mechanisms of cellular aging and the Alzheimer-associated pathobiochemical changes may lead to a better understanding of the pathogenesis of this detrimental disorder. Employing primary human fibroblast cultures from biopsy material of controls and presenilin–1 mutants the cellular processing of the amyloid precursor protein (APP) has been investigated. Indeed, the biochemical changes that occurred during the process of replicative senescence in these fibroblast cultures have a dramatic impact on the processing of APP. Moreover the oxidative stress that is accumulating over the aging process may also influence APP processing perhaps through an effect on the membrane subdomains. A better understanding of the influence of age at the cellular and molecular level of aging at a cellular and molecular level on Alzheimer’s associated biochemistry may lead to novel concepts of prevention and therapy. Moreover it is well known that during aging a variety of neuroprotective factors are depleted further supporting the idea that the aging process is rendering nerve cells more vulnerable to disease associated insults. A better understanding of the age process itself at a cellular and molecular level will help to understand age-associated neurodegenerative disorders.

Oxidative metabolites of 5-S-cysteinyldopamine inhibit the pyruvate dehydrogenase complex.

The principal neuropathological feature of Parkinson's disease is the degeneration of melanized dopamine neurons in the substantia nigra pars compacta (SNc). Characteristic pathobiochemical changes in the parkinsonian SNc include a fall of both dopamine (DA) and glutathione levels (GSH), increased activity of gamma-glutamyl transpeptidase, a key enzyme involved in the degradation of GSH to L-cysteine (CySH), together with evidence for elevated intraneuronal superoxide (O2-*), nitric oxide (NO.) and thence peroxynitrite (ONOO-) generation, and accelerated DA oxidation as indicated by a large rise of the 5-S-cysteinyldopamine (5-S-CyS-DA)/DA concentration ratio. The latter effect is consistent with an increased rate of DA oxidation by O2-* and ONOO- forming DA-o-quinone which reacts with CySH forming 5-S-CyS-DA. However, 5-S-CyS-DA is readily further oxidized to 7-(2-aminoethyl)-3,4-dihydro-5-hydroxy-2H-1,4-benzothiazine-3-carboxylic acid (DHBT-1). Previous studies have demonstrated that DHBT-1 is rapidly accumulated by isolated intact rat brain mitochondria and selectively inhibits complex I respiration and the alpha-ketoglutarate dehydrogenase (alpha-KGDH) complex. In this study it is demonstrated that DHBT-1 also inhibits the pyruvate dehydrogenase complex (PDHC). The mechanism underlying the inhibition of all of these enzyme complexes involves bioactivation of intramitochondrial DHBT-1 by oxidation to highly electrophilic metabolites that covalently bind to active site cysteine residues. Thus, oxidative metabolites of intraneuronal 5-S-CyS-DA may contribute to impaired mitochondrial complex I and alpha-KGDH activities known to occur in the parkinsonian SNc and suggest that impaired PDHC evoked by the same metabolites may also occur in PD.