Cell Tissue Damage Research Articles

Механизмы поражения соединительной ткани при фибромускулярной дисплазии и атеросклерозе: возможности визуализации

Multifocality, high prevalence and lack of consensus on the etiopathogenesis of atherosclerosis and fibromuscular dysplasia (FMD) in the human population are well known. However, the issues of comorbidity and mechanisms of connective tissue damage in these pathologies remain unclear. The purpose of this study was to determine the leading causes of pathological arterial stenosis in patients with clinical signs of vascular disorders. Materials and methods. The research involved 67 patients (mean age 51.12 ± 13.12 years) with clinical signs of vascular disorders, who had received neurological or neurosurgical treatment at Surgut Clinical Trauma Hospital. The subjects underwent computed tomography angiography of brachiocephalic and intracranial vessels. To assess the internal stigmatization of the processes under study, author’s scales were developed. Results. The data of the author’s scales clearly indicate the influence of the genetically determined FMD process on the manifestations of atherosclerosis. The most frequent combinations of FMD stigmas and atherosclerotic lesions identified in the course of the study can serve as markers of the severity of these pathologies. The results allow us to view FMD and atherosclerosis in the context of morphofunctional connective tissue disorders. Paradoxically, despite the systemic nature of the two processes, their gross manifestations were clearly localized. This is probably due to the time interval of connective tissue cell damage and its nature. In our opinion, pathology in atherosclerosis develops during postnatal ontogenesis due to the increasing cytokinetic activity of connective tissue cells under the influence of various factors (atherogenic lipoproteins circulating in the vascular bed, microbiome disturbance, etc.). In FMD, fibroblasts get damaged by genetic mutations at the stage of embryonic development (vasculogenesis), gross stigmas are formed in areas of blood vessels with the most rapid growth due to the haemodynamic conditions of the onset of blood circulation (angiogenesis).

Synergistic Effects of Heating Platens’ Temperature and Compression Ratio on the Periodic Hot-Press Drying of Chinese Fir Lumber

The effects of periodic hot-press drying on drying behavior and mechanical damage to Chinese fir lumber were investigated by taking the heating platens’ temperature (TP) and compression ratio (Rc) as experimental factors. The temperature and pressure inside lumber were analyzed during drying process. The results were as follows. The drying rate of lumber was significantly increased with increasing TP and Rc. Scanning electron microscope (SEM) micrographs showed that bordered pit membranes, cross-field pits, middle lamella between adjacent cells, and tracheid walls were damaged after drying, and the damage became more severe with higher TP and Rc. Detachments between ray parenchyma cells and tracheids were observed at 170 °C. Nitrogen-adsorption measurement results demonstrated that more cell wall pores in the 2.5~6.2 nm pore diameter range were generated at higher TP, resulting in an enlarged specific surface area and pore volume of cell walls. These structural changes contributed to accelerating moisture migration and decreasing the drying time. Furthermore, fluctuating pressure inside lumber was the main driving force leading to moisture migration and cell tissue damage in lumber during drying. The influence of TP on internal temperature (TM) and pressure (PM) was greater than Rc. With the increase in TP from 130 to 170 °C at the Rc of 10%, the maximum TM and PM were increased by 30.90% and 39.84%, respectively. However, TP should not be too high to prevent the formation of macro-cracks caused by high pressure, which may significantly affect wood’s mechanical properties. These results provide theoretical support for periodic hot-press drying processes’ improvement and high-value utilization of Chinese fir.

Polyvalent passive vaccine candidates from egg yolk antibodies (IgY) of important outer membrane proteins (PF1380 and ExbB) of Pseudomonas fluorescens in fish

Polyvalent antibodies can resist multiple bacterial species, and immunoglobulin Y (IgY) antibody can be economically prepared in large quantities from egg yolk; further, IgY polyvalent antibodies have application value in aquaculture. The outer membrane proteins (OMPs) PF1380 and ExbB of Pseudomonas fluorescens were expressed and purified, and the corresponding IgY antibodies were prepared. PF1380, ExbB, and the corresponding IgY antibodies could activate the innate immune responses of chicken and Carassius auratus. The passive immunization to C. auratus showed that the IgY antibodies of PF1380 and ExbB had an immune protection rate, down-regulated the expression of antioxidant-related factors (MDA, SOD, GSH-Px, and CAT) to reduce the antioxidant reaction, down-regulated the expression of inflammation-related genes (IL-6, IL-8, TNF-α, and IL-1β) to reduce the inflammatory reaction, maintained the integrity of visceral tissue structure, and reduced apoptosis and damage of tissue cells in relation to P. fluorescens and Aeromonas hydrophila infections. Thus, the IgY antibodies of PF1380 and ExbB could be considered as passive polyvalent vaccine candidates in aquaculture.

Roflumilast reduces myocardial ischemia reperfusion injury invivo and invitro by activating the AMPK signaling pathway.

Myocardial tissue cell damage induced by myocardial ischemia/reperfusion (MI/R) notably elevates the mortality rate, increases the complications of patients with myocardial infarction and decreases reperfusion benefit in patients suffering from acute myocardial infarction. Roflumilast protect against cardiotoxicity. Therefore, the present study aimed to investigate the effect of roflumilast on MI/R injury and the underlying mechanisms. To simulate MI/R in vivo and in vitro, the rat model of MI/R was established and H9C2 cells were subjected to hypoxia/reoxygenation (H/R) induction, respectively. The myocardial infarction areas were observed by 2,3,5-triphenyltetrazolium chloride staining. The myocardial enzyme levels in serum and levels of inflammatory cytokines and oxidative stress markers in cardiac tissue were assessed by corresponding assay kits. The cardiac damage was observed by hematoxylin and eosin staining. The mitochondrial membrane potential in cardiac tissue and H9C2 cells was detected using the JC-1 staining kit. The viability and apoptosis of H9C2 cells were detected by Cell Counting Kit-8 and TUNEL assay, respectively. The levels of inflammatory cytokines, oxidative stress markers and ATP in H/R-induced H9C2 cells were analyzed by corresponding assay kits. Western blotting was used for the estimation of AMP-activated protein kinase (AMPK) signaling pathway-, apoptosis- and mitochondrial regulation-associated protein levels. The mPTP opening was detected using a calcein-loading/cobalt chloride-quenching system. The results indicated that roflumilast decreased MI/R-induced myocardial infarction by alleviating myocardial injury and mitochondrial damage through the activation of the AMPK signaling pathway. In addition, roflumilast mitigated viability damage, alleviated oxidative stress, attenuated the inflammatory response and decreased mitochondrial damage in H/R-induced H9C2 cells by activating the AMPK signaling pathway. However, compound C, an inhibitor of the AMPK signaling pathway, reversed the effect of roflumilast on H/R-induced H9C2 cells. In conclusion, roflumilast alleviated myocardial infarction in MI/R rats and attenuated H/R-induced oxidative stress, inflammatory response and mitochondrial damage in H9C2 cells by activating the AMPK signaling pathway.

Research of impact of discharge parameters of electric impulse on the damage of tissue cells of the fig and the drying process and determination of its parameters

The results of experimental research of improving the process of drying the locally grown figs by their initial treatment in an electric pulse field are given in this article. The results of the experiment were processed by mathematical statistics methods. The degree of tissue damage of the fig fruit is related to electric impulse discharge voltage. The results of the experimental research were conducted in order to determine the degree of tissue damage of fig fruit related to electric impulse discharge voltage. Processing of the results of all the experiments presented in the article with statistical methods was carried out based on the above methodology. The rest of the experimental results and statistical processing results are given in the form of tables and conclusions.

Hormonal Regulation of Renal Fibrosis.

Fibrosis is a severe complication of many acute and chronic kidney pathologies. According to current concepts, an imbalance in the synthesis and degradation of the extracellular matrix by fibroblasts is considered the key cause of the induction and progression of fibrosis. Nevertheless, inflammation associated with the damage of tissue cells is among the factors promoting this pathological process. Most of the mechanisms accompanying fibrosis development are controlled by various hormones, which makes humoral regulation an attractive target for therapeutic intervention. In this vein, it is particularly interesting that the kidney is the source of many hormones, while other hormones regulate renal functions. The normal kidney physiology and pathogenesis of many kidney diseases are sex-dependent and thus modulated by sex hormones. Therefore, when choosing therapy, it is necessary to focus on the sex-associated characteristics of kidney functioning. In this review, we considered renal fibrosis from the point of view of vasoactive and reproductive hormone imbalance. The hormonal therapy possibilities for the treatment or prevention of kidney fibrosis are also discussed.

Cytotoxic and Inflammatory Effects of Electronic and Traditional Cigarettes on Oral Gingival Cells Using a Novel Automated Smoking Instrument: An In Vitro Study.

Information about the potential oral health effects of vaping from electronic cigarettes (e-cigs) is still sparse and inconsistent. The purpose of this study was to compare the safety and cytotoxicity of e-cig liquid aerosols versus traditional cigarette (t-cig) smoke on human epithelial oral cells. T-cig smoke and e-cig aerosols were generated by a newly developed automated smoking instrument in order to simulate realistic user puffing behaviors. Air–liquid interface transwell cell cultures were exposed to standardized puff topography (puff duration: 2 s, puff volume: 35 mL, puff frequency: 1 puff every 60 s) of reference t-cigs or commercially available e-cigs at different air dilutions. Cell viability, morphology, and death rate were evaluated with MTT and TUNEL assays. The inflammatory cytokine gene expression of inflammatory genes was assessed by quantitative RT-PCR. E-cigs and t-cigs indicated similar adverse effects by enhancing cytotoxicity and cell death in a dose-dependent manner. E-cig aerosol and t-cig smoke treatment expressed upregulation of inflammatory cytokines up to 3.0-fold (p < 0.05). These results indicate that e-cig smoking may contribute to oral tissue–cell damage and tissue inflammation. Our approach allows the production of e-cig aerosol and t-cig smoke in order to identify harmful effects in oral tissues in vitro.

EFFECTS OF RED DRAGON FRUIT PEEL EXTRACT ADMINISTRATION ON NEUTROPHIL COUNTS FOLLOWING PERIAPICAL RADIOGRAPHY EXPOSURE

Background: Radiation exposure from periapical imaging can cause cell damage in various tissues due to the formation of free radicals. Cell damage in the tissue can be observed from the number of neutrophils which are immune cells. Free radicals can be suppressed by administering exogenous antioxidants. One source of natural antioxidants is red dragon fruit, especially on its peel. Objective: To analyze the effect of periapical imaging x-ray radiation exposure after the administration of red dragon fruit peel extract on absolute neutrophil counts in mice. Method: This research was a true experimental study with a post-test only and control group design using 24 mice that were divided into 6 groups. The control group was not given any treatment while P1 to P5 group were given red dragon fruit peel extract at a dose of 100 mg/kg BW and exposed to radiation with different exposures. P1 group was exposed 1 time (0.63 mGy), P2 group was exposed 4 times (1.66 mGy), P3 group was exposed 8 times (4.37 mGy), P4 group was exposed 12 times (8.19 mGy), and group P5 was given no exposure. Results: There were changes in the number of neutrophils in all groups. The LSD Posthoc test results showed a significant difference between the control group (12.470 / mm3) and the P5 group (12.470 / mm3) compared to P3 group with 8 times exposure (40.348 / mm3). Conclusion: There is an effect of periapical radiographic x-ray radiation exposure by red dragon fruit peel extract on the absolute neutrophil count in mice. Keywords: Antioxidants, Neutrophils, Periapical Radiography, Radiation, Red Dragon Fruit Peel.

Phytochemical Analysis and Comprehensive Evaluation of Antimicrobial and Anti-oxidant Properties of L.acidissima

As the microorganisms have developed the inherent ability to develop and adopt a mechanism of resistance against antibiotics. The harmful side effects of antibiotic including their cost of drug development have slowly shifted toward the plant derived phytochemical based medicines. The screening of antimicrobial property of this medicinal plant shows apositive result against the different species of bacteria (S. aureus, P. aeruginosa and fungi (A. Niger, Fusarium). This study of phytochemicals shows the important part to prevent and protect the plant against the microorganisms as well as phytochemicals to provide the information about the compound which are responsible for the antimicrobial activity like Alkaloids, Phenolics, Flavonoids etc. This plant has enough amount of Total phenolics and hence, it has a high anti-oxidant activity. The anti-oxidant activity involve in the prevention of plant cell tissue damage. Anti-oxidant activity is measured by DPPH. The L. acidissima plant have many applications such as in bale diarrhea, dysentery, used for liver, cardiac tonic and effective for high cough, sore throat.

Phagocytosis of Astaxanthin-Loaded Microparticles Modulates TGFβ Production and Intracellular ROS Levels in J774A.1 Macrophages

Radiation-induced fibrosis is a serious long-lasting side effect of radiation therapy. Central to this condition is the role of macrophages that, activated by radiation-induced reactive oxygen species and tissue cell damage, produce pro-inflammatory cytokines, such as transforming growth factor beta (TGF). This, in turn, recruits fibroblasts at the site of the lesion that initiates fibrosis. We investigated whether astaxanthin, an antioxidant molecule extracted from marine and freshwater organisms, could help control macrophage activation. To this purpose, we encapsulated food-grade astaxanthin from Haematococcus pluvialis into micrometer-sized whey protein particles to specifically target macrophages that can uptake material within this size range by phagocytosis. The data show that astaxanthin-loaded microparticles are resistant to radiation, are well-tolerated by J774A.1 macrophages, induce in these cells a significant reduction of intracellular reactive oxygen species and inhibit the release of active TGF as evaluated in a bioassay with transformed MFB-F11 fibroblasts. Micro-encapsulation of bioactive molecules is a promising strategy to specifically target phagocytic cells and modulate their own functions.

Possible protective role of melatonin on heat stress induced apoptosis

During the onset of heat stroke, heat is the most fundamental cause of injury. It has been demonstrated in a number of animal and cell experiments that hyperthermia can directly induce tissue damage and cell death, and cells can activate apoptotic signals or direct necrosis depending on the extent of heat stress. In general, high heat stress activates apoptotic signals and induce apoptosis. Therefore, the form of damage of tissue cells during the onset of heat stroke is currently considered to be mainly apoptosis. In recent years, it has been found that the heat stress molecular biology research regulates the physiological activities of cells in a wide range and participates in the intracellular signal transduction process. Melatonin and its metabolites are broad-spectrum antioxidants and free radical scavengers that regulate a variety of molecular pathways, such as inflammation, proliferation, apoptosis, and metastasis, under different pathophysiological conditions. This article summarized the research on the effects of melatonin and heat shock on apoptosis, and evaluated the possible protective effects of melatonin on the pathogenesis of heat stroke, and provided new therapeutic ideas for the clinic.

In vitro toxicity assessment of nanocrystals in tissue-type cells and macrophage cells.

Nanocrystals (NCs), a type of innovative material particle, are a potential drug delivery platform that aims to improve the bioavailability of hydrophobic drugs. However, due to the lack of consideration of their toxicity, existing studies have not investigated whether the nanoscale properties of NCs, such as particle sizes, may lead to NC-induced toxicity. Because of the disparity between the rapid development of NCs and the lack of studies regarding NC toxicity, the present study investigated possible NC toxicity and clarified the relationship between particle sizes and NC toxicity. RAW264.7 and HepG2 cells were chosen as representatives of macrophage cells and tissue-type cells, respectively. Monosodium urate NCs were used as a drug model. Different particle sizes of monosodium urate NCs were prepared using precipitation methods. Methyl tetrazolium, lactate dehydrogenase, oxidative stress and apoptosis/necrosis assays were then used to evaluate cell damage and recovery. The results showed that small NC particle sizes produced higher toxicity than larger ones. In immune cells, these cytotoxic effects were greater than in tissue cells. After removal of small NCs, tissue cell damage could be significantly reversed, while immune cells were only slightly restored. However, after removal of large NCs, both cell types had almost no recovery. In summary, despite conventional wisdom, our research confirmed that NCs are not very safe and that NC particle sizes are closely related to the degree of NC toxicity.

Circulating cell-free DNA levels in Portuguese patients with psoriasis vulgaris according to severity and therapy

Inflammation has a key role in the pathogenesis of psoriasis. Circulating cell-free DNA (CFD) is a marker of tissue cell damage closely associated with inflammation. We aimed to understand the relation of CFD levels with psoriasis severity, defined by the Psoriasis Area and Severity Index (PASI), with inflammation and with psoriasis therapy. Forty-six patients with psoriasis vulgaris were evaluated before (T0) and after 12weeks (T12) of treatment with narrowband ultraviolet light B (NB-UVB; n=17), psoralen plus UVA (PUVA; n=20) or topical therapy (n=9). We evaluated interleukin (IL)-6 and circulating CFD levels. Compared with controls, at T0, patients presented significantly higher levels of circulating CFD. CFD presented a significant positive correlation with IL-6 and a trend towards a positive correlation with PASI. Multiple linear regression analysis identified IL-6 as an independent variable associated with CFD circulating levels. As shown by the PASI score, a trend towards higher values of CFD was observed in the severe psoriasis forms; moderate and severe psoriasis presented also significantly higher CFD values, compared with control. Both NB-UVB and PUVA treatments significantly decreased the levels of CFD. Patients with psoriasis, at the active stage of the disease, presented an increased inflammation associated with raised circulating CFD levels, which seem to be linked to psoriasis severity. Both NB-UVB and PUVA, anti-inflammatory therapies, were effective in decreasing CFD values. We propose that the evaluation of circulating CFD may provide a new biomarker to monitor psoriasis, its severity and its treatment.

OP172: The effect of hyperbaric oxygen therapy on treatment of wound complications after oral and (pharyngo) laryngeal salvage surgery

Purpose (Chemo) radiotherapy which is often used for cancer in the head and neck leads to damage of tissue cells and vasculature. Surgery in such compromised tissues increased complications rate, because wound healing with angiogenesis and fibroplasias, requires normal cell growth conditions. Hyperbaric oxygen therapy raises oxygen levels in hypoxic tissue, stimulates angiogenesis and fibroplasia. In this study, we have reviewed the possible clinical value of hyperbaric oxygen therapy for major wounds that show no signs of healing or fistulas after salvage surgery in patients treated with (chemo) radiation of the head and neck regions. Methods In this retrospective study, 16 patients with soft-tissue wounds without signs of healing after salvage surgery in (chemo) irradiated head and neck regions were treated with hyperbaric oxygen therapy. The patients were treated by HBO, 2.5 bars 90 min daily, usually 20 treatments. Results The healing processes seemed to be initiated and accelerated by HBO. 14 of the 16 the patients healed completely. There no life-threatening complications. Conclusion (Chemo) radiotherapy leads to damage of tissue cells and vasculature. Salvage surgery in such tissues has an increased complications rate, because wound healing requires angiogenesis and fibroplasias, all of which are jeopardized. Hyperbaric oxygen therapy raises oxygen levels in hypoxic tissue, stimulates angiogenesis and fibroplasias and is an effective and powerful treatment for postoperative wounds in oral and (pharyngo) laryngeal carcinoma surgery.

Plasma lipid pattern and red cell membrane structure in β-thalassemia patients in Jakarta

Background: Over the last 10 years, we have investigated thalassemia patients in Jakarta to obtain a comprehensive picture of iron overload, oxidative stress, and cell damage. Methods: In blood samples from 15 transfusion-dependent patients (group T), 5 non-transfused patients (group N) and 10 controls (group C), plasma lipids and lipoproteins, lipid-soluble vitamin E, malondialdehyde (MDA) and thiol status were measured.&nbsp; Isolated&nbsp; eryhtrocyte&nbsp; membranes&nbsp; were&nbsp; investigated&nbsp; with&nbsp; electron&nbsp; paramagnetic&nbsp; resonance&nbsp; (EPR)&nbsp; spectroscopy&nbsp; using doxyl-stearic acid and maleimido-proxyl spin lables. Data were analyzed statistically with ANOVA. Results: Plasma triglycerides were higher and cholesterol levels were lower in thalassemic patients compared to controls. Vitamin&nbsp; E,&nbsp; group&nbsp; C:&nbsp; 21.8&nbsp; vs&nbsp; T:&nbsp; 6.2&nbsp; μmol/L)&nbsp; and&nbsp; reactive&nbsp; thiols&nbsp; (C:&nbsp; 144&nbsp; vs.&nbsp; T:&nbsp; 61&nbsp; μmol/L)&nbsp; were&nbsp; considerably&nbsp; lower&nbsp; in&nbsp; transfused patients, who exert clear signs of oxidative stress (MDA, C: 1.96 vs T: 9.2 μmol/L) and of tissue cell damage, i.e.,&nbsp; high&nbsp; transaminases&nbsp; plasma&nbsp; levels.&nbsp; Non-transfused&nbsp; thalassemia&nbsp; patients &nbsp;have&nbsp; slight&nbsp; signs&nbsp; of&nbsp; oxidative&nbsp; stress,&nbsp; but&nbsp; no&nbsp; signifi&nbsp; cant&nbsp; indication&nbsp; of&nbsp; cell&nbsp; damage.&nbsp; Erythrocyte&nbsp; membrane&nbsp; parameters&nbsp; from&nbsp; EPR&nbsp; spectroscopy&nbsp; differ&nbsp; considerably&nbsp; between all groups. In transfusion-dependent patients the structure of the erythrocyte membrane and the gradients of polarity and fl uidity are destroyed in lipid domains; binding capacity of protein thiols in the membrane is lower and immobilized. Conclusion: In&nbsp; tranfusion-dependent&nbsp; thalassemic&nbsp; patients,&nbsp; plasma&nbsp; lipid&nbsp; pattern&nbsp; and&nbsp; oxidative&nbsp; stress&nbsp; are&nbsp; associated&nbsp; with structural damage of isolated erythrocyte membranes as measured by EPR spectroscopy with lipid and protein-thiol spin labels. (Med J Indones 2011; 20:178-84)

Clinical research of calcium folinate rescue in high-dose methotrexate therapy at different times

Objective To explore the clinical effects of calcium folinate(CF)rescue on high-dose methotrexate (HDMTX)therapy at different times.Methods Children with acute lymphocytic leukemia(ALL)who met the inclusion criteria were randomly divided into two groups in line with chemotherapy order:observation group(Group A)and control group(Group B).Chemotherapy regimens included remission induction chemotherapy(VDLD),consolidation therapy(CAT),shelters to prevent(HDMTX+CF),reinduction therapy.Group A was intravenously injected HDMTX for 24 hours and then rescued by CF for 12hours.Group B was intravenously injected HDMTX for 6 hours and then rescued by CF for 30 hours.Side effects after administration of medicine were observed,in particular,the gastrointestinal tract reaction,which included nausea and vomiting,oral mucous membrane reaction,leukocyte reaction,the toxicity of the heart,liver,kidney,nerve and response durations.Results There were significant differences in both groups on response degree in the gastrointestinal tract reaction,oral mucous membrane reaction,and leukocyte reaction (P 0.05).Conclusions There are differences in side effects of CF rescue on HDMTX therapy at different times.Both groups could reduce the toxic reaction,but the protocol that gives HDMTX for 24 hours and then rescues by CF for 12 hours is more conducive to repair the normal tissue cell's damage,improve chemotherapy efficacy and children's quality of life,with a better clinical value. Key words: Calcium folinate; Methotrexate; Toxicity; Rescue

Relation between iron content of serum ferritin and clinical status factors extracted by factor analysis in patients with hyperferritinemia

Objectives The aims of this study were to develop a new technique for determination of iron content of serum ferritin (ICF, μmol Fe/mg protein) and to investigate relations between ICF and clinical status in patients with hyperferritinemia. Methods ICF values were determined by a combination of immunoprecipitation of ferritin and direct colorimetric iron assay. One hundred fifty patients with hyperferritinemia were screened. Factor analysis of the results of 11 laboratory tests was applied to extract factors representing the clinical status of patients. Relations between the extracted factors and the ICF values or serum ferritin concentrations were assessed. Results Within-run coefficients of variation (CVs) of the ICF assay were ≦5.7%. The mean ICF value of 150 patients was 0.423 μmol/mg (SD, 0.211 μmol/mg). Three factors representing clinical status were identified: inflammation, tissue cell damage, and body iron status. Serum ferritin level correlated with all three factors. In contrast, ICF correlated significantly only with the factor representing tissue cell damage (r = 0.293, p = 0.001), and this correlation was independent of inflammation and iron status ( p = 0.008). Conclusions ICF changes in response to tissue cell damage independent of inflammatory and body iron statuses, whereas serum ferritin changes in response to all three pathologic statuses.

Microvascular coagulopathy and disseminated intravascular coagulation.

To review the dual characteristics of disseminated intravascular coagulation (DIC), as both a contributor to multiple organ failure as well as a symptom of severe underlying disease associated with systemic vascular changes. Published literature data and unpublished results from the authors. Clinical and experimental studies strongly suggest that DIC contributes to multiple organ failure and death in patients with severe systemic disorders such as sepsis. DIC is evoked by systemic cytokine activity, and the inflammatory response aggravates vascular permeability, inflammation, and cell damage in tissues. In addition to intravascular fibrin formation, thrombin and fibrin generation in tissues is also an important aspect of DIC. An example of DIC at the organ level is adult respiratory distress syndrome, where fibrin in the lung is a characteristic feature. Intravascular fibrin formation and occlusion may elicit a hypoxic response with induction of hypoxia related transcription factors. The resulting ischemic preconditioning may offer protective effects to the involved organ(s). Overall, the beneficial or harmful effects of activated coagulation and fibrin formation for organ pathology and recovery from DIC remain to be explored. This may be a critical element in the assessment of ischemia-reperfusion effects of specific anticoagulant therapy.

In situ assessment of cell viability

Cryobiological studies of tissues often require the simultaneous assessment of tissue structure and in situ cellular function. Localization of damage during cryopreservation occurs as a consequence of tissue structure and morphology and as a result of biophysical constraints imposed by diffusion and heat transfer. This study used five experimental model tissue systems: cells in suspension, cells attached to a substrate, a monolayer of cells attached to a substrate, porcine corneas, and intact porcine articular cartilage to examine the efficacy of assessing cell recovery using a novel fluorescent stain (SYTO-13). A graded freezing protocol was used to induce varying degrees of tissue damage. Recovery was assessed in the different tissue model systems using SYTO with ethidium bromide, fluorescein diacetate (FDA) with ethidium bromide, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). In each of the tissue model systems, the SYTO/EB assessment technique was shown to be equally effective as the existing techniques for the determination of cell recovery. In addition, the properties of fluorescence intensity and rate of release for SYTO were significantly better than those obtained using FDA. Assessment of in situ cell viability was clearly demonstrated using porcine corneas and articular cartilage. The SYTO/EB assay is superior to the existing techniques used for the localization of cell damage in tissues after cryopreservation.

Enhanced protection of human cells against ultraviolet light by antioxidant combinations involving dietary carotenoids

Antioxidants like β-carotene, α-tocopherol and ascorbic acid should be able to protect human cells against damage due to ultraviolet light. Cultured human fibroblasts have been irradiated with UVA or UVB light after incubation with the antioxidants or combinations of them. The efficiency of the protection by the antioxidants in dietary concentrations is estimated by cell counting following cell culture. In the case of UVA irradiation we find synergistic effects of combinations with β-carotene as the main protector. On the other hand, only additive effects of the tested combinations are observed in the experiments with UVB light. Our experiments show a protective effect of dietary antioxidants against human tissue cell damage by ultraviolet light.