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PubMed2002

[Progress in research on heat shock proteins in cardiovascular system].

Diverse physiological stresses (e.g., heat shock, ischemia and hemodynamics) produce multiple changes in a cell that affect metabolic processes and cellular structures. In response, stress proteins are synthesized, and are thought to mediate cytoprotection through biological function as molecular chaperones. Accumulated evidence indicates that HSP70, HSP90, HSP47, HSP32 and HSP27 play an important role during cardiac ischemia, ischemia preconditioning, cardiac hypertrophy and vascular wall injury.

Animals↗
PubMed2003

[Changes in the gene expression profile of the left heart ventricle during growth in the rat].

Wistar rats of 8, 10 and 12-week-old were chosen for study of the relationship between cardiac growth and its gene expression profile changes during maturation. The ultrasonic parameters of rat hearts were recorded before sacrifice, then total RNA of left ventricle were extracted and gene expression profiles were analyzed by cDNA microarray. During growth from 8 weeks to 12 weeks, the body weight increased by 45.5% (287+/-13 g vs 197+/-10 g), and the increment in the first two-week period was equal to that of the second two-week period. The mass of left ventricle and the posterior wall thickness increased by 27.7% (0.60+/-0.03 g vs 0.47+/-0.02 g) and 23.6% (2.04+/-0.04 mm vs 1.65+/-0.13 mm), respectively, and their increment in the first two-week period was much more than that in the second one. Meanwhile, the gene expression profile of the left ventricle changed significantly, which involved cellular structure, metabolism, oxidative stress, signal transduction, etc. Compared with the 8-week-old rats, these genes were mostly up-regulated in 10-week-old rats, while for 12-week-old rats, the gene expression profile of the left ventricle recovered to the pattern of 8-week-old rats again on the whole. These results suggest that the relationship between the changes in cardiac function and gene expression profile can be analyzed comprehensively with the technique of microarray, and that the changes in gene expression profile of the left ventricle during rat maturation adapt to the physiological growth of heart, which is of benefit for keeping the metabolism balance between materials and energy.

Animals↗
PubMed2003

[Retinal ischemia and nitric oxide].

Retinal ischemia is the main chain in the pathogenesis of vascular diseases of the eye. It was established that nitric oxide (NO) plays the key role in the development of ischemia. Recent understanding of the NO role, as a universal regulator of the cellular and tissue metabolism, is presented. The authors' and published data were used to design a scheme of pathogenesis of retinal ischemia with regard for the NO role. NO can produce both positive and negative effects depending on a stage of the process, NO concentration and on a number of other factors if they are present. Initial stages of hypoxia/ischemia are accompanied by an activation of all forms of NO-synthases (NOS) caused by the influence of biologically active substances (cytokines, prostaglandins, serotonin, bradykinin, glycolisis suboxide products etc.). The activation of inducible NOS, which synthesize a bigger quantity of NO possessing a direct cytotoxic action and contributing to the production of highly toxic radical of peroxinitrit, is in the focus of attention. The damage of cellular structures due to free-radical processes leads to the development of endothelial, macrophage and thrombocyte malfunctions, which manifest itself through a reduced activity of endothelial NOS and through disruption of NO-dependent processes (vasospasm, an increased aggregation of platelets and a reduced fibrinolytic activity). A sharp reduction of NO synthesis substrate (L-arginine) is observed in patients with retinal ischemia. The aggravation of ischemia causes a decrease of NO synthesis due to an exhaustion of L-arginine and its intensified consumption in the course of free-radical processes. The use of NO-inhibitors and of NO-donors at different stages of retinal ischemia prevents the development of neovascularization and proliferation.

Humans↗
PubMed2003

[PKC-dependent activation of P44/42 MAPKs and HSP70 in signal transduction pathways during hepatocyte ischemic preconditioning].

OBJECTIVE: To investigate the significance of PKC, P44/42 MAPKs and HSP70 signal transduction in IP. METHODS: Through an in vivo rat liver IP model, PKC inhibitor, activator and MEK inhibitor were utilized to analyze the phosphorylation of PKC and P44/42 MAPKs. HSP expression, AST/ALT concentration, cellular structure and ultrastructure were also observed. All the data were statistically analyzed. RESULTS: Compared with the control without IP, the phosphorylation of PKC was significantly increased in IP treated models and PKC activated group (P < 0.01) and P44/42 MAPKs and the expression of HSP were also obviously increased. In contrast, opposite changes were found in PKC or MEK inhibited groups, the phosphorylation PKC was decreased in PKC inhibited group (P < 0.01). CONCLUSION: The model has shown that PKC activation plays a pivotal role in the activation of P44/42 MAPKs pathway that participates in the preservation of liver cells. At the same time, HSP expression is regulated by signals in P44/42 MAPKs pathway.

Animals↗
PubMed2003

Assessment of the effect of Punica granatum (pomegranata) on the bioavailability of the radiopharmaceutical sodium pertechnetate (99mTc) in Wistar rats.

The many desirable characteristics of technetium-99m (99mTc) have stimulated the development of labeling techniques for different molecular and cellular structures. It is generally accepted that a variety of factors other than disease can alter the bioavailability of radiopharmaceuticals and one such factor is the drug therapy. The use of medicinal plants has increased in the last decades all over the world. Punica granatum (pomegranata) is used as food or as medication in folk medicine for antiviral, anthelmintic, antifungal, antibacterial and antimicrobial activity. We have studied in rats, the effect of the medicinal plant Punica granatum on the bioavailability of the radiopharmaceutical 99mTc-sodium pertechnetate (Na(99m)TcO4). The infusion of pomegranata was administered by intragastric via into Wistar rats during seven days. After that, the animals received by ocular plexus via, 0.1 ml of the Na(99m)TcO4 (3.7MBq) and the animals were rapidly sacrificed after 5, 20 and 40 min. The organs were isolated (brain, heart, thyroid, liver, lungs, kidneys, stomach, testis, intestines, pancreas, spleen, bladder, muscle and bone), the radioactivity determined in a well counter, the percentages of radioactivity (%ATI) in the organs were calculated and statistical analyses were performed by Wilcoxon test (p < 0.05). The results have shown a significant (p < 0.05) increase of the activity of the Na(99m)TcO4 in spleen, heart, stomach, liver, stout bowel, pancreas, lungs and testis at 5 min. Twenty minutes after the administration of the radiopharmaceutical, the analysis of the results reveals a significant (p < 0.05) increase of the %ATI in heart, stomach, femur, pancreas, lungs and kidneys. Forty minutes after the administration of the Na(99m)TcO4, the results show a significant (p < 0.05) increase in spleen, brain, heart, stomach, liver, stout bowel, muscle, femur, lungs, pancreas, kidneys and testis. These results can be justified by therapeutic effect of this extract and/or by generation of active metabolites capable to interfere with the biodistribution of the studied radiopharmaceutical.

Animals↗
PubMedDate not supplied

[Arsenite-induced lipid peroxidation in Saccharomyces cerevisiae].

The ability of sodium arsenite at concentrations of 10(-2), 10(-4), and 10(-6) M to induce lipid peroxidation in Saccharomyces cerevisiae cells was studied. Arsenite at the concentrations 10(-2) and 10(-4) M enhanced lipid peroxidation and inhibited the growth of yeast cells. Enhanced lipid peroxidation likely induced oxidative damage to various cellular structures, which led to suppression of the metabolic activity of cells. Arsenite at the concentration 10(-6) M did not activate lipid peroxidation in cells. All of the tested arsenite concentrations inhibited the activity of alpha-ketoglutarate dehydrogenase and pyruvate dehydrogenase in cells. The inference is made that the toxicity of arsenite may be related to its stimulating effect on intracellular lipid peroxidation.

Arsenites↗
PubMedDate not supplied

[Ultrastructural studies of cells in peripheral blood and cerebrospinal in meningococcal cerebrospinal meningitis].

Cells of peripheral blood and cerebrospinal fluid were studied in cases of meningococcal meningitis, and in peripheral blood of healthy controls. In the acute phase of the disease the neutrophils in cerebrospinal fluid showed evidence of phagocytosis activation with presence, among other signs, of numerous cytoplasmic processes. Stages of degeneration of these cells were observed with cytoplasm bulging into the nucleus, strong concentration of nuclear chromatin. In the light of a comparative assessment of cellular structures it was found that the population of neutrophils in peripheral blood is a more stable population showing no morphotic evidence of degeneration. In cerebrospinal fluid eosinophils three types of specific granules were found evidencing hydrolysis stimulation in these cells. In the acute phase of the disease the monocytes in the cerebrospinal fluid showed evidence of transformation, and during convalescence signs of degeneration appeared. Lymphocytes rarely found in the cerebrospinal fluid had features of metabolic stimulation (increased number of mitochondria, lysosomes and pinocytic vacuoles).

Adult↗
PubMed1992

In situ hybridisation: principles and applications.

In situ hybridisation (ISH) is based on the complementary pairing of labelled DNA or RNA probes with normal or abnormal nucleic acid sequences in intact chromosomes, cells or tissue sections. Compared with other molecular biology techniques applicable to anatomical pathology, ISH enjoys better rapport with histopathologists because of its similarity to immunohistochemistry. It has the unique advantage over other molecular biology techniques--largely based on probe hybridisation with nucleic acid extracted from homogenised tissue samples--of allowing localisation and visualisation of target nucleic acid sequences within morphologically identifiable cells or cellular structures. Probes for ISH may bear radioactive or non-radioactive labels. Isotopic probes (3H, 32P, 35S, 125I) are generally more sensitive than non-isotopic ones but are less stable, require longer processing times and stringent disposal methods. Numerous non-isotopic labels have been used; of these biotin and digoxigenin are the reporters of choice. Optimised non-isotopic systems of equivalent sensitivity to those which use radioactive-labelled probes have been described. In ISH, finding the optimal balance between good morphological preservation of cells and strong hybridisation signals is crucial. Tissue fixation and retention of cytoskeletal structures, unfortunately, impede diffusion of probes into tissues. ISH sensitivity is also influenced by inherent properties of the probe and hybridisation conditions. Although ISH is largely a research tool, it is already making strong inroads into diagnostic histopathology. It has been applied for the detection of various infective agents particularly CMV, HPV, HIV, JC virus, B19 parvovirus, HSV-1, EBV, HBV, hepatitis delta virus, Chlamydia trachomatis, salmonella and mycoplasma in tissue sections.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1992

Activation and regulation of the insulin receptor kinase.

For the insulin receptor and the EGF receptor it is believed that ligand occupancy results in interactions within the heterotetrameric alpha 2 beta 2 insulin receptor or between monomeric EGF receptors. These interactions then activate the intracellular receptor tyrosine kinase which induces receptor autophosphorylation and phosphorylation of cellular substrates. In the present study we have approached the nature of this receptor activation and autophosphorylation. We have investigated whether these phenomena occur via an intra--or an intermolecular process. To this end the following receptor model system consisting of two receptors was co-expressed in NIH 3T3 cells: a kinase inactive human insulin receptor (HIR K1018A) and a chimeric (EIR) receptor corresponding to the extracellular and transmembrane domains of the human EGF receptor and the cytosolic domain of the human insulin receptor beta subunit. Using this system we found that stimulation of the cells with EGF induced tyrosine autophosphorylation of the EGF-insulin receptor chimera (150 kd) and tyrosine phosphorylation of the beta-subunit of the kinase-deficient insulin receptor (95 kd). The phosphopeptides of the autophosphorylated cytoplasmic domain of the EGF-insulin receptor chimera were comparable to those of the transphosphorylated beta subunit of the kinase-deficient insulin receptor and the wild type human insulin receptor. When immunoaffinity purified EGF-insulin receptor hybrids and kinase-deficient insulin receptors were used in a cell lysate phosphorylation assay, it was found that addition of EGF produced [32P]-labeling of both receptor species. In conclusion, we have shown that tyrosine transphosphorylation can occur between homologous receptor domains. This transphosphorylation and transactivation could be a possible mechanism for signal amplification.2+ domain could influence interactions between the receptor and cellular structures and, as such, play a key role in signal transduction.

Animals↗
PubMed1992

[Basal-squamous carcinoma of the hypopharynx and larynx].

Another case of a very rare type of carcinoma is presented which was introduced recently as occurring in hypopharynx, larynx and tongue. Macroscopical description of an exophytic tumour of aryepiglottic fold and piriform recess in a 41-year old man is the second one in literature. Main histological feature of the tumour is a biphasic cellular structure with closely related basaloid and squamous components. Immunohistochemical expression of the squamous component concerned carcinoembryonic antigen, whereas S-100 protein, desmin and neuron specific granules. The small group of one own case and of 11 cases from the literature seems to support the idea that the tumour is aggressive, tending to early regional and remote metastases, and with shorter survival than other subtypes of epidermoid carcinoma.

Adult↗
PubMed1992

Changes in activity of cytochrome oxidase in the cochleae of guinea pigs with experimental endolymphatic hydrops.

Cochlear dysfunction may indicate inadequate generation of intracellular metabolic energy which is necessary for the regulation of the transport of ions and fluid as well as production of electro-energy in the cochlea. Changes in cochlear function in the early stages of endolymphatic hydrops attributed to dysfunction of the sensory hair cells and stria vascularis were investigated. The main source of metabolic energy, produced by intracellular respiration, is located in the stria vascularis and sensory hair cells. Since cytochrome oxidase is one of the most important respiratory enzymes, vibratome sections of hydropic and normal cochleae were stained cytochemically for cytochrome oxidase activity in this study. Decreased activity of this enzyme was consistently shown in the normal-appearing outer hair cells and stria vascularis, as well as the degenerated hair cells and stria vascularis, of the higher turns of the hydropic cochlea. The results coincide with those in other studies of electrophysiologic changes in cochlear function in hydropic animals. A decrease in the activity of respiratory enzymes was noted before the destruction of the cellular structures. The activity of cytochrome oxidase may serve as a useful indicator for demonstrating the functional status of cochlear hair cells and stria vascularis.

Animals↗
PubMedDate not supplied

[Pachymetry in the study of preservation of the cornea].

Rabbit corneas were preserved for between 7 and 14 days at + 4 degrees C in a whole eye in synthetic media (T.C. 199 and T.C. Earle) with or without added Dextran. In the absence of Dextran the corneas preserved at + 4 degrees C became thick. This thickening increased with the length of conservation. Dextran limited the hydration of the stroma. Measurement of the variations of corneal thickness during perfusion for 6 hours at 30 degrees C in T.C. Earle could be used as an index of the function of the corneal endothelium. Even after 14 days of preservation at + 4 degrees C the corneal endothelium retained the ability to reduce or prevent hydration during perfusion at 30 degrees C. Histological studies showed good conservation of the cellular structure after 7 days at + 4 degrees C. Pyknosis appeared after 14 days conservation. T.C. 199 preserved endothelial function better than T.C. Earle.

Animals↗
PubMedDate not supplied

Induction of karyological damage by bleomycin in polyploidizating rabbit hepatocytes.

The effects of the antitumor drug bleomycin on polyploidizating hepatocytes of immature rabbits were investigated by combining cytochemical (static microfluorometry) and morphological (fluorescence and electron microscopy) approaches. In addition to a decelerating effect of the drug on the cell kinetics, there were several types of karyological damage (micronuclei, internuclear chromatin bridges, mitotic chromosome bridges), thus demonstrating a clastogenic activity of bleomycin on the DNA, Moreover, anomalous nuclear and cytoplasmic divisions suggest interference of the drug with other cellular structures (mainly the microtubule network) responsible for the cell kinetics.

Animals↗
PubMedDate not supplied

[The assessment of the efficacy of bitemporal inductothermy in the combined treatment of obesity].

To treat obese patients with arterial hypertension, bitemporal inductothermy was proposed. It was to be used in association with diet N 8 and drugs, improving trophism in brain cellular structures. The treatment led to reduction of body mass, normalization of arterial pressure without hypotensive drugs, improvements in lipidogram and physiological reaction of vasopressin-renin-aldosteron system.

Adolescent↗
PubMed2003

4D imaging to assay complex dynamics in live specimens.

A full understanding of cellular dynamics is often difficult to obtain from time-lapse microscopy of single optical sections. New microscopes and image-processing software are now making it possible to rapidly record three-dimensional images over time. This four-dimensional imaging allows precise quantitative analysis and enhances visual exploration of data by allowing cellular structures to be interactively displayed from many angles. It has become a key tool for understanding the complex organization of biological processes in live specimens.

Animals↗
PubMedDate not supplied

[Modelling of Mg2+, ATP-dependent mitochondrial Ca ions transport in smooth muscle cells using protonophore CCCP-sensitive fluorescent tetracycline].

Mg2+, ATP-dependent Ca2+ accumulation in the rat myometrial mitochondria was investigated in complex experiment using Ca2+ isotope (45Ca2+) and Ca(2+)-sensitive label tetracycline. Monotonous increase of the fluorescence signal, insensitive to thapsigargin (100 nM) was observed with following establishing the stationary state of incubation at 2 min. which correlates with results obtained using isotope technique. Experiments with isotope label signify, that protonophore CCCP, ruthenium red and sodium azide, in concentration 1 microM, 10 microM and 10 mM respectively, totally inhibits the accumulation of the Ca ions in mitochondria. At the same time, in conditions of Mg2+, ATP-dependent Ca2+ accumulation modeling in these cellular structures, CCCP and sodium azide, used in the same concentration, diminished tetracycline fluorescence signal increase. In the same conditions, the introduction of the CCCP (1 mM) into the incubation medium at 75 sec. after initiation of the transport process induced reversible quenching of the tetracycline fluorescence signal to the level, observed in case of initial CCCP presence in the medium. According to data obtained in the experiment, using Ca2+ isotope, Ca(2+)-ionophore A-23187 induces both the reversible release of previously accumulated Ca ions, and cause reversible quenching of the tetracycline fluorescence signal to the level, observed in case of initial CCCP (1 mM) and sodium azide (10 mM) presence in the incubation medium. Conclusion was drawn that the thapsigargin-insensitive and CCCP, sodium azide and A-23187-sensitive tetracycline fluorescence increasing in case of modeling of Mg2+, ATP-dependent Ca2+ accumulation in myometrial mitochondria reflect the Ca2+ uniporter functioning in those subcellular structures.

Animals↗
PubMed1992

[Evaluation of bone marrow samples obtained by trephination biopsy].

A well performed and processed trephine renders a perfect idea about tissue and cellular structure of bone marrow. Gentle taking and adequate processing of a sample are a prerequisite for successful biopsy. The most convenient and often sufficient is the paraffine technique with an entry evaluation of the first section and setling up the group diagnosis. Another time, it stimulates further choice of immunohistology and electron microscopy. There are presented detailed evaluation schemes for marrow suppression, hyperplasias, myelofibroses and tumours. They were checked in a group of 400 cases.

Biopsy↗
PubMed2003

Corneal wound healing after photorefractive keratectomy: a 3-year confocal microscopy study.

PURPOSE: To perform a sequential quantitative analysis of corneal wound healing after photorefractive keratectomy (PRK) by using confocal microscopy in vivo. METHODS: In a prospective, nonrandomized, comparative trial performed in an institutional setting, 24 eyes of 14 patients received PRK to correct refractive errors between -1.25 and -5.75 D. Central corneas were examined preoperatively and at 1 day, 5 days, and 1, 3, 6, 12, 24, and 36 months after PRK by using confocal microscopy. A masked observer randomly examined 3 to 6 confocal scans per eye per visit to determine epithelial and stromal thickness, keratocyte density in 5 anterior-posterior stromal layers, corneal nerve density in the subbasal region and the stroma, and corneal light backscattering (corneal haze). RESULTS: Epithelial thickness increased 21% (P < .001) by 12 months after PRK and thereafter remained unchanged to 36 months after PRK. There was no change in stromal thickness between 1 and 36 months after PRK (P = .35). The dense keratocyte population in the preoperative anterior 10% of the stroma (32,380 +/- 5,848 cells/mm3) that was partially or completely removed during photoablation was not reconstituted at 36 months in the anterior 10% of the post-PRK stroma (17,720 +/- 4,308 cells/mm3, P < .001). Subbasal nerve fiber bundle density was decreased 60% at 12 months after PRK (P < .001) before returning to densities at 24 and 36 months after PRK that were not significantly different from preoperative values (P = 1.0). Activated keratocytes and corneal haze peaked at 3 months after PRK. CONCLUSIONS: Wounding of the cornea by PRK alters the normal structure, cellularity, and innervation of the cornea for up to 36 months.

Adult↗