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PubMed1998

Reactive oxygen species in the cellular pathophysiology of shock.

Reactive oxygen species (ROS) mediate the fine balance between cellular physiology and pathophysiology. Accordingly it is not surprising that cellular redox homeostasis is disrupted by shock events related to ischemia-reperfusion and inflammation. ROS may initiate as well as amplify the shock cellular insult in a number of ways which include important contributions to inflammation as well as lytic and apoptotic cell death. In addition, ROS in the setting of shock represent important antecedents to cellular proliferation, differentiation, and adaptation by virtue of altered transcription and translation of antioxidant enzymes, stress proteins, and a variety of cytokines. It is likely that an eventual important biochemical therapeutic goal in the setting of shock will involve re-establishing cellular redox homeostasis not only to ensure cellular structural integrity, but also to re-establish normal secondary cellular signal transduction mechanisms.

Humans↗
PubMed1989

Structure of the nucleus olfactorius anterior of the hedgehog (Erinaceus europaeus).

The cytoarchitecture, topography, and cellular structure of the nucleus olfactorius anterior (NOA) in the hedgehog have been studied in Nissl-stained and Golgi preparations. The NOA is an important receptive allocortical formation for olfactory fibers and the major source of association fibers relating the main olfactory bulb with the rest of the olfactory brain. It was divided into a bulbar part; four subdivisions named lateral, dorsal, medial, and ventral; an external part; and a posterior part. Except for the external and posterior subdivisions, the NOA is relatively homogeneous and, in spite of the apparent lack of sublamination in Niss-stained material, four clearly defined cellular laminae were distinguished by the Golgi method. These layers were found to be strikingly similar to those in the piriform cortex. Layer I contains the terminal ramifications of apical dendrites of pyramidal cells and the collaterals of the lateral olfactory tract. The superficial part of layer II contains extraverted pyramidal cells with two or three apical dendrites ramifying in layer I. Most pyramidal cells in the deep part of layer II and layer III are typical pyramidal cells with axons entering the commissura anterior. Some pyramidal cell axons bifurcate into two branches running in opposite directions in the commissura anterior. The interstitial zone below layer III contains deep pyramidal cells and polymorphic cells with ascending branches. Cells with intrinsic axons were classified into four main categories according to the distribution of their axonal ramifications: 1) cells with very restricted axons, 2) cells with axons oriented tangentially in the superficial part of layer II, 3) cells with ascending axons located in the deep part, and 4) chandelierlike cells. Finally, some functional considerations are discussed.

Animals↗
PubMed1984

Induction of lipid storage in cultured leukemic myeloid cells by pyrene-dodecanoic acid.

When incubated for 1-3 days in the presence of the fatty acid analog, 12-(1-pyrene)dodecanoic acid, the neutral lipid content of cultured human leukemic myeloid cells increased considerably, while that of the phospholipids increased to a much lesser extent. Among the neutral lipids, di- and monoacylglycerols predominated and a considerable portion of the fatty acyl residues of these newly synthesized neutral lipids consisted of pyrene-dodecanoic acid. Light microscopy showed evidence for the presence of highly fluorescent lipid droplets within the cells. Electron microscopy showed lipid globules, mostly devoid of a unit membrane, multivesicular inclusion bodies and some multilamellar membranous structures. In comparison, cells incubated with palmitic acid show neither these cellular structures, nor the increase of the neutral lipid content. The lipid storage, induced by pyrene-dodecanoic acid, is probably related to ineffective degradation of this fatty acid analog and might serve as an experimental model of cellular lipidosis.

Cell Division↗
PubMed2005

Intercellular communication: the Drosophila innexin multiprotein family of gap junction proteins.

Gap junctions belong to the most conserved cellular structures in multicellular organisms, from Hydra to man. They contain tightly packed clusters of hydrophilic membrane channels connecting the cytoplasms of adjacent cells, thus allowing direct communication of cells and tissues through the diffusion of ions, metabolites, and cyclic nucleotides. Recent evidence suggests that gap junctions are constructed by three different families of four transmembrane proteins: the Connexins and the Innexins found in vertebrates and in invertebrates, respectively, and the Innexin-like Pannexins, which were recently discovered in humans. This article focuses on the Drosophila Innexin multiprotein family, which is comprised of eight members. We highlight common structural features and discuss recent findings that suggest close similarities in cellular distribution, function, and regulation of Drosophila Innexins and vertebrate gap junction proteins.

Adherens Junctions↗
PubMed2002

Proteomic dissection of dome formation in a mammary cell line.

The study of the development of the mammary gland at the molecular level in animals is difficult because of the complex tissue organization. This review introduces a proteomic approach to investigate mammary gland development in a cell culture system that we have previously developed as an in vitro model for studying mammary cell differentiation. The model is based on two cell lines, one of which is able to differentiate spontaneously and produce hemispherical blisters, called domes, when confluent. Through proteomic dissection of dome-forming cells, two types of key regulatory genes have been identified: genes inducing cellular structural modifications and genes related to functional modifications. We identified several genes in the pathway leading to dome formation in vitro and showed that the functional and structural changes taking place in dome-forming cells correspond to cellular changes occurring in vivo when tubules and alveoli are developed in the mammary gland at pregnancy.

Animals↗
PubMed2000

Proteomics to study genes and genomes.

Proteomics, the large-scale analysis of proteins, will contribute greatly to our understanding of gene function in the post-genomic era. Proteomics can be divided into three main areas: (1) protein micro-characterization for large-scale identification of proteins and their post-translational modifications; (2) 'differential display' proteomics for comparison of protein levels with potential application in a wide range of diseases; and (3) studies of protein-protein interactions using techniques such as mass spectrometry or the yeast two-hybrid system. Because it is often difficult to predict the function of a protein based on homology to other proteins or even their three-dimensional structure, determination of components of a protein complex or of a cellular structure is central in functional analysis. This aspect of proteomic studies is perhaps the area of greatest promise. After the revolution in molecular biology exemplified by the ease of cloning by DNA methods, proteomics will add to our understanding of the biochemistry of proteins, processes and pathways for years to come.

Animals↗
PubMed2005

In vivo observation of papillae of the human tongue using confocal laser scanning microscopy.

The aim of this investigation was to visualize the epithelial structures of the tongue using confocal laser scanning microscopy (LSM). The human tongue epithelium of 28 healthy subjects, aged 21-67 years, mean age 38 years, 14 women and 14 men, was examined in vivo by LSM. Using LSM, a combination of the Heidelberg Retina Tomograph HRT II and the Rostock Cornea Module, up to 800-fold magnifications were obtained. On the tongue surface both filiform and fungiform papillae and their taste pores were easily identified. The epithelium of the tongue with its subcellular structures could be observed up to a depth of 50 microm, cellular structures up to 150 microm and subepithelial vessels up to 300 microm. Additionally the papillary crests and blood flow were visible. Confocal LSM seems suitable for noninvasive in vivo examination of the tongue. The hydraulic z scan, the manual start setting and the measurement of the depth allow a clear classification of the observed structures.

Adult↗
PubMed1994

The rat dorsal vagal nucleus: features of cellular and synaptic structure.

Using the stereological, histochemical and electron microscopic approaches the cellular and synaptic structure of the rat dorsal vagal nucleus (DVN) were studied. Cellular organization of the DVN does not allow to distinguish any separate subnuclei but a conspicuous population of mainly small neurons in rostral extension of its lateral part lacking AChE activity. DVN neurons with high and moderate AChE activities are manifest on the 5th postnatal day. Their number increases on the 7th day. In this critical period of the brain sexual differentiation, a sexual dimorphism was observed in the activity of DVN cholinergic neurons. The electron microscopic studies showed a wide variety of the DVN synaptic patterns. In the rat DVN were found complicated synaptic structures resembling glomeruli. Two types of synaptic glomeruli are distinguished. The results suggest that DVN can be regarded as a sex-dependent brain area involved in a high level of information processing.

Acetylcholinesterase↗
PubMedDate not supplied

Effect of ultrasonic assisted lipectomy (UAL) on breast tissue: histological findings.

As the use of ultrasound-assisted liposuction (UAL) increases, the technique grows more popular in breast surgery, especially in reduction mammaplasty and treatment of gynecomastia. The aim of our study was to investigate the effect of UAL on breast tissue using histological examinations, and analyze the effect of this technique on a cellular level. Biopsies from 10 patients undergoing ultrasonically assisted lipectomy prior to classic reduction mammaplasty were taken from the treated areas of the breast. Biopsies were fixed in formalin and embedded in paraffin. Sections were stained with hematoxilin-eosin, and analyzed for defective adipocytes, and the effects of UAL on breast tissue. Untreated breast tissue and breast tissue that had been treated only with conventional aspiration lipectomy served as controls. Sections were analyzed using light microscopy. Compared to the breast tissue treated only with conventional lipectomy, a stronger destruction of the cellular structure of adipocytes could be detected. The destruction was visible even in areas more distant from the aspiration channel. In contrast, the breast tissue was mostly intact, no signs of ultrasonic-induced cellular destruction were visible. The glandular structure was kept intact. Beside the direct mechanical destruction by the probe and the canula, no further alterations of the cellular integrity of the glandular parts were visible. In conclusion our results indicates that UAL is also a safe technique for use in breast surgery. Besides easy handling and improved modelling, the destructive effect of the ultrasound does not include the glandular breast tissue.

Breast↗
PubMed1989

Monoclonal antibody to a triggering structure expressed on rat natural killer cells and adherent lymphokine-activated killer cells.

To study the cellular structures involved in NK and lymphokine-activated killer (LAK) cell function, we have produced a panel of mAbs that modulate the cytolytic function of a population of cells with LAK activity that derive from large granular lymphocyte (LGL)/NK cells (adherent LAK [A-LAK] cells). In this report, we describe an mAb (3.2.3; IgG1k) that recognizes a triggering structure that is expressed on rat LGL/NK cells and A-LAK cells. This epitope is also expressed on polymorphonuclear leukocytes (PMN). The expression of the epitope identified by mAb 3.2.3 increased progressively on A-LAK cells after culture in the presence of rIL-2. mAb 3.2.3 enhanced the cytolytic activity of NK and A-LAK cells against FcR+ target cells, but not FcR- target cells. However, this effect was not induced by F(ab')2 fragments of 3.2.3. This antibody also induced the release of N-alpha-benzyloxycarbonyl-L-lysine thiobenzy esteresterase by A-LAK cells. These data suggest that the epitope identified by mAb 3.2.3 is on a triggering structure expressed on rat NK cells and A-LAK cells. The expression of the epitope recognized by mAb 3.2.3 on LGL/NK cells and PMN suggests that this structure may be analogous to that identified by the anti-CD16 (-FcR) mAbs. However, the molecule immunoprecipitated by mAb 3.2.3 was a 60-kD dimer composed of two 30-kD chains. These data suggest that mAb 3.2.3 recognizes a unique triggering structure. As mAb 3.2.3 is the first antibody recognizing a determinant with functional significance, selectively expressed on both rat NK cells and A-LAK cells, it will be a useful tool for the study of NK cell ontogeny and function, and the development of cells with LAK activity from the NK cell compartment.

Animals↗
PubMed1999

Effects of synthetic micro- and nano-structured surfaces on cell behavior.

Topographical cues, independent of biochemistry, generated by the extracellular matrix may have significant effects upon cellular behavior. Studies have documented that substratum topography has direct effects on the ability of cells to orient themselves, migrate, and produce organized cytoskeletal arrangements. Basement membranes are composed of extracellular matrix proteins and found throughout the vertebrate body, serving as substrata for overlying cellular structures. The topography of basement membranes is a complex meshwork of pores, fibers, ridges, and other features of nanometer sized dimensions. Synthetic surfaces with topographical features have been shown to influence cell behavior. These facts lead to the hypothesis that the topography of the basement membrane plays an important role in regulating cellular behavior in a manner distinct from that of the chemistry of the basement membrane. This paper describes the topography of the basement membrane and reviews the fabrication of synthetic micro- and nano-structured surfaces and the effects of such textured surfaces on cell behavior.

Animals↗
PubMed1992

Mechanism of general adaptation.

An analysis of theories and results of corresponding studies indicate that the adaptive processes in organisms have to be discriminated to specific and nonspecific adaptive responses. The integrated sum of specific adaptive responses constitute homeostatic regulation in order to maintain a constant level of rigid constants of the body's internal milieu. The constancy of rigid constants (temperature, pH, osmotic pressure, and contents of ions, water and p0(2)) is necessary to ensure the optimal activity of enzymes. The nonspecific adaptive responses are directed towards the mobilization of the organism's reserves for energy and protein synthesis. Additionally, a general activation of the body's defence faculties is included into the nonspecific adaptive responses. The nonspecific adaptive responses constitute a coordinated mechanism of general adaptation. The mobilization of the reserve for protein synthesis is connected with induction of the adaptive synthesis of the enzyme and structural proteins in order to restore and develop the functional capacity of cellular structures that were highly active during acute influence of various stressors.

Adaptation, Physiological↗
PubMed2000

Effects of permethrin on the salivary glands and neuroendocrine organs of unfed female Hyalomma (Hyalomma) dromedarii (Ixodoidea: Ixodidae).

Permethrin-impregnated fabric has been shown to be an effective repellent against various tick species. However, some tick species are not repelled by this chemical. In Hyalomma dromedarii (Koch), permethrin exposure is reported to actually enhance the tick's attachment behavior. This study evaluated the histological effects of permethrin exposure on the salivary glands and neuroendocrine organs of unfed, virgin H. dromedarii ticks of uniform age. Three fabric treatments consisting of unwashed-untreated (control), washed after treatment (0.125 mg [AI] / cm2) and unwashed-treated were used after 5- and 10-min exposure times for unfed, unmated females. For all of the organs examined, the cellular structure of treated ticks differed from controls as evidenced by increases in cellular activity, as well as significant increases in the size of the cells of the organs under study (P < 0.05). These data conclusively demonstrate that an unexpected enhanced attachment response observed in this tick species after permethrin exposure is the direct result of increased neurosecretory and salivary gland activity induced by that exposure.

Animal Feed↗
PubMed1962

Enzyme distribution in Pseudomonas aeruginosa.

Campbell, J. J. R. (The University of British Columbia, Vancouver, B.C., Canada), Loretta A. Hogg, and G. A. Strasdine. Enzyme distribution in Pseudomonas aeruginosa. J. Bacteriol. 83:1155-1160. 1962.-Previous studies on the distribution of enzymes in bacteria have indicated that, although individual enzymes were predominantly associated with a particular cellular structure, nevertheless some of the enzyme appeared to be present in all cellular fractions. In the present work with Pseudomonas aeruginosa, it was shown that, in general, an enzyme is present in only one cellular component. Hexokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconic dehydrogenase, gluconic dehydrogenase, malic dehydrogenase, fumarase, isocitric dehydrogenase, isocitritase, and catalase were detected only in the soluble cytoplasm of the cell. Glucose oxidase and succinic dehydrogenase were detected only in the "ghost" fraction. Diphosphopyridine nucleotide oxidase was present in both "ghost" and ribosomal fractions but was most concentrated in the "ghost". Although adenylic kinase was found to be present in all fractions, it was possible to fractionate cells so that almost all of the activity was associated with the soluble cytoplasm a minor amount being associated with the "ghost." Adenosine triphosphatase was most concentrated in the "ghost" but appreciable activity appeared in the cytoplasm. Polynucleotide phosphorylase appeared to be the only enzyme that was convincingly associated with the ribosomes. However, a small amount of activity was associated with the soluble cytoplasm and with the "ghosts."

Canada↗
PubMed1999

Mitochondria, oxidative stress, and antioxidant defences.

Mitochondria are strongly involved in production of reactive oxygen species, considered today as the main pathogenic agent of many diseases. A vicious circle of oxidative stress and damage to cellular structures can lead to either cell death by apoptosis or to a cellular energetic decline and ageing. The early involvement of mitochondria in apoptosis includes expression of pro-apoptotic factors, release of cytochrome c from the inter-membrane space and opening of the permeability transition pore: cytochrome c release appears to precede pore opening. The mitochondrial theory of ageing considers somatic mutations (deletions) of mitochondrial DNA induced by oxygen radicals as the primary cause of energy decline; experimentally, Complex I appears to be mostly affected. We have developed the Pasteur effect (enhancement of lactate production by mitochondrial inhibition) as a bio-marker of mitochondrial bioenergetics in human platelets, and found it to be decreased in aged individuals. Cells counteract oxidative stress by antioxidants; among lipophilic antioxidants coenzyme Q is the only one of endogenous biosynthesis; exogenous coenzyme Q, however, may protect cells from oxidative stress in vivo.

Aging↗
PubMed1985

A regional analysis of alpha-spectrin in the isolated Mauthner neuron and in isolated axons of the goldfish and rabbit.

Isolated dendrites, somata, and desheathed axons of the goldfish Mauthner neuron (M-cell), in addition to other isolated myelin sheath-free axons of the goldfish spinal cord and of rabbit lumbar ventral roots, were shown by immunochemical and immunofluorescence techniques to contain alpha-spectrin (fodrin). alpha-Spectrin appeared to be organized as a randomly distributed reticular network, localized to the surface of isolated neuronal cellular structures. In addition, alpha-spectrin was also distributed nonrandomly at specialized cellular sites. These sites included synaptic junctions and morphologically differentiated nodes of Ranvier (i.e., rabbit axons, but not goldfish axons). At the latter sites, it is possible to demonstrate that alpha-spectrin is co-localized with F-actin, as indicated by a striking correspondence of fluorescent images due to double labeling, using the indirect immunofluorescence technique with alpha-spectrin antiserum, and direct binding of F-actin by rhodamine-conjugated palloidin. However, the spectrin-actin network at synaptic junctions appears to be distributed over the entire area of junctional contact and is not just restricted to postsynaptic densities. The possibility of a duality of roles of spectrin in membrane-related motile and anchorage functions is discussed.

Animals↗
PubMed1998

A new structural class of proteasome inhibitors that prevent NF-kappa B activation.

The multicatalytic proteinase or proteasome is a highly conserved cellular structure that is responsible for the ATP-dependent proteolysis of many proteins involved in important regulatory cellular processes. We have identified a novel class of inhibitors of the chymotrypsin-like proteolytic activity of the 20S proteasome that exhibit IC50 values ranging from 0.1 to 0.5 microgram/mL (0.1 to 1 microM). In cell proliferation assays, these compounds inhibit growth with an IC50 ranging from 5 to 10 micrograms/mL (10-20 microM). A representative member of this class of inhibitors was tested in other biological assays. CVT-634 (5-methoxy-1-indanone-3-acetyl-leu-D-leu-1-indanylamide) prevented lipopolysaccharide (LPS), tumor necrosis factor (TNF)-, and phorbol ester-induced activation of nuclear factor kappa B (NF-kappa B) in vitro by preventing signal-induced degradation of I kappa B-alpha. In these studies, the I kappa B-alpha that accumulated was hyperphosphorylated, indicating that CVT-634 did not inhibit I kappa B-alpha kinase, the enzyme responsible for signal-induced phosphorylation of I kappa B-alpha. In vivo studies indicated that CVT-634 prevented LPS-induced TNF synthesis in a murine macrophage cell line. In addition, in mice pretreated with CVT-634 at 25 and 50 mg/kg and subsequently treated with LPS, serum TNF levels were significantly lower (225 +/- 59 and 83 +/- 41 pg/mL, respectively) than in those mice that were treated only with LPS (865 +/- 282 pg/mL). These studies suggest that specific inhibition of the chymotrypsin-like activity of the proteasome is sufficient to prevent signal-induced NF-kappa B activation and that the proteasome is a novel target for the identification of agents that may be useful in the treatment of diseases whose etiology is dependent upon the activation of NF-kappa B.

Adenosine Triphosphatases↗
PubMedDate not supplied

Reflectance confocal microscopy for characterization of mammary ductal structures and development of neoplasia in genetically engineered mouse models of breast cancer.

The earliest steps of breast cancer begin with aberrations in mammary ductal structure. Techniques that enable an investigator to image in situ and then analyze the same tissue using biochemical tools facilitates identification of genetic networks and signaling pathways active in the imaged structure. Cellular confocal microscopy (VivaCell-TiBa, Rochester, New York) is used to image mammary ductal structures and surrounding vasculature in situ in intact wild-type and genetically engineered mice that develop ER alpha-initiated ductal carcinoma in situ (DCIS) and ER alpha-driven invasive mammary cancer. In wild-type mice, normal mammary ductal structures that appear from puberty through lactation are visualized and serially sectioned optically, and a developmental atlas is created. Altering tissue preparation enabled visualization of the vasculature surrounding the ductal structures. In the genetically engineered mice, aberrant mammary ductal structures and cancers are imaged and compared to corresponding normal structures. Different preparation techniques are able to preserve tissue for routine histological analyses and RNA isolation. Comparative studies demonstrate that reflectance confocal imaging provides more cellular detail than carmine-alum-stained mammary gland whole mounts and equivalent detail with hematoxylin and eosin stained tissue sections. In summary, reflectance confocal microscopy is a tool that can be used to rapidly and accurately analyze mammary gland structure.

Adenocarcinoma↗