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At least 1,099 records · Page 61Linked to original sources
PubMed2005

Gene expression profiling of Japanese psoriatic skin reveals an increased activity in molecular stress and immune response signals.

Gene expression profiling was performed on biopsies of affected and unaffected psoriatic skin and normal skin from seven Japanese patients to obtain insights into the pathways that control this disease. HUG95A Affymetrix DNA chips that contained oligonucleotide arrays of approximately 12,000 well-characterized human genes were used in the study. The statistical analysis of the Affymetrix data, based on the ranking of the Student t-test statistic, revealed a complex regulation of molecular stress and immune gene responses. The majority of the 266 induced genes in affected and unaffected psoriatic skin were involved with interferon mediation, immunity, cell adhesion, cytoskeleton restructuring, protein trafficking and degradation, RNA regulation and degradation, signalling transduction, apoptosis and atypical epidermal cellular proliferation and differentiation. The disturbances in the normal protein degradation equilibrium of skin were reflected by the significant increase in the gene expression of various protease inhibitors and proteinases, including the induced components of the ATP/ubiquitin-dependent non-lysosomal proteolytic pathway that is involved with peptide processing and presentation to T cells. Some of the up-regulated genes, such as TGM1, IVL, FABP5, CSTA and SPRR, are well-known psoriatic markers involved in atypical epidermal cellular organization and differentiation. In the comparison between the affected and unaffected psoriatic skin, the transcription factor JUNB was found at the top of the statistical rankings for the up-regulated genes in affected skin, suggesting that it has an important but as yet undefined role in psoriasis. Our gene expression data and analysis suggest that psoriasis is a chronic interferon- and T-cell-mediated immune disease of the skin where the imbalance in epidermal cellular structure, growth and differentiation arises from the molecular antiviral stress signals initiating inappropriate immune responses.

Adult↗
PubMed2004

One hundred and one new microsatellite loci derived from ESTs (EST-SSRs) in bread wheat.

Four hundred and seventy-eight microsatellite markers derived from expressed sequence tags (EST-SSRs) were screened among three mapping populations (W-7984xOpata 85, WOpop; LumaixHanxuan, LHpop; WenmaixShanhongmai, WSpop). The number of polymorphic EST-SSR primer pairs found in WOpop, LHpop and WSpop was 92, 58 and 29 respectively. A total of 101 EST-SSR loci amplified from 88 primer sets were distributed over the 20 chromosomes of the reference maps (no markers were located on chromosome 4B). These 101 mapped EST-SSR markers add to the existing 450 microsatellite loci previously mapped in bread wheat. Seventy-four of the 101 loci showed significant similarities to known genes, including 24 genes involved in metabolism, 4 in cellular structures, 9 in stress resistance, 12 in transcription, 2 in development, 2 transporters and 21 storage proteins. Besides gliadin and glutenin, most of the 53 genes with putative functions were mapped for the first time by EST-SSR markers in bread wheat. Sequence alignment of the mapped wheat EST-SSR loci allowed tentative assignment of functionality to the other members of grasses family. Colinearity combined with homology information offers an attractive approach to comparative genomics.

Chromosome Mapping↗
PubMed2005

Examples of the application of optical process and quality sensing (OPQS) to beer brewing and polyurethane foaming processes.

Optical methods play an important role in process analytical technologies (PAT). Four examples of optical process and quality sensing (OPQS) are presented, which are based on three important experimental techniques: near-infrared absorption, luminescence quenching, and a novel method, photon density wave (PDW) spectroscopy. These are used to evaluate four process and quality parameters related to beer brewing and polyurethane (PU) foaming processes: the ethanol content and the oxygen (O2) content in beer, the biomass in a bioreactor, and the cellular structures of PU foam produced in a pilot production plant.

Beer↗
PubMed2006

Electrophysiology of turgor regulation in marine siphonous green algae.

We review electrophysiological measures of turgor regulation in some siphonous green algae, primarily the giant-celled marine algae, Valonia and Ventricaria, with particular comparison to the well studied charophyte algae Chara and Lamprothamnium. The siphonous green algae have a less negative plasma membrane potential, and are unlikely to have a proton-based chemiosmotic transport system, dominated by active electrogenic K(+) uptake. We also make note of the unusual cellular structure of the siphonous green algae. Hypertonic stress, due to increased external osmotic pressure, is accompanied by positive-going potential difference (PD), increase in conductance, and slow turgor regulation. The relationship between these is not yet resolved, but may involve changes in K(+ )conductance (G (K)) or active K(+) transport at both membranes. Hypotonic turgor regulation, in response to decreased external osmotic pressure, is approximately 3 times faster than hypertonic turgor regulation. It is accompanied by a negative-going PD, although conductance also increases. The conductance increase and the magnitude of the PD change are strongly correlated with the magnitude of hypotonic stress.

Chara↗
PubMed2003

Identification of tumor antigens and T-cell epitopes, and its clinical application.

The capability of antigen-specific CD8(+) and CD4(+) T lymphocytes to mediate antitumor immunity has generated remarkable interest in the identification of target antigens and their epitopes. The classical strategy to define tumor antigens is based on the employment of in vivo sensitized tumor-reactive T lymphocytes from cancer patients. These lymphocytes are used to screen an autologous tumor cDNA expression library for the target antigen. Alternatively, antibodies from the serum of cancer patients can be applied to screen a tumor-derived phage expression library for immunogenic cellular structures. In addition, potential target antigens have been selected by gene expression profiling searching for overexpressed gene products in neoplastic cells compared with normal tissues. B-cell target structures and overexpressed gene products have to be verified as T-cell antigens by the strategy of "reverse immunology." Therefore, T cells are sensitized in vitro by autologous dendritic cells loaded with predicted antigenic peptide ligands for a given HLA allele or with the global antigen. These different approaches led to the identification of a still growing number of antigenic peptides providing the basis for the development of new active and passive immunotherapies and for the monitoring of spontaneous and vaccine-induced T-cell responses. Some of these antigens and/or their epitopes are now validated in different clinical regimens for their capability to mediate potent T-cell immunity in cancer patients.

Antigen Presentation↗
PubMed1998

[In situ PCR and PCR in situ hybridization of paraffin-embedded tissue. New diagnostic possibilities in pathology].

In situ polymerase chain reaction (PCR) and PCR in situ hybridization are new diagnostic tools in dermatopathology. These techniques can combine the sensitivity of PCR with the advantage of in situ hybridization to localize specific cellular structures. With optical control of the PCR reaction product in these techniques, false-positive results due to contamination can be minimized. Several working protocols have been established which allow detection of DNA and RNA sequences in a rapid and reproducible manner. Two different methods have been established to detect the amplification product, the indirect PCR in situ hybridization (PCRisHyb), and the direct in situ PCR (isPCR). An easy and reproducible method for PCRisHyb and isPCR in formalin-fixed and paraffin-embedded tissue is described and the two techniques are compared. Using both isPCR and PCRisHyb, the amplification product can be visualized with an optimal morphological preservation of the tissue. Indirect PCRisHyb showed a slightly higher specificity whereas direct isPCR was the quicker, easier and less expensive method.

Chickenpox↗
PubMed2004

Somatic embryogenesis in Solanum tuberosum L.: a histological examination of key developmental stages.

A potential novel method of producing high-quality potato ( Solanum tuberosum L.) nuclear seeds is through the process of somatic embryogenesis (SE). Somatic embryo formation has been successfully reported in many plant species, but in potato, reliable SE systems are still at the experimental stage. A key factor in the success of any SE system is the ability to discriminate SE-specific cellular structures from those emerging through an organogenic route. In the investigation reported here we attempted to discriminate the progression of specific stages of potato SE by histological means. Internodal segment (INS) explants from 4- to 6-week-old cv. Desiree in vitro cultures were successively cultured on SE induction (for 2 weeks) and expression/regeneration media (for 3 weeks) with and without 2,4-dichlorophenoxyacetic acid (5 microM). Microscopic examination of histological slides prepared using INS explants at different stages revealed the presence of characteristic globular, heart and torpedo stages in the potato SE system along with other associated unique features such as protoderm development and discrete vascular connections. These results confirm the occurrence of potato SE as per the accepted definition of the term.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2026

Molecular mechanisms and agronomic strategies for thermotolerance in chili pepper (Capsicum annuum L.).

Heat stress is a primary environmental constraint on chili pepper (Capsicum annuum L.) productivity and fruit quality across global agricultural systems. Elevated temperatures adversely affect plant growth, flowering, fruit set, pod morphology, physiology, and metabolism. The severity of these impacts varies with the duration and intensity of heat exposure and with the stage of plant development. Reproductive development is especially vulnerable, resulting in compromised fruit formation and a decline in productivity. Heat stress disturbs photosynthesis, cellular structure integrity, and membrane stability through oxidative stress. Chili plants counter heat stress through complex molecular networks that encompass activation of antioxidant systems, heat shock protein (HSP) synthesis, osmolyte biosynthesis, and stress-responsive transcription factor expression. Recent advancements in genomics, transcriptomics, and metabolomics have elucidated fundamental regulatory pathways governing thermotolerance, highlighting the importance of heat-responsive genes, including CaHSPs, CaWRKYs, and CaNACs. This comprehensive review integrates contemporary understanding of physiological, biochemical, and molecular heat stress responses in chili pepper. Additionally, it evaluates potential agronomic and breeding strategies to strengthen crop adaptation to escalating global temperatures.

Capsicum↗
PubMed2001

Submucosal gland distribution in the mouse has a genetic determination localized on chromosome 9.

Submucosal glands (SMG) are important secretory glands that are present in the major airways and bronchioles of humans. In mice the structure, cellular composition, and density of SMG are similar to those seen in humans, but the glands are present only in the trachea. Characterization of SMG is important as they secrete bacteriocidal products such as lactoferrin, lysozyme, and defensins believed to be of importance in the innate defense system. Serous cells in SMG are the primary site of cystic fibrosis transmembrane conductance regulator (CFTR) gene expression and the initial site of histological abnormality in cystic fibrosis (CF) individuals. In this study, we examined four inbred strains of mice (A/J, C57BL/6N, FVB/N, and BALB/CAnN) and revealed that the extent to which glands descend in the mouse trachea varied between inbred strains. In particular, the A/J and C57BL/6N strains exhibited few SMG extending further than the first or second intercartilaginous space (mean depth of 0.4+/-0.11 and 1.5+/-0.32 tracheal rings respectively) in the trachea, whereas the FVB/N and BALB/CAnN strains had SMG extending beyond the fourth space (mean depths of 3.3+/-0.46 and 5.6+/-0.45 rings respectively). We have previously shown that in congenic C57Bl/ 6N Cftr mutant mice (CF mice), the SMG are distributed more distally than in wild-type C57Bl/6N but are indistinguishable from BALB/CAnN wild-type or CF mice. The implication that SMG distribution is influenced by Cftr gene expression (or a gene closely linked to Cftr) led us to investigate the genetic difference between C57Bl6/N and BALB/CAnN mice. In recombinant inbred strain (RIS) analysis (with BALB/CJ and C57BL/6J progenitors), two loci were identified as being linked to the SMG phenotype (peak likelihood statistic levels of 8.8 and 9.9 on Chrs 9 and 10 respectively, indicating suggestive linkage). A subsequent segregation analysis of an F2 intercross between the C57BL/6N and BALB/CAnN mice indicated that there were at least two major genetic factors responsible for SMG distribution. The loci indicated in the RI analysis were included in a targeted genome scan involving 235 F2 intercross animals (C57BL/6N and BALB/CAnN strain intercross). The genome scan confirmed the locus on Chr 9 (between genetic markers D9Mit11 and D9Mit182), designated Smgdl, as significantly linked to the SMG distribution phenotype (peak LOD score 5.8) within a 95% confidence interval of 12 cM.

Animals↗
PubMed2000

Plant Parasitic Nematodes: Habitats, Hormones, and Horizontally-Acquired Genes.

Plant parasitic nematodes are ubiquitous and cosmopolitan pathogens of vascular plants and exploit all parts of the roots and shoots, causing substantial crop damage. Nematodes deploy a broad spectrum of feeding strategies, ranging from simple grazing to the establishment of complex cellular structures (including galls) in host tissues. Various models of feeding site formation have been proposed, and a role for phytohormones has long been speculated, although whether they perform a primary or secondary function is unclear. On the basis of recent molecular evidence, we present several scenarios involving phytohormones in the induction of giant cells by root-knot nematode. The origin of parasitism by nematodes, including the acquisition of genes to synthesize or modulate phytohormones also is discussed, and models for horizontal gene transfer are presented.

Journal Article↗
PubMed2001

How to perform diffusion-weighted imaging.

Diffusion-weighted imaging (DWI) has become an invaluable tool in the management of patients with stroke. DWI relies on detecting the random diffusion of water molecules. In normal tissues this movement may be restricted by the presence of cellular structures, which provide a barrier to free movement. This occurs in myelinated white matter, where movement is restricted more across than along fibres. This directional dependence is termed anisotropic restricted diffusion. The diffusion of water molecules can be made the dominant contrast mechanism within an image by applying large magnetic field gradients. The pulsed gradient spin echo (PGSE) sequence provides sensitivity to diffusion with gradient pulses either side of the 180 degrees refocusing pulse. This sequence is generally heavily T2 weighted. In order to detect normal anisotropic properties within the different components of the medullary core, association, commissural and projection fibres, DWI must be performed with sensitisation in at least three directions. PGSE sequences have been used to obtain the diffusion coefficient (D*), a measure of mobility at the molecular level within tissue. In acute infarction D* is increased; in brain death it is decreased. Diffusion contrast needs to be optimised in relation to the highly T2-dependent nature of PGSE sequences. This also requires a more detailed knowledge of how D* changes in disease, but information on nonischaemic neurological conditions is still very limited.

Adult↗
PubMed2004

Localization of thrombomodulin in pericryptal fibroblasts of the rat duodenum.

Thrombomodulin (TM) contributes to the inactivation of thrombin which activates protein C, a major anticoagulant and anti-inflammatory protein. This report describes the distribution and localization of TM in the rat duodenum by light and electron microscopic immunohistochemistry. In addition to the endothelium of the entire vasculature, TM was found on the non-vascular structures, cellular networks of pericryptal fibroblasts surrounding the bases of the glandular crypts. TM was localized on the plasma membrane of the pericryptal fibroblasts which existed in the pericryptal spaces between the basal lamina of the epithelium and the collagenous sheets around the base of the crypt. TM-immunoreactive pericryptal fibroblasts were stellate-shaped cells and contacted with each other by their cytoplasmic processes forming an anastomosing syncytium around the base of the crypt. In contrast to pericryptal fibroblasts, TM was not localized in subepithelial fibroblasts in the villi or smooth muscle cells in the lamina muscularis mucosae and the muscularis. The functional significance of TM in pericryptal fibroblasts is discussed.

Animals↗
PubMed2000

Dendrimer-assisted patch-clamp sizing of nuclear pores.

Macromolecular translocation (MMT) across the nuclear envelope (NE) occurs exclusively through the nuclear pore complex (NPC). Therefore, the diameter of the NPC aqueous/electrolytic channel (NPCC) is important for cellular structure and function. The NPCC diameter was previously determined to be approximately equal to 10 nm with electron microscopy (EM) using the translocation of colloidal gold particles. Here we present patch-clamp and fluorescence microscopy data from adult cardiomyocyte nuclei that demonstrate the use of patch-clamp for assessing NPCC diameter. Fluorescence microscopy with B-phycoerythrin (BPE, 240 kDa) conjugated to a nuclear localization signal (NLS) demonstrated that these nuclei were competent for NPC-mediated MMT (NPC-MMT). Furthermore, when exposed to an appropriate cell lysate, the nuclei expressed enhanced green fluorescence protein (EGFP) after 5-10 h of incubation with the plasmid for this protein (pEGFP, 3.1 MDa). Nucleus-attached patch-clamp showed that colloidal gold particles were not useful probes; they modified NPCC gating. As a result of this finding, we searched for an inert class of particles that could be used without irreversibly affecting NPCC gating and found that fluorescently labeled Starburst dendrimers, a distinct class of polymers, were useful. Our patch-clamp and fluorescence microscopy data with calibrated dendrimers indicate that the cardiomyocyte NPCC diameter varies between 8 and 9 nm. These studies open a new direction in the investigation of live, continuous NPC dynamics under physiological conditions.

Animals↗
PubMed2002

Cellular and subcellular localisation of glutamine synthetase and glutamate dehydrogenase in grapes gives new insights on the regulation of carbon and nitrogen metabolism.

The subcellular localisation of glutamine synthetase (GS) and glutamate dehydrogenase (GDH) in grapevine (Vitis vinifera L.) leaves and flowers was investigated using immunogold-labelling experiments. In mature leaf tissue or fully developed flowers, GS was visualised both in the cytosol and in the chloroplasts, a high proportion of the protein being present in the phloem companion cells. GDH was preferentially located in the mitochondria of the phloem companion cells in both leaves and flowers. This observation suggests that, in conjunction with GS, GDH plays a major role in controlling the translocation of organic carbon and nitrogen metabolites in both vegetative and reproductive organs. Significant amounts of GDH protein were also visualised in multivesicular bodies within the flower receptacle. Although the function of such organelles is still unknown, its is possible that the presence of GDH in such cellular structures is important for the recycling of carbon and nitrogen molecules in senescing tissues in which the enzyme is generally induced.

Carbon↗
PubMed2003

An in vitro long-term culture model for normal human mammary gland: expression and regulation of steroid receptors.

Steroids and their nuclear receptors play crucial roles in the development and maintenance of normal functions of the human mammary gland (HMG). They have also been implicated in breast carcinogenesis. However, the study of steroid action in normal HMG has been hampered by experimental difficulties. By using a newly established in vitro long-term culture method, we successfully cultured normal HMG tissue for more than 2 months without detriment to its morphology or steroid receptor expression. Expression of the cellular structural and extracellular matrix proteins was similar to that prior to culture, and HMG tissue retained its properties of steroid receptor expression and regulation. Addition of 17-beta estrogen to mammary tissues markedly increased the expression of progesterone receptor (PR) but only slightly affected that of the estrogen receptor (ER). Medroxyprogesterone acetate down-regulated the expression of PR within 24-48 h and also increased the expression of androgen receptor. When HMG tissue was cultured in medium containing normal or dextran-coated charcoal-stripped fetal calf serum or normal human serum, the expression and regulation of steroid hormone receptors were similar, although different in extent. When serum was omitted, the morphology of HMG was normal after 1 week, but the expression and regulation of ER and PR were altered. Thus, as HMGs retain the capacity to express steroid receptors in culture, this long-term culture system is probably a good model for studying the regulation of the mammary gland by steroids.

Actins↗
PubMed2004

Changes in the distribution of ZO-1, occludin, and claudins in the rat uterine epithelium during the estrous cycle.

During the estrous cycle, the endometrium epithelium experiences marked cellular structural changes. For fertilization to proceed, maintenance of an adequate uterine environment by ovarian hormones is essential. Epithelial cells lining the uterine lumen are associated with each other by tight junctions (TJs), which regulate the passage of ions and molecules through the paracellular pathway. The aim of the present study was to assess by confocal immunofluorescence the distribution pattern of the TJ proteins ZO-1, occludin, and claudins 1-7 in the rat uterus during the estrous cycle. Our results reveal that on proestrus, the day when mating takes place, ZO-1, occludin, and claudins 1 and 5 are located in the TJs, while claudins 3 and 7 display a basolateral distribution. In contrast, on metestrus day, when no sexual mating occurs and the uterine lumen is devoid of secretions, none of these proteins were detected in the TJ region, and only a diffuse cytosolic staining was observed for some of the proteins. On estrus and diestrus days, an intermediate situation was encountered, since ZO-1 localized in the TJs, whereas occludin was no longer detectable in the TJs. The distribution of claudins during these stages varied from the lowermost portion of the basolateral membrane to its apex. In conclusion, the results show that the protein composition of TJs present in the luminal epithelial cells of the uterus changes during the different days of the estrous cycle, and suggest that the expression of TJ proteins participates in providing an adequate environment for a successful fertilization.

Animals↗
PubMed2000

Autophagy in the epithelial cells of murine seminal vesicle in vitro. Formation of large sheets of nascent isolation membranes, sequestration of the nucleus and inhibition by wortmannin and 3-ethyladenine.

The spontaneous autophagic activity in epithelial cells of isolated tissue slices of murine seminal vesicle is strongly enhanced by short (5 min) pretreatment in a medium containing 0.03% Triton X-100. In addition to the significant increase in the cytoplasmic volume fraction and the mean size of autophagic vacuoles, the appearance of shorter or longer smooth membrane pairs located between cisterns of rough endoplasmic reticulum (RER) and in the vicinity of nucleus is also greatly stimulated. Their morphological features observed after application of various fixation methods, freeze-substitution and freeze-fracture techniques show that they are unclosed nascent isolation membranes, representing a unique class of intracellular membranes. They may grow around the nucleus, leading to its complete autophagic sequestration and degradation, which is observed here for the first time. Treatment with 3-methyladenine or wortmannin inhibits the formation of autophagosomes, leading to their regression with a halving time of 7 min. In contrast, these inhibitors cause extremely fast shrinking of nascent isolating membranes, leading to their complete disappearance within 7 min. We propose that the early events of autophagy involve three main steps: initiation, growth and closure, and suggest that the growth of nascent isolation membranes is reversible i.e. the membranes may be subject to disassembly before their closure is completed. Bending and closure of the isolation membrane and the stability of neighbouring cellular structures appear as important determinants of size regulation. These early steps of autophagy are good candidates for very fast accommodation to changing conditions and subtle regulation by phosphoinositide kinases as indicated by wortmannin sensitivity.

Adenine↗
PubMed1998

Ultrastructural and lanthanum tracer examination of rapidly resorbing rat alveolar bone suggests that osteoclasts internalize dying bone cells.

Glutaraldehyde-formaldehyde fixed undecalcified alveolar bone from 7-day-old rats was prepared for light and electron microscopy. Colloidal lanthanum was used as an ultrastructural tracer, and both random and semi-serial sections were examined. Lanthanum penetrated the infoldings of the ruffled border and some nearby vacuoles and vesicles. The majority of vacuoles and vesicles were lanthanum-free. Some osteoclast profiles contained a large vacuole with a cell enclosed in its interior. The enclosed cell exhibited an irregular nucleus containing condensed peripheral chromatin, intact cytoplasmic organelles, conspicuous rough endoplasmic reticulum and large blebs on the cell surface. These features are characteristic of osteoblasts or bone-lining cells or immature osteocytes which may be undergoing apoptosis or necrosis. The observation of remnants of cellular structures within internalized osteoclast vacuoles, together with the above results, suggests that osteoclasts engulf and probably degrade dying osteoblasts/bone-lining cells or immature osteocytes.

Animals↗