bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of activation‐induced cytidine deaminase decreases throughout the life
Authors: Radu D. L. , Kodera T. , Bona C. 
Published: May 2007

AbstractActivation‐induced cytidine deaminase (AID) is an RNA editing enzyme, which contributes to generation of new functional genes from a restricted number of genes of plant and animal genome. This enzyme was involved in the process of somatic mutation and class switching in vertebrate. Since the rate of somatic mutations is variable throughout ontogeny, we have studied the transcription of AID in 3 to 24 month‐old Balb/c mice. Our results demonstrate a significant decrease of the transcription of the AID gene with aging. The decreased AID activity is not related to variation of phenotypic and functional properties of B cells throughout the life. This observation can explain the low rate of somatic mutation in aged animals.
Cytokine gene expression in monocytes of patients undergoing cardiopulmonary bypass surgery evaluated by real‐time PCR
Authors: Zimmermann Anja K. , Simon P. , Seeburger J. , Hoffmann J. , Ziemer G. , Aebert H. , Wendel H. P. 
Published: May 2007

AbstractCardiopulmonary bypass (CPB) surgery induces systemic release of proinflammatory cytokines causing unspecific inflammatory reactions. This study deals with the development of a sensitive technique for detecting changes at the mRNA level in monocytes of patients undergoing CPB surgery, by using real‐time PCR. Blood samples from patients undergoing elective coronary artery bypass grafting were obtained at six different time points. RNA was extracted from isolated monocytes and cDNA was synthesized by reverse transcriptase. CPB surgery induced gene expression of IL‐β, IL‐6, IL‐8, and TNF‐alpha, followed by a decrease below the preoperative expression values 6 h post CPB. High significant increases in gene expression for IL‐8 at the end of surgery (p = 0.001) were detected. Real‐time PCR is a powerful tool for getting simultaneously numerous sensitive, accurate, and reliable results from small amounts of biological material. This method avoids time‐consuming and hazardous post‐PCR manipulations and decreases the potential risk of PCR contamination.
Mast cells in tissue response to dentistry materials: an adhesive resin, a calcium hydroxide and a glass ionomer cement
Authors: De Oliveira Mussel R. L. , De Sá Silva E. , Costa Andréa Monte Alto , Mandarim‐De‐Lacerda C. A. 
Published: May 2007

AbstractSynthetic materials used in dentistry may trigger various inflammatory responses. In order to evaluate biocompatibility, standardized implants of Calcium Hydroxide (CH), Glass Ionomer Cement (GIC) and Light‐activated Dental Adhesive (LDA) were surgically introduced into Wistar rats’back bone. Six (experimental) animal groups, five each, and two Sham (S) groups were studied after 15 and 30 days from surgery. In each animal, the density of mast cells and interstitial fibrosis volume was evaluated by quantitative light microscopy. In addition, the interaction between the disk material and its fibrous capsule was evaluated by scanning electron microscopy. In addition, the interaction between the disk material and its fibrous capsule was evaluated by scanning electron microscopy. The density of mast cells per area (NA[mast cells]) was lower in CH group than in LDA group. GIC group displayed NA[mast cells]) results intermediate between CH and LDA groups (p<0.05). The smallest interstitial fibrosis volume density (VV(f)) was observed in CH group, the in GIC group, whilet he greatest in LDA group. After 30 days, the fibrosis in LDA group was 30% higher than in CH group (p<0.05). In S group, discreet fibrosis restricted to surgical area was present, with few mast cells near the vessels. Significant interaction between fibrous capsule and the surrounding disk material was most evident in CH group. The implanted materials induced mast cell migration, distinc fibrosis development, suggesting that CH is the most biocompatible material among those tested.
Genetic‐dependency of peroxisomal cell functions ‐ emerging aspects
Authors: Latruffe N. , Vamecq J. , Malki M. Cherkaoui 
Published: May 2007

AbstractThis paper reviews aspects concerning the genetic regulation of the expression of the well studied peroxisomal genes including those of fatty acid β‐oxidation enzymes; acyl‐CoA oxidase, multifunctional enzyme and thiolase from different tissues and species. An important statement is PPARα, which is now long known to be in rodents the key nuclear receptor orchestrating liver peroxisome proliferation and enhanced peroxisomal β‐oxidation, does not appear to control so strongly in man the expression of genes involved in peroxisomal fatty acid β‐oxidation related enzymes. In this respect, the present review strengthens among others the emerging concept that, in the humans, the main genes whose expression is up‐regulated by PPARα are mitochondrial and less peroxisomal genes. A special emphasis is also made on the animal cold adaptation and on need for sustained study of peroxisomal enzymes and genes; challenging that some essential roles of peroxisomes in cell function and regulation still remain to be discovered.
A new look at the cellular scaffold by embedment‐free electron microscopy method
Authors: Gajkowska Barbara , Wojesódzka Urszula 
Published: May 2007

AbstractThe basic scaffold of most cells is afforded by the cytoskeleton (comprising microfilaments, intermediate filaments and the microtubules). The conventional methods of electron microscopy fail to visualize filamentous cell structure. They can show only these filaments lying at the section surface. Heavy metal staining (I), and the optical properties of the resins used for embedding are similar to those of proteins hence most proteinaceous structures remain unresolved and the cytoplasm seems to be quite homogenous (II). Aldehyde fixation could cross‐link proteins and lead to the emergence of artificial structures (III). These limitations may be overcome by the use of the embedment‐free electron microscopy (EF‐EM). This technique present cellular scaffold as a purified, isolated, three‐dimensional network with various thickness of filaments. Our study on the dynamic aspect of cellular scaffold indicate that the thickness and arrangement of filaments depend on cell type and both physiological or pathological environments. Thank also to the adaptation of immunocytochemistry to EF‐EM it was possible to understand the nuclear matrix and cytomatrix structure in relation to function. Thus, combination these methods revealed findings suggesting the nuclear homing of proapoptotic proteins and their association with intermediate filaments.
Somatotroph to thyrotroph cell transdifferentiation during experimental hypothyroidism ‐ a light and electron‐microscopy study
Authors: Radian S. , Coculescu M. , Morris J. F. 
Published: May 2007

AbstractSomatotroph and thyrotroph pituitary cells share a common precursor cell expressing the transcription factor Pitl in ontogeny. Cells expressing both thyrotropin (TSH) and growth‐hormone (GH) are found in adult rat pituitary and in human pituitary adenomas in acromegaly, and these tumors contain both thyrotropin‐releasing hormone (TRH) and the TRH receptors (TRHR). It has been shown that stimulation of TSH expression in primary hypothyroidism promotes changes suggestive of somatotroph to thyrotroph cell transdifferentiation. We tested this hypothesis and the role of TRH in experimental primary hypothyroidism in rats. Adult female Long‐Evans rats, 6 months old, were administered the antithyroid drug methimazole (0,1% w/v) in the drinking water for 42 days. Animals were sacrificed by perfusion fixation under anaesthesia at weekly intervals and pituitary tissue processed in acrylic resin for immunofluorescence and immuno‐electronmicroscopy for TSH, GH and TRHR. In the hypothyroid rat pituitary immunofluorescent somatotrophs were greatly reduced in number and gradually replaced by thyrotrophs during methimazole administration. Colocalization of GH and TSH in the same cell was noted. Immunoelectronmicroscopy demonstrated the development of enlarged thyrotrophs with dilated rough endoplasmic reticulum containing an electron‐dense material and intracisternal granules, both of which are immunoreactive for TSH (‘thyroidectomy cells’). The somatotrophs showed reduced GH immunoreactivity and also the presence of TSH‐type, small‐size secretory granules. This suggests that, the greatly increased number of TSH‐cells in methimazole‐induced‐hypothyroidism is due, at least partially, to the transdifferentiation of somatotroph into thyrotroph cells. TRHR immunofluorescence was expressed in many somatotrophs in normal rat pituitary and unlike immunoreactive GH, its expression was enhanced during hypothyroidism. The number of TRHR‐immunoreactive cells increased in parallel with the number of TSH‐immunoreactive cells. This indicates a role for TRH stimulation in the transdifferentiation process. Taken together, these data suggest that, in addition to the cell mutation mechanism involving an early totipotential progenitor cell, transdifferentiation of existing somatotroph cells also plays a part in the pathogenesis of multihormonal GH‐secreting adenomas.
Relationship of tobacco smoking with GSTM1 gene polymorphism in laringeal cancer
Authors: Bardakci F. , Canbay E. , Degerli Naci , Coban L. , Canbay E. I. 
Published: May 2007

AbstractThis paper aimed to analyze the association of polymorphism of GSTM1 0/0 genotype with laryngeal cancer along a hospital based case‐control study. Polymorphisms of GSTM1 0/0 of samples from 36 patients with laryngeal cancer and 35 healthy controls were detected by PCR method. The reaction used as GSTM1 primers, using the sequence sense: 5′‐CTGCCCTACTTGGATTGATGGG‐3′ and antisense: 5′‐TGGATTGTAGCAGATCATGC‐3′. N Acetyl transferase 1 (NAT1) gene using the primers sense: 5′‐TAAAAGTAAAATGATTTGCTTTCG‐3′ and antisense: 5′‐GCTTTCTAGCATAAATCACCAA‐3′ was used as internal positive control. Two sided 2 and multivariation analysis were used to analyse the results. The proportions of GSTM1 deleted genotype in cases and controls were 47.2% and 54.3%, respectively. There was significant increment of GSTM 0/0 genotype frequency in moderate smokers group of patients compared to control (P=0.033, OR= 4.78, 95% CI=1.30‐7.13). We conclude that GSTM1 deleted genotype may be a genetic susceptibility marker for laryngeal cancer whose exposed to low doses carcinogens. The absence of this enzyme seems to have a role in the development of laryngeal cancer, in which the mechanism still needs further investigation.
Apoptotic rate in patients with myelodisplastic syndrome treated with modulatory compounds of pro‐apoptotic cytokines
Authors: Moldoveanu Elena , Moicean Andreea , Vidulescu Cristina , Marta Daciana , Colita Adriana 
Published: May 2007

AbstractExcessive apoptosis has a central role in ineffective hematopoiesis in myelodysplastic syndrome (MDS). The aim of the study was to quantify apoptosis and Bcl‐2 expression in patients with MDS and to use these parameters in the evaluation of treatment efficacy with compounds modulating proapoptotic cytokines. Bone marrow (BM) samples from eight MDS patients were studied: four with refractory anemia and four with refractory anemia with ringed sideroblasts. Two patients with Hodgkin disease without BM determination were studied for control. Therapy consisted in administration of pentoxyphylline, dexamethasone and ciprofloxacin. Biochemical assay of apoptosis and Bcl‐2 was performed using annexin V‐biotin conjugate antibody and anti‐human Bcl‐2 antibody respectively, followed by streptavidine‐peroxidase conjugate, and peroxidase substrate. Ultrastructural investigation of BM samples was performed with standard electron microscopy techniques. Most of BM hematopoietic cells in the MDS patients had ultrastructural features of various stages of apoptosis including chromatin condensation and margination, cytoplasm condensation and budding of nuclear and plasma membranes to produce apoptotic bodies. Bcl‐2 expression showed an inverse correlation with the rate of the apoptotic process. Periodic evaluation of these two parameters has shown an increase of Bcl‐2 expression and a decrease of apoptotic rate in patients who had responded to the treatment. Response to the treatment was appreciated in accordance with their transfusion needs. Treatment efficiency diminished in time. The rate of apoptosis was inversely correlated with the level of Bcl‐2 expression. These results confirm the importance of the apoptotic process evaluation in monitoring MDS treatment.
Endoplasmic reticulum Ca2+ homeostasis and neuronal death
Authors: Verkhratsky A. , Toescu E. C. 
Published: May 2007

AbstractThe endoplasmic reticulum (ER) is a universal signalling organelle, which regulates a wide range of neuronal functional responses. Calcium release from the ER underlies various forms of intracellular Ca2+ signalling by either amplifying Ca2+ entry through voltage‐gated Ca2+ channels by Ca2+‐induced Ca2+ release (CICR) or by producing local or global cytosolic calcium fluctuations following stimulation of metabotropic receptors through inositol‐1,4,5‐trisphosphate‐induced Ca2+ release (IICR). The ER Ca2+ store emerges as a single interconnected pool, thus allowing for a long‐range Ca2+ signalling via intra‐ER tunnels. The fluctuations of intra‐ER free Ca2+ concentration regulate the activity of numerous ER resident proteins responsible for post‐translational protein folding and modification. Disruption of ER Ca2+ homeostasis results in the developing of ER stress response, which in turn controls neuronal survival. Altered ER Ca2+ handling may be involved in pathogenesis of various, neurodegenerative diseases including brain ischemia and Alzheimer dementia.
Plasticity of purine release during cerebral ischemia: clinical implications?
Authors: Pearson T. , Currie Ailsa J. , Etherington Lori‐An V. , Gadalla Anne E. , Damian Karen , Llaudet E. , Dale N. , Frenguelli B. G. 
Published: May 2007

AbstractAdenosine is a powerful modulator of neuronal function in the mammalian central nervous system. During a variety of insults to the brain, adenosine is released in large quantities and exerts a neuroprotective influence largely via the A1receptor, which inhibits glutamate release and neuronal activity. Using novel enzyme‐based adenosine sensors, which allow high spatial and temporal resolution recordings of adenosine release in real time, we have investigated the release of adenosine during hypoxia/ischemia in thein vitrohippocampus. Our data reveal that during the early stages of hypoxia adenosine is likely releasedper seand not as a precursor such as cAMP or an adenine nucleotide. In addition, repeated hypoxia results in reduced production of extracellular adenosine and this may underlie the increased vulnerability of the mammalian brain to repetitive or secondary hypoxia/ischemia.
Human Natural Killer cell receptors: insights into their molecular function and structure
Authors: Biassoni R. , Cantoni Claudia , Marras D. , Giron‐Michel J. , Falco Michela , Moretta L. , Dimasi N. 
Published: May 2007

AbstractNK cells express receptors characterized by opposite functions that finely regulate their activities. Among inhibitory receptors, some are specific for different groups of MHC class I alleles, while others are still orphan receptors. On the contrary, various activating receptors are involved in the triggering of NK‐mediated natural cytotoxicity. In general, their engagement induces human NK cells to kill target cells that are either HLA class I‐negative or ‐deficient. Thus, the process of NK cell triggering mediated by Natural Cytotoxicity Receptors can be mainly considered as a non MHC‐restricted mechanism. Here, a brief description of the molecular nature of these receptors, as well as, of their 3D‐structures and of the implications for ligand recognition, is given.
Peroxisome biogenesis and the role of protein import
Authors: Brown Laura‐Anne , Baker Alison 
Published: May 2007

AbstractPeroxisomes are metabolic organelles with enzymatic content that are found in virtually all cells and are involved in β‐oxidation of fatty acids, hydrogen peroxide‐based respiration and defence against oxidative stress. The steps of their biogenesis involves “peroxins”, proteins encoded by PEX genes. Peroxins are involved in three key stages of peroxisome development: (1) import of peroxisomal membrane proteins; (2) import of peroxisomal matrix proteins and (3) peroxisome proliferation. Of these three areas, peroxisomal matrix‐protein import is by far the best understood and accounts for most of the available published data on peroxisome biogenesis. Defects in peroxisome biogenesis result in peroxisome biogenesis disorders (PBDs), which although rare, have no known cure to‐date. This review explores current understanding of each key area in peroxisome biogenesis, paying particular attention to the role of protein import.
Immunohistochemical assessment of proliferating cell nuclear antigen in primary hepatocellular carcinoma and dysplastic nodules
Authors: Saftoiu A. , Ciurea T. , Georgescu Claudia , Banita Monica , Comanescu Violeta , Rogoveanu I. , Gorunescu F. , Georgescu I. 
Published: May 2007

AbstractA complementary way for the assessment of HCC prognosis is represented by the analysis of molecular markers. Thus, immunohistochemical assessment of proliferation can describe tumor aggressiveness, probability of local recurrence or metastasis potential, being very useful for the assessment of recurrence‐free survival and survival until death. The aim of our study was to assess proliferating cell nuclear antigen activity in HCC and dysplastic nodules as compared with surrounding nonneoplasic areas. Immunohistochemical techniques were thus performed on the samples obtained by ultrasound‐guided liver biopsies or intraoperative biopsies, in 32 patients with HCC, as well as in 3 patients with dysplastic nodules ocurring in liver cirrhosis. Expression of PCNA within extranodular areas of the HCC patients in the absence or presence of cirrhosis, was increasing from 40% to 70%, respectively. PCNA expression further increased within intranodular areas of dysplastic nodules and HCC, to 100% and 96.88%, respectively. A progressive increase of the mean values of PCNA‐LI was also observed from extranodular areas without or with cirrhosis, towards intranodular areas of dysplastic nodules and HCC (4.2%, 6.8%, 31.9%, respectively). Dysplastic nodules can thus be considered lesions with a high‐proliferation rate, representing an early stage of hepatocarcinogenesis. This supported the current recommendations for borderline hepatocellular nodules identified by ultrasound, which indicate an aggressive treatment similar to malignant lesions. In summary, we demonstrated a progressively increasing rate of cellular proliferation, from extranodular non‐neoplasic areas to intranodular areas (dysplastic nodules and HCC), as reflected by an increased expression of proliferating cell nuclear antigen labelling index.
Sertoli‐Leydig cell tumor ‐ a rare androgen secreting ovarian tumor in postmenopausal women: case report and review of literature
Authors: Gheorghisan‐Galateanu Ancuta , Fica Simona , Terzea Dana Cristina , Caragheorgheopol Andra , Horhoianu V. 
Published: May 2007

AbstractSertoli‐Leydig cell tumors (SLCT) constitute only 1‐0.5% of all primary ovarian neoplasms. We report a SLCT in a postmenopausal woman aged 69 years. The physical examination revealed severe hirsutism. Basal hormonal evaluation showed high plasma testosterone and estradiol values, with suppressed plasma gonadotropins. Computer tomograph scan revealed a right ovarian tumor mass of 4,3/3 cm, confirming an androgen secreting ovarian tumor. The histopathological and immunocytochemical examination established the diagnosis of well differentiated Sertoli‐Leydig cell tumor. The tumor was positive for cytokeratin KL 1 and S‐100 protein and, in isolated tumor cells, positive for alpha‐fetoprotein. Postsurgical evolution was favorable; controls after 6 months and 3,5 years showed marked reduction of hirsutism, normal plasma testosterone values and gonadotropins in normal postmenopausal range. We discuss the complex aspects of etiology and pathogenesis, the clinical and hormonal settings, the role of immunocytochemical markers in diagnosis, as well as the therapy and the prognostic features of this ovarian tumor.
Discovery of the Porosome: revealing the molecular mechanism of secretion and membrane fusion in cells
Authors: Jena B. P. 
Published: May 2007

AbstractSecretion and membrane fusion are fundamental cellular processes involved in the physiology of health and disease. Studies within the past decade reveal the molecular mechanism of secretion and membrane fusion in cells. Studies reveal that membrane‐bound secretory vesicles dock and fuse at porosomes, which are specialized plasma membrane structures. Swelling of secretory vesicles result in a build‐up of intravesicular pressure, which allows expulsion of vesicular contents. The discovery of the porosome, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution, are discussed. The molecular mechanism of secretory vesicle fusion at the base of porosomes, and vesicle swelling, have been resolved. With these findings a new understanding of cell secretion has emerged and confirmed by a number of laboratories.
Functions of erg K+channels in excitable cells
Authors: Schwarz Jürgen R. , Bauer Christiane K. 
Published: May 2007

AbstractEther‐à‐go‐go‐related gene (erg) channels are voltage‐dependent K+channels mediating inward‐rectifying K+currents because of their peculiar gating kinetics. These characteristics are essential for repolarization of the cardiac action potential. Inherited and acquired malfunctioning of erg channels may lead to the long QT‐syndrome. However, erg currents have also been recorded in many other excitable cells, like smooth muscle fibres of the gastrointestinal tract, neuroblastoma cells or neuroendocrine cells. In these cells erg currents contribute to the maintenance of the resting potential. Changes in the resting potential are related to cell‐specific functions like increase in hormone secretion, frequency adaptation or increase in contractility.
Plasticity of GABAergic synapses in the neonatal rat hippocampus
Authors: Gaïarsa J.‐L. 
Published: May 2007

AbstractWhile the development and plasticity of excitatory synaptic connections have been studied into detail, little is known about the development of inhibitory synapses. As proposed for excitatory synapses, recent studies have indicated that activity‐dependent forms of synaptic plasticity, such as long‐term potentiation and long‐term depression, may play a role in the establishment of functional inhibitory synaptic connections. Here, I review these different forms of plasticity and focus on their possible role in the developing neuronal network.