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DIALNET OAI Articles (586,054 recursos)
Dialnet (Difusión de Alertas en la Red) es una plataforma de recursos y servicios documentales, cuyo objetivo fundamental se centra en mejorar la visibilidad y el acceso a la literatura científica hispana a través de Internet.

Ciencias biológicas

Mostrando recursos 1 - 20 de 17,481

1. An overview on the diversity of cellular organelles during the germ cell cycle - Chuva de Sousa Lopes, Susana M.; Roelen, Bernard A. J.
In mammals, germ cells undergo a long journey from specification until sexual maturation. During this journey, which takes place during the entire life cycle of mammals, the germ cells dynamically change their morphology, their expression profile and also the number and character of their cellular bodies. The focus of this review will be the diversity of cellular organelles present in the nucleus and cytoplasm at the different phases of germ cell development. We discuss how these organelles associate and behave to form a multitude of bodies that have long been observed by scientists, and how their presence or absence is...

2. Contemporary approaches for processing and handling of radical prostactomy specimens - Cheng, Liang; Sung, Ming-Tse
Standardized protocols for processing radical prostatectomy specimens are critical for superior patient management. It provides accurate information to the clinician in a reliable and consistent format to enhance patient care and prognosis. In recent years, processing protocols have been proposed by various authoritative groups, with similar suggestions for most parts of the practice guidelines; however, discrepancy in processing approaches still exists. Standardization improves the quality and consistency of pathology reports. In this review article, we incorporate the processing schemes for radical prostatectomy addressed in literature and propose a comprehensively standardized approach to evaluate radical prostatectomy specimens.

3. BDNF function and intracellular signaling in neurons - Numakawa, Tadahiro; Suzuki, Shingo; Kumamaru, Emi; Adachi, Naoki; Richards, Misty; Kunug, Hiroshi
Brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, are broadly expressed in the developing and adult mammalian brain. BDNF/TrkB-stimulated intracellular signaling is critical for neuronal survival, morphogenesis, and plasticity. It is well known that binding of BDNF to TrkB elicits various intracellular signaling pathways, including mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK), phospholipase C? (PLC?), and phosphoinositide 3-kinase (PI3K) pathways, and that BDNF exerts biological effects on neurons via activation of similar mechanisms. In addition to TrkB, a low-affinity receptor p75 is also involved in neuronal survival and plasticity. BDNF affects neurons positively or negatively through various intracellular signaling pathways...

4. Recent progress in the etiopathogenesis of pediatric biliary disease, particularly Caroli�s disease with congenital hepatic fibrosis and biliary atresia - Nakanuma, Yasuni; Harada, Kenichi; Sato, Yasunori; Ikeda, Hiroko
Recent progress in elucidating the etiopathogenesis of pediatric biliary diseases, particularly Caroli�s disease with congenital hepatic fibrosis (CHF) and biliary atresia (BA), is reviewed. The former is characterized by multiple saccular dilatations of the intrahepatic bile ducts. An animal model of this disease, the PCK rat, is being extensively studied. PCK rats and Calori�s disease with CHF belong to autosomal recessive polycystic kidney disease (ARPKD) with ductal plate malformation. Mutations of PKHD1 have been identified in ARPKD, and fibrocystin, a product of PKHD1 located in the cilia of bile ducts is lacking in the pathologic intrahepatic bile ducts of ARPKD....

5. Small cell carcinoma of the urinary bladder - Pant-Purohit, Mukta; López Beltrán, Antonio; Montironi, Rodolfo; MacLennan, Gregory T.; Cheng, Liang
Small cell carcinoma of the urinary bladder (SCCUB) is a rare and aggressive cancer of the bladder. SCCUB is part of neuroendocrine family of tumors that affect several organ systems including respiratory, gastrointestinal and male and female genitourinary tract. SCCUB affect males predominantly with common risk factors include smoking, bladder calculi, bladder manipulation, and chronic cystitis. Prognosis of SCCUB remains poor due to high metastatic potential and lack of symptoms in earlier stages of the disease. Pathogenesis of the disease is linked to loss of genetic material, hypermethylation of tumor suppressors and at times amplification of the chromosomal regions carrying...

6. Lectin-binding pattern of Senegalese sole Solea senegalensis (Kaup) testis - Desantis, S.; Zizza, Sara; García López, A.; Sciscioli, V.; Mañanós, Evaristo L.; Metrio, Gregorio de; Sarasquete Reiriz, María Carmen
The localization and characterization of oligosaccharide sequences in the testis of Senegalese sole Solea senegalensis was investigated using 12 lectins in combination with KOH saponification and sialidase digestion (K-s). The interstitial compartment contained all the sugar residues investigated, those bearing oligosaccharides terminating with sialic acid (Neu5Ac) ?2,3Galß1,4GlcNAc, Neu5AcGalNAc?1,3(LFucß1,2)Galß1,3/4GlcNAcß1 and GalNAc?1,3(LFuc1,2)Galß1,3/4GlcNAcß1 being more abundant in the medullar region than in the cortex. The melano-macrophage centres found in the interstitial compartment displayed glycans terminating with Galß1,3GalNAc. The basal lamina separating the germinal and interstitial compartments exhibited glycans with terminal/internal mannose, internal ßGlcNAc, and terminal Neu5Ac?2,6Gal/GalNAc, and Neu5AcGalß1,3GalNAc, Galß1,3GalNAc (PNA), Galß1,4GlcNAc, GalNAc, ?Gal,...

7. In vitro antigen-specific cytotoxic T cell response against esophageal carcinoma cells induced by HPV18E7-transfected dendritic cells - Wu, Lin; Yang, Wei; Chen, Lin-Xin; Chen, Shen-Ren; Zhang, Jin-Kun
Human Papillomavirus (HPV)-associated esophageal carcinoma (EC) is a high incidence tumor worldwide. Dendritic cell (DC)-based tumor vaccine is considered an alternative therapy to treat EC. Here we developed a DC-based vaccine by transfecting cord blood CD34+ stem cell-derived DC with HPV18E7 gene, observed its biological characteristics and the antigen-specific T-cell cytotoxicity on EC cells induced by HPV18E7-DC in vitro. Our results showed that 1) HPV18E7 gene transfer did not change the typical morphology of mature DC, 2) the representative phenotypes of mature DC (CD80, CD86, and CD83) were highly expressed in HPV18E7- DC (81.6%, 80.5%, and 86.6%, respectively), 3) the...

8. Tubular epithelial cell and podocyte apoptosis with de novo sirolimus based immunosuppression in renal allograft recipients with DGF - Munivenkatappa, R.; Haririan, A.; Papadimitriou, J.C.; Drachenberg, C.B.; Dinits Pensy, M.; Klassen, D.K.
Sirolimus is associated with prolonged delayed graft function (DGF) following renal transplantation and exacerbation of proteinuria. We assessed renal allograft biopsies from DGF patients treated with de novo sirolimus (n = 10) for renal tubular cell and podocyte apoptosis and expression of activated caspase-3, Bcl-2, and mTOR and compared them to biopsies from DGF patients not receiving sirolimus (n = 15). Both groups received mycophenolate mofetil, prednisone and antibody induction. Apoptosis was assessed using terminal deoxynucleodidyl transferase mediated dUTP nick end labeling (TUNEL) staining. Caspase-3, Bcl-2, and mTOR expression were assessed by immunohistochemistry. Sirolimus treated patients had 334±69 TUNEL positive...

9. Expression and distribution of the intermediate filament protein nestin and other stem cell related molecules in the human olfactory epithelium - Witt, Martin; Minovi, Amir; Prescher, Andreas; Gudziol, Volker; Dazert, Stefan; Hatt, Hanns; Benecke, Heike
The olfactory epithelium (OE) is unique in regenerating throughout life and thus is an attractive target for examining neurogenesis. The nestin protein was shown to be expressed in the OE of rodents and is suggested to be essentially involved in the process of regeneration. Here we report the expression and distribution of nestin in the human OE at RNA and protein level. Moreover, we analysed the expression profiles in dependence on age and olfactory capacity. After sinus surgery, biopsies were taken from the olfactory epithelium of 16 patients aged 20-80 years with documented differences in their olfactory function. Our studies...

10. The distribution of vasotocin and mesotocin immunoreactivity in the hypothalamic magnocellular neurosecretory nuclei of the Saharan herbivorous lizard, Uromastix acanthinurus Bell, 1825 (Sauria-Agamidae) - Barka-Dahane, Zohra; Bendjelloul, Mounira; Estabel, Jeanne; Exbrayat, Jean Marie
An immunohistochemical study of the magnocellular neurosecretory nuclei was performed in the hypothalamus of the desert lizard Uromastix acanthinurus using polyclonal antibodies against arginine vasotocin (AVT), mesotocin (MST) and neurophysins I and II (NpI, NpII). AVT- and MST-immunoreactivities were localized in individual neurons of the supraoptic, periventricular, and paraventricular nuclei and in scattered neurosecretory cells. The supraoptic nuclei (SONs) can be subdivided into rostral, medial and caudal portions. The rostral portion of the SONs was called the SON-ventral aggregation (V SON) because the neurosecretory neurons are present in the ventral part of the hypothalamus along the optic chiasma (OC). Their...

11. Control of cell shape and plasticity during development and disease by the actin-binding protein Drebrin - Dun, Xin-peng; Chilton, John K.
Drebrin is an actin-binding protein, originally identified in neuronal cells, involved in the regulation of actin filament organisation, especially during the formation of neurites and cell protrusions of motile cells. Drebrin is found in diverse non-neuronal cells, primarily in association with cell processes and intercellular junctions where it again plays a key role in actin remodelling. The downregulation of Drebrin in Alzheimer�s Disease and Down Syndrome and conversely its upregulation in various carcinomas indicate that Drebrin is an important component of the pathogenesis of multiple diseases.

12. Annexins as disease modifiers - Fatimathas, Lux; Moss, Stephen E.
The annexins are a family of calcium-dependent phospholipid binding proteins which are present in all eukaryotes. There are currently 12 identified human annexins all of which contain unique calcium binding sites, encoded in the highly conserved annexin repeat motifs within the C terminal core. In addition to the C terminal core the annexins contain a significantly more variable N terminal head. It is this domain which endows each annexin with unique functions in a diverse range of cellular processes including; endo- and exocytosis, cytoskeletal regulation and membrane conductance and organisation. Given their involvement in such a variety of processes it...

13. Tumor suppression by p53:: making cells senescent - Qian, Yingjuan; Chen, Xinbin
Cellular senescence is a permanent cell cycle arrest and a potent tumor suppression mechanism. The p53 tumor suppressor is a sequence-specific transcription factor and acts as a central hub sensing various stress signals and activating an array of target genes to induce cell cycle arrest, apoptosis, and senescence. Recent reports showed that restoration of p53 induces premature senescence and tumor regression in mice with hepatocarcinomas or sarcomas. Thus, p53-mediated senescence is capable of eliminating cancer cells in vivo. p63 and p73, two homologues of p53, have similar function in cell cycle arrest and apoptosis. However, the role of p63 and...

14. Stem cells and germ cells:: microRNA and gene expression signatures - Dyce, Paul William; Toms, Derek; Li, Julang
The study of primordial germ cell development in vivo is hampered by their low numbers and inaccessibility. Recent research has shown the ability of embryonic and adult stem cells to differentiate into primordial germ cells and more mature gametes and this generation of germ cells in vitro may be an attractive model for their study. One of the biggest challenges facing in vitro differentiation of stem cells into primordial germ cells is the lack of markers to clearly distinguish the two. As both cell types originate early in embryonic development they share many pluripotent markers such as OCT4, VASA, FRAGILIS,...

15. Non-compaction of the ventricular myocardium:: a cardiomyopathy in search of a pathoanatomical definition - Val Bernal, J. Fernando; Garijo, M. Francisca; Rodríguez Villar, Diana; Val, Daniel
Ventricular non-compaction is a rare cardiomyopathy characterized by numerous, excessively prominent ventricular trabeculations and deep intertrabecular recesses communicating with the ventricular cavity. The lesion is postulated to result from an intrauterine developmental arrest that stops compaction of the myocardial fiber meshwork. This cardiomyopathy affects the left ventricle, with or without concomitant right ventricular involvement. The disease is now seen with increasing frequency and it is clinically diagnosed by imaging techniques such as echocardiography or cardiac magnetic resonance. Current diagnostic criteria are considered too sensitive, particularly in black individuals. Therefore, this condition has generated considerable controversy and demands a new definition....

16. Etoposide induces G2/M arrest and apoptosis in neural progenitor cells via DNA damage and an ATM/p53-related pathway - Nam, Chunja; Doi, K.; Nakayama, H.
Etoposide (VP-16), an anti-tumor agent, is a topoisomerase II inhibitor that causes DNA damage. In our previous studies, it was shown that VP-16 induces S-phase accumulation and G2/M arrest, eventually resulting in apoptosis, through p53-related pathway in the mouse fetal brain. We injected 4 mg/kg of VP-16 into pregnant mice on day 12 of gestation, and the fetuses were investigated for the cell cycle checkpoint and mechanism of apoptosis. The transition of the neural progenitor cells in the fetuses was delayed as compared to that in the control, and most of the apoptotic cells were BrdU positive. VP-16-induced S-phase accumulation...

17. REG IV overexpression in an early stage of colorectal carcinogenesis:: An immunohistochemical study - Li, Xiao-Han; Zheng, Yang; Zheng, Hua-chuan; Takahashi, Hiroyuki; Yang, Xiang-Hong; Masuda, Shinji; Takano, Yasuo
To clarify the role of REG IV, a new member of the regenerating gene (REG) family, in tumorigenesis and progression of colorectal carcinoma (CRC), 320 CRC specimens, 123 corresponding adjacent non-cancerous mucosa (ANCMs), 46 corresponding non-adjacent non-cancerous mucosa (NANCMs) and 86 adenomas were investigated immunohistochemically to compare REG IV expression with clinicopathological features. In addition, double immunofluorescence labeling was performed to analyze the localization of REG IV and the intestinal mucin, MUC2. The expression of REG IV in CRCs was significantly lower than in NANCMs, ANCMs or adenomas, and inversely correlated with poor differentiation and venous invasion. In cases of...

18. TGF-ß1 and VEGF after fresh frozen bone allograft insertion in oral-maxillo-facial surgery - Rodella, L. F.; Favero, G.; Boninsegna, R.; Borgonovo, A.; Rezzani, R.; Santoro, F.
Bone regeneration technique using allografts is widely used in oral surgery to repair alveolar defects and to increase alveolar volume for endosseous implant insertions. Bone allografts promote the reabsorption and neo-synthesis of bone tissue, which are regulated by numerous cytokines, proteins and growth factors. In this study, six patients with insufficient alveolar volume for endosseous implant insertions, were treated with bone regeneration technique using Fresh Frozen Bone (FFB) allografts collected from the femoral head or the hip. Samples of bone graft collected during graft insertion surgery and biopsies collected six months later during implantology were fixed, decalcified and analyzed histomorphologically...

19. Intralesional administration of allogeneic bone marrow stromal cells reduces functional deficits after intracerebral hemorrhage - Otero, L.; Bonilla Horcajo, C.; Aguayo, C.; Zurita, Mercedes; Vaquero, Javier
When a severe neurological lesion occurs as a consequence of intracerebral bleeding, no effective treatment for improving the outcome is currently available. In the present study, intracerebral hemorrhage (ICH) was induced by stereotactic injection of 0.5 U of collagenase type IV in the striatum of adult Wistar rats, and three days later, intralesional administration of 2x106 allogeneic bone marrow stromal cells (BMSC) in saline (n:10), or saline only (n:10), was performed. In the following 30 days, functional outcome was evaluated in each animal by rotarod and the modified neurological severity score (mNSS) test. Progressive and functional improvement was observed in...

20. The pathobiological behaviors and prognosis associated with Japanese gastric adenocarcinomas of pure WHO histological subtypes - Zheng, Hua-chuan; Zheng, Yu-shuang; Xia, Pu; Xu, Xiao-yan; Xing, Ya-nan; Takahashi, Hiroyuki; Guan, Yi-fu; Takano, Yasuo
Japan is a high-risk region for gastric carcinoma with a comparatively early stage and favorable prognosis. To clarify the pathobiological behaviors and prognosis of Japanese gastric adenocarcinoma, we analyzed the clinicopathological characteristics of different WHO subtypes of carcinomas. The expression of ki-67, CPP32, p53, FHIT, maspin, parafibromin, GRP78, GRP94, EMMPRIN, VEGF, P-GSK3ß-ser9, fascin, cortactin, Arp2, Arp3 MUC-2, MUC-5AC and MUC-6 was examined using immunohistochemistry and tissue microarrays. The majority of cases were well-, poorly-, or moderately-differentiated subtype, whereas the minority were papillary or signet ring cell carcinoma (SRC). Patients with poorly-differentiated or SRC carcinoma were predominantly young and female. Poorly-differentiated...

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