Cells Only (cell + only)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Asymmetric division of spindle microtubules and microfilaments during bovine meiosis from metaphase I to metaphase III

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2005
Guang-Peng Li
Abstract The kinetics of spindle and chromosomes during bovine oocyte meiosis from meiosis I to meiosis III is described. The results of this study showed that (1) oocytes began to extrude the first polar body (Pb1) at the early anaphase I stage and the Pb1 totally separated from the mother cell only when oocytes reach the MII stage; (2) the morphology of the spindle changed from barrel-shaped at the metaphase stage to cylinder-shaped at early anaphase, and then to a thin, long triangle-shaped cone at late anaphase and telophase stages; (3) chromosome morphology went from an individual visible stage at metaphase to a less defined chromatin state during anaphase and telophase stages, and then back to visible individual chromosomes at the next metaphase; (4) chromatin that connected with the floor of the cone became the polar bodies and expelled, and almost all of the microtubules (MTs) and microfilaments (MFs) composing the spindles moved towards and contributed to the polar bodies; and (5) the size of the metaphase I (MI) spindle was larger than the metaphase II (MII) and metaphase III (MIII) spindles. The MII spindle, however, is more barrel-shaped than the MI spindle. This study suggests that spindle MTs and MFs during bovine oocyte meiosis are asymmetrically divided into the polar bodies. Mol. Reprod. Dev. 71: 220,226, 2005. © 2005 Wiley-Liss, Inc. [source]


Human immunodeficiency virus gag and pol-specific CD8 T cells in perinatal HIV infection

CYTOMETRY, Issue 5 2001
Thomas W. McCloskey
Abstract Background: Binding of fluorochrome-conjugated MHC class I tetramers is a powerful means to detect antigen-specific CD8 T lymphocytes. In human immunodeficiency virus (HIV) infection, cellular immune response is essential in curtailing HIV disease progression but gaps persist in our understanding of HIV-specific cells during the disease course. In this study, we evaluated tetramer binding HIV-specific CD8 T cells in HIV-infected children. Methods: Fluorescently labeled tetramers for HIV gag and pol were utilized to quantify antigen-specific cells by flow cytometry using a whole blood labeling method in a cohort of 19 HLA-A2+ HIV- infected children (age range 1 month to 17 years). Results: Fourteen children had detectable gag (median 0.4%) and pol (median 0.1%) binding CD8 T cells, three children had gag binding cells only, and two had neither. Numbers of gag and pol binding cells correlated with each other and each correlated independently with total CD8 T cells and total CD4 T cells. Conclusions: HIV gag and pol-specific CD8 T cells are maintained during the chronic phase of HIV infection in children and CD4 lymphocytes appear to be important for sustaining their levels. Cytometry (Comm. Clin. Cytometry) 46:265,270, 2001. © 2001 Wiley-Liss, Inc. [source]


Papanicolaou tests associated with cervical mucosal endometriosis: An analysis of cellular features and comparison to endocervical adenocarcinoma in situ

DIAGNOSTIC CYTOPATHOLOGY, Issue 8 2010
Charles V. Biscotti M.D.
Abstract Endometrium directly sampled from endocervical mucosal endometriosis can mimic endocervical adenocarcinoma in situ (AIS) in Papanicolaou (Pap) tests. We analyzed a series of Pap tests to investigate the cellular features of mucosal endometriosis and to assess the utility of stroma and apoptotic bodies in the differential diagnosis with AIS. Pap test samples from patients known to have endocervical mucosal endometriosis were compared with samples containing AIS. Pap tests from patients with mucosal endometriosis had lesional cells in 13 (62%) cases which includes glandular and stromal cells (10 cases), stroma only (two cases), and glandular cells only (one case). Three (23%) cases had gland-stromal aggregates. Three (23%) cases had mitotic figures and two (15%) had apoptotic bodies. By comparison, only one (8%) AIS case had endometrial-type stroma. Seven (58%) AIS cases had apoptotic bodies and three (25%) had mitotic figures. We conclude that Pap tests from patients with mucosal endometriosis usually (62%) have lesional cells. These lesional cells almost always include stroma, which is useful in the differential diagnosis with AIS. We identified stroma significantly more often in endometriosis cases (92%) than in AIS cases (8%). Pathologists should look for endometrial stroma when considering an interpretation of directly sampled endometrium. In the absence of stroma, AIS should be considered. Diagn. Cytopathol. 2010;38:551,554. 2009 Wiley-Liss, Inc. [source]


Challenging Wallacean and Linnean shortfalls: knowledge gradients and conservation planning in a biodiversity hotspot

DIVERSITY AND DISTRIBUTIONS, Issue 5 2006
Luis Mauricio Bini
ABSTRACT Knowledge about biodiversity remains inadequate because most species living on Earth were still not formally described (the Linnean shortfall) and because geographical distributions of most species are poorly understood and usually contain many gaps (the Wallacean shortfall). In this paper, we developed models to infer the size and placement of geographical ranges of hypothetical non-described species, based on the range size frequency distribution of anurans recently described in the Cerrado Biome, on the level of knowledge (number of inventories) and on surrogates for habitat suitability. The rationale for these models is as follow: (1) the range size frequency distribution of these species should be similar to the range-restricted species, which have been most recently described in the Cerrado Biome; (2) the probability of new discoveries will increase in areas with low biodiversity knowledge, mainly in suitable areas, and (3) assuming range continuity, new species should occupy adjacent cells only if the level of knowledge is low enough to allow the existence of undiscovered species. We ran a model based on the number of inventories only, and two models combining effects of number of inventories and two different estimates of habitat suitability, for a total of 100 replicates each. Finally, we performed a complementary analysis using simulated annealing to solve the set-covering problem for each simulation (i.e. finding the smallest number of cells so that all species are represented at least once), using extents of occurrence of 160 species (131 real anuran species plus 29 new simulated species). The revised reserve system that included information about unknown or poorly sampled taxa significantly shifted northwards, when compared to a system based on currently known species. This main result can be explained by the paucity of biodiversity data in this part of the biome, associated with its relatively high habitat suitability. As a precautionary measure, weighted by the inferred distribution data, the prioritization of a system of reserves in the north part of the biome appears to be defensible. [source]


Increased osteopontin expression following intranigral lipopolysaccharide injection in the rat

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2005
Joanna Iczkiewicz
Abstract Nigral cell death in Parkinson's disease is characterized by glial cell activation leading to inflammatory changes. Osteopontin (OPN) is a glycosylated phosphoprotein that is induced by inflammatory mediators and which we have previously shown to be present in the substantia nigra. However, the role of OPN in the nigral inflammation is not known. We now report on the effects of lipopolysaccharide (LPS)-induced glial cell activation in the substantia nigra of rats on OPN expression. LPS administration induced dopaminergic cell death as shown by reduced nigral tyrosine hydroxylase immunoreactivity. There was a corresponding time-dependent increase in both OPN mRNA, which was maximal at 48 h, and protein levels, which peaked at 72 h before returning to control levels by 120 h. This increase was accompanied by marked reactive gliosis as shown by increased OX-42, glial fibrillary acidic protein (GFAP) and ED1 immunoreactivity. OX-42-positive cells increased in a time-dependent manner, peaking at 72 h before returning to control levels at 120 h. Similarly, ED1-positive cells were present in their greatest numbers at 24 h but then gradually declined. These changes mirrored the alterations occurring in OPN protein and OPN mRNA, respectively. In contrast, GFAP-positive cells only started to increase in number at 120 h. Colocalization studies showed that OPN was present in both ED1- and OX-42-positive cells but not in GFAP-positive cells. These data confirm that intranigral injection of LPS induces a rapid and marked gliosis that accompanies the loss of tyrosine hydroxylase-positive neurones and suggest that, after glial cell activation, enhanced expression of OPN occurs linked to increased numbers of microglia and/or macrophages. This suggests that OPN may be functionally important in the control of inflammatory changes. [source]


Down-regulation of heme oxygenase-2 is associated with the increased expression of heme oxygenase-1 in human cell lines

FEBS JOURNAL, Issue 23 2006
Yuanying Ding
Intracellular heme concentrations are maintained in part by heme degradation, which is catalyzed by heme oxygenase. Heme oxygenase consists of two structurally related isozymes, HO-1 and HO-2. Recent studies have identified HO-2 as a potential oxygen sensor. To gain further insights into the regulatory role of HO-2 in heme homeostasis, we analyzed the expression profiles of HO-2 and the biochemical consequences of HO-2 knockdown with specific short interfering RNA (siRNA) in human cells. Both HO-2 mRNA and protein are expressed in the eight human cancer cell lines examined, and HO-1 expression is detectable in five of the cell lines, including HeLa cervical cancer and HepG2 hepatoma. Down-regulation of HO-2 expression with siRNA against HO-2 (siHO-2) caused induction of HO-1 expression at both mRNA and protein levels in HeLa and HepG2 cells. In contrast, knockdown of HO-1 expression did not noticeably influence HO-2 expression. HO-2 knockdown prolonged the half-life of HO-1 mRNA twofold in HeLa cells. Transient transfection assays in HeLa cells revealed that the 4.5-kb human HO-1 gene promoter was activated with selective knockdown of HO-2 in a sequence-dependent manner. Moreover, HO-2 knockdown caused heme accumulation in HeLa and HepG2 cells only when exposed to exogenous hemin. HO-2 knockdown may mimic a certain physiological change that is important in the maintenance of cellular heme homeostasis. These results suggest that HO-2 may down-regulate the expression of HO-1, thereby directing the co-ordinated expression of HO-1 and HO-2. [source]


Proteasome-driven turnover of tryptophan hydroxylase is triggered by phosphorylation in RBL2H3 cells, a serotonin producing mast cell line

FEBS JOURNAL, Issue 19 2002
Yoshiko Iida
We previously demonstrated in mast cell lines RBL2H3 and FMA3 that tryptophan hydroxylase (TPH) undergoes very fast turnover driven by 26S-proteasomes [Kojima, M., Oguro, K., Sawabe, K., Iida, Y., Ikeda, R., Yamashita, A., Nakanishi, N. & Hasegawa, H. (2000) J. Biochem (Tokyo) 2000, 127, 121,127]. In the present study, we have examined an involvement of TPH phosphorylation in the rapid turnover, using non-neural TPH. The proteasome-driven degradation of TPH in living cells was accelerated by okadaic acid, a protein phosphatase inhibitor. Incorporation of 32P into a 53-kDa protein, which was judged to be TPH based on autoradiography and Western blot analysis using anti-TPH serum and purified TPH as the size marker, was observed in FMA3 cells only in the presence of both okadaic acid and MG132, inhibitors of protein phosphatase and proteasome, respectively. In a cell-free proteasome system constituted mainly of RBL2H3 cell extracts, degradation of exogenous TPH isolated from mastocytoma P-815 cells was inhibited by protein kinase inhibitors KN-62 and K252a but not by H89. Consistent with the inhibitor specificity, the same TPH was phosphorylated by exogenous Ca2+/calmodulin-dependent protein kinase II in the presence of Ca2+ and calmodulin but not by protein kinase A (catalytic subunit). TPH protein thus phosphorylated by Ca2+/calmodulin-dependent protein kinase II was digested more rapidly in the cell-free proteasome system than was the nonphosphorylated enzyme. These results indicated that the phosphorylation of TPH was a prerequisite for proteasome-driven TPH degradation. [source]


Susceptibility to experimental biliary atresia linked to different hepatic gene expression profiles in two mouse strains

HEPATOLOGY RESEARCH, Issue 2 2010
Johannes Leonhardt
Aim:, To compare hepatic gene expression during the development of experimental biliary atresia (BA) in two different mouse strains. Methods:, Balb/c mice and C57Black/6 (Black/6) mice were infected with rhesus rotavirus (RRV) postpartum, clinical signs of BA and survival were noted. Liver sections were assessed for cluster of differentiation antigen (CD) 3, CD4 and CD8 expression, and the hepatic virus load was determined. Second, mice of both strains were sacrificed three days after infection. Isolated hepatic RNA was subjected to gene expression analysis using Affymetrix Gene Chip MOE 430 2.0. Results:, The incidence of BA was significantly lower in Black/6 mice compared to Balb/c mice (13.5% vs. 67%, P < 0.05). The mean virus titers were higher in mice with BA compared to mice without BA. Different gene profiles three days after virus infection were noted, with differential expression of 201 genes, including those regulating apoptosis, nucleic acid binding, transport function and particularly the immune response (chemokine C-C motif ligand 2, toll-like receptor 3, CD antigen 14, chemokine (C-X-C motif) ligands 10 and 11). This correlated with a significant increase of CD4 positive cells only in Balb/c mice with BA compared to healthy mice (13.5 vs. 5.0; P < 0.05). Black/6 mice did not exhibit any significant increase of CD3 or CD4 leukocytes despite cholestasis. Conclusion:, The different susceptibility to experimental BA was associated with an increase of CD4 T-cells in the liver of Balb/c mice, which is linked to different gene profiles at the onset of bile duct obstruction. [source]


The shared tumor associated antigen cyclin-A2 is recognized by high-avidity T-cells

INTERNATIONAL JOURNAL OF CANCER, Issue 10 2009
Eisei Kondo
Abstract Cyclin-A2, a key cell cycle regulator, has been shown to be overexpressed in various types of malignancies with little expression in normal tissue. Such tumor-associated genes potentially are useful targets for cancer immunotherapy. However, high-avidity cyclin-specific T cells are considered to be thymically deleted. We identified at least one nonameric HLA-A*0201 binding cyclin-A2 epitope by a reverse immunology approach. Using a highly efficient T-cell expansion system that is based on CD40-activated B (CD40-B) cells as sole antigen-presenting cells we successfully generated cyclin-A2 specific CTL from HLA-A*0201+ donors. Interestingly, high-avidity cyclin-A2 specific CTL lines, which recognized peptide-pulsed and antigen expressing target cells, were indeed generated by stimulation with CD40-B cells when pulsed with low concentrations of peptide, whereas CD40-B cells pulsed at saturating concentrations could only induce low-avidity CTL, which recognized peptide-pulsed target cells only. One high-avidity CTL line was subcloned and CTL clones, whose peptide concentration required for half-maximal lysis were less than 1 nM, could lyse cyclin-A2 expressing tumor cells. Taken together, cyclin A2 is an attractive candidate for immune intervention in a significant number of cancer patients and high-avidity T cells can be readily generated using CD40-B cells as antigen-presenting cells. © 2009 UICC [source]


Intra-abdominal testis with loop-like epididymis and intra-canalicular vas and vessels

INTERNATIONAL JOURNAL OF UROLOGY, Issue 9 2002
AHMED ANWAR
Abstract A case of intra-abdominal testis with loop-like epididymis and intra-canalicular vas and vessels is presented. A 3-year-old male with left impalpable testis since birth was admitted to our department. Physical examination and ultrasonography were inconclusive. Laparoscopy revealed a small left abdominal testis with surrounding adhesions close to the left-obliterated umbilical artery. The vas deferens and spermatic vessels were entering into the internal inguinal ring. The processus vaginalis was patent. At inguinal exploration the testis was atrophic and the epididymis was loop-like, joining the vas deferens in the inguinal canal. The spermatic vessels continued to the atrophic testis in a loop-like manner. The testis, epididymis and the vas deferens were removed. Histopathological examination of the testis revealed Sertoli cells only. If inguinal exploration had been performed without laparoscopy, the presence of the vas deferens and spermatic vessels in the inguinal canal with the absence of the testis could have been misdiagnosed as vanishing testis. Abdominal testis would thus have been missed, with increased risk of complications, particularly malignancy. [source]


Effect of endotoxin pretreatment on hepatic stellate cell response to ethanol and acetaldehyde

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2001
Silvia C Quiroz
Abstract Background and Aim: The role of endotoxin in alcohol-induced liver damage is well recognized. How pre-exposure to endotoxin might affect alcohol injury is not known. We herein studied the effect of endotoxin pretreatment on hepatic stellate cell (HSC) response to ethanol and acetaldehyde. Methods: Rat HSC (CFSC-2G) were exposed to media supplemented with 1 ,g/mL lipopolysaccharide (LPS). This was followed by a 24 h exposure to media containing LPS plus 50 mmol/L ethanol or 175 ,mol/L acetaldehyde. Lipid peroxidation, collagen, and tumor necrosis factor (TNF)-,, interleukin (IL)-1,, IL-6 and transforming growth factor (TGF)-,1 secretion were determined at the end of both periods of exposure. Results: Lipopolysaccharide pretreatment did not modify lipid peroxidation induced by ethanol or acetaldehyde alone. Glutathione (GSH) content decreased to 4.2 ± 0.5 and 16.3 ± 0.8 nmol protein after exposure to ethanol or acetaldehyde alone, and decreased further with LPS pretreatment (2.4 ± 0.2 and 2.7 ± 0.3 nmol/mg protein, respectively). Oxidized GSH (GSSG) content increased in ethanol and acetaldehyde LPS-pretreated cells only. Collagen secretion increased to 988 ± 82 and 1169 ± 91 ,g/106 cells after exposure to acetaldehyde or LPS alone. Lipopolysaccharide pretreatment enhanced collagen secretion significantly in both ethanol- and acetaldehyde-treated cells (969 ± 56 and 1360 ± 72 ,g/106 cells, respectively). Interleukin-6 production increased to 288 ± 48, 1195 ± 86 and 247 ± 35 pg/mL per 106 cells after ethanol, acetaldehyde and LPS exposure, and increased further with LPS pretreatment in ethanol-exposed cells (680 ± 23 pg/mL 106 cells). Conclusion: Lipopolysaccharide pretreatment of HSC adds to the damage produced by ethanol and acetaldehyde by diminishing GSH content and increasing GSSG content, collagen and IL-6 secretion. [source]


Poster Session BP07: Neurodegenerative Diseases

JOURNAL OF NEUROCHEMISTRY, Issue 2002
F. Jayman
Presynaptic terminals contain an abundant 140-amino acid phosphoprotein, dubbed ,-synuclein, which is accumulated in Lewy bodies typically observed in neurons in neurodegenerative diseases, such as Parkinson's disease. In this study, the role of ,-synuclein in regulating cycle, differentiation, and survival of neuronal cells was studied using a rat dopaminergic cell line ZN27D. To delineate specific effects of ,-synuclein the same cell line was engineered to express human ,-synuclein and a vector-transfected cell line RK27 was used as a second control. All three cell lines showed significant proliferation even in serum-free medium, and complete inhibition of cell division and differentiation could be achieved in the ZN27D cells only when both dibutyryl cAMP (dbcAMP) and retinoic acid were present. In contrast, the ,-synuclein expressing cells could be differentiated in the presence of only dbcAMP. Dose dependence of MPP+(1-methyl-4-phenylpyridinium iodide)-mediated caspase3 activation was studied in undifferentiated ZN27D cells. At 200 ,m MPP+ a significant cleavage of the caspase3 substrate PARP was observed and it was reversed in the presence of ,-synuclein. MPP+ also inhibited aminophospholipid translocase (APTL), a P-type ATPase that is responsible for inner plasma membrane localization of phophotidylserine in healthy cells. The role of ,-synuclein in regulating cell cycle, differentiation, APTL activity and cell death is being investigated further in the dopaminergic ZN27D cell line. [source]


Effect of tumour necrosis factor-, and irradiation alone or in combination on the viability of hepatocellular and biliary adenocarcinoma cell lines in vitro

LIVER INTERNATIONAL, Issue 6 2009
Blendi Qesaraku
Abstract Background: Tumour necrosis factor , (TNF-,) may exhibit antitumoral activity and can influence the reaction of both tumour and normal tissue to radiation. Aims: To test the effect of TNF-, and/or irradiation on hepatocellular (HepG2, Hep3B, Sk-Hep1, HuH7) and cholangiocellular (Sk-chA1, Mz-chA1) tumour cell lines. Methods: Colony formation, apoptosis analysis and trypan blue exclusion were used to assess cell viability. Doses of radiation (2,25 Gy) and TNF-, (100,50 000 U) as well as their respective sequencing were varied (24 and 12 h before and 6 h after). The expression of TNF-, and TNF receptors 1/2 was determined using real-time polymerase chain reaction and I,B, protein expression was detected by Western blot. Results: Sole irradiation induced a reduction in colony formation in all cell lines and sole TNF-, in HepG2 and Sk-chA1 cells only. No difference in apoptosis induction after TNF-, or irradiation was observed. Cellular death induced by the combination of TNF-, and radiation was not superior to the use of any of the two agents alone. All cell lines revealed that radiation induced upregulation of TNF-, whereas the extent of TNF receptor-specific transcription did not change. Furthermore, radiation-induced changes in I,B, expression were not detectable. Conclusions: Our data suggest that both TNF-, and radiation may be treatment options for hepatocellular and cholangiocellular carcinomas. Because TNF-, and radiation do not interact in terms of radiosensitization, anti-TNF-, treatment may have the potential to protect against hepatocellular injury after abdominal irradiation. However, further in vivo studies are needed to confirm that anti-TNF-, treatment does not compromise tumour control and actually attenuates radiation-induced liver injury. [source]


Birch pollen allergen Bet v 1 binds to and is transported through conjunctival epithelium in allergic patients

ALLERGY, Issue 6 2009
J. Renkonen
Background:, Previous work in type-I pollen allergies has mainly focused on lymphocytes and immune responses. Here, we begin to analyse with a systems biology view the differences in conjunctival epithelium obtained from healthy and allergic subjects. Methods:, Transcriptomics analysis combined with light and electron microscopic analysis of birch pollen allergen Bet v 1 located within conjunctival epithelial cells and tissues from birch allergic subjects and healthy controls was carried out. Results:, Bet v 1 pollen allergen bound to conjunctival epithelial cells within minutes after the exposure even during the nonsymptomatic winter season only in allergic, but not in healthy individuals. Light- and electron microscopy showed that Bet v 1 was transported through the epithelium within lipid rafts/caveolae and reached mast cells only in allergic patients, but not in healthy individuals. Transcriptomics yielded 22 putative receptors expressed at higher levels in allergic epithelium compared with healthy specimens. A literature search indicated that out of these receptors, eight (i.e. 37%) were associated with lipid rafts/caveolae, which suggested again that Bet v 1 transport is lipid raft/caveola-dependent. Conclusions:, We show a clear difference in the binding and uptake of Bet v 1 allergen by conjunctival epithelial cells in allergic vs healthy subjects and several putative lipid raft/caveolar receptors were identified, which could mediate or be co-transported with this entry. The application of discovery driven methodologies on human conjunctival epithelial cells and tissues can provide new hypotheses worth a further analysis to the molecular mechanisms of a complex multifactorial disease such as type-I birch pollen allergy. [source]


Histopathological varieties of oral carcinoma in situ: Diagnosis aided by immunohistochemistry dealing with the second basal cell layer as the proliferating center of oral mucosal epithelia

PATHOLOGY INTERNATIONAL, Issue 3 2010
Takanori Kobayashi
To make reproducible diagnoses for oral carcinoma in situ (CIS), combined immunohistochemistry directed at the positioning of squamous cell proliferation (Ki-67) and differentiation (keratin (K) 13 and K19) was used, both of which support histological evaluations by providing biological evidence. Normal/hyperplastic epithelia was defined by K19+ cells only in the first basal layer, K13+ cells in the third basal and upper layers, and sporadic Ki-67+ cells in the second basal layer. These profiles indicated that a proliferating center of the oral epithelium is located in the parabasal cell layer, and K19 and K13 can be regarded as markers for basal and prickle cells, respectively. Epithelial dysplasia was characterized by irregular stratification of Ki-67+ cells and the absence of K19/K13 in proliferating cells. Irregular emerging of K19+ and K13+ cells in proliferating foci with unique stratification of atypical Ki-67+ cells indicated CIS. When the definition was applied, surgical margins in 172 recurrent cases were shown to contain CIS (39.4%) and squamous cell carcinoma (55.8%), indicating that the new diagnostic criteria for CIS reflected clinical behaviors of the cases. The results indicate that oral CIS contain more histological variations, especially those with definite keratinization, than what had been previously defined. [source]


Expanding roles for AMP-activated protein kinase in neuronal survival and autophagy

BIOESSAYS, Issue 9 2009
Jeroen Poels
Abstract AMP-activated protein kinase (AMPK) is an evolutionarily conserved cellular switch that activates catabolic pathways and turns off anabolic processes. In this way, AMPK activation can restore the perturbation of cellular energy levels. In physiological situations, AMPK senses energy deficiency (in the form of an increased AMP/ATP ratio), but it is also activated by metabolic insults, such as glucose or oxygen deprivation. Metformin, one of the most widely prescribed anti-diabetic drugs, exerts its actions by AMPK activation. However, while the functions of AMPK as a metabolic regulator are fairly well understood, its actions in neuronal cells only recently gained attention. This review will discuss newly emerged functions of AMPK in neuroprotection and neurodegeneration. Additionally, recent views on the role of AMPK in autophagy, an important catabolic process that is also involved in neurodegeneration and cancer, will be highlighted. [source]


Entrapment of dispersed pancreatic islet cells in CultiSpher-S macroporous gelatin microcarriers: Preparation, in vitro characterization, and microencapsulation

BIOTECHNOLOGY & BIOENGINEERING, Issue 6 2001
S. Del Guerra
Abstract Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient nutrition to the core of the islets, represent a major barrier for long-term survival of intraperitoneal microencapsulated islet grafts. The use of dispersed cells might contribute to solve this problem due to the conceivably easier nutritional support to the cells. In the present study, purified bovine islets, prepared by collagenase digestion and density gradient purification, and dispersed bovine islet cells, obtained by trypsin and DNAsi (viability > 90%), were entrapped into either 2% (w/v) sodium alginate (commonly used for encapsulation purposes) or (dispersed islet cells only) macroporous gelatin microcarriers (CulthiSpher-S, commonly used for the production of biologicals by animal cells). Insulin release studies in response to glucose were performed within 1 week and after 1 month from preparation of the varying systems and showed no capability of dispersed bovine islet cells within sodium alginate microcapsules to sense glucose concentration changes. On the contrary, bovine islet cells entrapped in CulthiSpher-S microcarriers showed maintained capacity of increasing insulin secretion upon enhanced glucose concentration challenge. In this case, insulin release was approximately 60% of that from intact bovine islets within sodium alginate microcapsules. MTT and hematoxylineosin staining of islet cell-containing microcarriers showed the presence of viable and metabolically active cells throughout the study period. This encouraging functional data prompted us to test whether the microcarriers could be immunoisolated for potential use in transplantation. The microcarriers were embedded within 3% sodium alginate, which was then covered with a poly-L-lysine layer and a final outer alginate layer. Maintained insulin secretion function of this system was observed, which raises the possibility of using microencapsulated CulthiSpher-S microcarriers, containing dispersed pancreatic islet cells, in experimental transplantation studies. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 741,744, 2001. [source]


Photodynamic therapy-generated tumor cell lysates with CpG-oligodeoxynucleotide enhance immunotherapy efficacy in human papillomavirus 16 (E6/E7) immortalized tumor cells

CANCER SCIENCE, Issue 5 2007
Su-Mi Bae
Immunotherapy with photodynamic therapy (PDT) offers great promise as a new alternative for cancer treatment; however, its use remains experimental. In this study, we examined the immunotherapeutic significance of human papillomavirus (HPV)-immortalized tumor cell lysates induced by PDT with CpG-oligodeoxynucleotide (ODN). PDT-cell lysates were generated by irradiating Radachlorin (5 µg/mL) preloaded TC-1 cells carrying HPV 16 E7. PDT-cell lysates plus ODN coinjection for protection against E7-expressing tumors as well as specific immune responses were evaluated with the following tests: heat shock protein 70 (HSP70) enzyme-linked immunosorbent assay, in vitro and in vivo tumor growth inhibition, interferon-, (IFN-,) and tumor necrosis factor-, (TNF-,) assay, cytotoxic T-lymphocyte assay, and fluorescence activated cell sorting (FACS) analysis. PDT-cell lysates plus ODN coinjection showed a significant suppression of tumor growth at both prophylactic and therapeutic levels, compared to PDT (or F/T)-cell lysates or ODN alone. In addition, we evaluated the level of the immune response with the coinjection. HSP70, an important regulator of inflammatory and immune response, was observed in abundance in the PDT-cell lysates. IFN-, production and cytotoxic T lymphocytes (CTL) responses were induced by PDT-cell lysates plus ODN injection. The coinjection resulted in PDT-cell lysate-specific antibodies (IgG1, IgG2a, IgG2b, and IgG3) and T-helper cell responses significantly higher than PDT-cell lysates alone. Moreover, IFN-, production and CTL responses were significantly induced in the PDT-cell lysate plus ODN immunized groups. These enhanced immune responses appeared to be mediated by CD8+ T cells only. These data suggest that PDT-cell lysates plus ODN injection may be an effective approach to induce CTL immune responses as a possible immunotherapeutic strategy for cancer therapy. (Cancer Sci 2007; 98: 747,752) [source]


Tracing of intracellular zinc(II) fluorescence flux to monitor cell apoptosis by using FluoZin-3AM

CELL BIOCHEMISTRY AND FUNCTION, Issue 7 2009
Yi-Ming Li
Abstract Changes in the free zinc(II) concentration are closely related to cell proliferation and apoptosis, especially during the early apoptotic process. In the present paper, we demonstrated that zinc(II) probe FluoZin-3AM owns sensitive properties to distinguish different stages of apoptotic cell (induced by an anticancer agent, etoposide) according to trace intracellular zinc(II) fluorescence flux. When apoptosis in HeLa or K562 cells was artificially induced, FluoZin-3AM selectively and strongly stained apoptotic cells only at early and middle stages, which was attributed to significantly increased free zinc(II) flux during these stages. This conclusion was further verified by comparing it with the conventional apoptosis detector probe Annexin-V-FITC and PI. Furthermore, FluoZin-3AM was found cell permeable to detect the intracellular zinc(II) fluorescence enhancement to threefolds within 120,s with low cytotoxicity when zinc(II) was incorporated into the cell by zinc(II) ionophore pyrithione. All the above implied that monitoring intracellular zinc fluorescence flux was an effective method to distinguish cell apoptosis from necrosis, and FluoZin-3AM was found to be a suitable probe acting alone to fulfill the work. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Regional differences in maturation of germ cells of cryptorchid testes: role of environment

ACTA PAEDIATRICA, Issue 8 2009
Dragana Zivkovic
Abstract Objective:, To investigate differences in maturation of germ cells in cryptorchid testes in three different regions. Patients and methods:, A total of 103 consecutive patients were operated for unilateral undescended testis in Vojvodina, from March 2006 until September 2007, and had a testicular biopsy performed. Germ cells were counted, and the presence of Ad spermatogonia was noted. Biopsies were compared to biopsies of similar patients from two different regions: Philadelphia, USA (130), and Liestal, Switzerland (55 patients). Results:, In Vojvodina, 84.5% of patients had Sertoli cells only, or some spermatogonia, but no Ad spermatogonia, and 15.5% had Ad spermatogonia. In Philadelphia, 59.3% of patients had poor testicular histology, and 40.7% had Ad spermatogonia. In Liestal, 61.8% of patients had no, or some, spermatogonia, but no Ad spermatogonia, and 38.2% had Ad spermatogonia. There was a difference (p = 0.000025) between the patients with normal testicular histology from Philadelphia and those from Vojvodina, as well as between the patients from Vojvodina and Liestal (p = 0.0027). Conclusion:, The reduction in the number of germ cells in patients with cryptorchidism from Vojvodina is more pronounced than patients from either Switzerland or USA. This is a unique observation, since such a study has not been published yet. [source]


Anti-inflammatory effects of probiotic yogurt in inflammatory bowel disease patients

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
M. Lorea Baroja
Summary Our aim was to assess anti-inflammatory effects on the peripheral blood of subjects with inflammatory bowel disease (IBD) who consumed probiotic yogurt for 1 month. We studied 20 healthy controls and 20 subjects with IBD, 15 of whom had Crohn's disease and five with ulcerative colitis. All the subjects consumed Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 supplemented yogurt for 30 days. The presence of putative regulatory T (Treg) cells (CD4+ CD25high) and cytokines in T cells, monocytes and dendritic cells (DC) was determined by flow cytometry from peripheral blood before and after treatment, with or without ex vivo stimulation. Serum and faecal cytokine concentrations were determined by enzyme-linked immunosorbent assays. The proportion of CD4+ CD25high T cells increased significantly (P = 0·007) in IBD patients, mean (95% confidence interval: CI) 0·84% (95% CI 0·55,1·12) before and 1·25% (95% CI 0·97,1·54) after treatment, but non-significantly in controls. The basal proportion of tumour necrosis factor (TNF)-,+/interleukin (IL)-12+ monocytes and myeloid DC decreased in both subject groups, but of stimulated cells only in IBD patients. Also serum IL-12 concentrations and proportions of IL-2+ and CD69+ T cells from stimulated cells decreased in IBD patients. The increase in CD4+ CD25high T cells correlated with the decrease in the percentage of TNF-,- or IL-12-producing monocytes and DC. The effect of the probiotic yogurt was confirmed by a follow-up study in which subjects consumed the yogurt without the probiotic organisms. Probiotic yogurt intake was associated with significant anti-inflammatory effects that paralleled the expansion of peripheral pool of putative Treg cells in IBD patients and with few effects in controls. [source]