SEARCH · PubMed Health

Results for “ASC”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

PubMed1994

Enteral immunization and challenge of volunteers given enterotoxigenic E. coli CFA/II encapsulated in biodegradable microspheres.

The development of a safe and effective vaccine against enterotoxigenic Escherichia coli (ETEC) would be useful for travellers and for young children in endemic areas. A feasibility study of an enteral ETEC vaccine prototype consisting of colonization factor antigen II (CFA/II), containing two component antigens CS1 and CS3, encapsulated in biodegradable polymer microspheres (BPM) was conducted in healthy volunteers. Ten adult volunteers swallowed intestinal tubes on days 0, 7, 14 and 28; after collection of jejunal fluid samples, 1 mg of CFA/II in BPM was administered via the tube. Volunteers kept a diary of symptoms after each dose. Secretory IgA in jejunal fluids, serum responses and circulating antibody-secreting cells (ASC) were measured before and after vaccination. The vaccine was well tolerated. Five of ten volunteers developed IgA anti-CFA/II ASC by 7 days after the last dose of vaccine; these same five vaccinees had IgA anti-CS3 ASC, and three of these five vaccinees had IgA anti-CS1 ASC. Five of ten vaccinees developed rises in jejunal fluid sIgA anti-CFA/II with peak GMT of 1:42. About 8 weeks after the first dose of vaccine, ten vaccinees and ten unvaccinated control volunteers underwent challenge with 10(9) c.f.u. ETEC E24377A (O139:H28 LT+ST+CS1+CS3+). Ten of ten controls and seven of ten vaccinees developed diarrhoea (p = 0.11, 30% vaccine efficacy). Two of the three protected vaccinees had the highest numbers of ASC and highest sIgA titres during the course of immunization, suggesting that these responses were protective and that this vaccine development strategy has merit. Future studies with higher dosages and a different dosing schedule are planned.

Adult↗

PubMed2003

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator, Pteris vittata L.

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the compost-treated CCA soil was related to the increase of soil water-soluble As and As(V) transformation into As(III). Reduced As uptake in the ASC soil may be attributed to As adsorption to the compost. Chinese brake fern took up As mainly from the iron-bound fraction in the CCA soil and from the water-soluble/exchangeable As in the ASC soil. Without ferns for As adsorption, compost and phosphate amendments increased As leaching from the CCA soil, but had decreased leaching with ferns when compared to the control. For the ASC soil, treatments reduced As leaching regardless of fern presence. This study suggest that growing Chinese brake fern in conjunction with phosphate amendments increases the effectiveness of remediating As-contaminated soils, by increasing As uptake and decreasing As leaching.

Adsorption↗

PubMed2002

The Autosow raised miniature swine as a model for assessing the effects of dietary soy trypsin inhibitor.

Toxicological effects of dietary soy trypsin inhibitor (TI) were assessed in male miniature swine, a model chosen for its similarities to human digestive physiology and anatomy. The TI preparation was extracted from defatted raw soy flour. From 1 through 5 weeks of age, piglets were automatically fed either a TI liquid diet [Autosow TI group (ASTI)] or a control liquid diet [Autosow control group (ASC)]. From 6 to 39 weeks of age, these animals received either swine chow and TI or swine chow and control article. The TI diets were formulated to contain a TI activity of approximately 500 mg TI/100 g dry matter. A sow control (SC) group suckled from birth to 6 weeks of age and then fed as the ASC group with swine chow plus control article from 6 to 39 weeks of age. The SC piglets grew faster than ASC piglets during postnatal weeks 1 and 2; however, the ASC piglets were significantly heavier than the SC piglets (P=0.001) at 6 weeks of age. Compared with the ASC group, TI caused a moderate decrease in feed consumption and a moderate but reversible decrease in growth from 2 to 5 weeks of age, but not thereafter. Some control and TI-fed Autosow-reared piglets had loose stools until 6 weeks of age; the effect was significantly greater in the TI-fed group. Otherwise, all swine were active and had normal appearance and behavior.

Administration, Oral↗

PubMed2001

Molecular mechanisms associated with Se-allylselenocysteine regulation of cell proliferation and apoptosis.

Se-allylselenocysteine (ASC) has been shown to inhibit mammary carcinogenesis in vivo and cell growth in vitro. However, little is known about the molecular events that account for these effects. The goal of the present study was to use a mouse hyperplastic mammary epithelial cell line, TM12, to investigate the underlying mechanism(s) associated with ASC regulation of cell proliferation and apoptosis. Cells were treated with 50 microM ASC and assessed after 3, 6 and 12 h of exposure. A significant inhibition of cell proliferation, as measured by BrdU incorporation into DNA, was observed within 3 h of ASC treatment. This inhibitory effect was slightly magnified at the later time points. The induction of apoptosis was also rapid, and progressed from a 1.3-fold increase at 3 h to a 4.4-fold increase at 12 h. Consistent with these cellular events, the levels of phosphorylated Rb protein were greatly reduced at all times points. The other accompanying changes included increases in P53, P21 and P27. Collectively, the results demonstrate for the first time that ASC is able to cause an immediate response in the expression of cell cycle regulatory proteins that favor an arrest in proliferation and an augmentation in apoptosis.

Animals↗

PubMed2001

The selector gene cut represses a neural cell fate that is specified independently of the Achaete-Scute-Complex and atonal.

The peripheral nervous system (PNS) of Drosophila offers a powerful system to precisely identify individual cells and dissect their genetic pathways of development. The mode of specification of a subset of larval PNS cells, the multiple dendritic (md) neurons (or type II neurons), is complex and still poorly understood. Within the dorsal thoracic and abdominal segments, two md neurons, dbd and dda1, apparently require the proneural gene amos but not atonal (ato) or Achaete-Scute-Complex (ASC) genes. ASC normally acts via the neural selector gene cut to specify appropriate sensory organ identities. Here, we show that dbd- and dda1-type differentiation is suppressed by cut in dorsal ASC-dependent md neurons. Thus, cut is not only required to promote an ASC-dependent mode of differentiation, but also represses an ASC- and ato-independent fate that leads to dbd and dda1 differentiation.

Alleles↗

PubMed2006

Low-grade pap smears containing occasional high-grade cells as a predictor of high-grade dysplasia.

OBJECTIVES: This study compared clinical outcomes associated with Pap smear reports of atypical squamous cells cannot exclude HSIL (ASC-H) and those associated with "low-grade smears containing occasional cells suggestive of HSIL" (LSIL-H). In Alberta, women with ASC-H are referred for colposcopy, and women with LSIL are managed with follow-up Pap smears. LSIL-H is not included in the Bethesda classification and has not been characterized in terms of cytological features, reporting, management, and clinical course. METHODS: All ASC-H (n = 153) and LSIL-H (n = 189) Pap smears recorded in the regional laboratory information system between December 2000 and December 2001 were identified. All available histology for each associated patient over the subsequent two&year period was reviewed to determine if a high-grade histological lesion was ever confirmed in a biopsy, loop electrosurgical excision procedure (LEEP), or hysterectomy specimen. RESULTS: A high-grade squamous intraepithelial lesion was identified in 48% of the ASC-H group and 40% of the LSIL-H group (P = 0.136). Most of the HSIL histopathology was identified on the first colposcopic visit, suggesting that high-grade dysplasia may have been present at the time of the original Pap smear. CONCLUSIONS: Pap smears reporting ASC-H and LSIL-H predict a high-grade squamous intraepithelial lesion with similar accuracy. Since approximately 40% of patients with an LSIL-H Pap smear have either concurrent or subsequent high-grade cervical pathology, we also recommend immediate referral for colposcopy in this group of patients.

Adolescent↗

PubMed2026

Biomimetic Hydrogels with Nucleus Pulposus-like Viscoelasticity and ECM Peptides for Discogenic Differentiation of Stem Cells.

Intervertebral disc (IVD) degeneration is a leading cause of low back pain (LBP), primarily originating in the nucleus pulposus (NP). Regenerative strategies combining mesenchymal stem cells (MSCs) with biomaterials offer great potential for NP repair by replenishing cells and restoring extracellular matrix (ECM). However, key translational challenges remain, including limited stem cell differentiation, poor cell survival in the harsh degenerative niche, and insufficient biomaterial support. While matrix viscoelasticity has been shown to influence adipose-derived stem cell (ASC) discogenic differentiation, its interplay with cell-adhesive ligands for IVD regeneration remains unclear. Moreover, most current hydrogels fail to replicate the ultrafast stress relaxation properties of native non-degenerative human NP tissue. Here, we developed viscoelastic ECM peptide-functionalized hydrogels (VEPH), specifically designed to mimic healthy human NP biomechanics and promote ASC differentiation for NP regeneration. We biochemically conjugated NP ECM-derived adhesive peptides (IKVAV, hA5G26, CHAD) through maleimide-thiol click chemistry, achieving hydrogels with significantly faster stress relaxation (∼25 s) compared to conventional viscoelastic alginate hydrogels (>100 s). Our results demonstrated that VEPH supported >95% ASC viability and robust metabolic activity over 21 days in 3D culture. Notably, the IKVAV-functionalized hydrogel significantly enhanced ASC cell-matrix interactions, upregulated NP marker expression (KRT18, HIF-1α, ITGA3, and CD24), and promoted type-II collagen secretion, indicating an NP-committed cell fate. Our findings highlight the synergistic roles of matrix viscoelasticity and NP-specific biochemical cues in directing ASC discogenic differentiation and advancing novel biomaterial design for IVD regeneration.

cell-adhesive peptides↗

PubMed2003

pH-induced alteration and oxidative destruction of heme in purified chromaffin granule cytochrome b(561): implications for the oxidative stress in catecholaminergic neurons.

The transmembrane hemoprotein, cytochrome b(561) (b(561)), in the neuroendocrine secretory vesicles is shown to shuttle electrons from the cytosolic ascorbate (Asc) to the intravesicular matrix to provide reducing equivalents for the dopamine beta-monooxygenase (DbetaM) reaction. Intravesicular Asc may also play a role in relieving catecholamine-induced oxidative stress in catecholaminergic neurons. In the present study, we have examined the alteration of purified oxidized b(561) (b(561,ox)) under mild alkaline conditions to probe the structural and functional characteristics of the protein, using UV-vis and EPR spectroscopic and kinetic techniques. Our results show that low spin heme in oxidized b(561) (b(561,ox)) readily transforms to an altered high spin form and then slowly to an Asc nonreducible form, in a pH-, temperature-, and time-dependent manner, which can be described by single-exponential rate equations, A(t) = A(o)(1- e (-kt)) and A(t) = A(o)e(-kt), respectively. More than half of the Asc nonreducible altered b(561) could be converted back to the native b(561) by pH adjustment followed by dithionite reduction, suggesting the reversibility of the process. The heme center of the transformed Asc nonreducible protein is completely bleached instantaneously by dithionite in the presence of atmospheric oxygen, which appears to be mediated by molecular oxygen and/or hydrogen peroxide. These results demonstrate that the heme centers of the protein are susceptible to the pH-induced alteration and oxidative destruction, raising some questions regarding the proposed one alkaline labile, two-heme model of b(561) [Tsubaki, M.; Nakayama, M.; Okuyama, E.; Ichikawa, Y. (1997) J. Biol. Chem. 272, 23206-23210]. The pH-induced alteration and the destruction of heme under oxidative conditions may play a significant role in the amplification of oxidative stress in catecholaminergic neurons.

Animals↗

PubMed2001

Antiproliferative and apoptotic effect of ascorbyl stearate in human glioblastoma multiforme cells: modulation of insulin-like growth factor-I receptor (IGF-IR) expression.

Human glioblastomas (gliomas) are characterized as highly invasive and rapidly growing brain tumors. In this study, we present data on in vitro effect of ascorbyl stearate (Asc-S), a liphophilic derivative of ascorbic acid on cell proliferation, transformation, apoptosis and modulation of expression of insulin-like growth factor-I receptor (IGF-IR) in human glioblastoma multiforme (T98G) cells. Asc-S showed significant inhibition of fetal bovine serum and human recombinant insulin-like growth factor-I (IGF-I) dependent cell proliferation in a dose dependent manner. Treatment of T98G cells with 0, 50, 100 and 150 microM Asc-S for 24h slowed down the cell multiplication cycle with significant accumulation of cells at late S/G2-M phase of cycle. Asc-S treatment (100 microM) reversed the transformed phenotype as determined by clonogenecity in soft agar and also induced apoptosis of T98G. These changes were found to be associated with significant decrease in IGF-IR expression in dose and time dependent manner compared to untreated controls. The data clearly demonstrate that Asc-S has antiproliferative and apoptotic effect on T98G cells probably through modulation of IGF-IR expression and consequent facilitation of programmed cell death.

Agar↗

PubMed2000

Early mutation of precore (A1896) region prior to core promoter region mutation leads to decrease of HBV replication and remission of hepatic inflammation.

To evaluate the relationship between mutations and clinical courses, we investigated precore (preC) and core promoter (CP) mutations and serum HBV DNA levels in HBe-antibody-positive HBV carriers. Fifty-six asymptomatic carriers (ASC), 29 patients with chronic hepatitis who showed normal ALT levels for more than two years (CH-ASC), 31 patients with chronic hepatitis (CH), and 32 patients with hepatocellular carcinoma (HCC) were studied. Almost all patients (99.2%) had mutations in either CP or preC. Mutation only in preC (A1896) was present in 52.2% with ASC, 25.0% with CH-ASC, 16.1% with CH, and 8.0% with HCC, and was significantly higher in ASC (P < 0.01). The patients with only preC mutation showed low HBV DNA levels in each clinical stage. The mutation of preC (A1896) prior to the mutation of CP might control the replication of HBV, which leads to the remission of hepatitis.

Adult↗

PubMed2001

Primary cutaneous adenosquamous carcinoma: a case report and review of the literature.

BACKGROUND: Adenosquamous carcinoma (ASC) of skin is a rare but distinctive neoplasm that usually exhibits an aggressive course. To date, 13 well-documented and undisputed cases of primary cutaneous ASC have been reported. This term has been used for tumors with better prognosis, such as mucoepidermoid carcinomas and acantolytic squamous cell carcinomas, originating confusion. We report a primary cutaneous ASC and review the literature. METHODS: In this report a woman with primary ASC of the skin was studied. Histopathological examination and immunohistochemical stains were performed. RESULTS: The tumor had two components: conventional squamous cell carcinoma merging with adenocarcinoma. After a local recurrence and lymph node metastases, the patient has no evidence of disease 8 months later. CONCLUSIONS: Pathologists should reserve the term ASC for tumors exhibiting the above mentioned appearance. In such circumstances, a metastatic origin must always be excluded.

Aged↗

PubMed2003

Plasma-cell homing.

Recent studies indicate that chemoattractant cytokines (chemokines), together with tissue-specific adhesion molecules, coordinate the migration of antibody-secreting cells (ASCs) from their sites of antigen-driven differentiation in lymphoid tissues to target effector tissues. Developing ASCs downregulate the expression of receptors for lymphoid tissue chemokines and selectively upregulate the expression of chemokine receptors that might target the migration of IgA ASCs to mucosal surfaces, IgG ASCs to sites of tissue inflammation and both types of ASC to the bone marrow - an important site for serum antibody production. By directing plasma-cell homing, chemokines might help to determine the character and efficiency of mucosal, inflammatory and systemic antibody responses.

Chemokines↗

PubMedDate not supplied

High prevalence of influenza specific antibody secreting cells in nasal mucosa.

Secretory immunoglobulin A (SIgA) provides the first line of defence against pathogens initiating infection via the mucosal route, e.g. the influenza virus. The aim of this study was to examine the basal level of influenza-specific antibody-secreting cell (ASC) in the local mucosa of the upper respiratory tract. Nineteen patients scheduled for tonsillectomy were enrolled for the study, and they had not experienced influenza during the previous year. Tonsils, blood, oral fluid and a nasal biopsy were sampled, and the basal levels of ASC and antibodies (Abs) were determined. We found low numbers of influenza-specific ASC in the blood and tonsils, but there were about 10-100 times higher numbers of specific ASC in the nasal mucosa tissue despite no recent influenza exposure. Thus, the basal level of influenza-specific ASC in the mucosa of the respiratory tract may be important in the protection against influenza infection.

Adult↗

PubMed2002

Multicenter randomized controlled trial of the management of unresectable malignant mesothelioma proposed by the British Thoracic Society and the British Medical Research Council.

Malignant mesothelioma is almost invariably fatal. The incidence of the disease is rising rapidly in many countries, and there is no generally accepted standard treatment for patients with unresectable disease. According to current British Thoracic Society (BTS) guidelines, patients should be treated with active symptom control (ASC), involving (1) regular follow-up in a specialist clinic; (2) structured assessments of physical, psychological and social problems with appropriate action; (3) rapid involvement of additional specialists; and (4) parallel nursing support. Although many nonrandomized studies have reported tumor responses to anticancer chemotherapy, few have studied palliation and it is not known whether chemotherapy prolongs survival or provides clinically worthwhile palliation with acceptable toxicity when given in addition to ASC. We therefore plan to conduct a multicenter randomized controlled trial comparing (1) ASC alone, (2) ASC plus mitomycin vinblastine and cisplatin (MVP), and (3) ASC plus vinorelbine (N; Navelbine, Pierre Fabre Oncology, Winchester, UK). We chose these chemotherapy regimens because they have been shown in nonrandomized studies to provide good symptom control as recorded by patients. The outcome measures are overall survival, palliation of symptoms, performance status, analgesic usage, toxicity, quality of life, tumor response, and recurrence/progression-free survival. In a preliminary feasibility study, we are assessing the acceptability of the trial design to patients and the suitability of two standard quality-of-life instruments in mesothelioma. Data will help us to decide the final details of the large multicenter trial.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

Simplification of the new Bethesda 2001 classification system.

In 1989, a National Cancer Institute workshop resulted in the development of the Bethesda System for cytologic reporting of Papanicolaou smears. In the Bethesda III System (2001), potentially premalignant squamous lesions fall into 3 categories: Atypical squamous cells (ASC), low-grade squamous intraepithelial lesions (LGSIL), and high-grade intraepithelial lesions (HGSIL). The ASC category is subdivided into 2 categories: Those of unknown significance (ASC-US) and those in which high-grade lesions must be excluded (ASC-H). Further revision included the elimination of the category "benign cellular changes," which is now referred to as "negative for intraepithelial lesion or malignancy." The revision also refined the criteria for abnormal glandular epithelium, including atypical glandular cells (AGC). The principal modification in the updated system is the revision of the ASC category, which was done to facilitate triage of women for more intense screening when a true suspicion of a high-grade lesion was present.

Female↗

PubMed2002

PYPAF7, a novel PYRIN-containing Apaf1-like protein that regulates activation of NF-kappa B and caspase-1-dependent cytokine processing.

PYRIN-containing Apaf1-like proteins (PYPAFs) are members of the nucleotide-binding site/leucine-rich repeat (NBS/LRR) family of signal transduction proteins. We report here that PYPAF7 is a novel PYPAF protein that activates inflammatory signaling pathways. The expression of PYPAF7 is highly restricted to immune cells, and its gene maps to chromosome 19q13.4, a locus that contains a cluster of genes encoding numerous PYPAF family members. Co-expression of PYPAF7 with ASC results in the recruitment of PYPAF7 to distinct cytoplasmic loci and a potent synergistic activation of NF-kappa B. To identify other proteins involved in PYPAF7 and ASC signaling pathways, we performed a mammalian two-hybrid screen and identified pro-caspase-1 as a binding partner of ASC. Co-expression of PYPAF7 and ASC results in the synergistic activation of caspase-1 and a corresponding increase in secretion of interleukin-1 beta. In addition, PYPAF1 induces caspase-1-dependent cytokine processing when co-expressed with ASC. These findings indicate that PYPAF family members participate in inflammatory signaling by regulating the activation of NF-kappa B and cytokine processing.

Amino Acid Sequence↗

PubMed2006

Human erythrocyte membranes contain a cytochrome b561 that may be involved in extracellular ascorbate recycling.

Human erythrocytes contain an unidentified plasma membrane redox system that can reduce extracellular monodehydroascorbate by using intracellular ascorbate (Asc) as an electron donor. Here we show that human erythrocyte membranes contain a cytochrome b(561) (Cyt b(561)) and hypothesize that it may be responsible for this activity. Of three evolutionarily closely related Cyts b(561), immunoblots of human erythrocyte membranes showed only the duodenal cytochrome b(561) (DCytb) isoform. DCytb was also found in guinea pig erythrocyte membranes but not in erythrocyte membranes from the mouse or rat. Mouse erythrocytes lost a majority of the DCytb in the late erythroblast stage during erythropoiesis. Absorption spectroscopy showed that human erythrocyte membranes contain an Asc-reducible b-type Cyt having the same spectral characteristics as recombinant DCytb and biphasic reduction kinetics, similar to those of the chromaffin granule Cyt b(561). In contrast, mouse erythrocytes did not exhibit Asc-reducible b-type Cyt activity. Furthermore, in contrast to mouse erythrocytes, human erythrocytes much more effectively preserved extracellular Asc and transferred electrons from intracellular Asc to extracellular ferricyanide. These results suggest that the DCytb present in human erythrocytes may contribute to their ability to reduce extracellular monodehydroascorbate.

Animals↗

PubMed1977

Enrichment of antigen-specific B lymphocytes by the direct removal of B cells not bearing specificity for the antigen.

Antigen-specific B cells (ASC) were purified from other B cells by prior incubation with specific antigen followed by rosetting with erythrocytes conjugated with anti-mouse Ig and sedimenting on Ficoll-Isopaque. This procedure allowed the removal of most of the B cells, while those speicifc for the antigen used in incubation were retained. Relative to the B-cell content, ASC were enriched 64- to 132-fold. The method is highly specific in that B cells primed to two different antigens, turkey gamma globulin and sheep erythrocytes, could be separated from each other. The advantages of this indirect purification procedure over purification procedures which obtain ASC directly are the simplicity of obtaining the ASC and the ability of the ASC of respond to antigen without the addition of other cells.

Animals↗